0.3.31-alpha: version and release notes

Home, Work and three named places live in the Car card on Home, under Saved places. Type an
address or save where you're standing.

.github/FUNDING.yml

@@ -0,0 +1,15 @@
+# These are supported funding model platforms
+
+github: # Replace with up to 4 GitHub Sponsors-enabled usernames e.g., [user1, user2]
+patreon: # Replace with a single Patreon username
+open_collective: # Replace with a single Open Collective username
+ko_fi: # Replace with a single Ko-fi username
+tidelift: # Replace with a single Tidelift platform-name/package-name e.g., npm/babel
+community_bridge: # Replace with a single Community Bridge project-name e.g., cloud-foundry
+liberapay: Seb3thehacker
+issuehunt: # Replace with a single IssueHunt username
+lfx_crowdfunding: # Replace with a single LFX Crowdfunding project-name e.g., cloud-foundry
+polar: # Replace with a single Polar username
+buy_me_a_coffee: seb3thehacker
+thanks_dev: # Replace with a single thanks.dev username
+custom: # Replace with up to 4 custom sponsorship URLs e.g., ['link1', 'link2']

.github/ISSUE_TEMPLATE/bug_report.yml

@@ -5,7 +5,7 @@ body:
   - type: markdown
     attributes:
       value: |
-        Thanks for reporting. Check the [open issues](https://github.com/Seb3thehacker/gearslip/issues) first, in case someone has already reported it.
+        Thanks for reporting. Check the [open issues](https://github.com/twinksoftware/gearslip/issues) first, in case someone has already reported it.
 
   - type: input
     id: car

.github/dependabot.yml

@@ -0,0 +1,15 @@
+# Weekly pull requests for newer Gradle libraries and GitHub Actions, aimed at experimental,
+# where unreleased code lands. Security fixes come separately, as soon as an alert opens.
+version: 2
+updates:
+  - package-ecosystem: gradle
+    directory: /
+    target-branch: experimental
+    schedule:
+      interval: weekly
+    open-pull-requests-limit: 5
+  - package-ecosystem: github-actions
+    directory: /
+    target-branch: experimental
+    schedule:
+      interval: weekly

.github/release-notes.md

@@ -0,0 +1,24 @@
+Gearslip 0.3.31 brings saved places, a new music player and sixteen languages.
+
+## New
+- Save Home, Work and three places of your own under Saved places in the Car card on the phone's home screen. Say "navigate home" or "take me to work", and your map app gets the address.
+- Calls show on the car's own screens, and the car's phone button answers them.
+- A new music player: Now playing with a big cover, Browse with covers, and Up next. Beside the map, the player floats as a card; drag its edge to resize it.
+- Lyrics come from BetterLyrics, LRCLIB or KuGou, whichever has the song.
+- A Dark mode setting: black, black and colour, deep colour or grey. Black is the default.
+- Gearslip speaks Arabic, Chinese, Czech, Dutch, French, German, Italian, Japanese, Korean, Polish, Portuguese, Russian, Spanish, Swedish, Turkish and Ukrainian. Most started as machine translations, so fix your language on [Weblate](https://hosted.weblate.org/engage/gearslip/).
+- With experimental features on, car apps get the car's speed, fuel, range and compass, and cars with an instrument cluster screen get a turn card there.
+- A Manage storage screen in App info clears lyrics, voice models and old logs.
+
+## Changed
+- The nav bar floats on every screen.
+- The car's settings all sit under the Car card on the phone's home screen.
+- The Light app theme makes the phone app light too.
+- With the player beside the map, the map app's own buttons fold behind one button, so everything fits.
+- The USB audio choice is now called Through Gearslip.
+- Setup and Settings explain that some newer cars reject the built-in certificate and need your own.
+
+## Fixed
+- Older head units that take only AAC audio no longer drop the connection when music starts.
+- Long screens such as Settings, Messages and Vehicle data scroll all the way down.
+- Settings opens faster.

.github/workflows/codeql.yml

@@ -0,0 +1,50 @@
+name: CodeQL
+
+# Kotlin can only be scanned while it compiles, so this builds the debug app, the same way
+# release.yml does but without a signing key. Workflow files need no build.
+on:
+  push:
+    branches: [main, experimental]
+  pull_request:
+  schedule:
+    - cron: "0 9 * * 1"
+  workflow_dispatch:
+
+jobs:
+  analyze:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      security-events: write
+      actions: read
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - language: actions
+            build-mode: none
+          - language: java-kotlin
+            build-mode: manual
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: github/codeql-action/init@v4
+        with:
+          languages: ${{ matrix.language }}
+          build-mode: ${{ matrix.build-mode }}
+
+      - if: matrix.build-mode == 'manual'
+        uses: actions/setup-java@v4
+        with:
+          distribution: temurin
+          java-version: "21"
+
+      - if: matrix.build-mode == 'manual'
+        uses: gradle/actions/setup-gradle@v4
+
+      - if: matrix.build-mode == 'manual'
+        run: ./gradlew :gearslip:assembleDebug --no-daemon
+
+      - uses: github/codeql-action/analyze@v4
+        with:
+          category: "/language:${{ matrix.language }}"

.github/workflows/release.yml

@@ -45,4 +45,9 @@ jobs:
         uses: softprops/action-gh-release@v2
         with:
           files: ${{ steps.apk.outputs.path }}
+          # The hand-written notes go first; GitHub adds the full changelog link under them.
+          body_path: .github/release-notes.md
           generate_release_notes: true
+          # Every release starts as a pre-release: only phones on the Alpha update channel get it.
+          # Once it's tested, untick pre-release on GitHub and everyone gets it.
+          prerelease: true

.github/workflows/trivy.yml

@@ -0,0 +1,34 @@
+name: Security scan
+
+# Trivy looks through the repository for committed secrets and risky workflow or build
+# settings. Findings show under the Security tab, next to CodeQL's and Dependabot's.
+on:
+  push:
+    branches: [main, experimental]
+  pull_request:
+  schedule:
+    - cron: "0 9 * * 1"
+  workflow_dispatch:
+
+jobs:
+  trivy:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      security-events: write
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: aquasecurity/trivy-action@v0.36.0
+        with:
+          scan-type: fs
+          scanners: vuln,secret,misconfig
+          format: sarif
+          output: trivy.sarif
+          severity: MEDIUM,HIGH,CRITICAL
+
+      - uses: github/codeql-action/upload-sarif@v4
+        if: always()
+        with:
+          sarif_file: trivy.sarif
+          category: trivy

.gitignore

@@ -11,17 +11,16 @@ local.properties
 *.keystore
 keystore.properties
 
-# Native build cache.
+# Native build cache
 .cxx/
 
 # Testing
-/docs/cert-sweep.sh
-extraction/
 /cloned-repos
+docs-internal/
 
 # Internal
 *.pdf
-todo
+todo.md
 logs/
 
 # For AI code
@@ -30,3 +29,12 @@ CLAUDE.md
 
 # Other
 archive/
+.wrangler/
+stats-worker/
+
+# Certificates and keys never go in the repo; the app downloads or imports them on the phone.
+*.p12
+*.pfx
+*.pem
+*.crt
+*.key

CARS.md

@@ -0,0 +1,49 @@
+# Cars
+
+Drivers who share usage notes tell us which cars Gearslip works in. This list comes from
+those notes, and from our own testing. A car shows up here once Gearslip has reached its
+screen at least once.
+
+The year is the one the car reports. Some cars report the year of the head unit instead,
+and some don't say.
+
+## Works
+
+| Car | Year | Head unit |
+|---|---|---|
+| Audi | | MIB2+ (Alpine) |
+| Audi | | Harman |
+| Chevrolet, with myChevrolet | 2019, 2020, 2021 | myChevrolet |
+| Chevrolet, with MyLink | 2017 | MyLink |
+| Dacia | | Media Nav (LG ULC 4.1) |
+| Dacia | | LG ULC 4.5 |
+| Ford | 2018 | SYNC 3.0 (Panasonic) |
+| Ford Fiesta | 2019 | SYNC 3.2 (Panasonic) |
+| Ford Fusion | 2018 | SYNC 3.1 (Panasonic) |
+| Jeep Cherokee | 2019 | Uconnect 8.4 (Delphi) |
+| MG | 2019 | Desay SV |
+| Ram 1500 | 2018 | Uconnect 8.4 (Panasonic) |
+| Škoda | 2018 | MIB Standard2 (TechniSat) |
+| Subaru Outback | 2020 | Denso |
+| Toyota RAV4 | 2020 | Pioneer T1 |
+| Volkswagen | 2018 | MIB Standard2 (Delphi) |
+| Volkswagen | 2024 | ICAS3 |
+| Volvo XC90 | 2022 | SPA Plus (Mitsubishi Electric) |
+| Wuling | 2021 | Desay SV |
+| [LIVI](https://github.com/f-io/LIVI), the open-source head unit | | |
+
+## Not working yet
+
+| Car | Year | What happens |
+|---|---|---|
+| Honda | 2016 | The connection drops before Gearslip reaches the screen. |
+| Honda | 2019 | The connection drops before Gearslip reaches the screen. |
+| Mitsubishi Attrage | 2020 | The connection drops before Gearslip reaches the screen. |
+
+Some cars reject Gearslip's certificate before they say what they are, so they can't appear
+here by name. Most of these are from around 2020 or later.
+
+## Add your car
+
+Turn on usage notes in Gearslip's setup or Settings, and drive once. If your car is missing
+or listed wrongly, open an issue.

CLA.md

@@ -0,0 +1,105 @@
+# Gearslip Contributor License Agreement
+
+Version 1.0, October 2026
+
+Thank you for contributing to Gearslip. This agreement lets Twink Software LLC, the company
+behind Gearslip, use your contribution. You keep the copyright in your work. You sign once,
+and the agreement covers every contribution you make to Gearslip, past and future.
+
+## Why we ask
+
+Gearslip is free software under the GNU Affero General Public License, version 3 (the
+"AGPL"). Twink Software LLC also sells commercial licenses to companies that cannot meet the
+AGPL's terms, and that income helps pay for the project. Offering your code on those terms
+needs your permission, and this agreement gives it.
+
+## 1. Definitions
+
+- **"We"** and **"us"** mean Twink Software LLC, a California limited liability company
+  (Secretary of State entity number B20260081700), under that name or any other, and its
+  successors and assigns.
+- **"You"** means the person who signs this agreement.
+- **"Contribution"** means any work of authorship, such as code, documentation, or images,
+  that you submit to Gearslip, whether before or after you sign. A submission includes a
+  pull request, patch, or issue attachment sent to a repository or channel we manage. It
+  excludes anything you mark in writing as "Not a Contribution".
+
+## 2. Copyright license
+
+You grant us, and anyone who receives software from us, a perpetual, worldwide,
+non-exclusive, no-charge, royalty-free, irrevocable license to reproduce, prepare derivative
+works of, publicly display, publicly perform, sublicense, and distribute your Contributions
+and derivative works of them.
+
+This license lets us offer your Contributions under licenses other than the AGPL, including
+commercial licenses.
+
+## 3. Patent license
+
+You grant us, and anyone who receives software from us, a perpetual, worldwide,
+non-exclusive, no-charge, royalty-free, irrevocable patent license to make, have made, use,
+offer to sell, sell, import, and otherwise transfer your Contributions. This license covers
+only the patent claims you can license that your Contribution, alone or combined with
+Gearslip, would infringe.
+
+If anyone sues claiming that Gearslip or a Contribution infringes a patent, the patent
+licenses granted to that party for Gearslip end on the date the suit is filed.
+
+## 4. Our promise to you
+
+As long as we distribute a Contribution, we will also offer it under the AGPL or another
+license approved by the Open Source Initiative. Your work will always stay available as
+free software.
+
+## 5. Your promises
+
+You promise that:
+
+1. **The work is yours.** Each Contribution is your original creation, and you have the
+   right to grant these licenses.
+2. **Your employer agrees.** If your employer has rights in what you create, you have its
+   permission to contribute on its behalf, or it has waived its rights in your
+   Contributions.
+3. **You name other people's work.** If any part of a Contribution is not your own, you say
+   so when you submit it, and you name its source and its license.
+4. **You'll tell us of changes.** If any of these promises stops being true, you will tell
+   us.
+
+## 6. No warranty
+
+You provide your Contributions "as is", without warranties or conditions of any kind. You do
+not have to provide support for them.
+
+## 7. No obligation
+
+We are not required to use or include any Contribution.
+
+## 8. General
+
+- California law governs this agreement.
+- This agreement does not change the rights you have under the AGPL in Gearslip as
+  released.
+- We may publish a new version of this agreement. A new version applies only to
+  Contributions you make after you sign it; this version keeps covering the ones you made
+  under it.
+
+## Signing
+
+Most contributors sign on GitHub: the CLA Assistant bot comments on your first pull request,
+and you sign there with one click. Your GitHub account then serves as your signature.
+
+Translators sign on Weblate: it shows this agreement before your first translation, and
+accepting it there serves as your signature.
+
+To sign by hand instead, fill in the following and send it to us on Matrix. The address is
+on the [Seb3thehacker GitHub profile](https://github.com/Seb3thehacker).
+
+Name: ______________________________
+
+GitHub username: ______________________________
+
+Email: ______________________________
+
+Signature: ______________________________
+
+Date: ______________________________

CONTRIBUTING.md

@@ -5,7 +5,7 @@ start there if you aren't sure where to begin.
 
 ## Reporting a bug
 
-Open an issue on [GitHub](https://github.com/Seb3thehacker/gearslip/issues) and include:
+Open an issue on [GitHub](https://github.com/twinksoftware/gearslip/issues) and include:
 
 - your car's make, model, and year, and whether the head unit is the original one; and
 - the log from the drive. Open Logs on the phone app's home screen and tap Share log.
@@ -38,6 +38,19 @@ branch on `experimental`, and open your pull request against it.
 - Gearslip asks for no adb, root, or Shizuku. A feature must work with ordinary Android
   permissions and on-device consent dialogs.
 
+## Translating
+
+Translations happen on [Weblate](https://hosted.weblate.org/engage/gearslip/), not in pull
+requests. Pick your language, or start a new one, and translate in the browser. Weblate
+sends the finished work to this repository as a pull request.
+
+Keep the tone of the English: short, plain, and friendly. Leave placeholders such as `%1$s`
+and `%1$d` in place; Gearslip fills them with names and numbers. Untranslated strings show
+in English, so a partial translation is still useful.
+
+Before your first translation, Weblate asks you to accept the
+[Contributor License Agreement](CLA.md). That counts as signing it.
+
 ## Writing
 
 Text that users read, such as screens, release notes, and docs, follows Strunk's
@@ -46,6 +59,10 @@ voice, state things positively, cut needless words, and use the serial comma.
 
 ## License
 
-Gearslip is licensed under AGPL-3.0, and your contributions are too. The author also sells a
-commercial license, described in [NOTICE.md](NOTICE.md). By opening a pull request, you
-agree that your contribution may be offered under that license as well.
+Gearslip is licensed under AGPL-3.0, and your contributions are too. Twink Software LLC, which
+owns Gearslip, also sells a commercial license, described in [NOTICE.md](NOTICE.md).
+
+Before we can merge your first pull request, you sign the
+[Contributor License Agreement](CLA.md). You keep the copyright in your work, and it stays
+available as free software; the agreement lets us offer it under the commercial license too.
+A bot comments on your pull request with a link, and signing takes one click.

LICENSE

@@ -1,4 +1,4 @@
-Copyright (C) 2026 seb
+Copyright (C) 2026 Twink Software LLC and contributors
 
                     GNU AFFERO GENERAL PUBLIC LICENSE
                        Version 3, 19 November 2007

NOTICE.md

@@ -6,4 +6,4 @@ You may use, run, and modify Gearslip freely. If you distribute a modified versi
 
 ## Commercial licensing
 
-If the AGPL's terms don't work for you, the author sells a separate commercial license. The usual case is a company that wants to use Gearslip privately without publishing its changes. Terms, including any limits on modification, are set case by case. Contact me on Matrix; the address is on my profile.
+If the AGPL's terms don't work for you, Twink Software LLC, which owns Gearslip, sells a separate commercial license. The usual case is a company that wants to use Gearslip privately without publishing its changes. Terms, including any limits on modification, are set case by case. Contact us on Matrix; the address is on the [Seb3thehacker GitHub profile](https://github.com/Seb3thehacker).

README.md

@@ -2,64 +2,168 @@
 
 # Gearslip
 
-Bring any app to your car screen.
+An Android Auto alternative built for everyone.
+
+
+[![forthebadge](https://forthebadge.com/badges/compatibility-club-penguin.svg)](https://forthebadge.com)
+
+[<img src="https://raw.githubusercontent.com/ImranR98/Obtainium/main/assets/graphics/badge_obtainium.png" alt="Get it on Obtainium" height="80">](https://apps.obtainium.imranr.dev/redirect?r=obtainium://add/https://github.com/twinksoftware/gearslip)
+
+[![Translation status](https://hosted.weblate.org/widget/gearslip/app/svg-badge.svg)](https://hosted.weblate.org/engage/gearslip/)
+
+Gearslip speaks English, Arabic, Chinese, Czech, Dutch, French, German, Italian, Japanese,
+Korean, Polish, Portuguese, Russian, Spanish, Swedish, Turkish, and Ukrainian. Most of these
+started as machine translations, so some read awkwardly.
+[Fix or add your language on Weblate](https://hosted.weblate.org/engage/gearslip/).
+
+Questions, ideas?
+[Join the discussion on Matrix](https://matrix.to/#/!mf0_mgBd5KqKpc9FfX_wHp1jFCcwAtPrndIn_oGIyMk?via=matrix.org).
+
+## Which cars work
+
+Most cars work. Starting around 2020, some cars added newer security checks that reject
+the aasdk certificate, and in those cars Gearslip needs a certificate of your own. [CARS.md](CARS.md) lists the
+cars drivers have confirmed.
 
 ## What Gearslip is
 
 Gearslip is an Android Auto client for the phone. It speaks the Android Auto protocol
-directly to a car head unit over USB, with no Google software in the path. Gearslip acts
-as a Car App Library host: an app that ships a car interface hands Gearslip a template,
-and Gearslip renders that template natively on the car screen. Nothing is mirrored from
-the phone. For apps without a car interface, Gearslip offers a separate screen-sharing
-mode.
+directly to a car head unit, over USB or wirelessly, with no Google software in the path.
+Gearslip acts as a Car App Library host: an app that ships a car interface hands Gearslip
+a template, and Gearslip renders that template natively on the car screen. Nothing is
+mirrored from the phone. For apps without a car interface, Gearslip offers a separate
+screen-sharing mode.
+
+| | |
+|---|---|
+| ![The launcher, with every car app on the phone and the route in the bar below](docs/screenshots/launcher.png) | ![Vela Maps showing the route, with the music player beside the map](docs/screenshots/navigation.png) |
+| Your car apps in one place. A red X marks the ones that don't work yet. | Vela Maps navigating, with the player beside it. |
+| ![Metrolist's song, art, and controls in Gearslip's player](docs/screenshots/music.png) | ![A new message card over Vela Maps](docs/screenshots/message.png) |
+| Metrolist in Gearslip's player. | A new message, read aloud at a tap, over the map. |
+| ![The dashboard, with the weather, the week ahead, and recent notifications](docs/screenshots/dashboard.png) | ![DuckDuckGo open in Gearslip's web browser](docs/screenshots/web.png) |
+| The weather, your week, and what you missed. | Browse the web while parked. |
+| ![The voice assistant listening over Vela Maps](docs/screenshots/assistant.png) | ![Three routes to a coffee shop in Vela Maps, each with its time and distance](docs/screenshots/places.png) |
+| Ask for a place, a song, or an app. | Pick a route to coffee nearby. Each one shows its time and distance. |
 
 ## Features
 
 - **Phone calls.** Dial from a keypad, or search your contacts, then confirm before the
-  call goes out.
-- **Navigation.** Gearslip hosts real Car App Library map apps on the car screen; Organic
-  Maps and OsmAnd both work today.
+  call goes out. When a call comes in, answer or decline it on the car screen. During a
+  call, the nav bar shows who you're talking to, and you mute or hang up from there.
+- **Navigation.** Gearslip hosts real Car App Library map apps on the car screen.
+  Organic Maps, Vela, OsmAnd, Flitsmeister, MAPS.ME, and MapQuest work today. While you
+  navigate, a big turn card on the left shows the arrow, the distance, and your lane, and
+  the map keeps the right side.
 - **Music.** Browse, play, and queue tracks from a car-enabled media app, with a Now
-  Playing view, an Up Next queue, and lyrics.
-- **The web.** A browser template with its own on-screen keyboard, for anything that
-  doesn't ship a car interface of its own.
+  Playing view, an Up Next queue, and lyrics. Type a search, and apps that accept one
+  play the best match.
+- **The web.** A browser with an address bar, back and forward, and its own on-screen
+  keyboard, for anything that doesn't ship a car interface of its own.
 - **Weather and the day ahead.** A dashboard screen shows the week's calendar next to
   the current and coming weather.
+- **Voice.** Tap the mic, or press the talk button on the wheel, and say "navigate to the
+  nearest gas station", "play Daft Punk", or "call Mom". Say "help" for the full list.
+  Speech turns into text on the phone, and nothing you say leaves it.
 - **Messages.** New messages appear as a small card on the car screen. Gearslip reads
-  each one aloud, and you reply by voice or with a quick reply. Speech runs on the phone,
-  so it needs no Google account.
+  each one aloud, and you reply by voice or with a quick reply. Music pauses while
+  Gearslip speaks or listens. Speech runs on the phone, so it needs no Google account.
 - **Notifications.** Only messages, missed calls, alarms, and reminders interrupt you.
   The rest wait on the dashboard.
+- **Your apps, your order.** The launcher groups apps by kind: phone, maps, music,
+  messaging, and the rest. Press and hold an app to move it.
 - **Car controls.** Steering wheel buttons, control knobs, and D-pads all work.
+- **Your phone's colors.** The car screen and the phone app take their colors from your
+  phone's Material You palette, and every card and button matches.
 - **Themes.** Choose flat buttons or skeuomorphic ones that look like real keys.
+- **Settings on the phone.** The car's settings sit on the phone's home screen too, so you
+  can set things up before you drive. A change on either screen shows on both.
 
 ## Status
 
-- **The connection is wired only, for now.** Plug the phone into the head unit's USB port;
-  Gearslip does not yet offer a wireless option.
+- **Wired or wireless.** Plug the phone into the car's USB port, or, in a car with wireless
+  Android Auto, tap Connect wirelessly and pick the car. Pair the phone with the car over
+  Bluetooth first. After the first wireless drive, Android asks once whether Gearslip may
+  watch for that car; from then on, Gearslip connects whenever the car's Bluetooth does.
 - **Setup walks you through it.** First launch asks for the Android Auto certificate,
   then one permission at a time, each with a plain reason and an Allow or Skip. A help
   screen inside the car answers anything setup didn't cover.
-- **Templated apps work.** Gearslip renders all 16 template types that the Car App
-  Library defines, and it draws its own keyboard for search, sign-in, and text fields.
-  It has been tested against several real navigation and media apps.
+- **Templated apps work.** Gearslip renders the Car App Library's templates on the car
+  screen, and it draws its own keyboard for search, sign-in, and text fields. It has been
+  tested against several real navigation and media apps.
 - **Gearslip works with [LIVI](https://github.com/f-io/LIVI),** the open-source head unit
   used in homemade car dashboards.
 - **Some apps refuse Gearslip.** Spotify, Waze, and Google Messages use a version of
   Google's car library that accepts only Android Auto itself. Spotify still plays through
-  Gearslip's own player.
-- **For now, Gearslip works with cars from before 2020.** Newer head units reject its
-  certificate.
+  Gearslip's own player. TIDAL lets only approved apps browse its library.
 - **Calls use the car's Bluetooth,** as they do in Android Auto. Pair the phone with the
   car to hear calls through its speakers.
-- **Audio reaches the car by capturing playback, not by mirroring the screen.** Android
-  shows a screen-share consent dialog for this, even though Gearslip never reads the
-  screen; it is the only way an ordinary app can capture another app's audio. The dialog
-  appears once per drive.
+- **Music reaches the car over Bluetooth or through Gearslip.** Setup asks which.
+  Bluetooth is the default: Android never asks for permission, and your map app's voice
+  reaches the car too. Through Gearslip, the sound travels over the car connection, cable
+  or wireless. It sounds a little clearer, with no delay, but each drive Android asks you
+  to share your screen, which lets Gearslip send the sound. Gearslip never reads the
+  screen; capturing playback is the only way an ordinary app can pass another app's audio
+  along.
 - **Gearslip needs no adb, root, or Shizuku.** Every feature relies on an ordinary
-  Android permission or an on-device consent dialog. The setup guide offers two optional
-  adb commands: one removes the audio dialog for good, and the other keeps notifications
-  visible while audio plays.
+  Android permission or an on-device consent dialog. For audio through Gearslip, setup offers two
+  optional adb commands: one removes the audio dialog for good, and the other keeps
+  notifications visible while audio plays.
+- **Updates come from GitHub.** Once a day, Gearslip checks this repository's latest
+  release. When a new version is out, it downloads the APK, checks it against GitHub's
+  SHA-256, and installs it through Android's own installer. Turn off automatic checks in
+  Settings.
+
+## Verify your download
+
+Check that your copy of Gearslip is genuine with
+[AppVerifier](https://github.com/soupslurpr/AppVerifier): share this block to it, or compare it
+with the output of `apksigner verify --print-certs`.
+
+```
+app.seb3thehacker.gearslip
+4C:C5:6E:BD:D1:3A:54:D2:60:EC:A9:B7:E2:B2:AE:6B:30:E2:F2:25:BF:DA:8F:50:8F:07:09:ED:F0:84:94:8B
+```
+
+## Usage notes
+
+Gearslip can send short notes that show which cars it works in. They stay off unless you
+turn them on, in setup or in Settings.
+
+- **When they go out.** When you open Gearslip, at most once a day, and after each drive.
+  Nothing runs in the background.
+- **What they carry.** The Gearslip version and which boxes you ticked, plus whatever
+  those boxes cover: the Android version and whether the phone runs GrapheneOS, the phone
+  model, whether a car connected that day, and each car's head unit, model, year, screen
+  size, and connection result, with whether that drive used the cable or wireless and
+  whether music went through Gearslip or over Bluetooth. If you tick it, how each drive went: how far
+  the connection got, how long it lasted, and how it ended. Settings shows the exact note. Untick a phone detail, and
+  the server drops the copy it kept.
+- **What they leave out.** Your name, accounts, location, contacts, messages, and
+  anything you type or play.
+- **How phones are counted.** A random number counts each phone once. The server keeps
+  only a salted hash of it.
+- **Where they go.** To Gearslip's server. Like any website, it sees your IP address when a
+  note arrives, and it doesn't store it.
+
+Turn the notes off, and they stop at once.
+
+## How Gearslip is made
+
+Gearslip is my beloved child. I decide what it does and how it looks, and Claude writes nearly
+all of the code. I test every change myself before it ships: in a real car, with both a
+GrapheneOS phone and a stock Android phone, and on [LIVI](https://github.com/f-io/LIVI), the
+open-source head unit software. I watch the phone's temperature too, so a new feature doesn't
+cook it. Then I beg my friends to try it in their cars, so it works in as many makes, models,
+and years as possible. If something breaks, that's on me, so please open an issue.
+
+## Contributing
+
+Bug reports from real cars help most, and pull requests are welcome.
+[CONTRIBUTING.md](CONTRIBUTING.md) explains what to put in a report, which branch to work
+on, and the one-time agreement you sign before your first pull request merges.
+
+To help translate Gearslip into your language, join
+[Gearslip on Weblate](https://hosted.weblate.org/engage/gearslip/). No coding needed.
 
 ## Building
 
@@ -79,6 +183,17 @@ keystore. Without them, the debug build still works.
 [docs/BUILDING_APPS.md](docs/BUILDING_APPS.md) specifies how to write apps that Gearslip
 can render: templated apps, media apps, and the Gearslip app protocol.
 
+## How Gearslip talks to cars
+
+Gearslip is an independent program, written to work with car head units. What it knows of
+the protocol comes from public open-source projects such as
+[aasdk](https://github.com/opencardev/aasdk) and open-android-auto, and it contains none
+of Google's Android Auto code.
+
+Gearslip ships without a certificate. On first launch you choose where yours comes from:
+download the one the aasdk project publishes, or import a file of your own. The
+certificate stays on your phone. Gearslip never uploads, backs up, or logs it.
+
 ## Trademarks
 
 Android, Android Auto, Google Messages, and Waze are trademarks of Google LLC. Spotify is
@@ -87,5 +202,6 @@ any of these companies. All other names belong to their owners.
 
 ## License
 
-Gearslip is licensed under AGPL-3.0; see [LICENSE](LICENSE). The author offers a separate
-commercial license for private use outside the AGPL's terms; see [NOTICE.md](NOTICE.md).
+Gearslip belongs to Twink Software LLC and is licensed under AGPL-3.0; see [LICENSE](LICENSE).
+The LLC also sells a separate commercial license for private use outside the AGPL's terms; see
+[NOTICE.md](NOTICE.md).

docs/icon/archive/gearslip-icon-rounded.svg

@@ -1,14 +0,0 @@
-<svg xmlns="http://www.w3.org/2000/svg" width="432" height="432" viewBox="0 0 108 108">
-  <defs>
-    <linearGradient id="trail" x1="73.4" y1="46.0" x2="95.8" y2="44.5" gradientUnits="userSpaceOnUse">
-      <stop offset="0%" stop-color="#8C1F1F" stop-opacity="0"/>
-      <stop offset="100%" stop-color="#8C1F1F" stop-opacity="0.7"/>
-    </linearGradient>
-  </defs>
-  <rect width="108" height="108" fill="#0c0c0d"/>
-  <circle cx="54" cy="54" r="52" fill="#131415"/>
-  <path d="M 73.23,47.15 L 94.77,51.90 L 96.89,37.05 L 73.57,44.78 Z" fill="url(#trail)"/>
-  <path d="M 54.00,27.00 L 59.99,19.91 Q 61.02,18.69 62.50,19.30 L 72.52,23.45 Q 74.00,24.07 73.87,25.66 L 73.23,33.31 Q 73.09,34.91 73.70,36.39 L 80.39,52.52 Q 81.00,54.00 82.22,55.03 L 88.09,59.99 Q 89.31,61.02 88.70,62.50 L 84.55,72.52 Q 83.93,74.00 82.34,73.87 L 73.09,73.09 Q 73.09,73.09 73.09,73.09 L 73.09,73.09 Q 73.09,73.09 73.09,73.09 L 73.87,82.34 Q 74.00,83.93 72.52,84.55 L 62.50,88.70 Q 61.02,89.31 59.99,88.09 L 54.00,81.00 Q 54.00,81.00 54.00,81.00 L 54.00,81.00 Q 54.00,81.00 54.00,81.00 L 48.01,88.09 Q 46.98,89.31 45.50,88.70 L 35.48,84.55 Q 34.00,83.93 34.13,82.34 L 34.91,73.09 Q 34.91,73.09 34.91,73.09 L 34.91,73.09 Q 34.91,73.09 34.91,73.09 L 25.66,73.87 Q 24.07,74.00 23.45,72.52 L 19.30,62.50 Q 18.69,61.02 19.91,59.99 L 27.00,54.00 Q 27.00,54.00 27.00,54.00 L 27.00,54.00 Q 27.00,54.00 27.00,54.00 L 19.91,48.01 Q 18.69,46.98 19.30,45.50 L 23.45,35.48 Q 24.07,34.00 25.66,34.13 L 34.91,34.91 Q 34.91,34.91 34.91,34.91 L 34.91,34.91 Q 34.91,34.91 34.91,34.91 L 34.13,25.66 Q 34.00,24.07 35.48,23.45 L 45.50,19.30 Q 46.98,18.69 48.01,19.91 L 54.00,27.00 Q 54.00,27.00 54.00,27.00 L 54.00,27.00 Q 54.00,27.00 54.00,27.00 Z" fill="#8B9096"/>
-  <path d="M 92.78,34.42 L 99.94,37.20 Q 101.43,37.78 101.34,39.37 L 100.67,50.20 Q 100.58,51.80 99.03,52.19 L 91.58,54.08 Q 90.03,54.47 90.13,52.87 L 91.19,35.44 Q 91.29,33.84 92.78,34.42 Z" fill="#8C1F1F"/>
-  <circle cx="54" cy="54" r="12" fill="#0c0c0d"/>
-</svg>

docs/icon/gearslip-icon.svg

@@ -5,7 +5,6 @@
       <stop offset="100%" stop-color="#8C1F1F" stop-opacity="0.7"/>
     </linearGradient>
   </defs>
-  <rect width="108" height="108" fill="#0c0c0d"/>
   <circle cx="54" cy="54" r="52" fill="#131415"/>
   <path d="M 73.23,47.15 L 94.77,51.90 L 96.89,37.05 L 73.57,44.78 Z" fill="url(#trail)"/>
   <path d="M 54.00,27.00 L 61.02,18.69 L 74.00,24.07 L 73.09,34.91 L 81.00,54.00 L 89.31,61.02 L 83.93,74.00 L 73.09,73.09 L 73.09,73.09 L 74.00,83.93 L 61.02,89.31 L 54.00,81.00 L 54.00,81.00 L 46.98,89.31 L 34.00,83.93 L 34.91,73.09 L 34.91,73.09 L 24.07,74.00 L 18.69,61.02 L 27.00,54.00 L 27.00,54.00 L 18.69,46.98 L 24.07,34.00 L 34.91,34.91 L 34.91,34.91 L 34.00,24.07 L 46.98,18.69 L 54.00,27.00 Z" fill="#8B9096"/>

gearslip/build.gradle.kts

@@ -24,6 +24,12 @@ val keystoreProperties = Properties().apply {
     ).firstOrNull { it.exists() }?.inputStream()?.use { load(it) }
 }
 
+// Keeps build output out of the module folder: <root>/build/gearslip/... instead of
+// <root>/gearslip/build/..., so everything this project produces lands under one
+// root-level build/ directory. Set before android {}, which works out the path to R8's default
+// rules from it.
+layout.buildDirectory.set(rootProject.layout.buildDirectory.dir("gearslip"))
+
 android {
     namespace = "app.seb3thehacker.gearslip"
     compileSdk = 37
@@ -32,9 +38,13 @@ android {
         applicationId = "app.seb3thehacker.gearslip"
         minSdk = 31
         targetSdk = 37
-        versionCode = 7
-        versionName = "0.1.10-alpha"
+        versionCode = 13
+        // -PgearslipVersionName=0.1.99-test makes a build that thinks it's older, to try the updater.
+        versionName = project.findProperty("gearslipVersionName")?.toString() ?: "0.3.31-alpha"
         manifestPlaceholders["appLabel"] = "Gearslip"
+        // Where opted-in phones send their daily usage note: the stats-worker/ Worker's address,
+        // set as gearslipStatsUrl in gradle.properties. Left empty, nothing is ever sent.
+        buildConfigField("String", "STATS_URL", "\"${project.findProperty("gearslipStatsUrl") ?: ""}\"")
     }
 
     signingConfigs {
@@ -53,14 +63,27 @@ android {
     buildTypes {
         release {
             signingConfig = signingConfigs.findByName("release")
+            isMinifyEnabled = true
+            isShrinkResources = true
+            proguardFiles(getDefaultProguardFile("proguard-android-optimize.txt"), "proguard-rules.pro")
         }
-        // Its own package, so a dev build installs beside the release one instead of over it.
+        // Its own package, so a debug build installs beside the release one instead of over it.
         // Signed with the release key when it's here: both builds declare the car template
         // permission, and Android refuses a second app declaring it under a different key.
         debug {
             applicationIdSuffix = ".dev"
             signingConfigs.findByName("release")?.let { signingConfig = it }
-            manifestPlaceholders["appLabel"] = "Gearslip Dev"
+            manifestPlaceholders["appLabel"] = "Gearslip Debug"
+            // English (XA) and Arabic (XB) under the phone's languages: stretched, accented and
+            // right-to-left text, which shows what's still hardcoded and what doesn't fit.
+            isPseudoLocalesEnabled = true
+            // Shrunk with R8 like a release, so a debug install behaves like what ships (a keep
+            // rule missing for release shows up here first). -PnoR8 skips it for a quicker build.
+            if (!project.hasProperty("noR8")) {
+                isMinifyEnabled = true
+                isShrinkResources = true
+                proguardFiles(getDefaultProguardFile("proguard-android-optimize.txt"), "proguard-rules.pro")
+            }
         }
     }
 
@@ -68,10 +91,17 @@ android {
         buildConfig = true
     }
 
-    // Keeps build output out of the module folder: <root>/build/gearslip/... instead of
-    // <root>/gearslip/build/..., so everything this project produces lands under one
-    // root-level build/ directory.
-    layout.buildDirectory.set(rootProject.layout.buildDirectory.dir("gearslip"))
+    // Lists each language that has a translation in the app's locale config, so Android 13+
+    // offers it under the system's per-app languages. English is the unqualified default
+    // (res/resources.properties).
+    androidResources {
+        generateLocaleConfig = true
+    }
+
+    lint {
+        // Weblate fills languages in a string at a time; the rest fall back to English.
+        disable += "MissingTranslation"
+    }
 
     compileOptions {
         sourceCompatibility = JavaVersion.VERSION_21
@@ -79,21 +109,10 @@ android {
     }
 
     defaultConfig {
-        // Speech-to-text ships for 64-bit ARM only: every phone Gearslip runs on, and one copy
-        // of the native library instead of four.
+        // Speech-to-text (sherpa-onnx, in jniLibs) ships for 64-bit ARM only: every phone
+        // Gearslip runs on, and one copy of the native library instead of four.
         ndk { abiFilters += "arm64-v8a" }
     }
-    ndkVersion = "27.1.12297006"
-    externalNativeBuild {
-        cmake {
-            path = file("src/main/cpp/CMakeLists.txt")
-            version = "3.22.1"
-        }
-    }
-    androidResources {
-        // Model weights barely compress, and stored plainly they stream straight out of the APK.
-        noCompress += "bin"
-    }
 
     testOptions {
         // GearslipLog calls android.util.Log, which is a stub on the local JVM.
@@ -102,9 +121,10 @@ android {
 
 }
 
-// Renames the produced APK and moves it to the root build/ folder (<root>/build/Gearslip-debug.apk)
-// after the fact rather than fighting AGP's variant-output API across versions - simpler and
-// doesn't break when that API moves again.
+// Copies the produced APK to the root build/ folder (<root>/build/Gearslip-debug.apk) after the
+// fact rather than fighting AGP's variant-output API across versions - simpler and doesn't break
+// when that API moves again. A copy, not a move: AGP packages incrementally into the APK it left
+// last time, and with that file gone a build came out holding nothing but classes.dex.
 tasks.register("renameApk") {
     doLast {
         val rootBuildDir = rootProject.layout.buildDirectory.get().asFile
@@ -114,7 +134,6 @@ tasks.register("renameApk") {
             .forEach { apk ->
                 val renamed = File(rootBuildDir, "Gearslip-${apk.parentFile.name}.apk")
                 apk.copyTo(renamed, overwrite = true)
-                apk.delete()
             }
     }
 }

gearslip/proguard-rules.pro

@@ -0,0 +1,13 @@
+# R8 shrinks the release build; these keep what it can't see being used.
+
+# Names stay readable, so stack traces in shared logs need no mapping file. Shrinking does
+# the real work on size.
+-dontobfuscate
+
+# Gearslip hosts other apps' car screens: their templates arrive as Bundles, and the car
+# library rebuilds them by class name and reflection. Any model class an app might send has to
+# survive, used by Gearslip's code or not.
+-keep class androidx.car.app.** { *; }
+
+# Speech-to-text: the native library calls back into these classes by name.
+-keep class com.k2fsa.sherpa.onnx.** { *; }

gearslip/src/main/AndroidManifest.xml

@@ -4,6 +4,7 @@
 
     <!-- The projected WebView loads real pages; without this every load fails silently. -->
     <uses-permission android:name="android.permission.INTERNET" />
+    <uses-permission android:name="android.permission.REQUEST_INSTALL_PACKAGES" />
 
     <!--
       Phone mirroring. Android refuses to hand over a MediaProjection unless a foreground
@@ -19,6 +20,25 @@
     <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
     <uses-permission android:name="android.permission.FOREGROUND_SERVICE_LOCATION" />
 
+    <!--
+        Wireless Android Auto: Bluetooth reaches the paired car's Android Auto service, which
+        hands over its Wi-Fi details; Gearslip then joins that network to reach the car.
+    -->
+    <uses-permission android:name="android.permission.BLUETOOTH_CONNECT" />
+    <!-- Wireless auto-connect: Android tells Gearslip when a car it manages connects. -->
+    <uses-permission android:name="android.permission.REQUEST_OBSERVE_COMPANION_DEVICE_PRESENCE" />
+    <uses-feature android:name="android.software.companion_device_setup" android:required="false" />
+    <uses-permission android:name="android.permission.BLUETOOTH" android:maxSdkVersion="30" />
+    <uses-permission
+        android:name="android.permission.NEARBY_WIFI_DEVICES"
+        android:usesPermissionFlags="neverForLocation" />
+    <!-- Android 17 drops an app's traffic to the car's Wi-Fi without this. -->
+    <uses-permission android:name="android.permission.ACCESS_LOCAL_NETWORK" />
+    <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
+    <uses-permission android:name="android.permission.CHANGE_WIFI_STATE" />
+    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
+    <uses-permission android:name="android.permission.CHANGE_NETWORK_STATE" />
+
     <!-- The dashboard opened from the car clock: today's agenda and current weather. -->
     <uses-permission android:name="android.permission.READ_CALENDAR" />
 
@@ -74,6 +94,10 @@
          LAUNCHER query below to find, so the setup guide's Android Auto check needs this to see
          whether the package is installed at all. -->
     <package android:name="com.google.android.projection.gearhead" />
+    <!-- The opt-in usage note names the OS: GrapheneOS's setup app and /e/OS's app store give
+         them away (UsageStats.osName). -->
+    <package android:name="app.grapheneos.setupwizard" />
+    <package android:name="foundation.e.apps" />
     <intent>
         <action android:name="android.intent.action.MAIN" />
         <category android:name="android.intent.category.LAUNCHER" />
@@ -102,6 +126,7 @@
         android:roundIcon="@mipmap/ic_launcher"
         android:label="${appLabel}"
         android:supportsRtl="true"
+        android:manageSpaceActivity="app.seb3thehacker.gearslip.ui.ManageSpaceActivity"
         android:theme="@style/Theme.Gearslip">
 
         <provider
@@ -123,6 +148,7 @@
             android:name=".GearslipActivity"
             android:exported="true"
             android:launchMode="singleTop"
+            android:windowSoftInputMode="adjustResize"
             android:configChanges="orientation|screenSize|screenLayout|smallestScreenSize|keyboardHidden|uiMode|density|locale|layoutDirection|fontScale">
 
             <intent-filter>
@@ -137,6 +163,18 @@
           activity so Settings can switch off just this (AppSettings.setGearslipEnabled) and leave
           the head unit to Android Auto, without disabling the screen the switch is on.
         -->
+        <!-- App info › Storage › Manage space: clears lyrics, voice models and logs one at a time. -->
+        <activity
+            android:name=".ui.ManageSpaceActivity"
+            android:exported="true"
+            android:label="Gearslip storage" />
+
+        <activity
+            android:name=".PermissionActivity"
+            android:exported="false"
+            android:excludeFromRecents="true"
+            android:theme="@style/Theme.Gearslip.Invisible" />
+
         <activity-alias
             android:name=".GearslipUsbAccessory"
             android:targetActivity=".GearslipActivity"
@@ -222,5 +260,15 @@
                 <action android:name="android.telecom.CallScreeningService" />
             </intent-filter>
         </service>
+
+        <!-- Told when a car approved for wireless auto-connect comes up over Bluetooth. -->
+        <service
+            android:name=".wireless.CarPresenceService"
+            android:exported="true"
+            android:permission="android.permission.BIND_COMPANION_DEVICE_SERVICE">
+            <intent-filter>
+                <action android:name="android.companion.CompanionDeviceService" />
+            </intent-filter>
+        </service>
     </application>
 </manifest>

gearslip/src/main/cpp/CMakeLists.txt

@@ -1,36 +0,0 @@
-# Speech-to-text for voice replies and the assistant: whisper.cpp, pinned to one commit and
-# fetched at build time, so nothing outside this folder (cloned-repos included) is needed.
-cmake_minimum_required(VERSION 3.22)
-project(gearslip_speech CXX C)
-
-set(CMAKE_CXX_STANDARD 17)
-
-# Optimised in debug builds too. Unoptimised, Whisper runs several times slower, and a dev build
-# would make voice look far worse than what ships.
-foreach(lang C CXX)
-    set(CMAKE_${lang}_FLAGS_DEBUG "-O3 -DNDEBUG")
-endforeach()
-
-include(FetchContent)
-FetchContent_Declare(
-    whisper
-    URL https://github.com/ggml-org/whisper.cpp/archive/6e4ab854f67f743900934a703d5603419384c961.tar.gz
-    URL_HASH SHA256=55b585aec5e1bc03e2a5cea61da97c6406fa833996cf7daeed704972273cc039
-)
-
-set(BUILD_SHARED_LIBS OFF CACHE BOOL "" FORCE)
-set(WHISPER_BUILD_EXAMPLES OFF CACHE BOOL "" FORCE)
-set(WHISPER_BUILD_TESTS OFF CACHE BOOL "" FORCE)
-set(WHISPER_BUILD_SERVER OFF CACHE BOOL "" FORCE)
-set(GGML_OPENMP OFF CACHE BOOL "" FORCE)
-set(GGML_NATIVE OFF CACHE BOOL "" FORCE)
-# ARMv8.2 with half floats and dot products: every phone that runs Android 12 or later in
-# practice, and what makes Whisper fast enough to answer in under a second.
-set(GGML_CPU_ARM_ARCH "armv8.2-a+dotprod+fp16" CACHE STRING "" FORCE)
-FetchContent_MakeAvailable(whisper)
-
-add_library(gearslip_speech SHARED speech_jni.cpp)
-target_compile_options(gearslip_speech PRIVATE -O3)
-find_library(LOG_LIB log)
-target_link_libraries(gearslip_speech whisper android ${LOG_LIB})
-target_link_options(gearslip_speech PRIVATE -Wl,--gc-sections -Wl,-z,max-page-size=16384)

gearslip/src/main/cpp/speech_jni.cpp

@@ -1,86 +0,0 @@
-// The bridge between Kotlin's SpeechEngine and whisper.cpp: load a model, turn one recorded
-// phrase into text, free the model. Recording and deciding when a phrase ends stay in Kotlin.
-
-#include <jni.h>
-#include <android/asset_manager.h>
-#include <android/asset_manager_jni.h>
-#include <android/log.h>
-#include <algorithm>
-#include <cmath>
-#include <string>
-#include "whisper.h"
-
-#define TAG "GearslipSpeech"
-#define LOGI(...) __android_log_print(ANDROID_LOG_INFO, TAG, __VA_ARGS__)
-
-static whisper_context_params context_params() {
-    whisper_context_params p = whisper_context_default_params();
-    p.use_gpu = false;
-    return p;
-}
-
-// Streams a model straight out of the APK, so the bundled one is never copied to storage.
-static size_t asset_read(void *ctx, void *output, size_t size) {
-    int n = AAsset_read(static_cast<AAsset *>(ctx), output, size);
-    return n > 0 ? static_cast<size_t>(n) : 0;
-}
-static bool asset_eof(void *ctx) { return AAsset_getRemainingLength64(static_cast<AAsset *>(ctx)) <= 0; }
-static void asset_close(void *ctx) { AAsset_close(static_cast<AAsset *>(ctx)); }
-
-extern "C" JNIEXPORT jlong JNICALL
-Java_app_seb3thehacker_gearslip_speech_SpeechEngine_nativeInitAsset(JNIEnv *env, jobject, jobject assets, jstring jpath) {
-    AAssetManager *manager = AAssetManager_fromJava(env, assets);
-    const char *path = env->GetStringUTFChars(jpath, nullptr);
-    AAsset *asset = AAssetManager_open(manager, path, AASSET_MODE_STREAMING);
-    env->ReleaseStringUTFChars(jpath, path);
-    if (!asset) return 0;
-    whisper_model_loader loader = {asset, asset_read, asset_eof, asset_close};
-    return reinterpret_cast<jlong>(whisper_init_with_params(&loader, context_params()));
-}
-
-// Bytes, not a jstring: NewStringUTF wants modified UTF-8 and aborts on some of what Whisper can
-// write (four-byte characters), so Kotlin decodes the plain UTF-8 instead.
-extern "C" JNIEXPORT jbyteArray JNICALL
-Java_app_seb3thehacker_gearslip_speech_SpeechEngine_nativeTranscribe(
-    JNIEnv *env, jobject, jlong handle, jfloatArray jsamples, jstring jlang, jint threads) {
-    auto *ctx = reinterpret_cast<whisper_context *>(handle);
-    if (!ctx) return env->NewByteArray(0);
-    jsize n = env->GetArrayLength(jsamples);
-    jfloat *samples = env->GetFloatArrayElements(jsamples, nullptr);
-    const char *lang = env->GetStringUTFChars(jlang, nullptr);
-
-    whisper_full_params p = whisper_full_default_params(WHISPER_SAMPLING_GREEDY);
-    p.n_threads = threads;
-    p.language = lang;
-    p.translate = false;
-    p.no_context = true;
-    p.no_timestamps = true;
-    p.single_segment = true;
-    p.print_progress = false;
-    p.print_realtime = false;
-    p.print_special = false;
-    p.print_timestamps = false;
-    p.suppress_blank = true;
-    // The ACFT models are trained for a context cut to the audio's own length (1500 frames is
-    // 30 s, so 50 per second), which is what makes a three-second phrase fast. A little extra
-    // keeps the last word from being clipped.
-    p.audio_ctx = std::min(1500, static_cast<int>(std::ceil(n / 320.0)) + 32);
-
-    int rc = whisper_full(ctx, p, samples, n);
-    env->ReleaseStringUTFChars(jlang, lang);
-    env->ReleaseFloatArrayElements(jsamples, samples, JNI_ABORT);
-    if (rc != 0) {
-        LOGI("whisper_full failed: %d", rc);
-        return env->NewByteArray(0);
-    }
-    std::string text;
-    for (int i = 0; i < whisper_full_n_segments(ctx); i++) text += whisper_full_get_segment_text(ctx, i);
-    jbyteArray out = env->NewByteArray(static_cast<jsize>(text.size()));
-    env->SetByteArrayRegion(out, 0, static_cast<jsize>(text.size()), reinterpret_cast<const jbyte *>(text.data()));
-    return out;
-}
-
-extern "C" JNIEXPORT void JNICALL
-Java_app_seb3thehacker_gearslip_speech_SpeechEngine_nativeFree(JNIEnv *, jobject, jlong handle) {
-    if (handle) whisper_free(reinterpret_cast<whisper_context *>(handle));
-}

gearslip/src/main/java/app/seb3thehacker/gearslip/AppSettings.kt

@@ -9,7 +9,6 @@ object AppSettings {
 
     private const val PREFS = "gearslip_settings"
     private const val KEY_STARTUP_URL = "startup_url"
-    private const val KEY_SEEN_COMPAT_WARNING = "seen_compat_warning"
     private const val KEY_SKIPPED_CERT_SETUP = "skipped_cert_setup"
     private const val KEY_SEEN_PERMISSIONS_SETUP = "seen_permissions_setup"
     private const val KEY_GEARSLIP_ENABLED = "gearslip_enabled"
@@ -32,14 +31,6 @@ object AppSettings {
         prefs(context).edit().putString(KEY_STARTUP_URL, value.trim()).apply()
     }
 
-    /** Whether the newer-car compatibility warning has already been shown and dismissed once. */
-    fun hasSeenCompatWarning(context: Context): Boolean =
-        prefs(context).getBoolean(KEY_SEEN_COMPAT_WARNING, false)
-
-    fun setSeenCompatWarning(context: Context) {
-        prefs(context).edit().putBoolean(KEY_SEEN_COMPAT_WARNING, true).apply()
-    }
-
     /** Whether the certificate setup screen has been deliberately skipped. */
     fun hasSkippedCertSetup(context: Context): Boolean =
         prefs(context).getBoolean(KEY_SKIPPED_CERT_SETUP, false)

gearslip/src/main/java/app/seb3thehacker/gearslip/CarFocus.kt

@@ -0,0 +1,28 @@
+package app.seb3thehacker.gearslip
+
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+
+/**
+ * Who has the car's screen: Gearslip, or the car's own interface. Android Auto's "Exit" hands the
+ * screen back to the car with the session still running, so music keeps playing; the car's own
+ * Android Auto button brings Gearslip back. [GearslipRunner] fills in [request] while connected.
+ */
+object CarFocus {
+
+    private val projectedFlow = MutableStateFlow(true)
+
+    /** False while the car shows its own interface. */
+    val projected: StateFlow<Boolean> = projectedFlow
+
+    @Volatile internal var request: (() -> Unit)? = null
+
+    /** Asks the car to show its own interface. Does nothing when no car is connected. */
+    fun exitToCar() {
+        request?.invoke()
+    }
+
+    internal fun set(projected: Boolean) {
+        projectedFlow.value = projected
+    }
+}

gearslip/src/main/java/app/seb3thehacker/gearslip/CertProvider.kt

@@ -47,7 +47,10 @@ object CertProvider {
         val kind: Kind = Kind.SELF_SIGNED,
     )
 
-    /** Loaded fresh each call, so a newly imported or pushed cert takes effect on the next connect. */
+    /**
+     * The identity for the next connection. A newly imported or pushed cert takes effect on the
+     * next connect: see [loadFromFiles] for how the cache notices.
+     */
     fun load(context: Context): Identity = loadFromFiles(context) ?: run {
         val generated = SelfSignedCert.generate()
         Identity(
@@ -65,7 +68,38 @@ object CertProvider {
      */
     fun loadSupplied(context: Context): Identity? = loadFromFiles(context)
 
+    /**
+     * Unlocking a PKCS#12 file takes about a second on a Pixel 6, which a head unit waiting for
+     * its first reply may not wait out. So the unlocked identity is kept, keyed on the files it
+     * could come from: importing, downloading, removing or pushing a cert changes the key.
+     */
+    @Volatile private var cached: Pair<String, Identity>? = null
+
+    private fun sourcesKey(context: Context): String {
+        val dir = context.getExternalFilesDir(null)
+        val files = listOf(
+            importedFile(context, P12_NAME),
+            downloadedFile(context, P12_NAME),
+            dir?.let { File(it, P12_NAME) },
+            dir?.let { File(it, PASS_NAME) },
+        )
+        return files.joinToString("|") { f -> f?.let { "${it.path}:${it.lastModified()}:${it.length()}" } ?: "-" }
+    }
+
+    /** Unlocks the certificate ahead of time, so the first connection doesn't wait on it. */
+    fun warm(context: Context) {
+        runCatching { loadFromFiles(context) }
+    }
+
     private fun loadFromFiles(context: Context): Identity? {
+        val key = sourcesKey(context)
+        cached?.let { (k, identity) -> if (k == key) return identity }
+        val identity = unlockFromFiles(context) ?: return null
+        cached = key to identity
+        return identity
+    }
+
+    private fun unlockFromFiles(context: Context): Identity? {
         val imported = importedFile(context, P12_NAME)
         if (imported.isFile) {
             runCatching {

gearslip/src/main/java/app/seb3thehacker/gearslip/Changelog.kt

@@ -10,6 +10,47 @@ object Changelog {
     class Release(val versionCode: Int, val versionName: String, val changes: List<String>)
 
     val releases = listOf(
+        Release(
+            9, "0.3.00-alpha",
+            listOf(
+                "Wireless Android Auto: pair the phone with the car once, and leave the cable at home.",
+                "Voice control is built in. Say \"navigate to a gas station\", \"play\" a song or artist, or open an app by name.",
+                "\"Navigate to\" picks the nearest place and stops at the map app's start screen, so you only tap Start.",
+                "Gearslip turns speech into text on the phone, with no Google account. Download the voice models once in setup.",
+                "The car's rotary knob moves between buttons, so cars without a touchscreen work too.",
+                "Choose how music reaches the car: Bluetooth, or USB with no delay. Gearslip offers to pair with the car the first time.",
+                "The car speaks each turn from your map app, and shows the directions on its own display where it can.",
+                "The car shows what's playing, and music apps get their own like, shuffle and repeat buttons.",
+                "Pick how the car's buttons look. Change it any time in the car's settings.",
+                "A new destination mid-route replaces the old route, and switching map apps ends the old app's route.",
+                "The car warns you when the phone's location is off.",
+                "Gearslip finds new versions and installs them for you.",
+                "More cars play music over USB, show a sharper picture, and put taps where you press.",
+                "On GrapheneOS, Gearslip no longer needs exploit protection compatibility mode.",
+                "The app is half the size it was.",
+            ),
+        ),
+        Release(
+            8, "0.2.00-alpha",
+            listOf(
+                "Exit takes you to the car's own screen. Tap Android Auto on the car to come back.",
+                "Gearslip listens through the car's microphone when the car has one, so voice works with the phone in a pocket.",
+                "A voice reply sends when its bar runs out, even over road noise or the radio. Say \"cancel\" or \"change it\" before then.",
+                "Maps turn dark when the car switches to night mode.",
+                "A moving map no longer makes the car screen fall behind your taps.",
+                "Gearslip asks to send sound to the car as soon as you connect, so videos in the web browser play in the car too.",
+                "Cars that offer more than one kind of music audio, such as the 2022 Dacia Jogger, play sound again.",
+                "When the car shows a keyboard, you can type on the phone instead. The car's keyboard is taller too.",
+                "Every car screen has a back button.",
+                "App icons show whether an app works in Gearslip. Metrolist works and shows the green check.",
+                "LIVI connects again, and touch works on cars with a second screen.",
+                "The phone's Settings screen has a new layout, with What's new and the setup guide at the top.",
+                "You can choose to send short usage notes that help the project. They hold no name, account, or location, and they're off unless you turn them on.",
+                "Searching inside a media app moved to Settings > Experimental features.",
+                "Under Settings > Media audio, the choices are now Phone audio and Car audio.",
+                "Logs leave out your location and the car's serial number.",
+            ),
+        ),
         Release(
             7, "0.1.10-alpha",
             listOf(

gearslip/src/main/java/app/seb3thehacker/gearslip/ClusterVideo.kt

@@ -0,0 +1,164 @@
+package app.seb3thehacker.gearslip
+
+import android.content.Context
+import android.os.Handler
+import android.os.Looper
+import app.seb3thehacker.gearslip.car.ClusterScreen
+
+/**
+ * Gearslip's picture on the car's instrument-cluster screen: a second video sink, for a car that
+ * offers one, showing the turn card ([ClusterScreen]). The same exchange as the main screen's,
+ * on its own channel, with its own encoder and its own private display:
+ *
+ *   -> CHANNEL_OPEN_REQUEST   <- CHANNEL_OPEN_RESPONSE
+ *   -> Setup { H.264 }        <- Config { status, max_unacked, configuration_indices }
+ *   -> VideoFocusRequest      <- VideoFocusNotification { projected }
+ *   -> Start, CodecConfig, Data...   <- Ack
+ *
+ * No touch: a cluster has none. Experimental, behind [car.CarSettings.clusterVideoEnabled], and
+ * untested in a car: none in the notes has a cluster sink.
+ */
+internal class ClusterVideo(
+    private val context: Context,
+    private val service: ServiceDiscovery.VideoService,
+    private val send: (messageId: Int, body: ByteArray) -> Unit,
+) {
+    private val log = GearslipLog.tagged("CLUSTER")
+    private val main = Handler(Looper.getMainLooper())
+
+    val channelId get() = service.serviceId
+
+    private var configIndex = 0
+    @Volatile private var started = false
+    @Volatile private var running = true
+    @Volatile private var source: VideoSource? = null
+    private var projector: ScreenProjector? = null
+
+    private val ackLock = Object()
+    @Volatile private var inFlight = 0
+    @Volatile private var maxUnacked = 1
+    @Volatile private var lastAckAt = 0L
+    private var frames = 0
+
+    fun onMessage(messageId: Int, body: ByteArray) {
+        when (messageId) {
+            GearslipRunner.MSG_CHANNEL_OPEN_RESPONSE -> {
+                val status = Protobuf.readInt32Field(body, 1) ?: 0
+                log.i("<- ChannelOpenResponse: status=$status")
+                if (status != 0) return
+                send(GearslipRunner.MSG_MEDIA_SETUP, Protobuf.varintField(1, GearslipRunner.CODEC_H264_BP.toLong()))
+                log.i("-> Setup(codec=VIDEO_H264_BP)")
+            }
+
+            GearslipRunner.MSG_MEDIA_CONFIG -> {
+                val fields = Wire.fields(body)
+                Wire.varint(fields, 2)?.toInt()?.let { maxUnacked = maxOf(1, it) }
+                val offered = fields.filter { it.number == 3 && it.wireType == 0 }.map { it.varint.toInt() }
+                // The cluster gets the smallest picture it offers: a turn card needs no more.
+                configIndex = offered.minByOrNull { service.configs.getOrNull(it)?.pixelCount() ?: Int.MAX_VALUE } ?: 0
+                log.i("<- Config status=${Wire.varint(fields, 1)} max_unacked=$maxUnacked offered=$offered - using $configIndex")
+                val focus = Protobuf.varintField(2, GearslipRunner.VIDEO_FOCUS_PROJECTED.toLong()) + Protobuf.varintField(3, 1L)
+                send(GearslipRunner.MSG_VIDEO_FOCUS_REQUEST, focus)
+                log.i("-> VideoFocusRequest(mode=PROJECTED)")
+            }
+
+            GearslipRunner.MSG_VIDEO_FOCUS_NOTIFICATION -> {
+                val mode = Wire.varint(Wire.fields(body), 1)?.toInt() ?: GearslipRunner.VIDEO_FOCUS_PROJECTED
+                log.i("<- VideoFocusNotification: mode=$mode")
+                val projected = mode == GearslipRunner.VIDEO_FOCUS_PROJECTED || mode == GearslipRunner.VIDEO_FOCUS_PROJECTED_NO_INPUT
+                if (projected && !started) startStream()
+            }
+
+            GearslipRunner.MSG_MEDIA_ACK -> {
+                val acked = Wire.varint(Wire.fields(body), 2)?.toInt() ?: 1
+                synchronized(ackLock) {
+                    inFlight = maxOf(0, inFlight - maxOf(1, acked))
+                    lastAckAt = System.currentTimeMillis()
+                    ackLock.notifyAll()
+                }
+            }
+
+            else -> log.i("<- unhandled message id=$messageId (${body.size} bytes)")
+        }
+    }
+
+    private fun startStream() {
+        val config = service.configs.getOrNull(configIndex) ?: service.configs.firstOrNull() ?: return
+        val (width, height) = config.pixelSize() ?: run {
+            log.w("unsupported cluster resolution ${config.resolutionName}")
+            return
+        }
+        started = true
+        send(
+            GearslipRunner.MSG_MEDIA_START,
+            Protobuf.varintField(1, GearslipRunner.SESSION_ID.toLong()) + Protobuf.varintField(2, configIndex.toLong()),
+        )
+        log.i("-> Start(config=$configIndex -> $config)")
+        lastAckAt = System.currentTimeMillis()
+        val video = VideoSource(
+            width = width,
+            height = height,
+            frameRate = FRAME_RATE,
+            mode = VideoSource.Mode.SURFACE,
+            wireless = true, // a small share of the link: the main screen comes first
+            onCodecConfig = { csd ->
+                send(GearslipRunner.MSG_MEDIA_CODEC_CONFIG, csd)
+                log.i("-> CodecConfig (${csd.size} bytes)")
+            },
+            onFrame = { data, pts, _ -> sendFrame(data, pts) },
+        )
+        source = video
+        runCatching { video.start() }.onFailure {
+            log.e("cluster encoder failed to start", it)
+            return
+        }
+        val surface = video.inputSurface ?: return
+        val density = config.density.takeIf { it > 0 } ?: 160
+        main.post {
+            if (!running) return@post
+            projector = ScreenProjector(context).also {
+                it.start(surface, width, height, density, name = "gearslip-cluster") {
+                    // The margins the car crops off are kept clear, as on the main screen.
+                    ClusterScreen(config.widthMargin, config.heightMargin)
+                }
+            }
+        }
+    }
+
+    /** As on the main screen: wait for the car's acks rather than drop a frame. */
+    private fun sendFrame(data: ByteArray, presentationTimeUs: Long) {
+        synchronized(ackLock) {
+            while (running && inFlight >= maxUnacked) {
+                val since = System.currentTimeMillis() - lastAckAt
+                if (since > GearslipRunner.ACK_STALL_MS) {
+                    inFlight = 0
+                    lastAckAt = System.currentTimeMillis()
+                    break
+                }
+                ackLock.wait(GearslipRunner.ACK_STALL_MS - since + 1)
+            }
+        }
+        if (!running) return
+        val timestamp = ByteArray(8)
+        for (i in 0 until 8) timestamp[i] = ((presentationTimeUs shr ((7 - i) * 8)) and 0xFF).toByte()
+        synchronized(ackLock) { inFlight++ }
+        runCatching { send(GearslipRunner.MSG_MEDIA_DATA, timestamp + data) }.onFailure { running = false }
+        if (++frames <= 2) log.i("-> Data frame #$frames (${data.size} bytes)")
+    }
+
+    fun stop() {
+        running = false
+        synchronized(ackLock) { ackLock.notifyAll() }
+        main.post {
+            projector?.stop()
+            projector = null
+        }
+        source?.stop()
+        source = null
+    }
+
+    private companion object {
+        // A turn card changes a few times a minute; the encoder repeats the last frame between.
+        const val FRAME_RATE = 15
+    }
+}

gearslip/src/main/java/app/seb3thehacker/gearslip/FrameStretcher.kt

@@ -0,0 +1,190 @@
+package app.seb3thehacker.gearslip
+
+import android.graphics.SurfaceTexture
+import android.opengl.EGL14
+import android.opengl.EGLConfig
+import android.opengl.EGLContext
+import android.opengl.EGLDisplay
+import android.opengl.EGLExt
+import android.opengl.EGLSurface
+import android.opengl.GLES11Ext
+import android.opengl.GLES20
+import android.os.Handler
+import android.os.HandlerThread
+import android.view.Surface
+import java.nio.ByteBuffer
+import java.nio.ByteOrder
+import java.util.concurrent.CountDownLatch
+import java.util.concurrent.TimeUnit
+
+/**
+ * Stretches a [width] x [height] picture over the whole of an [outWidth] x [outHeight] encoder
+ * frame.
+ *
+ * For a head unit that squashes the frame onto a screen of another shape: Gearslip draws for the
+ * screen's real shape into [input], this stretches it the other way, and the car's squash brings
+ * it back. It works on the composited picture, so a map app's own surface is stretched with
+ * everything else - scaling Gearslip's UI alone would leave the map squashed.
+ */
+class FrameStretcher(
+    private val output: Surface,
+    val width: Int,
+    val height: Int,
+    private val outWidth: Int,
+    private val outHeight: Int,
+) {
+
+    private val thread = HandlerThread("gearslip-stretch").apply { start() }
+    private val handler = Handler(thread.looper)
+
+    private var display: EGLDisplay = EGL14.EGL_NO_DISPLAY
+    private var context: EGLContext = EGL14.EGL_NO_CONTEXT
+    private var eglSurface: EGLSurface = EGL14.EGL_NO_SURFACE
+    private var program = 0
+    private var texture: SurfaceTexture? = null
+    private val transform = FloatArray(16)
+
+    /** Where to draw. Valid once [start] returns true. */
+    lateinit var input: Surface
+        private set
+
+    /** Sets up on its own thread and waits for it; false if the GPU wouldn't play along. */
+    fun start(): Boolean {
+        val done = CountDownLatch(1)
+        var ok = false
+        handler.post {
+            ok = runCatching { setUp() }
+                .onFailure { GearslipLog.e("stretch: could not set up", it) }
+                .isSuccess
+            done.countDown()
+        }
+        done.await(2, TimeUnit.SECONDS)
+        if (!ok) release()
+        return ok
+    }
+
+    fun release() {
+        handler.post {
+            runCatching { if (::input.isInitialized) input.release() }
+            runCatching { texture?.release() }
+            texture = null
+            if (display != EGL14.EGL_NO_DISPLAY) {
+                EGL14.eglMakeCurrent(display, EGL14.EGL_NO_SURFACE, EGL14.EGL_NO_SURFACE, EGL14.EGL_NO_CONTEXT)
+                if (eglSurface != EGL14.EGL_NO_SURFACE) EGL14.eglDestroySurface(display, eglSurface)
+                if (context != EGL14.EGL_NO_CONTEXT) EGL14.eglDestroyContext(display, context)
+                EGL14.eglTerminate(display)
+            }
+            display = EGL14.EGL_NO_DISPLAY
+            thread.quitSafely()
+        }
+    }
+
+    private fun setUp() {
+        display = EGL14.eglGetDisplay(EGL14.EGL_DEFAULT_DISPLAY)
+        val version = IntArray(2)
+        check(EGL14.eglInitialize(display, version, 0, version, 1)) { "eglInitialize failed" }
+        val configs = arrayOfNulls<EGLConfig>(1)
+        val count = IntArray(1)
+        val attributes = intArrayOf(
+            EGL14.EGL_RED_SIZE, 8, EGL14.EGL_GREEN_SIZE, 8, EGL14.EGL_BLUE_SIZE, 8,
+            EGL14.EGL_RENDERABLE_TYPE, EGL14.EGL_OPENGL_ES2_BIT,
+            EGL_RECORDABLE_ANDROID, 1,
+            EGL14.EGL_NONE,
+        )
+        check(EGL14.eglChooseConfig(display, attributes, 0, configs, 0, 1, count, 0) && count[0] > 0) {
+            "no EGL config"
+        }
+        context = EGL14.eglCreateContext(
+            display, configs[0], EGL14.EGL_NO_CONTEXT,
+            intArrayOf(EGL14.EGL_CONTEXT_CLIENT_VERSION, 2, EGL14.EGL_NONE), 0,
+        )
+        eglSurface = EGL14.eglCreateWindowSurface(display, configs[0], output, intArrayOf(EGL14.EGL_NONE), 0)
+        check(EGL14.eglMakeCurrent(display, eglSurface, eglSurface, context)) { "eglMakeCurrent failed" }
+
+        program = link(VERTEX, FRAGMENT)
+        val ids = IntArray(1)
+        GLES20.glGenTextures(1, ids, 0)
+        GLES20.glBindTexture(GLES11Ext.GL_TEXTURE_EXTERNAL_OES, ids[0])
+        GLES20.glTexParameteri(GLES11Ext.GL_TEXTURE_EXTERNAL_OES, GLES20.GL_TEXTURE_MIN_FILTER, GLES20.GL_LINEAR)
+        GLES20.glTexParameteri(GLES11Ext.GL_TEXTURE_EXTERNAL_OES, GLES20.GL_TEXTURE_MAG_FILTER, GLES20.GL_LINEAR)
+        GLES20.glTexParameteri(GLES11Ext.GL_TEXTURE_EXTERNAL_OES, GLES20.GL_TEXTURE_WRAP_S, GLES20.GL_CLAMP_TO_EDGE)
+        GLES20.glTexParameteri(GLES11Ext.GL_TEXTURE_EXTERNAL_OES, GLES20.GL_TEXTURE_WRAP_T, GLES20.GL_CLAMP_TO_EDGE)
+
+        texture = SurfaceTexture(ids[0]).apply {
+            setDefaultBufferSize(width, height)
+            setOnFrameAvailableListener({ draw() }, handler)
+        }
+        input = Surface(texture)
+        GearslipLog.i("stretch: drawing ${width}x$height, stretched to fill ${outWidth}x$outHeight")
+    }
+
+    private fun draw() {
+        val tex = texture ?: return
+        runCatching {
+            tex.updateTexImage()
+            tex.getTransformMatrix(transform)
+            GLES20.glViewport(0, 0, outWidth, outHeight)
+            GLES20.glUseProgram(program)
+            val position = GLES20.glGetAttribLocation(program, "aPosition")
+            val coord = GLES20.glGetAttribLocation(program, "aCoord")
+            GLES20.glEnableVertexAttribArray(position)
+            GLES20.glVertexAttribPointer(position, 2, GLES20.GL_FLOAT, false, 0, QUAD)
+            GLES20.glEnableVertexAttribArray(coord)
+            GLES20.glVertexAttribPointer(coord, 2, GLES20.GL_FLOAT, false, 0, COORDS)
+            GLES20.glUniformMatrix4fv(GLES20.glGetUniformLocation(program, "uTransform"), 1, false, transform, 0)
+            GLES20.glDrawArrays(GLES20.GL_TRIANGLE_STRIP, 0, 4)
+            EGLExt.eglPresentationTimeANDROID(display, eglSurface, tex.timestamp)
+            EGL14.eglSwapBuffers(display, eglSurface)
+        }.onFailure { GearslipLog.e("stretch: draw failed", it) }
+    }
+
+    private fun link(vertex: String, fragment: String): Int {
+        fun compile(type: Int, source: String): Int = GLES20.glCreateShader(type).also {
+            GLES20.glShaderSource(it, source)
+            GLES20.glCompileShader(it)
+            val status = IntArray(1)
+            GLES20.glGetShaderiv(it, GLES20.GL_COMPILE_STATUS, status, 0)
+            check(status[0] != 0) { "shader: ${GLES20.glGetShaderInfoLog(it)}" }
+        }
+        return GLES20.glCreateProgram().also {
+            GLES20.glAttachShader(it, compile(GLES20.GL_VERTEX_SHADER, vertex))
+            GLES20.glAttachShader(it, compile(GLES20.GL_FRAGMENT_SHADER, fragment))
+            GLES20.glLinkProgram(it)
+            val status = IntArray(1)
+            GLES20.glGetProgramiv(it, GLES20.GL_LINK_STATUS, status, 0)
+            check(status[0] != 0) { "program: ${GLES20.glGetProgramInfoLog(it)}" }
+        }
+    }
+
+    private companion object {
+        /** EGL_RECORDABLE_ANDROID: the config must be able to feed a video encoder. */
+        const val EGL_RECORDABLE_ANDROID = 0x3142
+
+        val QUAD = floats(-1f, -1f, 1f, -1f, -1f, 1f, 1f, 1f)
+        val COORDS = floats(0f, 0f, 1f, 0f, 0f, 1f, 1f, 1f)
+
+        fun floats(vararg values: Float) = ByteBuffer.allocateDirect(values.size * 4)
+            .order(ByteOrder.nativeOrder()).asFloatBuffer().apply { put(values); position(0) }
+
+        const val VERTEX = """
+            attribute vec4 aPosition;
+            attribute vec4 aCoord;
+            uniform mat4 uTransform;
+            varying vec2 vCoord;
+            void main() {
+                gl_Position = aPosition;
+                vCoord = (uTransform * aCoord).xy;
+            }
+        """
+
+        const val FRAGMENT = """
+            #extension GL_OES_EGL_image_external : require
+            precision mediump float;
+            varying vec2 vCoord;
+            uniform samplerExternalOES sTexture;
+            void main() {
+                gl_FragColor = texture2D(sTexture, vCoord);
+            }
+        """
+    }
+}

gearslip/src/main/java/app/seb3thehacker/gearslip/Framing.kt

@@ -1,20 +1,10 @@
 package app.seb3thehacker.gearslip
 
 import java.io.ByteArrayOutputStream
+import java.io.IOException
+import java.io.OutputStream
 
-/**
- * Android Auto frame layout, transcribed from aasdk.
- *
- * FrameHeader::getData (src/Messenger/FrameHeader.cpp:47-55),
- * FrameSize::getData (src/Messenger/FrameSize.cpp:49-62) and
- * MessageOutStream::compoundFrame (src/Messenger/MessageOutStream.cpp:100-120):
- *
- *   byte 0     channel id
- *   byte 1     frameType | encryption | messageType
- *   bytes 2-3  uint16 BE  payload length of THIS frame
- *   bytes 4-7  uint32 BE  total message length - present ONLY when frameType == FIRST
- *   payload    uint16 BE message id, then the body
- */
+/** Android Auto framing with plaintext fragmentation before per-frame encryption. */
 object Frames {
 
     const val CHANNEL_CONTROL = 0
@@ -36,8 +26,11 @@ object Frames {
     const val MESSAGE_SPECIFIC = 0
     const val MESSAGE_CONTROL = 1 shl 2
 
-    /** aasdk splits at this size (MessageOutStream.hpp:62). Nothing the spike sends is close. */
-    const val MAX_FRAME_PAYLOAD = 0x4000
+    // Android Auto's default fragment budget includes the framing header. TLS adds overhead.
+    private const val FRAGMENT_SIZE = 0x3f00
+    private const val HEADER_SIZE = 4
+    private const val FIRST_HEADER_SIZE = 8
+    const val MAX_FRAME_PAYLOAD = FRAGMENT_SIZE - HEADER_SIZE
 
     class Frame(
         val channel: Int,
@@ -45,6 +38,7 @@ object Frames {
         val encrypted: Boolean,
         val messageType: Int,
         val payload: ByteArray,
+        val totalSize: Int? = null,
     )
 
     /**
@@ -60,6 +54,11 @@ object Frames {
         frameType: Int = TYPE_BULK,
         totalSize: Int? = null,
     ): ByteArray {
+        require(channel in 0..255 && payload.size <= 0xffff)
+        require(frameType in TYPE_MIDDLE..TYPE_BULK)
+        require(messageType == MESSAGE_SPECIFIC || messageType == MESSAGE_CONTROL)
+        require((frameType == TYPE_FIRST) == (totalSize != null))
+        require(totalSize == null || totalSize in 2..MAX_MESSAGE_SIZE)
         val flags = frameType or messageType or (if (encrypted) ENCRYPTED else 0)
         val header = byteArrayOf(
             channel.toByte(),
@@ -67,7 +66,7 @@ object Frames {
             ((payload.size shr 8) and 0xFF).toByte(),
             (payload.size and 0xFF).toByte(),
         )
-        if (frameType != TYPE_FIRST || totalSize == null) return header + payload
+        if (totalSize == null) return header + payload
         val extended = byteArrayOf(
             ((totalSize shr 24) and 0xFF).toByte(),
             ((totalSize shr 16) and 0xFF).toByte(),
@@ -77,6 +76,43 @@ object Frames {
         return header + extended + payload
     }
 
+    /** Splits plaintext before encryption; FIRST carries the complete plaintext length. */
+    fun writeMessage(
+        output: OutputStream,
+        channel: Int,
+        encrypted: Boolean,
+        messageType: Int,
+        message: ByteArray,
+        encrypt: (ByteArray) -> ByteArray,
+    ): Int {
+        require(message.size in 2..MAX_MESSAGE_SIZE)
+        val fragmented = message.size > FRAGMENT_SIZE - HEADER_SIZE
+        require(messageType != MESSAGE_CONTROL || !fragmented) { "Channel control messages cannot be fragmented" }
+        var offset = 0
+        var frames = 0
+        while (offset < message.size) {
+            val first = fragmented && offset == 0
+            val headerSize = if (first) FIRST_HEADER_SIZE else HEADER_SIZE
+            val end = minOf(offset + FRAGMENT_SIZE - headerSize, message.size)
+            val type = when {
+                !fragmented -> TYPE_BULK
+                first -> TYPE_FIRST
+                end == message.size -> TYPE_LAST
+                else -> TYPE_MIDDLE
+            }
+            val chunk = message.copyOfRange(offset, end)
+            output.write(build(channel, encrypted, if (encrypted) encrypt(chunk) else chunk,
+                messageType, type, if (type == TYPE_FIRST) message.size else null))
+            offset = end
+            frames++
+        }
+        return frames
+    }
+
+    // Local resource limits, not protocol constants. No supported media packet needs more.
+    private const val MAX_MESSAGE_SIZE = 16 * 1024 * 1024
+    private const val MAX_BUFFERED_SIZE = 32 * 1024 * 1024
+
     /**
      * Pulls whole frames out of an accumulating buffer.
      *
@@ -87,6 +123,8 @@ object Frames {
         private var pending = ByteArray(0)
 
         fun append(data: ByteArray, length: Int) {
+            require(length in 0..data.size)
+            if (length > MAX_BUFFERED_SIZE - pending.size) throw IOException("Frame buffer limit exceeded")
             val grown = ByteArray(pending.size + length)
             System.arraycopy(pending, 0, grown, 0, pending.size)
             System.arraycopy(data, 0, grown, pending.size, length)
@@ -106,30 +144,53 @@ object Frames {
             val total = headerLength + frameSize
             if (pending.size < total) return null
 
+            val messageSize = if (frameType == TYPE_FIRST) {
+                var size = 0L
+                for (i in 4..7) size = (size shl 8) or (pending[i].toLong() and 0xff)
+                if (size !in 2..MAX_MESSAGE_SIZE.toLong()) throw IOException("Invalid fragmented message length: $size")
+                size.toInt()
+            } else null
             val payload = pending.copyOfRange(headerLength, total)
             pending = pending.copyOfRange(total, pending.size)
             return Frame(
-                channel, frameType, (flags and ENCRYPTED) != 0, flags and MESSAGE_CONTROL, payload,
+                channel, frameType, (flags and ENCRYPTED) != 0, flags and MESSAGE_CONTROL, payload, messageSize,
             )
         }
     }
 
-    /** Rejoins FIRST/MIDDLE/LAST runs. Payloads arrive already decrypted. */
+    /** Rejoins messages on independent channels, validating their plaintext length and flags. */
     class Assembler {
-        private val partial = HashMap<Int, ByteArrayOutputStream>()
+        private class Partial(val first: Frame, val data: ByteArrayOutputStream = ByteArrayOutputStream())
+        private val partial = HashMap<Int, Partial>()
+        private var buffered = 0
 
-        fun offer(frame: Frame, payload: ByteArray): ByteArray? = when (frame.frameType) {
-            TYPE_BULK -> payload
-            TYPE_FIRST -> {
-                partial[frame.channel] = ByteArrayOutputStream().apply { write(payload) }
-                null
+        fun offer(frame: Frame, payload: ByteArray): ByteArray? {
+            if (frame.frameType == TYPE_BULK) {
+                if (partial.containsKey(frame.channel)) fail("Complete message interrupted fragments")
+                return payload
             }
-            TYPE_MIDDLE -> {
-                partial[frame.channel]?.write(payload)
-                null
-            }
-            TYPE_LAST -> partial.remove(frame.channel)?.apply { write(payload) }?.toByteArray()
-            else -> null
+            val message = if (frame.frameType == TYPE_FIRST) {
+                if (frame.totalSize == null || partial.containsKey(frame.channel)) fail("Invalid first fragment")
+                Partial(frame).also { partial[frame.channel] = it }
+            } else partial[frame.channel] ?: fail("Fragment without a first frame")
+            val first = message.first
+            if (first.encrypted != frame.encrypted || first.messageType != frame.messageType) fail("Fragment flags changed")
+            val expected = first.totalSize ?: fail("Missing total size")
+            if (expected !in 2..MAX_MESSAGE_SIZE || payload.size > expected - message.data.size()) fail("Fragment exceeds message length")
+            if (payload.size > MAX_BUFFERED_SIZE - buffered) fail("Fragment buffer limit exceeded")
+            message.data.write(payload)
+            buffered += payload.size
+            if (frame.frameType != TYPE_LAST) return null
+            if (message.data.size() != expected) fail("Truncated fragmented message")
+            partial.remove(frame.channel)
+            buffered -= message.data.size()
+            return message.data.toByteArray()
+        }
+
+        private fun fail(message: String): Nothing {
+            partial.clear()
+            buffered = 0
+            throw IOException(message)
         }
     }
 }

gearslip/src/main/java/app/seb3thehacker/gearslip/GearslipActivity.kt

@@ -8,13 +8,16 @@ import android.hardware.usb.UsbAccessory
 import android.hardware.usb.UsbManager
 import android.media.projection.MediaProjection
 import android.media.projection.MediaProjectionManager
+import android.net.Uri
 import android.os.Bundle
 import android.os.ParcelFileDescriptor
+import android.provider.Settings
 import android.view.MotionEvent
 import android.view.Surface
-import android.view.WindowManager
 import androidx.activity.ComponentActivity
 import androidx.activity.compose.setContent
+import androidx.compose.runtime.collectAsState
+import androidx.compose.runtime.getValue
 import androidx.activity.enableEdgeToEdge
 import androidx.activity.result.contract.ActivityResultContracts.StartActivityForResult
 import android.content.res.Configuration
@@ -27,6 +30,7 @@ import app.seb3thehacker.gearslip.car.CarEnvironment
 import app.seb3thehacker.gearslip.car.CarSettings
 import app.seb3thehacker.gearslip.car.CarUi
 import app.seb3thehacker.gearslip.car.Prefetch
+import app.seb3thehacker.gearslip.stats.UsageStats
 import app.seb3thehacker.gearslip.ui.GearslipApp
 import app.seb3thehacker.gearslip.ui.GearslipTheme
 import java.io.FileInputStream
@@ -40,8 +44,12 @@ import java.io.FileOutputStream
  * rotation or theme change from recreating it and dropping the connection.
  */
 class GearslipActivity : ComponentActivity(), Projection {
+    private val mainHandler = android.os.Handler(android.os.Looper.getMainLooper())
+
 
     private var descriptor: ParcelFileDescriptor? = null
+    /** The wireless session's socket, when the car came over Wi-Fi instead of USB. */
+    private var wirelessSocket: java.net.Socket? = null
     private var runner: GearslipRunner? = null
     private var screenProjector: ScreenProjector? = null
     private var worker: Thread? = null
@@ -69,7 +77,13 @@ class GearslipActivity : ComponentActivity(), Projection {
     private val audioPermission = registerForActivityResult(
         androidx.activity.result.contract.ActivityResultContracts.RequestPermission(),
     ) { granted ->
-        if (granted) askAudioCapture() else {
+        if (granted) askAudioCapture()
+        else if (!shouldShowRequestPermissionRationale(android.Manifest.permission.RECORD_AUDIO)) {
+            // Refused twice: Android now says no without showing anything, so the phone must.
+            GearslipLog.w("audio: record permission blocked - Android no longer asks")
+            CarAudio.micBlocked()
+            micBlockedNotice.value = true
+        } else {
             GearslipLog.w("audio: record permission declined")
             CarAudio.denied()
         }
@@ -82,18 +96,37 @@ class GearslipActivity : ComponentActivity(), Projection {
         } else {
             GearslipLog.w("audio: capture consent declined")
             CarAudio.denied()
+            if (!CarSettings.audioChoiceAsked) offerBluetooth.value = true
         }
     }
 
+    /** Raised when the microphone permission is blocked; see [MicBlockedDialog]. */
+    private val micBlockedNotice = kotlinx.coroutines.flow.MutableStateFlow(false)
+
+    /** Raised once, after the first "no" to the capture dialog; see [AudioChoiceDialog]. */
+    private val offerBluetooth = kotlinx.coroutines.flow.MutableStateFlow(false)
+
     private val detachReceiver = object : BroadcastReceiver() {
         override fun onReceive(context: Context?, intent: Intent?) {
             if (intent?.action == UsbManager.ACTION_USB_ACCESSORY_DETACHED) {
                 GearslipLog.w("accessory detached")
-                closeAccessory()
+                // A wireless session has no accessory to lose; leave it running.
+                if (wirelessSocket == null) closeAccessory()
             }
         }
     }
 
+    /** Android's one-time "Allow" for a car to connect by itself; see [WirelessAuto]. */
+    private var approvingCar: String? = null
+    private val carApproval = registerForActivityResult(
+        androidx.activity.result.contract.ActivityResultContracts.StartIntentSenderForResult(),
+    ) { result ->
+        val address = approvingCar ?: return@registerForActivityResult
+        approvingCar = null
+        if (result.resultCode == RESULT_OK) app.seb3thehacker.gearslip.wireless.WirelessAuto.approved(this, address)
+        else app.seb3thehacker.gearslip.wireless.WirelessAuto.declined(this, address)
+    }
+
     /** Setting Gearslip as the phone's caller ID and spam app - what lets it decline a ringing call. */
     private val callScreeningRole = registerForActivityResult(StartActivityForResult()) { result ->
         if (result.resultCode != RESULT_OK) GearslipLog.w("calls: call screening role declined")
@@ -107,11 +140,19 @@ class GearslipActivity : ComponentActivity(), Projection {
         // is both a bad first impression and unreliable: Android does not consistently show more
         // than one system permission dialog fired back-to-back, which was silently dropping some.
         enableEdgeToEdge()
-        window.addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON)
 
         GearslipLog.init(this)
         GearslipLog.installCrashHandler()
         GearslipLog.i("Gearslip ready")
+        app.seb3thehacker.gearslip.wireless.WirelessLink.onConnected = { socket ->
+            runOnUiThread { startWireless(socket) }
+        }
+        app.seb3thehacker.gearslip.wireless.WirelessAuto.showApproval = { chooser, address ->
+            runOnUiThread {
+                approvingCar = address
+                carApproval.launch(androidx.activity.result.IntentSenderRequest.Builder(chooser).build())
+            }
+        }
         CarSettings.init(this)
         AppSettings.applyGearslipEnabled(this)
         // A capture that died without tidying up would leave notifications exposed to every
@@ -124,7 +165,33 @@ class GearslipActivity : ComponentActivity(), Projection {
 
         setContent {
             GearslipTheme {
-                GearslipApp(onDisconnect = ::closeAccessory, onRequestCallScreening = ::requestCallScreeningRole)
+                GearslipApp(onDisconnect = { closeAccessory() }, onRequestCallScreening = ::requestCallScreeningRole)
+                val offer by offerBluetooth.collectAsState()
+                if (offer) {
+                    fun close() {
+                        CarSettings.markAudioChoiceAsked()
+                        offerBluetooth.value = false
+                    }
+                    app.seb3thehacker.gearslip.ui.AudioChoiceDialog(
+                        onUseBluetooth = {
+                            CarSettings.setPipeAudio(false)
+                            close()
+                        },
+                        onKeepAsking = ::close,
+                    )
+                }
+                val micNotice by micBlockedNotice.collectAsState()
+                if (micNotice) {
+                    app.seb3thehacker.gearslip.ui.MicBlockedDialog(
+                        onOpenSettings = {
+                            micBlockedNotice.value = false
+                            startActivity(
+                                Intent(Settings.ACTION_APPLICATION_DETAILS_SETTINGS, Uri.fromParts("package", packageName, null)),
+                            )
+                        },
+                        onDismiss = { micBlockedNotice.value = false },
+                    )
+                }
             }
         }
 
@@ -148,6 +215,12 @@ class GearslipActivity : ComponentActivity(), Projection {
     override fun onStart() {
         super.onStart()
         Prefetch.warm(this)
+        UsageStats.onAppOpened(this)
+        app.seb3thehacker.gearslip.update.UpdateChecker.onAppOpened(this)
+        // Back from the app's settings with the microphone turned on: try car audio again.
+        if (checkSelfPermission(android.Manifest.permission.RECORD_AUDIO) == android.content.pm.PackageManager.PERMISSION_GRANTED) {
+            CarAudio.micAllowed()
+        }
     }
 
     override fun onNewIntent(intent: Intent) {
@@ -157,6 +230,8 @@ class GearslipActivity : ComponentActivity(), Projection {
 
     override fun onDestroy() {
         super.onDestroy()
+        app.seb3thehacker.gearslip.wireless.WirelessLink.onConnected = null
+        app.seb3thehacker.gearslip.wireless.WirelessAuto.showApproval = null
         runCatching { unregisterReceiver(detachReceiver) }
         PhoneMirror.onStartRequested = null
         PhoneMirror.onTokenReady = null
@@ -245,6 +320,12 @@ class GearslipActivity : ComponentActivity(), Projection {
     }
 
     private fun handleIntent(intent: Intent?) {
+        // Debug builds only: opens the audio choice for a look, without turning down a real prompt.
+        if (BuildConfig.DEBUG && intent?.getBooleanExtra("show_audio_choice", false) == true) offerBluetooth.value = true
+        if (intent?.action == app.seb3thehacker.gearslip.wireless.WirelessAuto.ACTION_CAR_NEARBY) {
+            connectToNearbyCar(intent.getStringExtra(app.seb3thehacker.gearslip.wireless.WirelessAuto.EXTRA_ADDRESS))
+            return
+        }
         if (intent?.action != UsbManager.ACTION_USB_ACCESSORY_ATTACHED) return
         // Switched off in Settings: the system shouldn't route the car here at all, but if it
         // does, leave the accessory alone.
@@ -262,6 +343,39 @@ class GearslipActivity : ComponentActivity(), Projection {
         start(accessory)
     }
 
+    /** A known car came up over Bluetooth: connect wirelessly, unless USB or another try is already on it. */
+    private fun connectToNearbyCar(address: String?) {
+        if (address == null) return
+        if (!AppSettings.gearslipEnabled(this)) {
+            GearslipLog.i("auto-connect: Gearslip is switched off - not connecting")
+            return
+        }
+        if (descriptor != null) {
+            GearslipLog.i("auto-connect: the car is on USB already - staying on USB")
+            return
+        }
+        // Only a session that's still running counts. One the car ended (a ByeBye, a dropped
+        // network) leaves its runner behind, since only Gearslip ending a session clears it, and
+        // that used to make every later auto-connect quietly do nothing.
+        if (worker?.isAlive == true || app.seb3thehacker.gearslip.wireless.WirelessLink.busy) {
+            GearslipLog.i("auto-connect: a session is already running")
+            return
+        }
+        if (runner != null) closeAccessory(stopWireless = false)
+        if (checkSelfPermission(android.Manifest.permission.BLUETOOTH_CONNECT) != android.content.pm.PackageManager.PERMISSION_GRANTED) {
+            GearslipLog.w("auto-connect: needs the Nearby devices permission")
+            return
+        }
+        val adapter = getSystemService(android.bluetooth.BluetoothManager::class.java)?.adapter
+        val device = adapter?.let { runCatching { it.getRemoteDevice(address) }.getOrNull() }
+        if (device == null) {
+            GearslipLog.w("auto-connect: Bluetooth couldn't hand over the car")
+            return
+        }
+        GearslipLog.i("auto-connect: connecting")
+        app.seb3thehacker.gearslip.wireless.WirelessLink.start(this, device)
+    }
+
     private fun start(accessory: UsbAccessory) {
         // A fresh ATTACHED intent means the system wants a new session, whatever state the old
         // one is in - closing first guarantees openAccessory() below never fights a descriptor
@@ -292,16 +406,44 @@ class GearslipActivity : ComponentActivity(), Projection {
         worker = Thread { runner.run() }.apply { name = "gearslip"; start() }
     }
 
+    /** A wireless session: the same runner, on the socket [WirelessLink] opened to the car. */
+    private fun startWireless(socket: java.net.Socket) {
+        closeAccessory(stopWireless = false)
+        if (!AppSettings.gearslipEnabled(this)) {
+            GearslipLog.i("wireless: Gearslip is switched off - not connecting")
+            runCatching { socket.close() }
+            return
+        }
+        GearslipLog.i("wireless: starting a session over Wi-Fi to ${socket.inetAddress?.hostAddress}:${socket.port}")
+        wirelessSocket = socket
+        val runner = GearslipRunner(
+            input = socket.getInputStream(),
+            output = socket.getOutputStream(),
+            identityProvider = { CertProvider.load(this) },
+            projection = this,
+            vehicleProfileFor = { info -> VehicleProfiles.find(VehicleProfiles.load(this), info) },
+            wireless = true,
+        )
+        this.runner = runner
+        worker = Thread { runner.run() }.apply { name = "gearslip"; start() }
+    }
+
     private fun describe(accessory: UsbAccessory) {
         GearslipLog.i("accessory: manufacturer=${accessory.manufacturer} model=${accessory.model}")
         GearslipLog.i("           version=${accessory.version} description=${accessory.description}")
     }
 
-    private fun closeAccessory() {
+    private fun closeAccessory() = closeAccessory(stopWireless = true)
+
+    /** Ends the session, wired or wireless. [stopWireless] also drops the car's Bluetooth and Wi-Fi. */
+    private fun closeAccessory(stopWireless: Boolean) {
         runner?.stop()
         SessionReport.print()
         runCatching { descriptor?.close() }
         descriptor = null
+        runCatching { wirelessSocket?.close() }
+        wirelessSocket = null
+        if (stopWireless) app.seb3thehacker.gearslip.wireless.WirelessLink.stop(this)
         runner = null
     }
 
@@ -323,7 +465,9 @@ class GearslipActivity : ComponentActivity(), Projection {
     }
 
     override fun onTouch(action: Int, actionIndex: Int, points: List<TouchPoint>) {
-        runOnUiThread {
+        // To the front of the main thread's queue: a touch waiting behind other work is lag the
+        // driver feels, while the work it jumps ahead of can wait a frame.
+        mainHandler.postAtFrontOfQueue {
             // Mirroring drives one phone touch at a time, so it follows the first finger only.
             if (PhoneMirror.active.value) points.firstOrNull()?.let { relayTouch(action, it.x, it.y) }
             else screenProjector?.dispatchTouch(action, actionIndex, points)
@@ -331,6 +475,8 @@ class GearslipActivity : ComponentActivity(), Projection {
     }
 
     override fun onProjectionStopped() {
+        // Before the car UI goes, while the media connection is still up.
+        app.seb3thehacker.gearslip.car.CarServices.pausePhoneMedia()
         runOnUiThread {
             PhoneMirror.requestStop()
             app.seb3thehacker.gearslip.car.CarKeys.focusSink = null

gearslip/src/main/java/app/seb3thehacker/gearslip/GearslipLog.kt

@@ -52,6 +52,46 @@ object GearslipLog {
         file = File(dir, "gearslip-$name.log")
         i("log file: ${file?.absolutePath}")
         SessionReport.init(context)
+        // One file per launch adds up; the newest are the ones anyone asks for.
+        io.execute { logFiles(dir).drop(KEEP_FILES).forEach { it.delete() } }
+    }
+
+    private const val KEEP_FILES = 30
+
+    private fun logFiles(dir: File): List<File> =
+        dir.listFiles { f -> f.isFile && f.name.startsWith("gearslip-") && f.name.endsWith(".log") }
+            ?.sortedByDescending { it.name }.orEmpty()
+
+    /** A log from an earlier launch: when it started, and what a glance at it tells. */
+    class PastLog(val file: File, val started: Date?, val crashed: Boolean, val car: String?)
+
+    /**
+     * Earlier launches' logs, newest first. Each launch starts a fresh file, so after a crash the
+     * one that saw it is here rather than on the live screen.
+     */
+    fun pastLogs(context: Context): List<PastLog> {
+        val dir = context.getExternalFilesDir(null) ?: return emptyList()
+        val parse = SimpleDateFormat("yyyyMMdd-HHmmss", Locale.US)
+        return logFiles(dir).filter { it != file }.map { f ->
+            val text = runCatching { f.readText() }.getOrDefault("")
+            PastLog(
+                file = f,
+                started = runCatching { parse.parse(f.name.removePrefix("gearslip-").removeSuffix(".log")) }.getOrNull(),
+                crashed = "FATAL uncaught" in text,
+                car = Regex("""car="([^"]+)"""").findAll(text).lastOrNull()?.groupValues?.get(1),
+            )
+        }
+    }
+
+    /** An earlier launch's log, copied to the cache dir for sharing like [shareableFile]. */
+    fun shareableFile(context: Context, past: File): android.net.Uri {
+        val dir = File(context.cacheDir, "shared").apply { mkdirs() }
+        dir.listFiles()?.forEach { it.delete() }
+        val out = File(dir, "gearslip-log-${past.name.removePrefix("gearslip-").removeSuffix(".log")}.txt")
+        past.copyTo(out, overwrite = true)
+        return androidx.core.content.FileProvider.getUriForFile(
+            context, "${context.packageName}.logshare", out,
+        )
     }
 
     fun snapshot(): List<String> = synchronized(live) { live.toList() }

gearslip/src/main/java/app/seb3thehacker/gearslip/PermissionActivity.kt

@@ -0,0 +1,49 @@
+package app.seb3thehacker.gearslip
+
+import android.app.Activity
+import android.app.ActivityOptions
+import android.content.Context
+import android.content.Intent
+import android.os.Bundle
+import android.view.Display
+
+/**
+ * Asks for runtime permissions on the phone's own screen, for a car screen that can't show
+ * Android's dialog itself. It has no look of its own: the dialog appears, the answer is given,
+ * and it finishes.
+ */
+class PermissionActivity : Activity() {
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        val wanted = intent.getStringArrayExtra(EXTRA_PERMISSIONS)
+            ?.filter { checkSelfPermission(it) != android.content.pm.PackageManager.PERMISSION_GRANTED }
+            .orEmpty()
+        if (wanted.isEmpty() || savedInstanceState != null) {
+            if (wanted.isEmpty()) finish()
+            return
+        }
+        requestPermissions(wanted.toTypedArray(), REQUEST)
+    }
+
+    override fun onRequestPermissionsResult(requestCode: Int, permissions: Array<out String>, grantResults: IntArray) {
+        super.onRequestPermissionsResult(requestCode, permissions, grantResults)
+        GearslipLog.i("permissions: ${permissions.zip(grantResults.toList()).joinToString { (p, r) -> "${p.substringAfterLast('.')}=${r == 0}" }}")
+        finish()
+    }
+
+    companion object {
+        private const val EXTRA_PERMISSIONS = "permissions"
+        private const val REQUEST = 1
+
+        /** Shows the permission dialog on the phone, whichever screen [context] belongs to. */
+        fun ask(context: Context, permissions: Array<String>) {
+            val intent = Intent(context, PermissionActivity::class.java)
+                .putExtra(EXTRA_PERMISSIONS, permissions)
+                .addFlags(Intent.FLAG_ACTIVITY_NEW_TASK)
+            val options = ActivityOptions.makeBasic().setLaunchDisplayId(Display.DEFAULT_DISPLAY)
+            runCatching { context.startActivity(intent, options.toBundle()) }
+                .onFailure { GearslipLog.w("permissions: could not ask on the phone: ${it.message}") }
+        }
+    }
+}

gearslip/src/main/java/app/seb3thehacker/gearslip/PhoneTls.kt

@@ -1,5 +1,6 @@
 package app.seb3thehacker.gearslip
 
+import java.io.ByteArrayOutputStream
 import java.net.Socket
 import java.nio.ByteBuffer
 import java.security.KeyStore
@@ -11,23 +12,10 @@ import javax.net.ssl.SSLEngine
 import javax.net.ssl.SSLEngineResult
 import javax.net.ssl.SSLEngineResult.HandshakeStatus
 import javax.net.ssl.SSLPeerUnverifiedException
+import javax.net.ssl.SSLException
 import javax.net.ssl.X509ExtendedTrustManager
 
-/**
- * The phone end of the Android Auto TLS session.
- *
- * Two things here are the opposite of what aasdk does, because aasdk implements the head
- * unit and the head unit is the TLS *client*: it calls TLS_client_method() and
- * SSL_set_connect_state (src/Transport/SSLWrapper.cpp:97-140, src/Messenger/Cryptor.cpp:87),
- * and SSL_set_accept_state appears nowhere in that codebase. So the phone is the TLS
- * **server** and its certificate goes out as the server certificate - sent unconditionally
- * on every handshake, which is precisely what we are testing.
- *
- * TLS here is not layered over the socket: handshake bytes travel inside
- * MESSAGE_ENCAPSULATED_SSL control messages (id 3). That rules out SSLSocket and makes
- * SSLEngine - a buffer-to-buffer engine, the JSSE counterpart of aasdk's memory BIO pair -
- * the right tool.
- */
+/** TLS server for projection. Handshake records travel in control message 3, not a TLS socket. */
 class PhoneTls(keyStore: KeyStore, password: CharArray) {
     private val log = GearslipLog.tagged("TLS")
 
@@ -36,7 +24,7 @@ class PhoneTls(keyStore: KeyStore, password: CharArray) {
     private var appBuffer = ByteBuffer.allocate(32 * 1024)
     private var netBuffer = ByteBuffer.allocate(32 * 1024)
 
-    var handshakeComplete: Boolean = false
+    @Volatile var handshakeComplete: Boolean = false
         private set
 
     init {
@@ -52,6 +40,7 @@ class PhoneTls(keyStore: KeyStore, password: CharArray) {
             useClientMode = false
             // want, not need: we ask the head unit for its certificate so the run also tells
             // us what real units present, but we never make the session depend on getting one.
+            // Homemade head units may have none.
             wantClientAuth = true
             enabledProtocols = arrayOf("TLSv1.2") // aasdk pins TLS 1.2
         }
@@ -88,7 +77,7 @@ class PhoneTls(keyStore: KeyStore, password: CharArray) {
                     if (netBuffer.hasRemaining()) {
                         outgoing += ByteArray(netBuffer.remaining()).also { netBuffer.get(it) }
                     }
-                    if (result.status == SSLEngineResult.Status.CLOSED) break@loop
+                    if (result.status == SSLEngineResult.Status.CLOSED) throw SSLException("TLS closed during handshake")
                 }
 
                 HandshakeStatus.NEED_UNWRAP -> {
@@ -100,7 +89,7 @@ class PhoneTls(keyStore: KeyStore, password: CharArray) {
                             appBuffer = ByteBuffer.allocate(appBuffer.capacity() * 2)
                             continue@loop
                         }
-                        SSLEngineResult.Status.CLOSED -> break@loop
+                        SSLEngineResult.Status.CLOSED -> throw SSLException("TLS closed during handshake")
                         else -> Unit
                     }
                 }
@@ -124,7 +113,7 @@ class PhoneTls(keyStore: KeyStore, password: CharArray) {
     /** Wraps a control-channel payload for an ENCRYPTED frame. */
     fun encrypt(plain: ByteArray): ByteArray {
         val source = ByteBuffer.wrap(plain)
-        val out = java.io.ByteArrayOutputStream()
+        val out = ByteArrayOutputStream()
         while (source.hasRemaining()) {
             netBuffer.clear()
             val result = engine.wrap(source, netBuffer)
@@ -132,6 +121,9 @@ class PhoneTls(keyStore: KeyStore, password: CharArray) {
                 netBuffer = ByteBuffer.allocate(netBuffer.capacity() * 2)
                 continue
             }
+            if (result.status != SSLEngineResult.Status.OK || result.bytesConsumed() == 0) {
+                throw SSLException("TLS could not encrypt application data: ${result.status}")
+            }
             netBuffer.flip()
             val chunk = ByteArray(netBuffer.remaining())
             netBuffer.get(chunk)
@@ -140,14 +132,10 @@ class PhoneTls(keyStore: KeyStore, password: CharArray) {
         return out.toByteArray()
     }
 
-    /**
-     * Unwraps one ENCRYPTED frame's payload. aasdk decrypts per frame
-     * (MessageOutStream::compoundFrame encrypts per frame), so each frame's payload is
-     * self-contained ciphertext.
-     */
+    /** Each encrypted projection frame contains complete TLS records. */
     fun decrypt(cipher: ByteArray): ByteArray {
         val source = ByteBuffer.wrap(cipher)
-        val out = java.io.ByteArrayOutputStream()
+        val out = ByteArrayOutputStream()
         while (source.hasRemaining()) {
             appBuffer.clear()
             val result = engine.unwrap(source, appBuffer)
@@ -157,10 +145,9 @@ class PhoneTls(keyStore: KeyStore, password: CharArray) {
                     continue
                 }
                 SSLEngineResult.Status.BUFFER_UNDERFLOW -> {
-                    log.w("decrypt: record split across frames (${source.remaining()} bytes left over)")
-                    break
+                    throw SSLException("Incomplete TLS record in an encrypted frame")
                 }
-                SSLEngineResult.Status.CLOSED -> break
+                SSLEngineResult.Status.CLOSED -> throw SSLException("TLS peer closed the connection")
                 else -> Unit
             }
             appBuffer.flip()

gearslip/src/main/java/app/seb3thehacker/gearslip/Protobuf.kt

@@ -2,14 +2,7 @@ package app.seb3thehacker.gearslip
 
 import java.io.ByteArrayOutputStream
 
-/**
- * Just enough protobuf to run the spike, hand-rolled so there is no protoc step.
- *
- * Only three messages are ever written (AuthResponse is only read):
- *   ServiceDiscoveryRequest { optional string label_text = 4; optional string device_name = 5; }
- *   PingResponse            { required int64 timestamp = 1; }
- *   AuthResponse            { required int32 status = 1; }
- */
+/** Protobuf field encoding and diagnostic rendering for the projection protocol. */
 object Protobuf {
 
     fun varint(value: Long): ByteArray {
@@ -31,6 +24,9 @@ object Protobuf {
         return varint(((field shl 3) or 2).toLong()) + varint(bytes.size.toLong()) + bytes
     }
 
+    fun bytesField(field: Int, bytes: ByteArray): ByteArray =
+        varint(((field shl 3) or 2).toLong()) + varint(bytes.size.toLong()) + bytes
+
     fun varintField(field: Int, value: Long): ByteArray =
         varint((field shl 3).toLong()) + varint(value)
 
@@ -38,29 +34,7 @@ object Protobuf {
     fun readInt32Field(data: ByteArray, field: Int): Int? = readInt64Field(data, field)?.toInt()
 
     /** Reads a varint field whole, for int64s such as a ping's timestamp. */
-    fun readInt64Field(data: ByteArray, field: Int): Long? {
-        var pos = 0
-        while (pos < data.size) {
-            val (tag, afterTag) = readVarint(data, pos) ?: return null
-            pos = afterTag
-            val number = (tag ushr 3).toInt()
-            when ((tag and 7L).toInt()) {
-                0 -> {
-                    val (value, afterValue) = readVarint(data, pos) ?: return null
-                    pos = afterValue
-                    if (number == field) return value
-                }
-                2 -> {
-                    val (len, afterLen) = readVarint(data, pos) ?: return null
-                    pos = afterLen + len.toInt()
-                }
-                5 -> pos += 4
-                1 -> pos += 8
-                else -> return null
-            }
-        }
-        return null
-    }
+    fun readInt64Field(data: ByteArray, field: Int): Long? = Wire.varint(Wire.fields(data), field)
 
     /**
      * Shallow field dump. Used on ServiceDiscoveryResponse: its make/model/year strings
@@ -68,6 +42,7 @@ object Protobuf {
      * proof that the session is live and we are decrypting correctly.
      */
     fun describe(data: ByteArray, indent: String = "  "): String {
+        if (indent.length > 32) return "$indent(nested message)\n"
         val sb = StringBuilder()
         var pos = 0
         while (pos < data.size) {
@@ -86,6 +61,7 @@ object Protobuf {
                 }
                 2 -> {
                     val (len, afterLen) = readVarint(data, pos) ?: break
+                    if (len < 0 || len > data.size - afterLen) break
                     val end = afterLen + len.toInt()
                     if (end > data.size) break
                     val body = data.copyOfRange(afterLen, end)
@@ -114,6 +90,7 @@ object Protobuf {
         var pos = start
         while (pos < data.size && shift <= 63) {
             val b = data[pos].toInt() and 0xFF
+            if (shift == 63 && b > 1) return null
             result = result or ((b and 0x7F).toLong() shl shift)
             pos++
             if (b and 0x80 == 0) return result to pos
@@ -132,45 +109,68 @@ object Wire {
         val out = mutableListOf<Field>()
         var pos = 0
         while (pos < data.size) {
-            val tag = readVarint(data, pos) ?: break
+            val tag = readVarint(data, pos) ?: return emptyList()
             pos = tag.second
             val number = (tag.first ushr 3).toInt()
+            if (tag.first ushr 3 !in 1..0x1fff_ffffL) return emptyList()
             when ((tag.first and 7L).toInt()) {
                 0 -> {
-                    val v = readVarint(data, pos) ?: break
+                    val v = readVarint(data, pos) ?: return emptyList()
                     pos = v.second
                     out += Field(number, 0, v.first, null)
                 }
-                1 -> { if (pos + 8 > data.size) break; pos += 8 }
+                1 -> { if (data.size - pos < 8) return emptyList(); pos += 8 }
                 2 -> {
-                    val len = readVarint(data, pos) ?: break
+                    val len = readVarint(data, pos) ?: return emptyList()
+                    if (len.first < 0 || len.first > data.size - len.second) return emptyList()
                     val end = len.second + len.first.toInt()
-                    if (end > data.size || end < len.second) break
+                    if (end > data.size || end < len.second) return emptyList()
                     out += Field(number, 2, 0, data.copyOfRange(len.second, end))
                     pos = end
                 }
-                5 -> { if (pos + 4 > data.size) break; pos += 4 }
-                else -> break
+                5 -> { if (data.size - pos < 4) return emptyList(); pos += 4 }
+                else -> return emptyList()
             }
         }
         return out
     }
 
     fun varint(fields: List<Field>, number: Int): Long? =
-        fields.firstOrNull { it.number == number && it.wireType == 0 }?.varint
+        fields.lastOrNull { it.number == number && it.wireType == 0 }?.varint
 
     fun bytes(fields: List<Field>, number: Int): ByteArray? =
-        fields.firstOrNull { it.number == number && it.wireType == 2 }?.bytes
+        fields.lastOrNull { it.number == number && it.wireType == 2 }?.bytes
 
     fun allBytes(fields: List<Field>, number: Int): List<ByteArray> =
         fields.filter { it.number == number && it.wireType == 2 }.mapNotNull { it.bytes }
 
+    /** Protobuf readers accept both packed and unpacked repeated numeric fields. */
+    fun repeatedInts(fields: List<Field>, number: Int): List<Int> =
+        repeatedLongs(fields, number)?.map(Long::toInt).orEmpty()
+
+    /** Null means a packed field contained an incomplete or overflowing varint. */
+    fun repeatedLongs(fields: List<Field>, number: Int): List<Long>? = buildList {
+        for (field in fields.filter { it.number == number }) {
+            if (field.wireType == 0) add(field.varint)
+            else if (field.wireType == 2) {
+                val bytes = field.bytes ?: continue
+                var position = 0
+                while (position < bytes.size) {
+                    val (value, next) = readVarint(bytes, position) ?: return null
+                    add(value)
+                    position = next
+                }
+            }
+        }
+    }
+
     private fun readVarint(data: ByteArray, start: Int): Pair<Long, Int>? {
         var result = 0L
         var shift = 0
         var pos = start
         while (pos < data.size && shift <= 63) {
             val b = data[pos].toInt() and 0xFF
+            if (shift == 63 && b > 1) return null
             result = result or ((b and 0x7F).toLong() shl shift)
             pos++
             if (b and 0x80 == 0) return result to pos

gearslip/src/main/java/app/seb3thehacker/gearslip/ProtocolVersion.kt

@@ -0,0 +1,17 @@
+package app.seb3thehacker.gearslip
+
+/**
+ * Advertises our supported 1.x version, as Android Auto does for older head units. Head units that
+ * offer a newer major version (LIVI asks for 6.1, a RAV4 and the DHU for 4.2) still accept a 1.x
+ * answer, so only a major version of 0 is refused.
+ */
+internal object ProtocolVersion {
+    data class Response(val major: Int, val minor: Int, val supported: Boolean) {
+        val bytes: ByteArray get() = byteArrayOf(
+            (major ushr 8).toByte(), major.toByte(), (minor ushr 8).toByte(), minor.toByte(),
+            if (supported) 0 else -1, if (supported) 0 else -1,
+        )
+    }
+
+    fun respond(major: Int, minor: Int): Response = Response(1, 7, major >= 1 && minor in 0..0xffff)
+}

gearslip/src/main/java/app/seb3thehacker/gearslip/ScreenProjector.kt

@@ -51,7 +51,7 @@ class ScreenProjector(private val context: Context) {
      * preview passes "gearslip-preview".
      */
     fun start(
-        surface: Surface,
+        surface: Surface?,
         width: Int,
         height: Int,
         densityDpi: Int,
@@ -198,6 +198,12 @@ class ScreenProjector(private val context: Context) {
      */
     fun dispatchKey(keyCode: Int, down: Boolean) {
         val target = root ?: return
+        // Keys handed straight to the view skip the step where Android leaves touch mode, and in
+        // touch mode Compose's buttons refuse focus, so the knob had nothing to move between.
+        if (target.isInTouchMode) {
+            target.requestFocusFromTouch()
+            GearslipLog.i("keys: left touch mode for the knob/D-pad (now in touch mode: ${target.isInTouchMode})")
+        }
         // Nothing on the display takes keys until something in it holds focus.
         if (target.findFocus() == null) target.requestFocus()
         val shift = keyCode == app.seb3thehacker.gearslip.car.CarKeys.KEYCODE_SHIFT_TAB
@@ -213,6 +219,14 @@ class ScreenProjector(private val context: Context) {
         target.dispatchKeyEvent(event)
     }
 
+    /**
+     * Points the display at another surface, or none, without restarting what it shows. The
+     * preview's SurfaceView comes and goes as the phone turns; the car UI on it carries on.
+     */
+    fun setSurface(surface: Surface?) {
+        virtualDisplay?.surface = surface
+    }
+
     fun stop() {
         runCatching { presentation?.dismiss() }
         runCatching { owner?.destroy() }

gearslip/src/main/java/app/seb3thehacker/gearslip/ServiceDiscovery.kt

@@ -51,7 +51,17 @@ object ServiceDiscovery {
             "$resolutionName @ $frameRateName, density=$density, margin=${widthMargin}x$heightMargin"
     }
 
-    class VideoService(val serviceId: Int, val codecType: Int, val configs: List<VideoConfig>) {
+    /**
+     * [displayId] is MediaSinkService field 6: 0, the default, is the main screen. [displayType]
+     * is field 7 (0 main, 1 instrument cluster, 2 auxiliary), or null when the car leaves it out.
+     */
+    class VideoService(
+        val serviceId: Int,
+        val codecType: Int,
+        val configs: List<VideoConfig>,
+        val displayId: Int = 0,
+        val displayType: Int? = null,
+    ) {
         val codecName: String get() = CODECS[codecType] ?: "unknown($codecType)"
     }
 
@@ -75,7 +85,7 @@ object ServiceDiscovery {
     fun findAudioServices(response: ByteArray): List<AudioService> = buildList {
         for (channel in Wire.allBytes(Wire.fields(response), 1)) {
             val service = Wire.fields(channel)
-            val id = Wire.varint(service, 1)?.toInt() ?: continue
+            val id = serviceId(service) ?: continue
             val sink = Wire.bytes(service, 3) ?: continue
             val sinkFields = Wire.fields(sink)
             val audioConfigs = Wire.allBytes(sinkFields, 3)
@@ -98,6 +108,117 @@ object ServiceDiscovery {
         }
     }
 
+    /**
+     * The media sink to stream to. Gearslip sends raw PCM, so a PCM sink wins: the 2022 Dacia
+     * Jogger (LGE ULC 4.5) lists an AAC media sink on channel 3 before a PCM one on channel 5,
+     * and PCM pushed into the AAC sink was acked but played as silence. With no PCM sink, the
+     * first media sink is the best there is.
+     */
+    fun pickMediaSink(sinks: List<AudioService>): AudioService? {
+        val media = sinks.filter { it.streamType == STREAM_MEDIA }
+        return media.firstOrNull { it.codecType == CODEC_PCM } ?: media.firstOrNull()
+    }
+
+    /**
+     * The channel the car takes "now playing" on (MediaPlaybackStatusService, Service field 9),
+     * which feeds its cluster and media screens. It carries no settings. Null when the car has none.
+     */
+    fun findMediaStatusChannel(response: ByteArray): Int? = findChannelWith(response, 9)
+
+    /**
+     * The channel the car takes call status on (PhoneStatusService, Service field 10), for its
+     * cluster and phone screens. It carries no settings. Null when the car has none.
+     */
+    fun findPhoneStatusChannel(response: ByteArray): Int? = findChannelWith(response, 10)
+
+    class NavStatusService(val serviceId: Int, val minimumIntervalMs: Int)
+
+    /** The cluster advertises its minimum update interval in NavigationStatusService field 1. */
+    fun findNavStatusService(response: ByteArray): NavStatusService? =
+        Wire.allBytes(Wire.fields(response), 1).firstNotNullOfOrNull { channel ->
+            val service = Wire.fields(channel)
+            val id = serviceId(service) ?: return@firstNotNullOfOrNull null
+            val navigation = Wire.bytes(service, 8) ?: return@firstNotNullOfOrNull null
+            val interval = Wire.varint(Wire.fields(navigation), 1) ?: return@firstNotNullOfOrNull null
+            if (interval !in 0L..Int.MAX_VALUE.toLong()) return@firstNotNullOfOrNull null
+            NavStatusService(id, interval.toInt())
+        }
+
+    private fun serviceId(fields: List<Wire.Field>): Int? =
+        Wire.varint(fields, 1)?.takeIf { it in 1L..255L }?.toInt()
+
+    private fun findChannelWith(response: ByteArray, serviceField: Int): Int? =
+        Wire.allBytes(Wire.fields(response), 1).firstNotNullOfOrNull { channel ->
+            val service = Wire.fields(channel)
+            if (Wire.bytes(service, serviceField) != null) serviceId(service) else null
+        }
+
+    /**
+     * The car's microphone, from MediaSourceService (Service field 5):
+     *   MediaSourceService { MediaCodecType available_type = 1; AudioConfiguration audio_config = 2;
+     *                        bool available_while_in_call = 3; }
+     * Null when the head unit has none.
+     */
+    fun findMicService(response: ByteArray): AudioService? {
+        for (channel in Wire.allBytes(Wire.fields(response), 1)) {
+            val service = Wire.fields(channel)
+            val id = serviceId(service) ?: continue
+            val source = Wire.fields(Wire.bytes(service, 5) ?: continue)
+            val f = Wire.fields(Wire.bytes(source, 2) ?: continue)
+            return AudioService(
+                serviceId = id,
+                streamType = 0,
+                codecType = Wire.varint(source, 1)?.toInt() ?: CODEC_PCM,
+                configs = listOf(
+                    AudioConfig(
+                        sampleRate = Wire.varint(f, 1)?.toInt() ?: 16_000,
+                        bits = Wire.varint(f, 2)?.toInt() ?: 16,
+                        channels = Wire.varint(f, 3)?.toInt() ?: 1,
+                    ),
+                ),
+            )
+        }
+        return null
+    }
+
+    /**
+     * The car's Bluetooth, from BluetoothService (Service field 6):
+     *   BluetoothService { string car_address = 1; repeated BluetoothPairingMethod methods = 2 [packed]; }
+     * Null when the car offers no pairing over the link.
+     */
+    class BluetoothService(val serviceId: Int, val carAddress: String, val pairingMethods: List<Int>)
+
+    /** A carmaker's own channel (service field 12), for its apps on the phone: GM's is "com.gm.vip". */
+    class VendorService(val serviceId: Int, val name: String)
+
+    fun findVendorServices(response: ByteArray): List<VendorService> =
+        Wire.allBytes(Wire.fields(response), 1).mapNotNull { channel ->
+            val service = Wire.fields(channel)
+            val id = Wire.varint(service, 1)?.toInt() ?: return@mapNotNull null
+            val fields = Wire.fields(Wire.bytes(service, 12) ?: return@mapNotNull null)
+            val name = Wire.bytes(fields, 1)?.let { String(it, Charsets.UTF_8) } ?: return@mapNotNull null
+            VendorService(id, name)
+        }
+
+    fun findBluetoothService(response: ByteArray): BluetoothService? {
+        for (channel in Wire.allBytes(Wire.fields(response), 1)) {
+            val service = Wire.fields(channel)
+            val id = Wire.varint(service, 1)?.toInt() ?: continue
+            val fields = Wire.fields(Wire.bytes(service, 6) ?: continue)
+            val address = Wire.bytes(fields, 1)?.let { String(it, Charsets.UTF_8) } ?: continue
+            // Packed as declared, though a car may send each method as its own varint.
+            val methods = Wire.repeatedInts(fields, 2)
+            return BluetoothService(id, address, methods)
+        }
+        return null
+    }
+
+    const val STREAM_GUIDANCE = 1
+    const val STREAM_MEDIA = 3
+    const val CODEC_PCM = 1
+    const val CODEC_AAC_LC = 2
+    const val CODEC_AAC_LC_ADTS = 4
+
     private val STREAMS = mapOf(0 to "NONE", 1 to "GUIDANCE", 2 to "SYSTEM_AUDIO", 3 to "MEDIA", 4 to "TELEPHONY")
 
     private val RESOLUTIONS = mapOf(
@@ -120,8 +241,8 @@ object ServiceDiscovery {
      *                         repeated TouchScreen touchscreen = 2; ... }
      *   TouchScreen { required int32 width = 1; required int32 height = 2; type = 3; }
      *
-     * Touch coordinates arrive in this space (1258x708 on the 2018 Uconnect) and must be
-     * scaled to the projected video size before injection. [keycodesSupported] is what the
+     * Touch reports use projected video coordinates; these dimensions describe the input
+     * hardware and help select a video configuration. [keycodesSupported] is what the
      * head unit says it will actually send over the Input channel as key events (steering-wheel
      * buttons, etc.) - not every unit reports the same set, so it's kept for diagnostics and to
      * know ahead of time whether a button like voice/PTT is even wired up on this hardware.
@@ -131,48 +252,63 @@ object ServiceDiscovery {
         val touchWidth: Int,
         val touchHeight: Int,
         val keycodesSupported: List<Int> = emptyList(),
+        /** InputSourceService field 5: which screen this input belongs to, 0 for the main one. */
+        val displayId: Int = 0,
     )
 
-    fun findInputService(response: ByteArray): InputService? {
+    /**
+     * The input for the screen Gearslip projects to ([displayId]). A head unit with two screens
+     * offers an input service for each: LIVI lists an empty one for its second screen first,
+     * and taking that one left every touch on the real touchscreen ignored.
+     */
+    fun findInputService(response: ByteArray, displayId: Int = 0): InputService? {
+        val inputs = inputServices(response)
+        return inputs.firstOrNull { it.displayId == displayId }
+            ?: inputs.firstOrNull { it.touchWidth > 0 && it.touchHeight > 0 }
+            ?: inputs.firstOrNull()
+    }
+
+    private fun inputServices(response: ByteArray): List<InputService> = buildList {
         for (channel in Wire.allBytes(Wire.fields(response), 1)) {
             val service = Wire.fields(channel)
-            val id = Wire.varint(service, 1)?.toInt() ?: continue
+            val id = serviceId(service) ?: continue
             val input = Wire.bytes(service, 4) ?: continue
             val inputFields = Wire.fields(input)
             // A unit with only a knob and buttons has no touchscreen entry; it still has keys.
             val touchFields = Wire.bytes(inputFields, 2)?.let { Wire.fields(it) }.orEmpty()
             val width = Wire.varint(touchFields, 1)?.toInt() ?: 0
             val height = Wire.varint(touchFields, 2)?.toInt() ?: 0
-            // Declared packed, but some units send each keycode as its own field.
-            val keycodes = inputFields.filter { it.number == 1 }.flatMap { f ->
-                f.bytes?.let(::packedVarints) ?: listOf(f.varint.toInt())
-            }
-            return InputService(id, width, height, keycodes)
-        }
-        return null
-    }
-
-    /** Decodes a `[packed=true]` repeated varint field's raw bytes into individual values. */
-    private fun packedVarints(data: ByteArray): List<Int> = buildList {
-        var pos = 0
-        while (pos < data.size) {
-            var result = 0L
-            var shift = 0
-            while (pos < data.size) {
-                val b = data[pos].toInt() and 0xFF
-                result = result or ((b and 0x7F).toLong() shl shift)
-                pos++
-                if (b and 0x80 == 0) break
-                shift += 7
-            }
-            add(result.toInt())
+            val keycodes = Wire.repeatedInts(inputFields, 1)
+            add(InputService(id, width, height, keycodes, Wire.varint(inputFields, 5)?.toInt() ?: 0))
         }
     }
 
+    /**
+     * The main screen's video sink. A head unit with a second screen, such as LIVI with a
+     * cluster display, offers a sink for each; the one without a display id (0) is the main one.
+     */
     fun findVideoService(response: ByteArray): VideoService? {
+        val sinks = videoServices(response)
+        return sinks.firstOrNull { it.displayId == 0 } ?: sinks.firstOrNull()
+    }
+
+    /**
+     * The instrument cluster's video sink: one marked as a cluster, or, from a car that marks
+     * none, a second sink beside the main screen's. Null when the car has no cluster screen.
+     */
+    fun findClusterVideoService(response: ByteArray): VideoService? {
+        val sinks = videoServices(response)
+        val main = findVideoService(response) ?: return null
+        return sinks.firstOrNull { it.displayType == DISPLAY_TYPE_CLUSTER && it.serviceId != main.serviceId }
+            ?: sinks.firstOrNull { it.displayType == null && it.serviceId != main.serviceId && it.displayId != main.displayId }
+    }
+
+    private const val DISPLAY_TYPE_CLUSTER = 1
+
+    private fun videoServices(response: ByteArray): List<VideoService> = buildList {
         for (channel in Wire.allBytes(Wire.fields(response), 1)) {
             val service = Wire.fields(channel)
-            val id = Wire.varint(service, 1)?.toInt() ?: continue
+            val id = serviceId(service) ?: continue
             val sink = Wire.bytes(service, 3) ?: continue
 
             val sinkFields = Wire.fields(sink)
@@ -190,27 +326,25 @@ object ServiceDiscovery {
                     heightMargin = Wire.varint(f, 4)?.toInt() ?: 0,
                 )
             }
-            return VideoService(id, codecType, configs)
+            add(VideoService(id, codecType, configs, Wire.varint(sinkFields, 6)?.toInt() ?: 0, Wire.varint(sinkFields, 7)?.toInt()))
         }
-        return null
     }
 
     /**
-     * The head unit's sensor feed, from SensorSourceService (Service field 5):
-     *   SensorSourceService { repeated SensorType sensors = 1; }
-     *   SensorType { required int32 type = 1; }
+     * The head unit's sensor feed, from SensorSourceService (Service field 2; field 5 is the car's mic):
+     *   SensorSourceService { repeated Sensor sensors = 1; }
+     *   Sensor { required SensorType sensor_type = 1; }
      *
-     * Field numbers for what actually rides inside each SensorEvent once subscribed are not
-     * pinned down here - unlike video/audio/input, there's no independent source to check them
-     * against, so [CarSensors] shows the raw decode instead of trusting a guessed field map.
+     * SensorBatch contains repeated messages in fields 1 through 22 matching these type ids.
+     * The vehicle data screen keeps their raw contents for diagnostics.
      */
     class SensorService(val serviceId: Int, val types: List<Int>)
 
     fun findSensorService(response: ByteArray): SensorService? {
         for (channel in Wire.allBytes(Wire.fields(response), 1)) {
             val service = Wire.fields(channel)
-            val id = Wire.varint(service, 1)?.toInt() ?: continue
-            val sensorSource = Wire.bytes(service, 5) ?: continue
+            val id = serviceId(service) ?: continue
+            val sensorSource = Wire.bytes(service, 2) ?: continue
             val types = Wire.allBytes(Wire.fields(sensorSource), 1).mapNotNull {
                 Wire.varint(Wire.fields(it), 1)?.toInt()
             }

gearslip/src/main/java/app/seb3thehacker/gearslip/SessionReport.kt

@@ -1,6 +1,7 @@
 package app.seb3thehacker.gearslip
 
 import android.content.Context
+import app.seb3thehacker.gearslip.stats.UsageStats
 import android.os.Build
 
 /**
@@ -28,12 +29,30 @@ object SessionReport {
         UNKNOWN("unclassified"),
     }
 
+    /**
+     * How far a session got, in the order a connection is built. The usage note's "Where
+     * connections fail" share sends the furthest one reached, so a failure says where it broke.
+     */
+    enum class Stage(val key: String) {
+        USB("usb"),             // the link opened; the car may have said nothing
+        VERSIONS("versions"),   // the car said which protocol it speaks
+        TLS("tls"),             // the secure link is up
+        ACCEPTED("accepted"),   // the car accepted the certificate
+        CHANNELS("channels"),   // the car listed its channels and said who it is
+        VIDEO("video"),         // the car's screen is set up for Gearslip
+        STREAMING("streaming"), // video frames are reaching the car
+    }
+
     private var appVersion = "?"
     private var appCode = 0L
 
     @Volatile private var startedAt = 0L
     @Volatile var category = Category.NONE; private set
     @Volatile private var failure = ""
+    @Volatile var stage = Stage.USB; private set
+    /** What the car or the phone said when it broke: a TLS alert, an auth status, a ByeBye reason, an errno. */
+    @Volatile private var failCode = ""
+    @Volatile private var failedAfter = 0L
     @Volatile private var protocolVersion = ""
     @Volatile private var certSource = ""
     @Volatile private var certIssuer = ""
@@ -48,41 +67,114 @@ object SessionReport {
     @Volatile private var lastState = ""
     private var printed = false
 
+    private var appContext: Context? = null
+
     fun init(context: Context) {
+        appContext = context.applicationContext
         val info = runCatching { context.packageManager.getPackageInfo(context.packageName, 0) }.getOrNull()
         appVersion = info?.versionName ?: "?"
         appCode = info?.longVersionCode ?: 0
     }
 
-    fun begin() {
+    /** How this drive reached the car, and how its music did: "usb" or "wireless", "usb" or "bluetooth". */
+    @Volatile var link = ""; private set
+    @Volatile var audioMode = ""; private set
+
+    fun begin(wireless: Boolean) {
         startedAt = System.currentTimeMillis()
+        link = if (wireless) "wireless" else "usb"
+        audioMode = if (app.seb3thehacker.gearslip.car.CarSettings.pipeAudio.value) "usb" else "bluetooth"
         category = Category.NONE
         failure = ""; protocolVersion = ""; certSource = ""; certIssuer = ""
+        stage = Stage.USB; failCode = ""; failedAfter = 0
         tlsProtocol = ""; tlsCipher = ""; authStatus = null
+        headUnitInfo = null
+        carScreen = ""; carDpi = 0
         headUnit = ""; profile = ""; video = ""; lastStream = ""; lastState = ""
         printed = false
     }
 
-    fun protocolVersion(major: Int, minor: Int) { protocolVersion = "$major.$minor" }
+    /** Moves the session's furthest stage on; never back. */
+    private fun reached(next: Stage) { if (next > stage) stage = next }
+
+    fun protocolVersion(major: Int, minor: Int) { protocolVersion = "$major.$minor"; reached(Stage.VERSIONS) }
     fun certificate(source: String, issuer: String) { certSource = source; certIssuer = issuer }
-    fun tls(protocol: String, cipher: String) { tlsProtocol = protocol; tlsCipher = cipher }
-    fun auth(status: Int) { authStatus = status }
+    fun tls(protocol: String, cipher: String) { tlsProtocol = protocol; tlsCipher = cipher; reached(Stage.TLS) }
+    fun auth(status: Int) { authStatus = status; if (status == 0) reached(Stage.ACCEPTED) }
     fun headUnit(info: String) { headUnit = info }
+
+    /** Who the car said it is, for the opt-in usage note; null until service discovery. */
+    @Volatile var headUnitInfo: ServiceDiscovery.HeadUnitInfo? = null
+        set(value) { field = value; if (value != null) reached(Stage.CHANNELS) }
+
+    /** The car screen's usable size once its margins are cropped, and its density; blank before video starts. */
+    @Volatile var carScreen = ""; private set
+    @Volatile var carDpi = 0; private set
+    fun carScreen(size: String, dpi: Int) { carScreen = size; carDpi = dpi; reached(Stage.VIDEO) }
     fun profile(name: String?) { profile = name ?: "none matched" }
     fun video(summary: String) { video = summary }
     fun audio(summary: String) { audio = summary }
-    fun stream(summary: String) { lastStream = summary }
+    fun stream(summary: String) { lastStream = summary; reached(Stage.STREAMING) }
 
-    /** Records the first failure only: later ones are usually fallout from it. */
-    fun fail(category: Category, detail: String, state: String = "") {
+    /**
+     * Records the first failure only: later ones are usually fallout from it. [code] is the short
+     * thing the car or the phone said, like "auth -3" or "bye 1", for the usage note.
+     */
+    fun fail(category: Category, detail: String, state: String = "", code: String = "") {
         if (this.category != Category.NONE) return
         this.category = category
         failure = detail
         lastState = state
+        failCode = code
+        failedAfter = if (startedAt == 0L) 0 else (System.currentTimeMillis() - startedAt) / 1000
     }
 
     fun fail(category: Category, detail: String, t: Throwable, state: String = "") =
-        fail(category, "$detail (${GearslipLog.rootCause(t)})", state)
+        fail(category, "$detail (${GearslipLog.rootCause(t)})", state, codeOf(t))
+
+    /**
+     * A short code from an exception, never its whole message: the TLS alert's name, the errno
+     * of a USB failure, or else the exception's class.
+     */
+    private fun codeOf(t: Throwable): String {
+        var root = t
+        while (root.cause != null && root.cause !== root) root = root.cause!!
+        val text = "${t.message} ${root.message}"
+        Regex("(?i)alert[ _:]*\\(?([a-z_ ]{3,40}?)\\)?(?:\\s|$|[,;.])").find(text)?.let {
+            return "alert ${it.groupValues[1].trim().lowercase().replace(' ', '_')}"
+        }
+        Regex("\\b(E[A-Z]{2,12})\\b").find(text)?.let { return it.groupValues[1] }
+        return root.javaClass.simpleName.take(40)
+    }
+
+    /**
+     * One session for the usage note's "Where connections fail" share: how far it got, how and
+     * when it ended, and with which kind of certificate. Counts and codes only, nothing personal.
+     */
+    fun sessionNote(): org.json.JSONObject {
+        val seconds = if (startedAt == 0L) 0 else (System.currentTimeMillis() - startedAt) / 1000
+        val source = certSource.lowercase()
+        return org.json.JSONObject()
+            .put("stage", stage.key)
+            .put("ended", category.name.lowercase())
+            .put("code", failCode)
+            .put("failed_at", if (category == Category.NONE) 0 else rounded(failedAfter))
+            .put("seconds", rounded(seconds))
+            .put("cert", when {
+                "imported" in source -> "imported"
+                "downloaded" in source -> "downloaded"
+                "self" in source -> "self-signed"
+                source.isEmpty() -> ""
+                else -> "other"
+            })
+    }
+
+    /** Seconds rounded so a drive's length can't be matched to anything: 5 s, then minutes, then 5 minutes. */
+    private fun rounded(s: Long): Long = when {
+        s < 60 -> (s + 2) / 5 * 5
+        s < 3600 -> (s + 30) / 60 * 60
+        else -> (s + 150) / 300 * 300
+    }
 
     /** The report as plain text, for the log file and for anything that gets sent. */
     fun render(): String {
@@ -121,6 +213,25 @@ object SessionReport {
         if (printed || startedAt == 0L) return
         printed = true
         render().lines().forEach { GearslipLog.i(it) }
+        appContext?.let { context ->
+            // Video started means the car showed Gearslip: that's a working car, and unplugging or
+            // switching the car off at the end shows up as a USB or ByeBye "failure" that isn't one.
+            val reached = carScreen.isNotEmpty()
+            val outcome = when {
+                reached && category in setOf(Category.NONE, Category.USB, Category.BYEBYE) -> "connected"
+                reached -> "connected, then ${category.label}"
+                category == Category.NONE -> "ended before video"
+                else -> category.label
+            }
+            runCatching {
+                UsageStats.recordSession(context, headUnitInfo, protocolVersion, outcome, carScreen, carDpi, sessionNote(), link, audioMode)
+            }
+            if (outcome == "connected") runCatching {
+                app.seb3thehacker.gearslip.stats.WorkedPrompt.onDriveWorked(context, headUnitInfo, protocolVersion, carScreen, carDpi)
+                app.seb3thehacker.gearslip.ui.DonatePrompt.onDriveWorked(context)
+            }
+            runCatching { app.seb3thehacker.gearslip.update.UpdateChecker.onDriveEnded(context) }
+        }
         GearslipLog.flush()
     }
 

gearslip/src/main/java/app/seb3thehacker/gearslip/SessionStatus.kt

@@ -20,7 +20,7 @@ object SessionStatus {
         Snapshot(
             Phase.IDLE,
             "Not connected",
-            "Plug the phone into the car's USB port. Gearslip opens by itself when the head unit connects.",
+            "Plug into the car's USB port, or connect wirelessly. Gearslip opens by itself when the car answers.",
         ),
     )
 

gearslip/src/main/java/app/seb3thehacker/gearslip/TlsSelfTest.kt

@@ -4,33 +4,25 @@ import java.net.Socket
 import java.nio.ByteBuffer
 import java.security.SecureRandom
 import java.security.cert.X509Certificate
+import javax.net.ssl.KeyManagerFactory
 import javax.net.ssl.SSLContext
 import javax.net.ssl.SSLEngine
 import javax.net.ssl.SSLEngineResult
 import javax.net.ssl.SSLEngineResult.HandshakeStatus
 import javax.net.ssl.X509ExtendedTrustManager
 
-/**
- * Runs [PhoneTls] against an in-process TLS client and checks that a full handshake plus a
- * data round trip works.
- *
- * This exists because of one specific hazard: a bug in the certificate, the key manager or
- * the engine wiring produces a dead connection in the car that is indistinguishable from a
- * head unit rejecting us - and the whole point of the spike is a trustworthy go/no-go
- * signal. Run this on the bench first; if it passes, a failure in the car is about the head
- * unit, not about this code.
- */
+/** Checks mutual TLS and an encrypted data round trip with an in-process head-unit peer. */
 object TlsSelfTest {
     private val log = GearslipLog.tagged("TLS")
 
-    fun run(identity: CertProvider.Identity): Boolean {
+    fun run(identity: CertProvider.Identity, withClientCertificate: Boolean = true): Boolean {
         log.i("=== TLS self-test starting ===")
         log.i("cert source: ${identity.source}")
         log.i("  subject = ${identity.certificate.subjectX500Principal}")
         log.i("  issuer  = ${identity.certificate.issuerX500Principal}")
         return try {
             val server = PhoneTls(identity.keyStore, identity.password)
-            val client = Driver(clientEngine())
+            val client = Driver(clientEngine(withClientCertificate))
 
             var outbound = client.pump(null) // ClientHello
             var rounds = 0
@@ -49,8 +41,7 @@ object TlsSelfTest {
                 return false
             }
 
-            // Data round trip, exercising the same encrypt path the spike uses for
-            // ServiceDiscoveryRequest.
+            // Exercise the same encrypt path used by ServiceDiscoveryRequest.
             val plaintext = "gearslip round trip".toByteArray()
             val decrypted = client.decrypt(server.encrypt(plaintext))
             if (!decrypted.contentEquals(plaintext)) {
@@ -66,9 +57,15 @@ object TlsSelfTest {
         }
     }
 
-    private fun clientEngine(): SSLEngine {
+    private fun clientEngine(withCertificate: Boolean): SSLEngine {
         val context = SSLContext.getInstance("TLSv1.2")
-        context.init(null, arrayOf(TrustAll()), SecureRandom())
+        val keyManagers = if (withCertificate) {
+            val client = SelfSignedCert.generate(commonName = "Self-test head unit")
+            KeyManagerFactory.getInstance(KeyManagerFactory.getDefaultAlgorithm()).apply {
+                init(client.keyStore, SelfSignedCert.PASSWORD)
+            }.keyManagers
+        } else null
+        context.init(keyManagers, arrayOf(TrustAll()), SecureRandom())
         return context.createSSLEngine().apply {
             useClientMode = true
             enabledProtocols = arrayOf("TLSv1.2")

gearslip/src/main/java/app/seb3thehacker/gearslip/VideoSource.kt

@@ -23,6 +23,8 @@ class VideoSource(
     private val height: Int,
     private val frameRate: Int,
     private val mode: Mode = Mode.TEST_CARD,
+    /** Over Wi-Fi: a fraction of the cable bitrate, so the link keeps up and sound isn't starved. */
+    private val wireless: Boolean = false,
     private val onCodecConfig: (ByteArray) -> Unit,
     private val onFrame: (data: ByteArray, presentationTimeUs: Long, keyFrame: Boolean) -> Unit,
 ) {
@@ -40,12 +42,25 @@ class VideoSource(
         private set
 
     private var codec: MediaCodec? = null
+
+    /** The bitrate the encoder started at, the most [setBitRate] ever goes back up to. */
+    var fullBitRate = 0
+        private set
+
+    /** What the encoder is asked for right now. */
+    @Volatile var bitRate = 0
+        private set
     private var worker: Thread? = null
     @Volatile private var running = false
     private var frameIndex = 0L
 
     fun start() {
-        val bitRate = (width.toLong() * height * frameRate * BITS_PER_PIXEL).toInt().coerceIn(MIN_BIT_RATE, MAX_BIT_RATE)
+        val level = levelFor(width, height, frameRate)
+        val bitRate = defaultBitRate(width, height, frameRate, level).let {
+            if (wireless) (it * WIRELESS_SHARE).toInt().coerceAtMost(WIRELESS_MAX_BIT_RATE) else it
+        }
+        fullBitRate = bitRate
+        this.bitRate = bitRate
         fun format(tuned: Boolean) = MediaFormat.createVideoFormat(MIME, width, height).apply {
             setInteger(
                 MediaFormat.KEY_COLOR_FORMAT,
@@ -60,8 +75,21 @@ class VideoSource(
             // Drops already ask for a fresh keyframe, so a long interval costs nothing in recovery
             // and spares the link a big frame every second.
             setInteger(MediaFormat.KEY_I_FRAME_INTERVAL, I_FRAME_INTERVAL_S)
+            if (mode == Mode.SURFACE) {
+                // A surface encoder only makes a frame when the screen changes, and many decoders
+                // show a frame only once the next one arrives. So the last change before the
+                // screen goes still (a menu closing) sat in the car's decoder until something
+                // else moved. Repeating the last frame after a short pause pushes it through;
+                // a repeat of an unchanged screen costs a few bytes. scrcpy does the same.
+                setLong(MediaFormat.KEY_REPEAT_PREVIOUS_FRAME_AFTER, REPEAT_AFTER_US)
+                // An app that draws nonstop (a moving map) renders at the phone's refresh rate,
+                // faster than the car acks. Every extra frame queued inside the encoder, and the
+                // car's screen fell 25 seconds behind. Capping the input drops the extras before
+                // they're encoded, so the car always gets the newest frame.
+                setFloat(MediaFormat.KEY_MAX_FPS_TO_ENCODER, frameRate.toFloat())
+            }
             setInteger(MediaFormat.KEY_PROFILE, MediaCodecInfo.CodecProfileLevel.AVCProfileBaseline)
-            setInteger(MediaFormat.KEY_LEVEL, MediaCodecInfo.CodecProfileLevel.AVCLevel31)
+            setInteger(MediaFormat.KEY_LEVEL, level.codecLevel)
             if (tuned) {
                 // Hints only: a car screen wants each frame now, not the best frame a moment later.
                 setInteger(MediaFormat.KEY_BITRATE_MODE, MediaCodecInfo.EncoderCapabilities.BITRATE_MODE_VBR)
@@ -85,7 +113,7 @@ class VideoSource(
         codec = encoder
         running = true
 
-        log.i("encoder started: ${width}x$height @ ${frameRate}fps, ${bitRate / 1000} kbps, H.264 Baseline, mode=$mode")
+        log.i("encoder started: ${width}x$height @ ${frameRate}fps, ${bitRate / 1000} kbps${if (wireless) " (wireless)" else ""}, H.264 Baseline level ${level.label}, mode=$mode")
 
         worker = Thread {
             runCatching { pump(encoder) }
@@ -110,9 +138,28 @@ class VideoSource(
         }.onFailure { log.w("requestSyncFrame failed: ${it.message}") }
     }
 
+    /**
+     * Changes the bitrate while streaming, without a new keyframe or a restart. Used to back off
+     * when the car (or the Wi-Fi to it) can't keep up, and to climb back once it can.
+     */
+    fun setBitRate(bps: Int) {
+        val target = bps.coerceIn(fullBitRate / 4, fullBitRate)
+        if (target == bitRate) return
+        runCatching {
+            codec?.setParameters(Bundle().apply { putInt(MediaCodec.PARAMETER_KEY_VIDEO_BITRATE, target) })
+            bitRate = target
+        }.onFailure { log.w("setBitRate failed: ${it.message}") }
+    }
+
     fun stop() {
         running = false
-        worker?.join(1_000)
+        // Stop is called from threads that are themselves being shut down. An interrupt here
+        // used to escape as an uncaught exception and take the whole app down with the session.
+        try {
+            worker?.join(1_000)
+        } catch (e: InterruptedException) {
+            Thread.currentThread().interrupt()
+        }
         runCatching { inputSurface?.release() }
         inputSurface = null
         runCatching { codec?.stop() }
@@ -210,11 +257,50 @@ class VideoSource(
         const val TIMEOUT_US = 10_000L
         const val SURFACE_TIMEOUT_US = 100_000L
 
-        /** Enough for sharp text and map lines; 800x480 at 30fps comes out at 4 Mbps. */
-        const val BITS_PER_PIXEL = 0.3
-        const val MIN_BIT_RATE = 4_000_000
-        const val MAX_BIT_RATE = 12_000_000
+        /**
+         * 800x480 at 30fps gets 8 Mbps: about the most that size can show, enough that a moving
+         * video in the browser stays sharp. Bigger screens get more, but less than in proportion,
+         * since large frames compress better: bitrate grows with pixels^0.75. 60fps gets 1.5x,
+         * because frames that close together are mostly alike.
+         */
+        const val BASE_BIT_RATE = 8_000_000.0
+        const val BASE_PIXELS = 800.0 * 480
+        /** No car's decoder is asked for more than this, whatever its level allows. */
+        const val MAX_BIT_RATE = 25_000_000
+
+        /**
+         * The H.264 levels a car screen can need, smallest first: macroblocks a second each
+         * decodes, and the Baseline bitrate it must handle. The encoder declares the smallest
+         * that fits, and the bitrate stays within it, so a car decoder isn't asked for more than
+         * the level it was told about.
+         */
+        enum class Level(val label: String, val codecLevel: Int, val macroblocksPerSecond: Int, val maxBitRate: Int) {
+            L31("3.1", MediaCodecInfo.CodecProfileLevel.AVCLevel31, 108_000, 14_000_000),
+            L32("3.2", MediaCodecInfo.CodecProfileLevel.AVCLevel32, 216_000, 20_000_000),
+            L4("4", MediaCodecInfo.CodecProfileLevel.AVCLevel4, 245_760, 20_000_000),
+            L42("4.2", MediaCodecInfo.CodecProfileLevel.AVCLevel42, 522_240, 50_000_000),
+        }
+
+        fun levelFor(width: Int, height: Int, frameRate: Int): Level {
+            val perSecond = ((width + 15) / 16) * ((height + 15) / 16) * frameRate
+            return Level.entries.firstOrNull { perSecond <= it.macroblocksPerSecond } ?: Level.L42
+        }
+
+        fun defaultBitRate(width: Int, height: Int, frameRate: Int, level: Level): Int {
+            val size = Math.pow(width.toDouble() * height / BASE_PIXELS, 0.75)
+            val rate = if (frameRate > 30) 1.5 else 1.0
+            return (BASE_BIT_RATE * size * rate).toInt().coerceAtMost(minOf(level.maxBitRate, MAX_BIT_RATE))
+        }
+        /**
+         * A car's Wi-Fi is shared, noisy and far slower than its nominal rate, and the sound rides
+         * the same link behind the video. Real Android Auto sends a few Mbps wirelessly; at the
+         * cable rate (15-20 Mbps for 720p) a laptop hotspot fell seconds behind and the music
+         * cut in and out. 720p30 comes out near 5.4 Mbps.
+         */
+        const val WIRELESS_SHARE = 0.35
+        const val WIRELESS_MAX_BIT_RATE = 8_000_000
         const val I_FRAME_INTERVAL_S = 5
+        private const val REPEAT_AFTER_US = 100_000L
 
         /** (Y, Cb, Cr) - white, yellow, cyan, green, magenta, red, blue. */
         val BAR_COLOURS = listOf(

gearslip/src/main/java/app/seb3thehacker/gearslip/audio/AacEncoder.kt

@@ -0,0 +1,103 @@
+package app.seb3thehacker.gearslip.audio
+
+import android.media.MediaCodec
+import android.media.MediaCodecInfo
+import android.media.MediaFormat
+
+/**
+ * Turns captured PCM into AAC-LC for a car whose music channel takes nothing else. Cars that
+ * offer PCM never get here: AAC costs a little delay and quality, and every car that works today
+ * is a PCM car.
+ *
+ * Android's encoder hands back raw access units, which is what AUDIO_AAC_LC expects. For
+ * AUDIO_AAC_LC_ADTS each unit gets the 7-byte ADTS header in front, so the car can find the
+ * frame edges itself. The encoder's first output is its configuration, not audio, and is skipped.
+ */
+internal class AacEncoder(private val sampleRate: Int, private val channels: Int, private val adts: Boolean) {
+
+    private val codec: MediaCodec = MediaCodec.createEncoderByType(MediaFormat.MIMETYPE_AUDIO_AAC).apply {
+        val format = MediaFormat.createAudioFormat(MediaFormat.MIMETYPE_AUDIO_AAC, sampleRate, channels).apply {
+            setInteger(MediaFormat.KEY_AAC_PROFILE, MediaCodecInfo.CodecProfileLevel.AACObjectLC)
+            setInteger(MediaFormat.KEY_BIT_RATE, if (channels == 1) 96_000 else 192_000)
+            setInteger(MediaFormat.KEY_MAX_INPUT_SIZE, 16 * 1024)
+        }
+        configure(format, null, null, MediaCodec.CONFIGURE_FLAG_ENCODE)
+        start()
+    }
+    private val info = MediaCodec.BufferInfo()
+    private var samplesIn = 0L
+
+    /** Encodes [size] bytes of 16-bit PCM and returns the AAC frames that came out, oldest first. */
+    fun encode(pcm: ByteArray, size: Int): List<ByteArray> {
+        var offset = 0
+        val out = ArrayList<ByteArray>()
+        while (offset < size) {
+            val index = codec.dequeueInputBuffer(INPUT_WAIT_US)
+            if (index < 0) {
+                drain(out)
+                continue
+            }
+            val buffer = codec.getInputBuffer(index) ?: continue
+            val n = minOf(buffer.remaining(), size - offset)
+            buffer.put(pcm, offset, n)
+            val presentationUs = samplesIn * 1_000_000L / sampleRate
+            codec.queueInputBuffer(index, 0, n, presentationUs, 0)
+            samplesIn += n / (2 * channels)
+            offset += n
+            drain(out)
+        }
+        return out
+    }
+
+    private fun drain(out: MutableList<ByteArray>) {
+        while (true) {
+            val index = codec.dequeueOutputBuffer(info, 0)
+            if (index < 0) return
+            if (info.flags and MediaCodec.BUFFER_FLAG_CODEC_CONFIG == 0 && info.size > 0) {
+                val buffer = codec.getOutputBuffer(index)
+                if (buffer != null) {
+                    val frame = ByteArray(info.size)
+                    buffer.position(info.offset)
+                    buffer.get(frame)
+                    out.add(if (adts) adtsHeader(frame.size) + frame else frame)
+                }
+            }
+            codec.releaseOutputBuffer(index, false)
+        }
+    }
+
+    /** ADTS for one AAC-LC frame: sync word, no CRC, and the frame's length including this header. */
+    private fun adtsHeader(payload: Int): ByteArray {
+        val length = payload + 7
+        val freq = FREQUENCIES.indexOf(sampleRate).let { if (it < 0) 3 else it }
+        val profile = 1 // AAC-LC is object type 2, written as type minus one
+        return byteArrayOf(
+            0xFF.toByte(),
+            0xF1.toByte(),
+            ((profile shl 6) or (freq shl 2) or (channels shr 2)).toByte(),
+            (((channels and 3) shl 6) or (length shr 11)).toByte(),
+            ((length shr 3) and 0xFF).toByte(),
+            (((length and 7) shl 5) or 0x1F).toByte(),
+            0xFC.toByte(),
+        )
+    }
+
+    fun release() {
+        runCatching { codec.stop() }
+        runCatching { codec.release() }
+    }
+
+    companion object {
+        private const val INPUT_WAIT_US = 10_000L
+        private val FREQUENCIES = listOf(96000, 88200, 64000, 48000, 44100, 32000, 24000, 22050, 16000, 12000, 11025, 8000, 7350)
+
+        /** The two-byte AudioSpecificConfig for AAC-LC: object type 2, rate index, channel count. */
+        fun audioSpecificConfig(sampleRate: Int, channels: Int): ByteArray {
+            val freq = FREQUENCIES.indexOf(sampleRate).let { if (it < 0) 3 else it }
+            return byteArrayOf(
+                ((2 shl 3) or (freq shr 1)).toByte(),
+                (((freq and 1) shl 7) or (channels shl 3)).toByte(),
+            )
+        }
+    }
+}

gearslip/src/main/java/app/seb3thehacker/gearslip/audio/AudioCaptureService.kt

@@ -16,6 +16,7 @@ import android.media.AudioRecord
 import android.media.projection.MediaProjection
 import android.media.projection.MediaProjectionManager
 import android.os.IBinder
+import android.os.Process
 import app.seb3thehacker.gearslip.GearslipLog
 import kotlin.math.abs
 
@@ -147,6 +148,9 @@ class AudioCaptureService : Service() {
 
         reading = true
         thread = Thread({
+            // A busy phone (a map app drawing, the video encoder) would otherwise starve this
+            // loop, and the car hears every late read as a skip.
+            Process.setThreadPriority(Process.THREAD_PRIORITY_URGENT_AUDIO)
             val buffer = ByteArray(CHUNK_BYTES)
             var peak = 0
             var heardAt = System.currentTimeMillis()

gearslip/src/main/java/app/seb3thehacker/gearslip/audio/AudioLink.kt

@@ -4,6 +4,8 @@ import app.seb3thehacker.gearslip.GearslipLog
 import app.seb3thehacker.gearslip.Protobuf
 import app.seb3thehacker.gearslip.ServiceDiscovery
 import app.seb3thehacker.gearslip.Wire
+import java.util.concurrent.CountDownLatch
+import java.util.concurrent.TimeUnit
 
 /**
  * The phone end of the head unit's media audio sink, the audio twin of the video channel:
@@ -22,6 +24,18 @@ class AudioLink(
     private val service: ServiceDiscovery.AudioService,
     private val sendOnChannel: (messageId: Int, body: ByteArray) -> Unit,
     private val sendControl: (messageId: Int, body: ByteArray) -> Unit,
+    /** Log name: "audio" for the media sink, "guidance" for the directions sink. */
+    private val tag: String = "audio",
+    private val sessionId: Int = SESSION_ID,
+    /**
+     * Media asks the car for focus when it starts. Directions ask only around each announcement,
+     * through [askForSpeakers], and only when the music isn't already ours.
+     */
+    private val asksFocus: Boolean = true,
+    private val onReady: (AudioLink) -> Unit = { CarAudio.attach(it) },
+    private val onClose: (AudioLink) -> Unit = { CarAudio.detach(it) },
+    /** The car took the sound back after giving it, as when the driver switches to the radio. */
+    private val onTakenBack: () -> Unit = {},
 ) : CarAudio.Link {
 
     private var configIndex = 0
@@ -33,11 +47,19 @@ class AudioLink(
     // The Uconnect asks for 4 on its video channel; assume the same until its Config says otherwise.
     @Volatile private var maxUnacked = 4
     @Volatile private var lastAckAt = 0L
+    private var stalls = 0
     private var chunks = 0
     private var bytes = 0L
     private var dropped = 0
     @Volatile private var configTimer: Thread? = null
+    /** Underflows the car reported this drive, and the silence still to slip in ahead of the next chunk. */
+    private var underflows = 0
+    @Volatile private var padMs = 0
+    @Volatile private var pendingPadMs = 0
     private val ackLock = Object()
+    /** Only for a sink that takes AAC and nothing else; PCM sinks get the capture as it is. */
+    @Volatile private var aac: AacEncoder? = null
+    private val aacSink get() = service.codecType == ServiceDiscovery.CODEC_AAC_LC || service.codecType == ServiceDiscovery.CODEC_AAC_LC_ADTS
 
     private val config get() = service.configs.getOrNull(configIndex) ?: service.configs.firstOrNull()
     override val sampleRate get() = config?.sampleRate ?: 48_000
@@ -45,29 +67,71 @@ class AudioLink(
 
     val channelId get() = service.serviceId
 
+    /** Sending audio now, which for media means the car has handed us the speakers. */
+    val streaming get() = started
+
+    @Volatile private var holdsSpeakers = false
+    @Volatile private var focusAnswer: CountDownLatch? = null
+    @Volatile private var answerDueBy = 0L
+
+    /** True just after [askForSpeakers] or [handBackSpeakers], when the car's next focus answer is ours. */
+    fun expectsFocusAnswer() = System.currentTimeMillis() < answerDueBy
+
+    /**
+     * For directions when nothing of ours is playing, so the car's speakers belong to the radio
+     * or a Bluetooth phone. Android Auto asks for them before each announcement, letting the
+     * other source duck, and hands them back afterwards. Speaking without asking left a 2025
+     * Nissan's Bosch head unit rebooting mid-drive (issue #35).
+     *
+     * Waits briefly for the car's answer and speaks anyway without one, as some cars never answer.
+     */
+    fun askForSpeakers() {
+        if (holdsSpeakers) return
+        val answer = CountDownLatch(1)
+        focusAnswer = answer
+        answerDueBy = System.currentTimeMillis() + FOCUS_WAIT_MS
+        holdsSpeakers = true
+        sendControl(MSG_FOCUS_REQUEST, Protobuf.varintField(1, FOCUS_GAIN_TRANSIENT_MAY_DUCK.toLong()))
+        GearslipLog.i("$tag: -> AudioFocusRequest(GAIN_TRANSIENT_MAY_DUCK)")
+        if (!answer.await(FOCUS_WAIT_MS, TimeUnit.MILLISECONDS)) {
+            GearslipLog.i("$tag: no focus answer after ${FOCUS_WAIT_MS}ms - speaking anyway")
+        }
+        focusAnswer = null
+    }
+
+    /** Gives back what [askForSpeakers] took, so the other source comes back to full volume. */
+    fun handBackSpeakers() {
+        if (!holdsSpeakers) return
+        holdsSpeakers = false
+        answerDueBy = System.currentTimeMillis() + FOCUS_WAIT_MS
+        runCatching { sendControl(MSG_FOCUS_REQUEST, Protobuf.varintField(1, FOCUS_RELEASE.toLong())) }
+        GearslipLog.i("$tag: -> AudioFocusRequest(RELEASE)")
+    }
+
     fun opened(status: Int) {
-        GearslipLog.i("audio: <- ChannelOpenResponse (media audio): status=$status")
+        GearslipLog.i("$tag: <- ChannelOpenResponse: status=$status")
         if (status != 0) {
-            GearslipLog.w("audio: the head unit refused the media audio channel (status $status)")
+            GearslipLog.w("$tag: the head unit refused the $tag channel (status $status)")
             return
         }
-        // AVChannelSetupRequest { required uint32 config_index = 1 }. This field is an index into
-        // the sink's own audio_configs, not a codec id - sending the codec type asks for a config
-        // the sink does not have, and it answers with a status that never reaches READY.
-        sendOnChannel(MSG_SETUP, Protobuf.varintField(1, 0L))
-        GearslipLog.i("audio: -> Setup(config_index=0) on channel ${service.serviceId}, codec ${service.codecName}")
+        // Setup { required MediaCodecType type = 1 }: the codec the car advertised for this sink
+        // (aasdk's current protos, and LIVI reads it as the codec). Gearslip used to send 0 here,
+        // read from an older proto as a config index; 0 is no codec at all, and the 2024 VW
+        // answered UNEXPECTED_MESSAGE (id 255), never acked a chunk and played nothing.
+        sendOnChannel(MSG_SETUP, Protobuf.varintField(1, service.codecType.toLong()))
+        GearslipLog.i("$tag: -> Setup(codec=${service.codecName}) on channel ${service.serviceId}")
         armConfigFallback()
     }
 
     /**
-     * The 2018 Uconnect answers our Setup with a two-byte message we cannot identify (id 255, no
-     * body) rather than the AVChannelSetupResponse the video channel gets, so the sink never
-     * reaches READY and no audio is ever sent.
+     * The 2018 Uconnect, a Dacia ULC 4.5 and the 2024 VW answered the old Setup (codec 0) with
+     * UNEXPECTED_MESSAGE (id 255, no body) rather than a Config, so the sink never reached READY.
+     * [MSG_SETUP_ANSWER] still takes that as the go-ahead, in case a car rejects the real codec too.
      *
-     * Service discovery already told us everything that message would have: the sink is PCM at
-     * 48000Hz stereo and it has exactly one configuration. So rather than wait forever for a
-     * message that is not coming, assume the advertised configuration and carry on. If that guess
-     * is wrong the head unit simply will not ack, which the write path already reports.
+     * Service discovery already told us everything a Config would have: the sink's rate, channels
+     * and its one configuration. So for a car that answers nothing at all, wait a moment and then
+     * assume the advertised configuration. If that guess is wrong the head unit simply will not
+     * ack, which the write path already reports.
      */
     private fun armConfigFallback() {
         val timer = Thread({
@@ -76,19 +140,25 @@ class AudioLink(
             } catch (e: InterruptedException) {
                 return@Thread
             }
-            if (ready) return@Thread
-            GearslipLog.w(
-                "audio: no usable Config after ${CONFIG_WAIT_MS}ms - falling back to the sink the " +
-                    "head unit advertised (${sampleRate}Hz x$channels, config_index=0, max_unacked=$maxUnacked)",
-            )
-            configIndex = 0
-            ready = true
-            CarAudio.attach(this)
+            useAdvertisedSink("no usable Config after ${CONFIG_WAIT_MS}ms")
         }, "gearslip-audio-config").apply { isDaemon = true }
         configTimer = timer
         timer.start()
     }
 
+    @Synchronized
+    private fun useAdvertisedSink(why: String) {
+        if (ready) return
+        configTimer?.interrupt()
+        GearslipLog.i(
+            "$tag: $why - using the sink the head unit advertised " +
+                "(${sampleRate}Hz x$channels, config_index=0, max_unacked=$maxUnacked)",
+        )
+        configIndex = 0
+        ready = true
+        onReady(this)
+    }
+
     fun onMessage(messageId: Int, body: ByteArray) {
         when (messageId) {
             MSG_CHANNEL_OPEN_RESPONSE -> opened(Protobuf.readInt32Field(body, 1) ?: 0)
@@ -98,22 +168,24 @@ class AudioLink(
                 val status = Wire.varint(fields, 1)?.toInt()
                 val window = Wire.varint(fields, 2)?.toInt()
                 val indices = fields.filter { it.number == 3 && it.wireType == 0 }.map { it.varint.toInt() }
-                GearslipLog.i("audio: <- Config status=$status max_unacked=$window indices=$indices")
+                GearslipLog.i("$tag: <- Config status=$status max_unacked=$window indices=$indices")
                 if (window != null) maxUnacked = maxOf(1, window)
                 configIndex = indices.firstOrNull() ?: 0
                 if (status == STATUS_READY) {
                     configTimer?.interrupt()
                     ready = true
-                    GearslipLog.i("audio: sink ready - ${sampleRate}Hz x$channels ${config?.bits}bit")
-                    CarAudio.attach(this)
+                    GearslipLog.i("$tag: sink ready - ${sampleRate}Hz x$channels ${config?.bits}bit")
+                    onReady(this)
                 } else {
                     GearslipLog.w(
-                        "audio: the sink is not ready (status=$status, 1=WAIT 2=READY) - " +
+                        "$tag: the sink is not ready (status=$status, 1=WAIT 2=READY) - " +
                             "nothing will be sent until it is",
                     )
                 }
             }
 
+            MSG_UNDERFLOW -> onUnderflow()
+
             MSG_ACK -> {
                 val acked = Wire.varint(Wire.fields(body), 2)?.toInt() ?: 1
                 synchronized(ackLock) {
@@ -123,9 +195,11 @@ class AudioLink(
                 }
             }
 
-            // Whatever the head unit answers Setup with, we need its bytes to identify it.
-            else -> {
-                GearslipLog.i("audio: <- unhandled message id=$messageId (${body.size} bytes)")
+            // Whatever else the head unit answers Setup with, we need its bytes to identify it.
+            else -> if (messageId == MSG_SETUP_ANSWER && body.isEmpty()) {
+                useAdvertisedSink("<- empty Setup answer (id $messageId)")
+            } else {
+                GearslipLog.i("$tag: <- unhandled message id=$messageId (${body.size} bytes)")
                 GearslipLog.hex("   audio msg", body, limit = 64)
             }
         }
@@ -138,52 +212,144 @@ class AudioLink(
      */
     fun onFocus(state: Int) {
         val name = FOCUS_STATES[state] ?: "unknown($state)"
-        GearslipLog.i("audio: <- AudioFocusResponse state=$name")
-        focusGranted = state == FOCUS_STATE_GAIN || state == FOCUS_STATE_GAIN_TRANSIENT
+        GearslipLog.i("$tag: <- AudioFocusResponse state=$name")
+        if (!asksFocus) {
+            // Directions speak whatever the answer: a lost turn is worse than a loud one.
+            answerDueBy = 0L
+            focusAnswer?.countDown()
+            return
+        }
+        val had = focusGranted
+        focusGranted = state == FOCUS_STATE_GAIN || state == FOCUS_STATE_GAIN_TRANSIENT ||
+            state == FOCUS_STATE_GAIN_MEDIA_ONLY
         if (focusGranted) startStream() else stop()
+        // A ducking request leaves the music playing; a loss means another source has the speakers.
+        if (had && (state == FOCUS_STATE_LOSS || state == FOCUS_STATE_LOSS_TRANSIENT)) onTakenBack()
     }
 
+    /**
+     * The car ran out of sound to play (AudioUnderflowNotification, no body): its buffer emptied
+     * before the next chunk arrived, which the driver hears as a gap. Capture runs in real time, so
+     * the car's buffer only ever holds what the window lets through. A little silence slipped in
+     * ahead of the next chunk puts it that far ahead, so the next slow patch is soaked up rather
+     * than heard. Capped, as each step adds a little delay to the music.
+     */
+    private fun onUnderflow() {
+        underflows++
+        val step = if (started && padMs < MAX_PAD_MS) PAD_STEP_MS else 0
+        padMs += step
+        pendingPadMs += step
+        if (underflows <= 3 || underflows % 20 == 0) {
+            GearslipLog.w("$tag: <- AudioUnderflow ($underflows this drive) - running ${padMs}ms ahead now")
+        }
+    }
+
+    /** Silence for [ms], whole frames of this sink's format. */
+    private fun silence(ms: Int): ByteArray = ByteArray(sampleRate * ms / 1000 * channels * 2)
+
     override fun start() {
         if (!ready || started) return
-        if (!focusRequested) {
+        if (asksFocus && !focusRequested) {
             focusRequested = true
             sendControl(MSG_FOCUS_REQUEST, Protobuf.varintField(1, FOCUS_GAIN.toLong()))
-            GearslipLog.i("audio: -> AudioFocusRequest(GAIN); waiting for the head unit to hand the sink over")
+            GearslipLog.i("$tag: -> AudioFocusRequest(GAIN); waiting for the head unit to hand the sink over")
         }
         // Some head units grant the sink silently and never answer. Do not let that be the end of
         // it: start anyway, and let the acks say whether anything is being taken.
         startStream()
     }
 
+    /**
+     * Guards starting and stopping. [start] starts the stream at once for head units that never
+     * answer the focus request, and the car's answer arrives on another thread and starts it
+     * too: without this both got through, so the car got Start twice and two AAC encoders, and a
+     * 2014 head unit dropped the connection on the first audio.
+     */
+    private val startLock = Any()
+
     private fun startStream() {
+        synchronized(startLock) { startStreamLocked() }
+    }
+
+    private fun startStreamLocked() {
         if (!ready || started) return
         sendOnChannel(
             MSG_START,
-            Protobuf.varintField(1, SESSION_ID.toLong()) + Protobuf.varintField(2, configIndex.toLong()),
+            Protobuf.varintField(1, sessionId.toLong()) + Protobuf.varintField(2, configIndex.toLong()),
         )
+        // Raw AAC-LC has no header of its own: the car needs the codec config before the first frame.
+        if (service.codecType == ServiceDiscovery.CODEC_AAC_LC) {
+            val asc = AacEncoder.audioSpecificConfig(sampleRate, channels)
+            sendOnChannel(MSG_CODEC_CONFIG, asc)
+            GearslipLog.hex("$tag: -> CodecConfig (AudioSpecificConfig)", asc)
+        }
         inFlight = 0
         lastAckAt = System.currentTimeMillis()
+        if (aacSink && aac == null) {
+            aac = runCatching { AacEncoder(sampleRate, channels, adts = service.codecType == ServiceDiscovery.CODEC_AAC_LC_ADTS) }
+                .onSuccess { GearslipLog.i("$tag: the car takes ${service.codecName} only - encoding to AAC") }
+                .onFailure { GearslipLog.e("$tag: couldn't start the AAC encoder", it) }
+                .getOrNull()
+        }
         started = true
-        GearslipLog.i("audio: -> Start(session=$SESSION_ID, config=$configIndex) - streaming ${sampleRate}Hz x$channels")
+        GearslipLog.i("$tag: -> Start(session=$sessionId, config=$configIndex) - streaming ${sampleRate}Hz x$channels")
     }
 
     override fun stop() {
+        synchronized(startLock) { stopLocked() }
+    }
+
+    private fun stopLocked() {
         if (!started) return
         started = false
         synchronized(ackLock) { ackLock.notifyAll() }
         runCatching {
-            sendOnChannel(MSG_STOP, Protobuf.varintField(1, SESSION_ID.toLong()))
+            sendOnChannel(MSG_STOP, Protobuf.varintField(1, sessionId.toLong()))
             if (focusRequested) sendControl(MSG_FOCUS_REQUEST, Protobuf.varintField(1, FOCUS_RELEASE.toLong()))
         }
         focusRequested = false
         focusGranted = false
-        GearslipLog.i("audio: -> Stop, AudioFocusRequest(RELEASE) after $chunks chunks / $bytes bytes")
+        aac?.release()
+        aac = null
+        GearslipLog.i("$tag: -> Stop, AudioFocusRequest(RELEASE) after $chunks chunks / $bytes bytes")
         chunks = 0
         bytes = 0
+        // A new stream starts with the car's buffer empty again: earn the lead back if it's needed.
+        padMs = 0
+        pendingPadMs = 0
     }
 
     override fun write(pcm: ByteArray, size: Int) {
         if (!started) return
+        val pad = pendingPadMs
+        if (pad > 0) {
+            pendingPadMs = 0
+            val quiet = silence(pad)
+            writeNow(quiet, quiet.size)
+        }
+        writeNow(pcm, size)
+    }
+
+    private fun writeNow(pcm: ByteArray, size: Int) {
+        val encoder = aac
+        if (encoder == null) {
+            send(pcm.copyOf(size))
+            return
+        }
+        val frames = try {
+            encoder.encode(pcm, size)
+        } catch (e: Exception) {
+            // A codec that dies mid-drive leaves the car silent, as it was before AAC; log it once.
+            GearslipLog.e("$tag: AAC encoding failed - no more audio this drive", e)
+            aac = null
+            started = false
+            return
+        }
+        frames.forEach(::send)
+    }
+
+    /** One Data message, once the car has room for it. */
+    private fun send(payload: ByteArray) {
         // Wait for the car to catch up rather than throw the chunk away: a dropped chunk is a gap
         // the driver hears, while a short wait is soaked up by the capture buffer behind us.
         synchronized(ackLock) {
@@ -191,7 +357,11 @@ class AudioLink(
                 val waited = System.currentTimeMillis() - lastAckAt
                 if (waited > STALL_MS) {
                     // A lost ack must not silence the stream for good; after a stall assume the window cleared.
-                    GearslipLog.w("audio: no ack for ${STALL_MS}ms with $inFlight in flight - reopening the window")
+                    // A car that never acks (the 2024 VW, the Bolt) hits this every chunk: say so
+                    // once, then now and then, so the rest of the log stays readable.
+                    if (stalls++ % 500 == 0) {
+                        GearslipLog.w("$tag: no ack for ${STALL_MS}ms with $inFlight in flight - reopening the window ($stalls times)")
+                    }
                     inFlight = 0
                     break
                 }
@@ -206,20 +376,20 @@ class AudioLink(
         val micros = System.nanoTime() / 1_000
         for (i in 0 until 8) timestamp[i] = ((micros shr ((7 - i) * 8)) and 0xFF).toByte()
         try {
-            sendOnChannel(MSG_DATA, timestamp + pcm.copyOf(size))
+            sendOnChannel(MSG_DATA, timestamp + payload)
         } catch (e: java.io.IOException) {
-            GearslipLog.e("audio: the link died mid-stream", e)
+            GearslipLog.e("$tag: the link died mid-stream", e)
             started = false
             return
         }
         synchronized(ackLock) { inFlight++ }
         chunks++
-        bytes += size
+        bytes += payload.size
         // The first chunk proves the whole path; after that, an occasional line is enough to show
         // the car is still taking audio and to catch a window that has quietly closed.
         if (chunks == 1 || chunks % CHUNK_LOG_EVERY == 0) {
             GearslipLog.i(
-                "audio: -> $chunks chunks / $bytes bytes, inFlight=$inFlight/$maxUnacked, " +
+                "$tag: -> $chunks chunks / $bytes bytes, inFlight=$inFlight/$maxUnacked, " +
                     "dropped=$dropped, focus=${if (focusGranted) "granted" else "not granted"}",
             )
         }
@@ -229,8 +399,9 @@ class AudioLink(
         configTimer?.interrupt()
         configTimer = null
         stop()
+        handBackSpeakers()
         ready = false
-        CarAudio.detach(this)
+        onClose(this)
     }
 
     companion object {
@@ -238,23 +409,35 @@ class AudioLink(
         const val MSG_FOCUS_RESPONSE = 19
         private const val MSG_CHANNEL_OPEN_RESPONSE = 8
         private const val MSG_DATA = 0
+        private const val MSG_CODEC_CONFIG = 1
         private const val MSG_SETUP = 32768
         private const val MSG_START = 32769
         private const val MSG_STOP = 32770
         private const val MSG_CONFIG = 32771
         private const val MSG_ACK = 32772
+        private const val MSG_SETUP_ANSWER = 255
+        private const val MSG_UNDERFLOW = 32779 // 0x800B, car to phone, no body
+        private const val PAD_STEP_MS = 60
+        private const val MAX_PAD_MS = 240
         private const val STATUS_READY = 2
         private const val FOCUS_GAIN = 1
+        private const val FOCUS_GAIN_TRANSIENT_MAY_DUCK = 3
         private const val FOCUS_RELEASE = 4
+        private const val FOCUS_WAIT_MS = 500L
         private const val FOCUS_STATE_GAIN = 1
         private const val FOCUS_STATE_GAIN_TRANSIENT = 2
+        private const val FOCUS_STATE_GAIN_MEDIA_ONLY = 6
+        private const val FOCUS_STATE_LOSS = 3
+        private const val FOCUS_STATE_LOSS_TRANSIENT = 5
         private const val SESSION_ID = 2
         private const val STALL_MS = 2_000L
         private const val CHUNK_LOG_EVERY = 200 // about every four seconds
-        private const val CONFIG_WAIT_MS = 2_500L
+        private const val CONFIG_WAIT_MS = 1_000L
 
+        // AudioFocusStateNotification.AudioFocusState in aasdk.
         private val FOCUS_STATES = mapOf(
-            1 to "GAIN", 2 to "GAIN_TRANSIENT", 3 to "LOSS", 4 to "LOSS_TRANSIENT",
+            1 to "GAIN", 2 to "GAIN_TRANSIENT", 3 to "LOSS", 4 to "LOSS_TRANSIENT_CAN_DUCK",
+            5 to "LOSS_TRANSIENT", 6 to "GAIN_MEDIA_ONLY", 7 to "GAIN_TRANSIENT_GUIDANCE_ONLY",
         )
     }
 }

gearslip/src/main/java/app/seb3thehacker/gearslip/audio/CarAudio.kt

@@ -44,6 +44,9 @@ object CarAudio {
 
     @Volatile private var link: Link? = null
 
+    /** Opens the car's media channel, left closed while music went over Bluetooth; null once open. */
+    @Volatile var openSink: (() -> Unit)? = null
+
     /** Rate and channel count the capture should use: the car's, or a sensible default. */
     val sampleRate get() = link?.sampleRate ?: 48_000
     val channels get() = link?.channels ?: 2
@@ -71,6 +74,7 @@ object CarAudio {
         when (_capture.value) {
             Capture.ON, Capture.ASKING, Capture.DENIED -> return
             Capture.OFF -> if (link == null) {
+                openSink?.invoke()
                 GearslipLog.i("audio: waiting for the car to offer an audio sink")
             } else {
                 ask()
@@ -100,6 +104,26 @@ object CarAudio {
         _capture.value = Capture.DENIED
     }
 
+    private val _micBlocked = MutableStateFlow(false)
+
+    /** The microphone permission is off for good: Android refuses without asking, so say why. */
+    val micBlocked: StateFlow<Boolean> = _micBlocked.asStateFlow()
+
+    fun micBlocked() {
+        _micBlocked.value = true
+        denied()
+    }
+
+    /** The driver turned the permission back on mid-drive: ask for capture again. */
+    fun micAllowed() {
+        if (!_micBlocked.value) return
+        _micBlocked.value = false
+        if (_capture.value == Capture.DENIED) {
+            _capture.value = Capture.OFF
+            if (wanted) request()
+        }
+    }
+
     internal fun captureStarted() {
         _capture.value = Capture.ON
         link?.start()

gearslip/src/main/java/app/seb3thehacker/gearslip/audio/CarMic.kt

@@ -0,0 +1,136 @@
+package app.seb3thehacker.gearslip.audio
+
+import app.seb3thehacker.gearslip.GearslipLog
+import app.seb3thehacker.gearslip.Protobuf
+import app.seb3thehacker.gearslip.ServiceDiscovery
+import app.seb3thehacker.gearslip.Wire
+import java.util.concurrent.LinkedBlockingQueue
+import java.util.concurrent.TimeUnit
+
+/**
+ * The car's own microphone, which most head units offer over the same link as the screen:
+ *
+ *   -> CHANNEL_OPEN_REQUEST          <- CHANNEL_OPEN_RESPONSE
+ *   -> Setup { config_index }        <- Config
+ *   -> VoiceSessionNotification { START }   (control channel)
+ *   -> MicrophoneRequest { open }    <- MicrophoneResponse { status, session_id }
+ *   <- Data { 8-byte timestamp, PCM }...   -> Ack { session_id, ack }
+ *   -> MicrophoneRequest { open = false }
+ *   -> VoiceSessionNotification { END }
+ *
+ * The channel opens with the session, but the car only records between [start] and [stop], and
+ * only inside a voice session: the 2024 VW answered a bare MicrophoneRequest with status -7.
+ * Speech wants 16 kHz mono; a car that records at a multiple of that is averaged down to it, and
+ * one that doesn't isn't used, so voice falls back to the phone's microphone.
+ */
+class CarMic(
+    private val service: ServiceDiscovery.AudioService,
+    private val sendOnChannel: (messageId: Int, body: ByteArray) -> Unit,
+    private val voiceSession: (start: Boolean) -> Unit,
+) {
+    val channelId get() = service.serviceId
+
+    private val config = service.configs.first()
+    private val step = config.sampleRate / RATE
+    private val usable = service.codecType == ServiceDiscovery.CODEC_PCM && config.bits == 16 &&
+        config.sampleRate % RATE == 0 && step >= 1 && config.channels in 1..2
+
+    @Volatile private var ready = false
+    @Volatile private var listening = false
+    @Volatile private var session = 0
+    private var packets = 0
+    private val chunks = LinkedBlockingQueue<ShortArray>()
+
+    fun onMessage(messageId: Int, body: ByteArray) {
+        when (messageId) {
+            MSG_CHANNEL_OPEN_RESPONSE -> {
+                val status = Protobuf.readInt32Field(body, 1) ?: 0
+                GearslipLog.i("mic: <- ChannelOpenResponse: status=$status")
+                if (status != 0) return
+                // Setup { type = the codec }, as for audio: 0 got UNEXPECTED_MESSAGE from the VW.
+                sendOnChannel(MSG_SETUP, Protobuf.varintField(1, service.codecType.toLong()))
+                ready = usable
+                if (!usable) {
+                    GearslipLog.w(
+                        "mic: the car records ${service.codecName} ${config.sampleRate}Hz/${config.bits}bit/x${config.channels}, " +
+                            "which speech can't use - voice stays on the phone's microphone",
+                    )
+                }
+            }
+
+            MSG_CONFIG -> GearslipLog.i("mic: <- Config status=${Wire.varint(Wire.fields(body), 1)}")
+
+            MSG_MIC_RESPONSE -> {
+                val fields = Wire.fields(body)
+                session = Wire.varint(fields, 2)?.toInt() ?: 0
+                GearslipLog.i("mic: <- MicrophoneResponse status=${Wire.varint(fields, 1)} session=$session")
+            }
+
+            MSG_DATA -> {
+                sendOnChannel(MSG_ACK, Protobuf.varintField(1, session.toLong()) + Protobuf.varintField(2, 1L))
+                if (!listening || body.size <= TIMESTAMP_BYTES) return
+                if (packets++ == 0) GearslipLog.i("mic: first audio from the car (${body.size - TIMESTAMP_BYTES} bytes)")
+                chunks.offer(toSpeechRate(body))
+            }
+
+            else -> GearslipLog.i("mic: <- unhandled message id=$messageId (${body.size} bytes)")
+        }
+    }
+
+    /** Little-endian PCM after the timestamp, mixed to mono and averaged down to [RATE]. */
+    private fun toSpeechRate(body: ByteArray): ShortArray {
+        val frameBytes = 2 * config.channels
+        val frames = (body.size - TIMESTAMP_BYTES) / frameBytes
+        val out = ShortArray(frames / step)
+        for (i in out.indices) {
+            var sum = 0
+            for (s in 0 until step) {
+                val at = TIMESTAMP_BYTES + (i * step + s) * frameBytes
+                for (c in 0 until config.channels) {
+                    val o = at + 2 * c
+                    sum += (body[o].toInt() and 0xFF) or (body[o + 1].toInt() shl 8)
+                }
+            }
+            out[i] = (sum / (step * config.channels)).toShort()
+        }
+        return out
+    }
+
+    /** Asks the car to start recording. False when it can't, so the phone's microphone is used. */
+    fun start(): Boolean {
+        if (!ready) return false
+        chunks.clear()
+        packets = 0
+        listening = true
+        voiceSession(true)
+        sendOnChannel(MSG_MIC_REQUEST, Protobuf.varintField(1, 1L) + Protobuf.varintField(4, 1L))
+        GearslipLog.i("mic: -> MicrophoneRequest(open)")
+        return true
+    }
+
+    /** The next piece of audio, or null if the car sent nothing for [timeoutMs]. */
+    fun read(timeoutMs: Long): ShortArray? = chunks.poll(timeoutMs, TimeUnit.MILLISECONDS)
+
+    fun stop() {
+        if (!listening) return
+        listening = false
+        sendOnChannel(MSG_MIC_REQUEST, Protobuf.varintField(1, 0L))
+        voiceSession(false)
+        GearslipLog.i("mic: -> MicrophoneRequest(close) after $packets packets, voice session ended")
+    }
+
+    companion object {
+        /** The connected car's microphone, or null with no car or one that has none. */
+        @Volatile var current: CarMic? = null
+
+        const val RATE = 16_000
+        private const val TIMESTAMP_BYTES = 8
+        private const val MSG_CHANNEL_OPEN_RESPONSE = 8
+        private const val MSG_DATA = 0
+        private const val MSG_SETUP = 32768
+        private const val MSG_CONFIG = 32771
+        private const val MSG_ACK = 32772
+        private const val MSG_MIC_REQUEST = 32773
+        private const val MSG_MIC_RESPONSE = 32774
+    }
+}

gearslip/src/main/java/app/seb3thehacker/gearslip/call/CarCalls.kt

@@ -23,19 +23,19 @@ data class Caller(val number: String, val name: String?) {
 sealed interface CallUiState {
     data object None : CallUiState
     data class Ringing(val caller: Caller, val canDecline: Boolean) : CallUiState
-    data class Active(val caller: Caller?) : CallUiState
+    /** [since] is the uptime the call went off-hook, for the timer. */
+    data class Active(val caller: Caller?, val since: Long) : CallUiState
 }
 
 /**
- * Tracks the phone's call state for the car screen, and answers or declines through the two
+ * Tracks the phone's call state for the car screen, and answers or declines through the
  * doors a sideloaded app can use: [android.telecom.TelecomManager.acceptRingingCall] to answer,
- * and [GearslipCallScreening]'s response to decline one that is still ringing.
+ * [GearslipCallScreening]'s response to decline one that is still ringing, and
+ * [android.telecom.TelecomManager.endCall] to hang up, which needs only ANSWER_PHONE_CALLS for an
+ * ordinary carrier call. Mute is the phone's microphone mute, put back when the call ends.
  *
- * Ending a call already answered needs MODIFY_PHONE_STATE, a privileged permission Gearslip
- * cannot hold, so a call taken here is finished the way it would be without Gearslip at all -
- * from the phone itself, a paired headset, or the car's own Bluetooth if it has any. Call audio
- * stays on the phone's normal voice path too; nothing here sends it over the USB link, which
- * only ever carries media playback.
+ * Call audio stays on the phone's normal voice path; nothing here sends it over the USB link,
+ * which only ever carries media playback.
  */
 object CarCalls {
 
@@ -47,9 +47,14 @@ object CarCalls {
     private var pendingRespond: ((allow: Boolean) -> Unit)? = null
     private var ringingCaller: Caller? = null
 
+    private val _muted = MutableStateFlow(false)
+    val muted: StateFlow<Boolean> = _muted.asStateFlow()
+    private var audio: android.media.AudioManager? = null
+
     fun start(context: Context) {
         if (watcher != null) return
         if (context.checkSelfPermission(Manifest.permission.READ_PHONE_STATE) != PackageManager.PERMISSION_GRANTED) return
+        audio = context.getSystemService(android.media.AudioManager::class.java)
         val manager = context.getSystemService(TelephonyManager::class.java) ?: return
         val callback = object : TelephonyCallback(), TelephonyCallback.CallStateListener {
             override fun onCallStateChanged(state: Int) = onPhoneState(state)
@@ -66,6 +71,7 @@ object CarCalls {
         watcher = null
         pendingRespond = null
         ringingCaller = null
+        unmute()
         _state.value = CallUiState.None
     }
 
@@ -74,11 +80,15 @@ object CarCalls {
             TelephonyManager.CALL_STATE_IDLE -> {
                 pendingRespond = null
                 ringingCaller = null
+                // A mute left on would silence the microphone for everything after the call.
+                unmute()
                 _state.value = CallUiState.None
             }
             TelephonyManager.CALL_STATE_OFFHOOK -> {
                 pendingRespond = null
-                _state.value = CallUiState.Active(ringingCaller)
+                if (_state.value !is CallUiState.Active) {
+                    _state.value = CallUiState.Active(ringingCaller, android.os.SystemClock.uptimeMillis())
+                }
             }
             TelephonyManager.CALL_STATE_RINGING -> {
                 // The number itself only ever arrives through the screening service; if this
@@ -109,6 +119,39 @@ object CarCalls {
         runCatching { respond(false) }.onFailure { GearslipLog.w("calls: decline failed: ${it.message}") }
     }
 
+    /** A call Gearslip itself is placing, so the call pill can say who it's to. */
+    fun outgoingCall(context: Context, number: String) {
+        ringingCaller = Caller(number, lookUpName(context, number))
+    }
+
+    fun end(context: Context) {
+        if (context.checkSelfPermission(Manifest.permission.ANSWER_PHONE_CALLS) != PackageManager.PERMISSION_GRANTED) {
+            GearslipLog.w("calls: ending a call needs ANSWER_PHONE_CALLS, which was never granted")
+            return
+        }
+        val telecom = context.getSystemService(TelecomManager::class.java) ?: return
+        @Suppress("DEPRECATION")
+        runCatching { telecom.endCall() }
+            .onSuccess { if (!it) GearslipLog.w("calls: the phone wouldn't end the call") }
+            .onFailure { GearslipLog.w("calls: end failed: ${it.message}") }
+    }
+
+    fun toggleMute() {
+        val manager = audio ?: return
+        val want = !_muted.value
+        runCatching { manager.isMicrophoneMute = want }
+            .onFailure { GearslipLog.w("calls: mute failed: ${it.message}") }
+        // Read back rather than trusted: some phones let the call app overrule it.
+        _muted.value = manager.isMicrophoneMute
+        if (_muted.value != want) GearslipLog.w("calls: the phone didn't take the mute change")
+    }
+
+    private fun unmute() {
+        if (!_muted.value) return
+        runCatching { audio?.isMicrophoneMute = false }
+        _muted.value = false
+    }
+
     fun answer(context: Context) {
         if (context.checkSelfPermission(Manifest.permission.ANSWER_PHONE_CALLS) != PackageManager.PERMISSION_GRANTED) {
             GearslipLog.w("calls: answer needs ANSWER_PHONE_CALLS, which was never granted")

gearslip/src/main/java/app/seb3thehacker/gearslip/call/CarPhoneStatus.kt

@@ -0,0 +1,108 @@
+package app.seb3thehacker.gearslip.call
+
+import android.os.SystemClock
+import android.view.KeyEvent
+import app.seb3thehacker.gearslip.GearslipLog
+import app.seb3thehacker.gearslip.Protobuf
+import app.seb3thehacker.gearslip.Wire
+import app.seb3thehacker.gearslip.car.CarKeys
+
+/**
+ * Tells the car about calls, so its own screens show them: the instrument cluster, the steering
+ * wheel display, the car's phone page. Android Auto does the same over the car's
+ * PhoneStatusService (Service field 10):
+ *
+ *   -> PhoneStatusUpdate { repeated PhoneCall calls = 1 }
+ *        PhoneCall { state = 1 (1 in call, 4 incoming, 6 muted); duration_seconds = 2;
+ *                    number = 3; name = 4 }
+ *   <- PhoneStatusInput { input = 1 { action = 1 (7 call) }; caller = 2; name = 3 }
+ *
+ * Read once a second from [CarCalls]. An update goes when the call changes, and every second
+ * while one is going, so the car's timer counts along; no calls goes once, as an empty list.
+ * The car's own call button answers through [CarKeys], like the steering wheel's.
+ */
+class CarPhoneStatus(
+    val channelId: Int,
+    private val sendOnChannel: (messageId: Int, body: ByteArray) -> Unit,
+) {
+    @Volatile private var running = false
+    private var sent: String? = null
+
+    fun onMessage(messageId: Int, body: ByteArray) {
+        when (messageId) {
+            MSG_CHANNEL_OPEN_RESPONSE -> {
+                val status = Protobuf.readInt32Field(body, 1)
+                GearslipLog.i("phone status: <- ChannelOpenResponse: status=$status")
+                if (status == 0) start()
+            }
+            MSG_INPUT -> onInput(body)
+            else -> GearslipLog.i("phone status: <- unhandled message id=$messageId (${body.size} bytes)")
+        }
+    }
+
+    private fun start() {
+        if (running) return
+        running = true
+        Thread({
+            while (running) {
+                runCatching { tick() }.onFailure { GearslipLog.w("phone status: ${it.message}") }
+                Thread.sleep(TICK_MS)
+            }
+        }, "gearslip-phone-status").start()
+    }
+
+    fun stop() {
+        running = false
+    }
+
+    private fun tick() {
+        val call = when (val state = CarCalls.state.value) {
+            CallUiState.None -> null
+            is CallUiState.Ringing -> Call(STATE_INCOMING, 0, state.caller)
+            is CallUiState.Active -> Call(
+                if (CarCalls.muted.value) STATE_MUTED else STATE_IN_CALL,
+                ((SystemClock.uptimeMillis() - state.since) / 1000).coerceAtLeast(0),
+                state.caller,
+            )
+        }
+        // Only a call that's going changes from one second to the next.
+        val key = call?.let { "${it.state}|${it.caller?.number}|${it.caller?.name}|${if (it.state == STATE_INCOMING) 0 else it.seconds}" } ?: ""
+        if (key == sent) return
+        val changed = call?.state != lastState
+        sent = key
+        lastState = call?.state
+        val body = call?.let { Protobuf.bytesField(1, it.encode()) } ?: ByteArray(0)
+        sendOnChannel(MSG_STATUS, body)
+        if (changed) GearslipLog.i("phone status: -> ${call?.let { STATE_NAMES[it.state] } ?: "no calls"}")
+    }
+
+    private var lastState: Int? = null
+
+    private class Call(val state: Int, val seconds: Long, val caller: Caller?) {
+        fun encode(): ByteArray {
+            var body = Protobuf.varintField(1, state.toLong()) + Protobuf.varintField(2, seconds)
+            caller?.number?.takeIf { it.isNotBlank() }?.let { body += Protobuf.stringField(3, it) }
+            caller?.name?.takeIf { it.isNotBlank() }?.let { body += Protobuf.stringField(4, it) }
+            return body
+        }
+    }
+
+    /** The car's own phone buttons. Only "call" does anything: it answers, as the wheel's does. */
+    private fun onInput(body: ByteArray) {
+        val action = Wire.bytes(Wire.fields(body), 1)?.let { Wire.varint(Wire.fields(it), 1)?.toInt() }
+        GearslipLog.i("phone status: <- input action=${action ?: "?"}")
+        if (action == ACTION_CALL) CarKeys.onKey(KeyEvent.KEYCODE_CALL, down = true, longPress = false)
+    }
+
+    companion object {
+        private const val TICK_MS = 1_000L
+        private const val MSG_CHANNEL_OPEN_RESPONSE = 8
+        private const val MSG_STATUS = 32769 // 0x8001
+        private const val MSG_INPUT = 32770 // 0x8002
+        private const val STATE_IN_CALL = 1
+        private const val STATE_INCOMING = 4
+        private const val STATE_MUTED = 6
+        private const val ACTION_CALL = 7
+        private val STATE_NAMES = mapOf(STATE_IN_CALL to "in a call", STATE_INCOMING to "ringing", STATE_MUTED to "in a call, muted")
+    }
+}

gearslip/src/main/java/app/seb3thehacker/gearslip/car/AssistantCommands.kt

@@ -1,10 +1,14 @@
 package app.seb3thehacker.gearslip.car
 
 import android.content.Context
+import app.seb3thehacker.gearslip.media.CarMedia
+import app.seb3thehacker.gearslip.speech.VoiceFocus
 import java.text.DateFormat
 import java.util.Date
 import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.delay
 import kotlinx.coroutines.withContext
+import kotlinx.coroutines.withTimeoutOrNull
 
 /**
  * Turns what [CarAssistant] heard into an action plus something to say back.
@@ -17,9 +21,16 @@ import kotlinx.coroutines.withContext
 object AssistantCommands {
 
     suspend fun handle(context: Context, navigator: CarNavigator, frame: CarEnvironment.Frame, heardRaw: String): String {
-        val heard = heardRaw.lowercase().trim()
+        val heard = natural(heardRaw)
+        VoiceHelp.hide()
+        if (heard in HELP_WORDS || heard.startsWith("what can i say") || heard.startsWith("what can you do")) {
+            VoiceHelp.show()
+            return "Here's what you can say."
+        }
+        if (heard.matches(Regex("(fuck|f\\*+) (you|off)( too)?"))) return "Fuck you too."
 
         navigateCommand(context, navigator, frame, heard)?.let { return it }
+        playSearchCommand(context, navigator, heard)?.let { return it }
         mediaCommand(heard)?.let { return it }
         navCommand(navigator, heard)?.let { return it }
         infoCommand(heard)?.let { return it }
@@ -29,6 +40,47 @@ object AssistantCommands {
         return "I don't know how to do that yet."
     }
 
+    /**
+     * What was said, minus the padding people wrap a command in: "hey", "can you", "I want to",
+     * "please", "thanks". Each command below then only has to know its own words.
+     */
+    private fun natural(raw: String): String {
+        var t = raw.lowercase().replace(Regex("[.,!?]"), " ").replace(Regex("\\s+"), " ").trim()
+        var changed = true
+        while (changed) {
+            changed = false
+            for (lead in LEAD_FILLERS) if (t.startsWith("$lead ")) { t = t.removePrefix("$lead ").trim(); changed = true }
+            for (tail in TAIL_FILLERS) if (t.endsWith(" $tail")) { t = t.removeSuffix(" $tail").trim(); changed = true }
+        }
+        return t
+    }
+
+    /** The part after the first of [triggers] that [text] starts with, or null. */
+    private fun after(text: String, triggers: List<String>): String? =
+        triggers.firstOrNull { text.startsWith(it) }?.let { text.removePrefix(it).trim() }
+
+    private suspend fun allEntries(context: Context): List<Entry> {
+        val vehicleData = CarSettings.experimentalFeaturesEnabled.value && CarSettings.carSensorsEnabled.value
+        val builtIn = BuiltInApps.entries.filter { it.builtIn !== BuiltInApps.VehicleData || vehicleData }
+        return builtIn + (LauncherCache.entries ?: withContext(Dispatchers.IO) { LauncherCache.load(context) })
+    }
+
+    /**
+     * Best label match: exact, then a label starting with [name], then one containing it. Spaces
+     * and punctuation don't count, since the recognizer may hear "MapQuest" as "map quest".
+     */
+    private fun <T> bestMatch(items: List<T>, name: String, label: (T) -> String): T? {
+        val n = squash(name.removePrefix("the ").removePrefix("my ").removeSuffix(" app"))
+        if (n.isEmpty()) return null
+        items.firstOrNull { squash(label(it)) == n }?.let { return it }
+        // Loose matches need a real word: "pizza in a" mustn't pick "Organic Maps" for its "a".
+        if (n.length < 3) return null
+        return items.firstOrNull { squash(label(it)).startsWith(n) }
+            ?: items.firstOrNull { squash(label(it)).contains(n) }
+    }
+
+    private fun squash(s: String) = s.lowercase().filter { it.isLetterOrDigit() }
+
     /**
      * "navigate to X [with|using|on|via Y]" - Y picks the nav app by (partial) label; without it,
      * whichever nav app was used last, or the only one installed, or the first one found. Starts
@@ -42,29 +94,68 @@ object AssistantCommands {
         frame: CarEnvironment.Frame,
         heard: String,
     ): String? {
-        val trigger = NAVIGATE_TRIGGERS.firstOrNull { heard.startsWith(it) } ?: return null
-        var destination = heard.removePrefix(trigger).trim()
+        // "use Organic Maps to get to X", "open OsmAnd and navigate to X": the app comes first.
+        // "take me home", "go home": no "to", so no trigger would catch them.
+        var text = if (Regex("^(?:(?:take|bring|get|drive) me|go|drive|head|get|directions|go back|head back) home$").matches(heard)) {
+            "navigate to home"
+        } else {
+            heard
+        }
+        var leadingApp: String? = null
+        Regex("^(?:use|using|with|open|in|on) (.+?) (?:to |and )(.+)$").find(text)?.let { m ->
+            if (after(m.groupValues[2], NAVIGATE_TRIGGERS) != null) {
+                leadingApp = m.groupValues[1]
+                text = m.groupValues[2]
+            }
+        }
+        var destination = after(text, NAVIGATE_TRIGGERS) ?: return null
         if (destination.isBlank()) return "Where to?"
 
-        var appName: String? = null
-        for (sep in listOf(" with ", " using ", " on ", " via ")) {
-            val at = destination.lastIndexOf(sep)
-            if (at > 0) {
-                appName = destination.substring(at + sep.length).trim()
+        val entries = allEntries(context)
+        // "go to Spotify" means the app, and "go to settings" the screen; "go to Target" is a place.
+        val asApp = destination.removePrefix("the ").removeSuffix(" app")
+        if (text.startsWith("go to ") &&
+            (asApp in SCREEN_WORDS || asApp in APP_NICKNAMES || entries.any { it.label.lowercase() == asApp })
+        ) {
+            return null
+        }
+        val navApps = entries.filter { it.template?.isNavigation == true }
+        if (navApps.isEmpty()) return "You don't have any navigation apps installed."
+
+        // "X with Organic Maps", "X on OsmAnd": split only when the end names a nav app, so a
+        // place like "Starbucks on Main Street" stays whole.
+        var chosenApp = leadingApp?.let { name -> bestMatch(navApps, name) { it.label } ?: return "I couldn't find a navigation app called $name." }
+        if (chosenApp == null) {
+            for (sep in listOf(" with ", " using ", " on ", " via ", " in ", " through ")) {
+                val at = destination.lastIndexOf(sep)
+                if (at <= 0) continue
+                val app = bestMatch(navApps, destination.substring(at + sep.length)) { it.label } ?: continue
+                chosenApp = app
                 destination = destination.substring(0, at).trim()
                 break
             }
         }
+        // "the nearest gas station" -> "gas station": the map app already searches around the car
+        // and AutoRoute picks the nearest result, and Organic Maps took "nearest" as part of the name.
+        val (place, nearby) = plainPlace(destination)
+        destination = place
         if (destination.isBlank()) return "Where to?"
+        // "home", "work", or a name from Saved places: its address is the search.
+        var spoken: String? = null
+        SavedPlaces.match(context, destination)?.let { (slot, saved) ->
+            val name = when (slot) {
+                SavedPlaces.HOME -> "home"
+                SavedPlaces.WORK -> "work"
+                else -> saved.label
+            }
+            if (saved.address.isBlank()) {
+                return "You haven't saved a $name address yet. Add it under Saved places in Gearslip's settings on your phone."
+            }
+            destination = saved.address
+            spoken = if (slot == SavedPlaces.HOME) "home" else "to $name"
+        }
 
-        val entries = LauncherCache.entries ?: withContext(Dispatchers.IO) { LauncherCache.load(context) }
-        val navApps = entries.filter { it.template?.isNavigation == true }
-        if (navApps.isEmpty()) return "You don't have any navigation apps installed."
-
-        val requestedApp = appName
-        val chosen = when {
-            requestedApp != null -> navApps.firstOrNull { it.label.lowercase().contains(requestedApp) }
-                ?: return "I couldn't find a navigation app called $requestedApp."
+        val chosen = chosenApp ?: when {
             navApps.size == 1 -> navApps.first()
             else -> navApps.firstOrNull { it.componentId == CarSettings.lastNav.value } ?: navApps.first()
         }
@@ -72,29 +163,105 @@ object AssistantCommands {
 
         CarServices.connectNav(template, frame, destination)
         navigator.home()
-        return "Navigating to $destination with ${chosen.label}."
+        spoken?.let { return "Navigating $it with ${chosen.label}." }
+        return if (nearby) "Finding the nearest $destination with ${chosen.label}." else "Navigating to $destination with ${chosen.label}."
+    }
+
+    /** [destination] without "a", "the nearest", "near me" and the like, and whether any of that said "close by". */
+    private fun plainPlace(destination: String): Pair<String, Boolean> {
+        var t = destination
+        var nearby = false
+        var changed = true
+        while (changed) {
+            changed = false
+            for (lead in PLACE_LEADS) if (t.startsWith(lead)) {
+                t = t.removePrefix(lead).trim(); changed = true
+                if (lead.trim() !in ARTICLES) nearby = true
+            }
+            for (tail in PLACE_TAILS) if (t.endsWith(tail)) { t = t.removeSuffix(tail).trim(); changed = true; nearby = true }
+        }
+        return t to nearby
+    }
+
+    /**
+     * "play X" with something after it: a song, artist, album or playlist, asked of the music app
+     * that's open through its own search ([CarMedia.search]). A bare "play", or "play music",
+     * falls through to resume.
+     */
+    private suspend fun playSearchCommand(context: Context, navigator: CarNavigator, heard: String): String? {
+        var query = after(heard, PLAY_TRIGGERS) ?: return null
+        query = query.removePrefix("some ").trim()
+        if (query.isEmpty() || query in RESUME_WORDS) return null
+        val media = CarServices.media
+
+        // "play Daft Punk on Metrolist": switch to that app first, if it's one we know.
+        for (sep in listOf(" on ", " in ", " from ", " with ", " using ")) {
+            val at = query.lastIndexOf(sep)
+            if (at <= 0) continue
+            val apps = withContext(Dispatchers.IO) { app.seb3thehacker.gearslip.media.MediaCatalog.installed(context) }
+            val wanted = bestMatch(apps, query.substring(at + sep.length)) { it.label } ?: continue
+            query = query.substring(0, at).trim()
+            if (query.isEmpty() || query in RESUME_WORDS) {
+                CarServices.openMedia(wanted, autoplay = true)
+                navigator.media()
+                return "Opening ${wanted.label}."
+            }
+            if (CarServices.mediaApp.value?.component != wanted.component) {
+                CarServices.openMedia(wanted)
+                navigator.media()
+                // Give it a moment to connect before asking it to search.
+                withTimeoutOrNull(APP_CONNECT_MS) {
+                    while (media.appLabel == null || (!media.canSearchLibrary && !media.now.value.canSearch)) delay(200)
+                }
+            }
+            break
+        }
+
+        // No music app open, or its connection is gone (the app was closed): use the one played
+        // last, the way "play X" works on Android Auto.
+        val phase = media.phase.value
+        if (media.appLabel == null || phase == CarMedia.Phase.IDLE || phase == CarMedia.Phase.REJECTED) {
+            if (!CarServices.reopenLastMedia()) return "Open a music app first, then ask again."
+            navigator.media()
+        }
+        withTimeoutOrNull(APP_CONNECT_MS) {
+            while (media.phase.value != CarMedia.Phase.READY || media.appLabel == null ||
+                (!media.canSearchLibrary && !media.now.value.canSearch)
+            ) delay(200)
+        }
+        val app = media.appLabel ?: return "Your music app didn't open in time. Try again."
+        if (!media.canSearchLibrary && !media.now.value.canSearch) {
+            return "$app ignores voice searches. Pick something on its screen instead."
+        }
+        media.playBestMatch(query)
+        return "Looking for $query on $app."
     }
 
     private fun mediaCommand(heard: String): String? {
         val media = CarServices.media
         return when {
-            "pause" in heard || heard.startsWith("stop") -> {
-                if (media.now.value.playing) media.togglePlay()
+            "pause" in heard || heard.startsWith("stop") || heard == "quiet" || heard == "shut up" -> {
+                media.pause()
+                VoiceFocus.afterRelease { media.pause() }
                 "Paused."
             }
-            "resume" in heard || (heard.startsWith("play") && "playing" !in heard) -> {
+            "resume" in heard || "unpause" in heard || heard in RESUME_PHRASES ||
+                (heard.startsWith("play") && "playing" !in heard) -> {
                 if (!media.now.value.playing) media.togglePlay()
                 "Playing."
             }
-            "next" in heard || "skip" in heard -> {
+            "next" in heard || "skip" in heard || heard.startsWith("change the song") -> {
                 media.next()
                 "Skipping."
             }
-            "previous" in heard || "last song" in heard || "back song" in heard -> {
+            "previous" in heard || "last song" in heard || "back song" in heard || "go back a song" in heard ||
+                "play that again" in heard || "replay" in heard -> {
                 media.previous()
                 "Playing the previous track."
             }
-            "what" in heard && "playing" in heard -> {
+            ("what" in heard && "playing" in heard) || "what song" in heard || "who sings" in heard ||
+                "who's singing" in heard || "who is singing" in heard || "what's this song" in heard ||
+                "name of this song" in heard -> {
                 val now = media.now.value
                 if (now.isActive) listOf(now.title, now.artist).filter { it.isNotBlank() }.joinToString(" by ")
                 else "Nothing's playing."
@@ -104,11 +271,19 @@ object AssistantCommands {
     }
 
     private fun navCommand(navigator: CarNavigator, heard: String): String? = when {
-        "go home" in heard || heard == "home" -> {
+        heard == "go back" || heard == "back" -> {
+            navigator.back()
+            "Going back."
+        }
+        heard in EXIT_WORDS -> {
+            BuiltInApps.Exit.open(navigator)
+            "Back to the car's screen."
+        }
+        "go home" in heard || heard == "home" || heard == "home screen" || "go to the home screen" in heard -> {
             navigator.home()
             "Heading home."
         }
-        "open apps" in heard || heard == "apps" || "app list" in heard -> {
+        "open apps" in heard || heard == "apps" || "app list" in heard || "all apps" in heard || "my apps" in heard || heard == "go to apps" -> {
             navigator.apps()
             "Here are your apps."
         }
@@ -128,9 +303,10 @@ object AssistantCommands {
     }
 
     private fun infoCommand(heard: String): String? = when {
-        "what time" in heard || "what's the time" in heard ->
+        "what time" in heard || "what's the time" in heard || heard == "time" || "the time" in heard ->
             "It's ${DateFormat.getTimeInstance(DateFormat.SHORT).format(Date())}."
-        "weather" in heard -> {
+        "weather" in heard || "going to rain" in heard || "gonna rain" in heard || "how hot" in heard ||
+            "how cold" in heard || "temperature outside" in heard -> {
             val data = (Weather.state.value as? WeatherState.Ready)?.data
             if (data != null) "${data.temp}${data.tempUnit} and ${Weather.describe(data.code)} in ${data.place}."
             else "I don't have the weather yet."
@@ -139,12 +315,11 @@ object AssistantCommands {
     }
 
     private suspend fun callCommand(context: Context, heard: String): String? {
-        val name = when {
-            heard.startsWith("call ") -> heard.removePrefix("call ")
-            heard.startsWith("phone ") -> heard.removePrefix("phone ")
-            heard.startsWith("dial ") -> heard.removePrefix("dial ")
-            else -> return null
-        }.trim()
+        val name = (
+            after(heard, CALL_TRIGGERS)
+                ?: Regex("^give (.+) a (?:call|ring)$").find(heard)?.groupValues?.get(1)
+                ?: return null
+            ).replace(Regex(" (?:on|at) (?:their |his |her )?(?:mobile|cell|phone|home|work)$"), "").trim()
         if (name.isBlank()) return "Who should I call?"
         if (!hasCallPermissions(context)) return "Gearslip needs the phone and contacts permissions first, from the phone screen."
 
@@ -162,21 +337,69 @@ object AssistantCommands {
         frame: CarEnvironment.Frame,
         heard: String,
     ): String? {
-        val name = when {
-            heard.startsWith("open ") -> heard.removePrefix("open ")
-            heard.startsWith("launch ") -> heard.removePrefix("launch ")
-            heard.startsWith("start ") -> heard.removePrefix("start ")
-            else -> return null
-        }.trim()
+        val name = (after(heard, OPEN_TRIGGERS) ?: return null)
+            .removePrefix("the ").removePrefix("my ").removeSuffix(" app").trim()
         if (name.isBlank()) return null
+        val wanted = APP_NICKNAMES[name] ?: name
 
-        val entries = LauncherCache.entries ?: withContext(Dispatchers.IO) { LauncherCache.load(context) }
-        val match = entries.firstOrNull { it.label.lowercase().contains(name) }
+        // Gearslip's own apps come first in the list, so "phone" opens its dialer, not the phone's.
+        val match = bestMatch(allEntries(context), wanted) { it.label }
             ?: return "I couldn't find an app called $name."
 
         launchEntry(match, navigator, frame)
         return "Opening ${match.label}."
     }
 
-    private val NAVIGATE_TRIGGERS = listOf("navigate to ", "directions to ", "take me to ", "drive to ")
+    private val EXIT_WORDS = setOf("exit", "exit gearslip", "close gearslip", "quit", "quit gearslip", "open exit")
+
+    /** Other names people use for Gearslip's own apps. */
+    private val APP_NICKNAMES = mapOf(
+        "web" to "browser", "internet" to "browser", "the web" to "browser", "web browser" to "browser",
+        "dialer" to "phone", "the dialer" to "phone", "keypad" to "phone",
+        "screen share" to "screen sharing", "screen mirroring" to "screen sharing", "mirroring" to "screen sharing",
+    )
+
+    private val NAVIGATE_TRIGGERS = listOf(
+        "navigate to ", "navigate me to ", "directions to ", "get directions to ", "give me directions to ",
+        "take me to ", "drive to ", "drive me to ", "get me to ", "go to ", "head to ", "route to ",
+        "how do i get to ", "show me the way to ", "find a route to ", "navigation to ", "get to ",
+        // Last, so "navigate to" wins: the recognizer sometimes drops the "to".
+        "navigate me ", "navigate ", "find me the nearest ", "find the nearest ", "find the closest ",
+    )
+
+    private val ARTICLES = setOf("a", "an", "the", "some")
+    // Longest first, so "the nearest " goes before "the ".
+    private val PLACE_LEADS = listOf(
+        "the nearest ", "the closest ", "a nearby ", "the nearby ", "nearest ", "closest ", "nearby ",
+        "a ", "an ", "some ",
+    )
+    private val PLACE_TAILS = listOf(" near me", " nearby", " near here", " around here", " close by", " closest to me")
+
+    private val PLAY_TRIGGERS = listOf("play me ", "play ", "put on ", "listen to ", "i want to hear ", "shuffle ")
+
+    private val CALL_TRIGGERS = listOf("call ", "phone ", "dial ", "ring ", "make a call to ", "place a call to ", "start a call with ")
+
+    private val OPEN_TRIGGERS = listOf("open ", "launch ", "start ", "go to ", "switch to ", "show me ", "bring up ", "pull up ")
+
+    /** Screens "go to X" means rather than a place. */
+    private val SCREEN_WORDS = setOf("settings", "home", "the home screen", "home screen", "apps", "my apps", "all apps")
+
+    /** Padding stripped from the front of a command, longest first where they overlap. */
+    private val LEAD_FILLERS = listOf(
+        "hey gearslip", "ok gearslip", "okay gearslip", "gearslip", "hey", "ok", "okay", "um", "uh", "so",
+        "please", "can you please", "can you", "could you", "would you", "will you", "can i", "could i",
+        "i want you to", "i want to", "i'd like to", "i would like to", "i wanna", "i need to", "i need you to",
+        "let's", "lets", "go ahead and", "just", "now", "quickly",
+    )
+
+    /** Longest first, so "right now" goes whole rather than leaving "right". */
+    private val TAIL_FILLERS = listOf("thank you very much", "thank you", "right now", "for me", "please", "thanks", "now")
+
+    private const val APP_CONNECT_MS = 5_000L
+
+    private val HELP_WORDS = setOf("help", "commands", "voice commands", "list commands", "show commands")
+
+    private val RESUME_WORDS = setOf("music", "the music", "some music", "something", "it", "again", "that", "my music")
+
+    private val RESUME_PHRASES = setOf("keep playing", "continue", "keep going", "start the music", "music on", "turn the music back on")
 }

gearslip/src/main/java/app/seb3thehacker/gearslip/car/AssistantOverlay.kt

@@ -4,7 +4,21 @@ import app.seb3thehacker.gearslip.car.theme.*
 import android.content.Intent
 import android.net.Uri
 import android.provider.Settings
+import androidx.compose.animation.core.FastOutSlowInEasing
+import androidx.compose.animation.core.RepeatMode
+import androidx.compose.animation.core.animateFloat
+import androidx.compose.animation.core.infiniteRepeatable
+import androidx.compose.animation.core.rememberInfiniteTransition
+import androidx.compose.animation.core.tween
 import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Box
+import androidx.compose.ui.draw.drawBehind
+import androidx.compose.ui.geometry.Offset
+import androidx.compose.ui.graphics.Brush
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.graphics.drawscope.scale
+import androidx.compose.ui.text.style.TextAlign
+import androidx.compose.ui.text.style.TextOverflow
 import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.layout.fillMaxWidth
@@ -30,47 +44,66 @@ import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.unit.dp
 
 /**
- * The band that appears while [CarAssistant] is listening, thinking or speaking - a thin strip
- * across the top, same idea as [CallOverlay]'s active-call banner, so it never blocks the screen
- * the driver was already looking at.
+ * What the assistant hears and says, laid over the bottom of whatever screen is up: a dark shade
+ * so white words read over a bright map, and a glow along the bottom edge in the phone's own
+ * colours that breathes while listening. The shade passes touches through; only the buttons take them.
  */
 @Composable
 fun AssistantOverlay(modifier: Modifier = Modifier) {
     val state by CarAssistant.state.collectAsState()
     if (state.phase == CarAssistant.Phase.IDLE) return
     val context = LocalContext.current
+    val listening = state.phase == CarAssistant.Phase.LISTENING && state.ready
+    val glow = MaterialTheme.colorScheme.primary
+    val glow2 = MaterialTheme.colorScheme.tertiary
+    val breathe by rememberInfiniteTransition(label = "glow").animateFloat(
+        0.55f, 1f, infiniteRepeatable(tween(900, easing = FastOutSlowInEasing), RepeatMode.Reverse), label = "glow",
+    )
+    val strength = when (state.phase) {
+        CarAssistant.Phase.LISTENING -> if (state.ready) breathe else 0.3f
+        CarAssistant.Phase.ERROR -> 0.3f
+        else -> 0.6f
+    }
 
-    Surface(
-        color = MaterialTheme.colorScheme.primaryContainer,
-        contentColor = MaterialTheme.colorScheme.onPrimaryContainer,
-        modifier = modifier.fillMaxWidth(),
-    ) {
-        Row(
-            Modifier.padding(horizontal = 16.dp, vertical = 10.dp),
-            verticalAlignment = Alignment.CenterVertically,
-            horizontalArrangement = Arrangement.spacedBy(12.dp),
-        ) {
-            PulsingMic(state.phase == CarAssistant.Phase.LISTENING)
-            Column(Modifier.weight(1f)) {
-                Text(
-                    when (state.phase) {
-                        CarAssistant.Phase.LISTENING -> "Listening…"
-                        CarAssistant.Phase.THINKING -> "…"
-                        CarAssistant.Phase.SPEAKING -> state.reply
-                        CarAssistant.Phase.ERROR -> state.reply
-                        CarAssistant.Phase.IDLE -> ""
-                    },
-                    style = MaterialTheme.typography.titleSmall,
-                    fontWeight = FontWeight.SemiBold,
-                    maxLines = 2,
-                )
-                if (state.heard.isNotBlank() && state.phase != CarAssistant.Phase.SPEAKING) {
-                    Text(
-                        "\"${state.heard}\"",
-                        style = MaterialTheme.typography.bodySmall,
+    Box(
+        modifier
+            .fillMaxWidth()
+            .drawBehind {
+                drawRect(Brush.verticalGradient(0f to Color.Transparent, 0.45f to Color.Black.copy(alpha = 0.6f), 1f to Color.Black.copy(alpha = 0.85f)))
+                // A wide, flat oval of light rising from the bottom edge.
+                scale(1f, 0.22f, Offset(size.width / 2, size.height)) {
+                    drawCircle(
+                        Brush.radialGradient(
+                            0f to glow.copy(alpha = 0.9f * strength), 0.5f to glow2.copy(alpha = 0.35f * strength), 1f to Color.Transparent,
+                            center = Offset(size.width / 2, size.height), radius = size.width * 0.55f,
+                        ),
+                        radius = size.width * 0.55f, center = Offset(size.width / 2, size.height),
                     )
                 }
             }
+            .padding(start = 16.dp, end = 16.dp, top = 56.dp, bottom = 20.dp),
+    ) {
+        Row(verticalAlignment = Alignment.CenterVertically, horizontalArrangement = Arrangement.spacedBy(16.dp)) {
+            PulsingMic(listening)
+            Column(Modifier.weight(1f), horizontalAlignment = Alignment.CenterHorizontally) {
+                val (small, big) = when (state.phase) {
+                    CarAssistant.Phase.LISTENING -> "" to state.heard.ifBlank { if (state.ready) "Listening…" else "One moment…" }
+                    CarAssistant.Phase.THINKING -> "" to state.heard.ifBlank { "…" }
+                    else -> state.heard to state.reply
+                }
+                if (small.isNotBlank()) {
+                    Text(small, color = Color.White.copy(alpha = 0.7f), style = MaterialTheme.typography.bodyLarge, maxLines = 1, overflow = TextOverflow.Ellipsis)
+                }
+                Text(
+                    big,
+                    color = if (big == "Listening…" || big == "One moment…" || big == "…") Color.White.copy(alpha = 0.7f) else Color.White,
+                    style = MaterialTheme.typography.headlineSmall,
+                    fontWeight = FontWeight.SemiBold,
+                    textAlign = TextAlign.Center,
+                    maxLines = 2,
+                    overflow = TextOverflow.Ellipsis,
+                )
+            }
             if (state.missingPermission) {
                 GsButton(tone = GsTone.Tonal, onClick = {
                     context.startActivity(

gearslip/src/main/java/app/seb3thehacker/gearslip/car/BluetoothAudioCheck.kt

@@ -0,0 +1,146 @@
+package app.seb3thehacker.gearslip.car
+
+import android.Manifest
+import android.annotation.SuppressLint
+import android.bluetooth.BluetoothA2dp
+import android.bluetooth.BluetoothAdapter
+import android.bluetooth.BluetoothManager
+import android.bluetooth.BluetoothProfile
+import android.content.BroadcastReceiver
+import android.content.Context
+import android.content.Intent
+import android.content.IntentFilter
+import android.content.pm.PackageManager
+import android.os.Handler
+import android.os.Looper
+import app.seb3thehacker.gearslip.GearslipLog
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+
+/**
+ * With Bluetooth audio chosen, music only reaches the car if the phone is connected to it over
+ * Bluetooth. Twenty seconds after the car shows Gearslip, long enough for a car to connect on its
+ * own, this checks. If the phone isn't connected, the car and the phone's Home screen both say so,
+ * until it connects or the drive ends.
+ *
+ * When the car named its Bluetooth address, only that device counts. Otherwise any audio
+ * connection does, since there's no telling which device is the car.
+ */
+object BluetoothAudioCheck {
+
+    private val _missing = MutableStateFlow(false)
+    /** True while Bluetooth audio is chosen and the phone isn't connected to the car for it. */
+    val missing: StateFlow<Boolean> = _missing
+
+    private val _carDismissed = MutableStateFlow(false)
+    /** The driver tapped OK on the car's card; it stays away for the rest of this drive. */
+    val carDismissed: StateFlow<Boolean> = _carDismissed
+
+    private val log = GearslipLog.tagged("bluetooth")
+    private val main = Handler(Looper.getMainLooper())
+    private var appContext: Context? = null
+    private var armed = false
+    private var receiver: BroadcastReceiver? = null
+
+    fun init(context: Context) {
+        appContext = context.applicationContext
+    }
+
+    /** The car shows Gearslip. Called again whenever the video restarts, so it arms once per drive. */
+    fun onProjecting() = main.post {
+        if (armed) return@post
+        armed = true
+        main.postDelayed(::start, WAIT_MS)
+    }
+
+    fun onCarDisconnected() = main.post {
+        armed = false
+        main.removeCallbacksAndMessages(null)
+        stopWatching()
+        _missing.value = false
+        _carDismissed.value = false
+    }
+
+    fun dismissOnCar() {
+        _carDismissed.value = true
+    }
+
+    /** "Don't show again" on the car: turns the warning off in Settings, for every car. */
+    fun neverAgain() {
+        CarSettings.setBluetoothWarning(false)
+        log.i("Bluetooth audio warning turned off")
+        _carDismissed.value = true
+        _missing.value = false
+    }
+
+    private fun start() {
+        if (!armed) return
+        check()
+        // Connecting later clears the warning, and losing the connection brings it back.
+        val context = appContext ?: return
+        val r = object : BroadcastReceiver() {
+            override fun onReceive(context: Context, intent: Intent) {
+                main.postDelayed(::check, SETTLE_MS)
+            }
+        }
+        context.registerReceiver(
+            r,
+            IntentFilter(BluetoothA2dp.ACTION_CONNECTION_STATE_CHANGED).apply {
+                addAction(BluetoothAdapter.ACTION_STATE_CHANGED)
+            },
+            Context.RECEIVER_EXPORTED,
+        )
+        receiver = r
+    }
+
+    @SuppressLint("MissingPermission")
+    private fun check() {
+        if (!armed) return
+        val context = appContext ?: return
+        if (CarSettings.pipeAudio.value) {
+            set(false, "audio goes through Gearslip")
+            return
+        }
+        if (!CarSettings.bluetoothWarning.value) {
+            set(false, "the warning is turned off")
+            return
+        }
+        if (context.checkSelfPermission(Manifest.permission.BLUETOOTH_CONNECT) != PackageManager.PERMISSION_GRANTED) {
+            log.i("can't check the audio connection: the Bluetooth permission isn't granted")
+            return
+        }
+        val adapter = context.getSystemService(BluetoothManager::class.java)?.adapter ?: return
+        if (!adapter.isEnabled) {
+            set(true, "Bluetooth is off")
+            return
+        }
+        val car = CarBluetooth.carAddress?.uppercase()
+        adapter.getProfileProxy(context, object : BluetoothProfile.ServiceListener {
+            override fun onServiceConnected(profile: Int, proxy: BluetoothProfile) {
+                val connected = runCatching { proxy.connectedDevices }.getOrDefault(emptyList())
+                adapter.closeProfileProxy(profile, proxy)
+                val ok = if (car != null) connected.any { it.address.uppercase() == car } else connected.isNotEmpty()
+                main.post {
+                    set(!ok, if (ok) "connected to the car" else "not connected to the car")
+                }
+            }
+
+            override fun onServiceDisconnected(profile: Int) {}
+        }, BluetoothProfile.A2DP)
+    }
+
+    private fun set(missing: Boolean, why: String) {
+        if (!armed || _missing.value == missing) return
+        _missing.value = missing
+        log.i("Bluetooth audio: $why")
+    }
+
+    private fun stopWatching() {
+        val r = receiver ?: return
+        receiver = null
+        runCatching { appContext?.unregisterReceiver(r) }
+    }
+
+    private const val WAIT_MS = 20_000L
+    private const val SETTLE_MS = 1_000L
+}

gearslip/src/main/java/app/seb3thehacker/gearslip/car/BluetoothPairOverlay.kt

@@ -0,0 +1,116 @@
+package app.seb3thehacker.gearslip.car
+
+import androidx.compose.ui.res.stringResource
+import app.seb3thehacker.gearslip.R
+import app.seb3thehacker.gearslip.car.theme.*
+import androidx.compose.foundation.background
+import androidx.compose.foundation.clickable
+import androidx.compose.foundation.interaction.MutableInteractionSource
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.padding
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Surface
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.collectAsState
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.remember
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.text.style.TextAlign
+import androidx.compose.ui.unit.dp
+
+/**
+ * Asks once per car whether to pair it over Bluetooth, then waits while the phone shows its
+ * pairing dialog. See [CarBluetooth]. With no pairing to do, says when Bluetooth audio isn't
+ * connected (see [BluetoothAudioCheck]), or else when the phone's location is off (see
+ * [LocationCheck]). Unlike the call prompt, a tap outside the card does nothing:
+ * the driver picks Pair or Not now.
+ */
+@Composable
+internal fun BluetoothPairOverlay() {
+    val prompt by CarBluetooth.prompt.collectAsState()
+    val bluetoothAudio = !CarSettings.pipeAudio.collectAsState().value
+    when (prompt) {
+        CarBluetooth.Prompt.NONE -> {
+            val missing by BluetoothAudioCheck.missing.collectAsState()
+            val dismissed by BluetoothAudioCheck.carDismissed.collectAsState()
+            val warn by CarSettings.bluetoothWarning.collectAsState()
+            val locationOff by LocationCheck.off.collectAsState()
+            val locationDismissed by LocationCheck.carDismissed.collectAsState()
+            if (missing && bluetoothAudio && warn && !dismissed) PairCard(
+                title = stringResource(R.string.home_bt_title),
+                body = stringResource(R.string.overlay_bt_body),
+                secondary = stringResource(R.string.overlay_dont_show) to BluetoothAudioCheck::neverAgain,
+                primary = stringResource(R.string.overlay_ok) to BluetoothAudioCheck::dismissOnCar,
+            ) else if (locationOff && !locationDismissed) PairCard(
+                title = stringResource(R.string.overlay_location_off),
+                body = stringResource(R.string.overlay_location_body),
+                secondary = stringResource(R.string.overlay_dont_show) to LocationCheck::neverAgain,
+                primary = stringResource(R.string.overlay_ok) to LocationCheck::dismissOnCar,
+            )
+        }
+        CarBluetooth.Prompt.ASK -> PairCard(
+            title = stringResource(R.string.overlay_pair_title),
+            body = stringResource(if (bluetoothAudio) R.string.overlay_pair_body_music else R.string.overlay_pair_body),
+            secondary = stringResource(R.string.worked_not_now) to CarBluetooth::notNow,
+            primary = stringResource(R.string.overlay_pair) to CarBluetooth::pair,
+        )
+        CarBluetooth.Prompt.PAIRING -> PairCard(
+            title = stringResource(R.string.overlay_confirm_title),
+            body = stringResource(R.string.overlay_confirm_body),
+            secondary = null,
+            primary = stringResource(R.string.carset_hide) to CarBluetooth::hide,
+        )
+    }
+}
+
+@Composable
+private fun PairCard(title: String, body: String, secondary: Pair<String, () -> Unit>?, primary: Pair<String, () -> Unit>) {
+    Box(
+        Modifier.fillMaxSize().background(Color.Black.copy(alpha = 0.6f)).clickable(
+            indication = null,
+            interactionSource = remember { MutableInteractionSource() },
+            onClick = {},
+        ),
+        contentAlignment = Alignment.Center,
+    ) {
+        Surface(
+            shape = MaterialTheme.shapes.extraLarge,
+            color = MaterialTheme.colorScheme.surfaceContainerHigh,
+            modifier = Modifier.fillMaxWidth(0.85f).padding(16.dp),
+        ) {
+            Column(
+                Modifier.padding(32.dp),
+                verticalArrangement = Arrangement.spacedBy(20.dp),
+                horizontalAlignment = Alignment.CenterHorizontally,
+            ) {
+                Text(title, style = MaterialTheme.typography.headlineSmall, fontWeight = FontWeight.Bold)
+                Text(
+                    body,
+                    style = MaterialTheme.typography.titleMedium,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant,
+                    textAlign = TextAlign.Center,
+                )
+                Row(Modifier.fillMaxWidth(), horizontalArrangement = Arrangement.spacedBy(16.dp)) {
+                    secondary?.let { (label, onClick) ->
+                        GsButton(onClick = onClick, tone = GsTone.Outline, modifier = Modifier.weight(1f).height(56.dp)) {
+                            Text(label, style = MaterialTheme.typography.titleMedium)
+                        }
+                    }
+                    GsButton(onClick = primary.second, modifier = Modifier.weight(1f).height(56.dp)) {
+                        Text(primary.first, style = MaterialTheme.typography.titleMedium)
+                    }
+                }
+            }
+        }
+    }
+}

gearslip/src/main/java/app/seb3thehacker/gearslip/car/CallOverlay.kt

@@ -1,5 +1,7 @@
 package app.seb3thehacker.gearslip.car
 
+import androidx.compose.ui.res.stringResource
+import app.seb3thehacker.gearslip.R
 import androidx.compose.foundation.shape.CircleShape
 import app.seb3thehacker.gearslip.car.theme.*
 import androidx.compose.foundation.layout.Arrangement
@@ -33,21 +35,17 @@ import app.seb3thehacker.gearslip.call.CallUiState
 import app.seb3thehacker.gearslip.call.CarCalls
 
 /**
- * Sits above whatever the car is showing while a call is ringing or under way. Ringing takes the
- * whole screen, because nothing else matters more right now; an active call is a thin band along
- * the top, since from here the driver can only see who it is, not end it - see [CarCalls].
+ * Takes the whole car screen while a call is ringing, because nothing else matters more right
+ * now. A call under way moves into the nav bar instead (see NavCallPill), so it covers nothing.
  */
 @Composable
-fun CallOverlay(modifier: Modifier = Modifier) {
+fun CallOverlay() {
     val state by CarCalls.state.collectAsState()
     val context = LocalContext.current.applicationContext
 
     when (val s = state) {
-        // Covers the box regardless of where the caller aligned it, so the alignment below is
-        // only ever felt by the active-call banner, which is the one that isn't full-screen.
         is CallUiState.Ringing -> IncomingCall(s, onAnswer = { CarCalls.answer(context) }, onDecline = CarCalls::decline)
-        is CallUiState.Active -> ActiveCallBanner(s, modifier)
-        CallUiState.None -> {}
+        else -> {}
     }
 }
 
@@ -67,7 +65,7 @@ private fun IncomingCall(s: CallUiState.Ringing, onAnswer: () -> Unit, onDecline
             )
             Spacer(Modifier.height(16.dp))
             Text(
-                "Incoming call",
+                stringResource(R.string.call_incoming),
                 style = MaterialTheme.typography.titleMedium,
                 color = MaterialTheme.colorScheme.onSurfaceVariant,
             )
@@ -80,13 +78,13 @@ private fun IncomingCall(s: CallUiState.Ringing, onAnswer: () -> Unit, onDecline
             )
             Spacer(Modifier.height(56.dp))
             Row(horizontalArrangement = Arrangement.spacedBy(48.dp)) {
-                CallButton(Icons.Filled.Close, "Decline", MaterialTheme.colorScheme.error, enabled = s.canDecline, onClick = onDecline)
-                CallButton(Icons.Filled.Call, "Answer", MaterialTheme.colorScheme.primary, enabled = true, onClick = onAnswer)
+                CallButton(Icons.Filled.Close, stringResource(R.string.call_decline), MaterialTheme.colorScheme.error, enabled = s.canDecline, onClick = onDecline)
+                CallButton(Icons.Filled.Call, stringResource(R.string.call_answer), MaterialTheme.colorScheme.primary, enabled = true, onClick = onAnswer)
             }
             if (!s.canDecline) {
                 Spacer(Modifier.height(20.dp))
                 Text(
-                    "Already ringing out loud - answer here, or let it ring.",
+                    stringResource(R.string.call_ringing),
                     style = MaterialTheme.typography.bodySmall,
                     color = MaterialTheme.colorScheme.onSurfaceVariant,
                 )
@@ -110,25 +108,3 @@ private fun CallButton(icon: ImageVector, label: String, color: Color, enabled:
         Text(label, style = MaterialTheme.typography.labelLarge)
     }
 }
-
-@Composable
-private fun ActiveCallBanner(s: CallUiState.Active, modifier: Modifier = Modifier) {
-    Surface(
-        color = MaterialTheme.colorScheme.primaryContainer,
-        contentColor = MaterialTheme.colorScheme.onPrimaryContainer,
-        modifier = modifier.fillMaxWidth(),
-    ) {
-        Row(
-            Modifier.padding(horizontal = 20.dp, vertical = 10.dp),
-            horizontalArrangement = Arrangement.Center,
-        ) {
-            Icon(Icons.Filled.Call, contentDescription = null, modifier = Modifier.size(20.dp))
-            Spacer(Modifier.height(0.dp))
-            Text(
-                "  On a call" + (s.caller?.let { " with ${it.label}" } ?: ""),
-                style = MaterialTheme.typography.labelLarge,
-                fontWeight = FontWeight.SemiBold,
-            )
-        }
-    }
-}

gearslip/src/main/java/app/seb3thehacker/gearslip/car/CarAppStage.kt

@@ -1,5 +1,7 @@
 package app.seb3thehacker.gearslip.car
 
+import androidx.compose.ui.res.stringResource
+import app.seb3thehacker.gearslip.R
 import app.seb3thehacker.gearslip.car.theme.*
 import android.view.SurfaceHolder
 import android.view.SurfaceView
@@ -11,11 +13,14 @@ import androidx.compose.ui.input.pointer.PointerEventPass
 import androidx.compose.ui.input.pointer.util.VelocityTracker
 import kotlin.math.hypot
 import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.fillMaxHeight
+import androidx.compose.foundation.layout.width
 import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.height
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Surface
 import androidx.compose.material3.Text
@@ -34,8 +39,11 @@ import androidx.compose.ui.Modifier
 import androidx.compose.ui.geometry.Offset
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.input.pointer.pointerInput
+import androidx.compose.ui.layout.boundsInWindow
+import androidx.compose.ui.layout.onGloballyPositioned
 import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.unit.dp
+import androidx.compose.material.icons.filled.Close
 import androidx.compose.ui.viewinterop.AndroidView
 import app.seb3thehacker.gearslip.GearslipLog
 import app.seb3thehacker.gearslip.host.CarAppConnection
@@ -59,13 +67,40 @@ fun CarAppStage(
 ) {
     val template by connection.template.collectAsStateWithLifecycle()
 
+    val cover = remember { ChromeCover() }
+    val navBar = LocalNavBarInset.current
+
     Box(Modifier.fillMaxSize()) {
         // The app's own drawing goes underneath; everything else is the host's rendering of
         // the template it described, laid over the top.
-        if (status.surfaceRequested) {
-            AppSurface(connection, frame, template, Modifier.fillMaxSize())
+        androidx.compose.runtime.CompositionLocalProvider(LocalChromeCover provides cover, LocalCarAppConnection provides connection) {
+            if (status.surfaceRequested) {
+                AppSurface(connection, frame, template, Modifier.fillMaxSize())
+            }
+            // The docked player floats over one side of the map: the chrome keeps clear of it,
+            // and the app hears that side is covered, so its map centres in the rest.
+            val panel = LocalSidePanelInset.current
+            val panelAtStart = LocalCardsAtEnd.current
+            TemplateChrome(
+                template,
+                Modifier.fillMaxSize().padding(
+                    top = if (embedded) 0.dp else CHROME_BAR,
+                    bottom = navBar,
+                    start = if (panelAtStart) panel else 0.dp,
+                    end = if (panelAtStart) 0.dp else panel,
+                ),
+            )
+            if (panel > 0.dp) {
+                Box(
+                    Modifier
+                        .align(if (panelAtStart) Alignment.CenterStart else Alignment.CenterEnd)
+                        .fillMaxHeight()
+                        .width(panel)
+                        .covers("side-panel", if (panelAtStart) CoverEdge.START else CoverEdge.END),
+                )
+            }
+            BottomCover(navBar, Modifier.align(Alignment.BottomCenter))
         }
-        TemplateChrome(template, Modifier.fillMaxSize().padding(top = if (embedded) 0.dp else CHROME_BAR))
         if (!embedded) ChromeBar(status, onDisconnect, Modifier.align(Alignment.TopCenter))
     }
 }
@@ -84,14 +119,29 @@ private fun AppSurface(
     modifier: Modifier = Modifier,
 ) {
     var size by remember { mutableStateOf(0 to 0) }
+    var bounds by remember { mutableStateOf<androidx.compose.ui.geometry.Rect?>(null) }
+    val cover = LocalChromeCover.current
 
-    // The app lays its map out around whatever the host covers, so a template change moves the
-    // visible area even though the surface itself hasn't changed.
-    LaunchedEffect(template, size) {
-        val (width, height) = size
+    // The app lays its map out around whatever the host covers, so a template change or a card
+    // changing size moves the visible area even though the surface itself hasn't changed.
+    val (width, height) = size
+    val measured = bounds?.takeIf { width > 0 && height > 0 }?.let { cover?.visibleWithin(it, width, height) }
+    // The card column moves the map's centre but isn't taken out of the stable area: apps size
+    // their own overlays from it, and Vela's speedometer shrank to fit the strip right of the cards.
+    val cardsAtEnd = LocalCardsAtEnd.current
+    val cardEdge = cardEdge
+    val measuredStable = bounds?.takeIf { width > 0 && height > 0 }?.let { cover?.visibleWithin(it, width, height, skip = cardEdge) }
+    LaunchedEffect(template, size, measured, measuredStable, cardsAtEnd) {
         if (width > 0 && height > 0) {
-            val visible = visibleAreaFor(template, width, height)
-            connection.reportAreas(visible = visible, stable = visible)
+            val visible = visibleAreaFor(template, width, height, measured, cardsAtEnd)
+            // Waze seems to centre its car in the stable area rather than the visible one, so it
+            // gets the cards taken out of that too. Test: see whether its car moves out from under them.
+            val stable = if (!isContentTemplate(template) && connection.appPackage != "com.waze") {
+                visibleAreaFor(template, width, height, measuredStable, cardsAtEnd)
+            } else {
+                visible
+            }
+            connection.reportAreas(visible = visible, stable = stable)
         }
     }
 
@@ -101,7 +151,9 @@ private fun AppSurface(
     // new one on it before releasing the old: the old display's disconnect then takes the new one's
     // connection with it and the map freezes for good. The nav bar hiding for the search keyboard
     // and the lyrics pane opening both resize this area.
-    androidx.compose.foundation.layout.BoxWithConstraints(modifier) {
+    androidx.compose.foundation.layout.BoxWithConstraints(
+        modifier.onGloballyPositioned { bounds = it.boundsInWindow() },
+    ) {
         val epoch by connection.surfaceEpoch.collectAsState()
         androidx.compose.runtime.key(constraints.maxWidth, constraints.maxHeight, epoch) {
             SurfaceHost(connection, frame, onSize = { size = it }, Modifier.fillMaxSize())
@@ -189,28 +241,31 @@ private fun ChromeBar(
     onDisconnect: () -> Unit,
     modifier: Modifier = Modifier,
 ) {
+    // The app's name and a way out, nothing else: which template is showing, or whether the
+    // app has drawn yet, is for the log, not the driver.
     Surface(
-        color = Color.Black.copy(alpha = 0.55f),
-        contentColor = Color.White,
-        modifier = modifier.fillMaxWidth(),
+        color = MaterialTheme.colorScheme.surfaceContainer,
+        contentColor = MaterialTheme.colorScheme.onSurface,
+        modifier = modifier.fillMaxWidth().height(CHROME_BAR),
     ) {
         Row(
-            Modifier.padding(horizontal = 16.dp, vertical = 6.dp),
+            Modifier.padding(horizontal = 16.dp),
             verticalAlignment = Alignment.CenterVertically,
         ) {
-            Column(Modifier.weight(1f)) {
-                Text(
-                    status.app ?: "Car app",
-                    style = MaterialTheme.typography.titleSmall,
-                    fontWeight = FontWeight.SemiBold,
-                )
-                val detail = buildList {
-                    status.template?.let { add(it) }
-                    add(if (status.surfaceAttached) "drawing" else "waiting for the app")
-                }.joinToString(" - ")
-                Text(detail, style = MaterialTheme.typography.bodySmall)
-            }
-            GsButton(onClick = onDisconnect, tone = GsTone.Tonal) { Text("Stop") }
+            Text(
+                status.app ?: stringResource(R.string.stage_car_app),
+                style = MaterialTheme.typography.titleSmall,
+                fontWeight = FontWeight.SemiBold,
+                modifier = Modifier.weight(1f),
+            )
+            GsIconButton(
+                androidx.compose.material.icons.Icons.Filled.Close,
+                status.app?.let { stringResource(R.string.stage_close, it) } ?: stringResource(R.string.stage_close_app),
+                onDisconnect,
+                size = 36.dp,
+                iconSize = 20.dp,
+                shape = androidx.compose.foundation.shape.CircleShape,
+            )
         }
     }
 }
@@ -220,3 +275,6 @@ private val CHROME_BAR = 44.dp
 
 /** Slower than this when the finger lifts and it was a drag that stopped, not a fling. */
 private const val FLING_MIN_PX_S = 400f
+
+/** The app connection a template on screen belongs to: the map app's, or the one opened from the launcher. */
+internal val LocalCarAppConnection = androidx.compose.runtime.staticCompositionLocalOf { CarServices.nav }

gearslip/src/main/java/app/seb3thehacker/gearslip/car/CarApps.kt

@@ -1,5 +1,7 @@
 package app.seb3thehacker.gearslip.car
 
+import androidx.annotation.StringRes
+import app.seb3thehacker.gearslip.R
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.filled.Call
 import androidx.compose.material.icons.filled.Search
@@ -13,7 +15,9 @@ import app.seb3thehacker.gearslip.ProjectedContent
 /** One tile in the launcher and the screen it opens. */
 class CarApp(
     val id: String,
+    /** English, for matching what a driver says; [labelRes] is what the screen shows. */
     val label: String,
+    @param:StringRes val labelRes: Int,
     val icon: ImageVector,
     val content: @Composable () -> Unit,
 )
@@ -22,16 +26,16 @@ class CarApp(
 object CarApps {
 
     val all: List<CarApp> = listOf(
-        CarApp("web", "Web", Icons.Filled.Search) {
+        CarApp("web", "Browser", R.string.app_browser, Icons.Filled.Search) {
             WebApp(content = ProjectedContent.resolve(LocalContext.current))
         },
-        CarApp("phone", "Screen sharing", Icons.Filled.Share) {
+        CarApp("phone", "Screen sharing", R.string.app_screen_sharing, Icons.Filled.Share) {
             PhoneAppsScreen()
         },
-        CarApp("dialer", "Phone", Icons.Filled.Call) {
+        CarApp("dialer", "Phone", R.string.carset_phone, Icons.Filled.Call) {
             PhoneDialerScreen()
         },
-        CarApp("settings", "Settings", Icons.Filled.Settings) {
+        CarApp("settings", "Settings", R.string.settings_title, Icons.Filled.Settings) {
             CarSettingsScreen()
         },
     )

gearslip/src/main/java/app/seb3thehacker/gearslip/car/CarAssistant.kt

@@ -15,6 +15,7 @@ import androidx.core.content.ContextCompat
 import app.seb3thehacker.gearslip.call.CallUiState
 import app.seb3thehacker.gearslip.call.CarCalls
 import app.seb3thehacker.gearslip.speech.SpeechEngine
+import app.seb3thehacker.gearslip.speech.VoiceFocus
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.StateFlow
 
@@ -37,6 +38,8 @@ object CarAssistant {
         val heard: String = "",
         val reply: String = "",
         val missingPermission: Boolean = false,
+        /** False from the press until the microphone is actually open, so the overlay doesn't claim to listen early. */
+        val ready: Boolean = false,
     )
 
     private val _state = MutableStateFlow(State())
@@ -88,6 +91,7 @@ object CarAssistant {
         tts?.stop()
         _state.value = State(Phase.LISTENING)
         listenOnce(
+            onListening = { _state.value = _state.value.copy(ready = true) },
             onPartial = { text -> _state.value = _state.value.copy(heard = text) },
             onHeard = { _state.value = _state.value.copy(phase = Phase.THINKING) },
             onResult = { text ->
@@ -119,15 +123,19 @@ object CarAssistant {
             _state.value = _state.value.copy(phase = Phase.IDLE)
             return
         }
+        appContext?.let(VoiceFocus::acquire)
         engine.setOnUtteranceProgressListener(object : UtteranceProgressListener() {
             override fun onStart(utteranceId: String?) {}
             override fun onDone(utteranceId: String?) {
+                VoiceFocus.release()
                 _state.value = _state.value.copy(phase = Phase.IDLE)
             }
             @Deprecated("Deprecated in Java, no replacement on this API level")
             override fun onError(utteranceId: String?) {
+                VoiceFocus.release()
                 _state.value = _state.value.copy(phase = Phase.IDLE)
             }
+            override fun onStop(utteranceId: String?, interrupted: Boolean) { VoiceFocus.release() }
         })
         engine.speak(text, TextToSpeech.QUEUE_FLUSH, null, "gearslip-assistant")
     }
@@ -138,17 +146,19 @@ object CarAssistant {
      */
     fun say(text: String, onDone: () -> Unit) {
         val engine = tts
-        if (engine == null || !ttsReady || text.isBlank()) {
+        val context = appContext
+        if (engine == null || context == null || !ttsReady || text.isBlank()) {
             mainHandler.post(onDone)
             return
         }
+        VoiceFocus.acquire(context)
         engine.setOnUtteranceProgressListener(object : UtteranceProgressListener() {
             override fun onStart(utteranceId: String?) {}
-            override fun onDone(utteranceId: String?) { mainHandler.post(onDone) }
+            override fun onDone(utteranceId: String?) { VoiceFocus.release(); mainHandler.post(onDone) }
             @Deprecated("Deprecated in Java, no replacement on this API level")
-            override fun onError(utteranceId: String?) { mainHandler.post(onDone) }
+            override fun onError(utteranceId: String?) { VoiceFocus.release(); mainHandler.post(onDone) }
             // Stopped part way: whoever stopped it has already moved on.
-            override fun onStop(utteranceId: String?, interrupted: Boolean) {}
+            override fun onStop(utteranceId: String?, interrupted: Boolean) { VoiceFocus.release() }
         })
         engine.speak(text, TextToSpeech.QUEUE_FLUSH, null, "gearslip-say")
     }
@@ -167,15 +177,16 @@ object CarAssistant {
         onSpeaking: () -> Unit = {},
     ) {
         cancel()
-        listenOnce(onPartial, onHeard = {}, onResult, onError, cue, onSpeaking)
+        listenOnce(onPartial, onHeard = {}, onResult = onResult, onError = onError, cue = cue, onSpeaking = onSpeaking)
     }
 
     /**
-     * One phrase, through Gearslip's own [SpeechEngine]. The phone's recognizer is only a fallback
-     * for when the engine itself can't run, since plenty of phones (GrapheneOS among them) have none.
+     * One phrase, through Gearslip's own [SpeechEngine], or the phone's recognizer when the driver
+     * chose it in settings. Never the phone's on its own: on most phones that's Google's.
      */
     private fun listenOnce(
         onPartial: (String) -> Unit,
+        onListening: () -> Unit = {},
         onHeard: () -> Unit,
         onResult: (String) -> Unit,
         onError: (String) -> Unit,
@@ -183,24 +194,24 @@ object CarAssistant {
         onSpeaking: () -> Unit = {},
     ) {
         val context = appContext ?: return onError("Speech isn't ready yet.")
+        if (CarSettings.systemSpeech.value && SpeechRecognizer.isRecognitionAvailable(context)) {
+            return systemListen(context, onListening, onPartial, onHeard, onResult, onError)
+        }
         SpeechEngine.listen(
             context,
             cue = cue,
             onSpeaking = onSpeaking,
+            onPartial = onPartial,
+            onListening = onListening,
             onHeard = onHeard,
             onResult = onResult,
-            onError = { message ->
-                if (message == SpeechEngine.NOT_LOADED && SpeechRecognizer.isRecognitionAvailable(context)) {
-                    systemListen(context, onPartial, onHeard, onResult, onError)
-                } else {
-                    onError(message)
-                }
-            },
+            onError = onError,
         )
     }
 
     private fun systemListen(
         context: Context,
+        onListening: () -> Unit,
         onPartial: (String) -> Unit,
         onHeard: () -> Unit,
         onResult: (String) -> Unit,
@@ -209,7 +220,7 @@ object CarAssistant {
         val r = SpeechRecognizer.createSpeechRecognizer(context)
         recognizer = r
         r.setRecognitionListener(object : RecognitionListener {
-            override fun onReadyForSpeech(params: Bundle?) {}
+            override fun onReadyForSpeech(params: Bundle?) = onListening()
             override fun onBeginningOfSpeech() {}
             override fun onRmsChanged(rmsdB: Float) {}
             override fun onBufferReceived(buffer: ByteArray?) {}

gearslip/src/main/java/app/seb3thehacker/gearslip/car/CarBluetooth.kt

@@ -0,0 +1,257 @@
+package app.seb3thehacker.gearslip.car
+
+import androidx.annotation.StringRes
+import app.seb3thehacker.gearslip.R
+import android.Manifest
+import android.annotation.SuppressLint
+import android.bluetooth.BluetoothAdapter
+import android.bluetooth.BluetoothDevice
+import android.bluetooth.BluetoothManager
+import android.content.BroadcastReceiver
+import android.content.Context
+import android.content.Intent
+import android.content.IntentFilter
+import android.content.pm.PackageManager
+import android.os.Handler
+import android.os.Looper
+import androidx.car.app.CarToast
+import app.seb3thehacker.gearslip.AppSettings
+import app.seb3thehacker.gearslip.GearslipLog
+import app.seb3thehacker.gearslip.Protobuf
+import app.seb3thehacker.gearslip.ServiceDiscovery
+import app.seb3thehacker.gearslip.Wire
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import java.security.MessageDigest
+
+/**
+ * Pairs the phone with the car over Bluetooth the first time they meet, so calls (and music, when
+ * the driver chose Bluetooth audio) reach the car's speakers. Android Auto does this on its own;
+ * Gearslip asks first, on the car screen.
+ *
+ * The car names its Bluetooth address in its service list. When the driver taps Pair, Gearslip
+ * opens the car's Bluetooth channel and sends what Android Auto sends:
+ *
+ *   -> CHANNEL_OPEN_REQUEST                 <- CHANNEL_OPEN_RESPONSE
+ *   -> PairingRequest { phone_address, method }
+ *   <- PairingResponse { status, already_paired }
+ *
+ * then starts pairing from the phone. Two things Android Auto has that Gearslip can't: the
+ * phone's own Bluetooth address (apps get a placeholder), and confirming the pairing code without
+ * asking. So a car may turn the request down, and the phone always shows its pairing dialog. The
+ * channel stays closed unless the driver taps Pair: every new channel is a risk to cars that work.
+ */
+object CarBluetooth {
+
+    enum class Prompt { NONE, ASK, PAIRING }
+
+    private val _prompt = MutableStateFlow(Prompt.NONE)
+    val prompt: StateFlow<Prompt> = _prompt
+
+    private val log = GearslipLog.tagged("bluetooth")
+    private val main = Handler(Looper.getMainLooper())
+    private var appContext: Context? = null
+
+    /** This session's car: its channel, and how to open and write to it. */
+    private class Car(
+        val service: ServiceDiscovery.BluetoothService,
+        val open: () -> Unit,
+        val send: (messageId: Int, body: ByteArray) -> Unit,
+    )
+
+    @Volatile private var car: Car? = null
+    @Volatile private var bondStarted = false
+    /** From the Pair tap until it succeeds or fails, whether or not the card still shows. */
+    @Volatile private var pairing = false
+    private var receiver: BroadcastReceiver? = null
+
+    /** The car's Bluetooth address, when it named one in its service list. */
+    val carAddress: String? get() = car?.service?.carAddress
+
+    /** The car's Bluetooth channel once the driver has asked to pair, -1 otherwise. */
+    val channelId: Int get() = car?.takeIf { pairing }?.service?.serviceId ?: -1
+
+    fun init(context: Context) {
+        appContext = context.applicationContext
+    }
+
+    /** Called once the car lists its services. Asks on the car screen only if there's pairing to do. */
+    fun onCarConnected(
+        service: ServiceDiscovery.BluetoothService,
+        open: () -> Unit,
+        send: (messageId: Int, body: ByteArray) -> Unit,
+    ) {
+        car = Car(service, open, send)
+        bondStarted = false
+        log.i("the car offers Bluetooth pairing, methods=${service.pairingMethods}")
+        val device = device() ?: return
+        when {
+            device.bondState == BluetoothDevice.BOND_BONDED -> log.i("already paired with this car")
+            declined(service.carAddress) -> log.i("not paired, and the driver said not now for this car")
+            else -> _prompt.value = Prompt.ASK
+        }
+    }
+
+    fun onCarDisconnected() {
+        car = null
+        pairing = false
+        main.post {
+            stopWatching()
+            _prompt.value = Prompt.NONE
+        }
+    }
+
+    /** The driver tapped Pair. */
+    fun pair() {
+        val c = car ?: return
+        val device = device() ?: return
+        pairing = true
+        _prompt.value = Prompt.PAIRING
+        watchBonding(device)
+        c.open()
+        log.i("-> ChannelOpenRequest on channel ${c.service.serviceId}")
+        // If the car never answers on its channel, pair from the phone anyway.
+        main.postDelayed({ startBond("the car didn't answer the pairing request") }, CAR_REPLY_WAIT_MS)
+        main.postDelayed({
+            if (pairing) finish(R.string.bt_pair_unfinished)
+        }, GIVE_UP_MS)
+    }
+
+    /** The driver tapped Not now: this car isn't asked about again. */
+    fun notNow() {
+        car?.service?.carAddress?.let { address ->
+            val context = appContext ?: return@let
+            val list = AppSettings.getString(context, KEY_DECLINED, "").split(",").filter { it.isNotEmpty() }
+            AppSettings.putString(context, KEY_DECLINED, (list + hash(address)).distinct().joinToString(","))
+        }
+        _prompt.value = Prompt.NONE
+    }
+
+    /** Hides the pairing card. The phone's own dialog carries on. */
+    fun hide() {
+        _prompt.value = Prompt.NONE
+    }
+
+    fun onMessage(messageId: Int, body: ByteArray) {
+        val c = car ?: return
+        when (messageId) {
+            MSG_CHANNEL_OPEN_RESPONSE -> {
+                val status = Protobuf.readInt32Field(body, 1) ?: 0
+                log.i("<- ChannelOpenResponse: status=$status")
+                if (status != 0) {
+                    main.post { startBond("the car wouldn't open its Bluetooth channel") }
+                    return
+                }
+                val method = c.service.pairingMethods.firstOrNull { it == METHOD_NUMERIC_COMPARISON }
+                    ?: c.service.pairingMethods.firstOrNull() ?: METHOD_NUMERIC_COMPARISON
+                c.send(
+                    MSG_PAIRING_REQUEST,
+                    Protobuf.stringField(1, phoneAddress()) + Protobuf.varintField(2, method.toLong()),
+                )
+                log.i("-> PairingRequest(method=$method)")
+            }
+            MSG_PAIRING_RESPONSE -> {
+                val fields = Wire.fields(body)
+                log.i("<- PairingResponse status=${Wire.varint(fields, 1)} already_paired=${Wire.varint(fields, 2) == 1L}")
+                // Some cars start pairing themselves once they answer; give them a moment first.
+                main.postDelayed({ startBond("the car answered") }, CAR_BOND_WAIT_MS)
+            }
+            // Carries the pairing code. Android shows it to the driver, so it stays out of the log.
+            MSG_AUTHENTICATION_DATA -> log.i("<- AuthenticationData (${body.size} bytes)")
+            else -> log.i("<- unhandled message id=$messageId (${body.size} bytes)")
+        }
+    }
+
+    @SuppressLint("MissingPermission")
+    private fun startBond(why: String) {
+        if (bondStarted || !pairing) return
+        val device = device() ?: return
+        if (device.bondState != BluetoothDevice.BOND_NONE) return
+        bondStarted = true
+        val started = runCatching { device.createBond() }.getOrDefault(false)
+        log.i("pairing from the phone ($why): ${if (started) "started" else "refused"}")
+        if (!started) finish(R.string.bt_pair_not_started)
+    }
+
+    private fun watchBonding(device: BluetoothDevice) {
+        val context = appContext ?: return
+        stopWatching()
+        val r = object : BroadcastReceiver() {
+            @Suppress("DEPRECATION")
+            override fun onReceive(context: Context, intent: Intent) {
+                val changed = intent.getParcelableExtra<BluetoothDevice>(BluetoothDevice.EXTRA_DEVICE) ?: return
+                if (changed.address != device.address) return
+                val state = intent.getIntExtra(BluetoothDevice.EXTRA_BOND_STATE, BluetoothDevice.BOND_NONE)
+                val previous = intent.getIntExtra(BluetoothDevice.EXTRA_PREVIOUS_BOND_STATE, BluetoothDevice.BOND_NONE)
+                log.i("bond state $previous -> $state")
+                when {
+                    state == BluetoothDevice.BOND_BONDING -> bondStarted = true
+                    state == BluetoothDevice.BOND_BONDED -> finish(R.string.bt_paired)
+                    previous == BluetoothDevice.BOND_BONDING -> finish(R.string.bt_pair_unfinished)
+                }
+            }
+        }
+        context.registerReceiver(r, IntentFilter(BluetoothDevice.ACTION_BOND_STATE_CHANGED), Context.RECEIVER_EXPORTED)
+        receiver = r
+    }
+
+    private fun finish(@StringRes message: Int) {
+        pairing = false
+        stopWatching()
+        main.removeCallbacksAndMessages(null)
+        _prompt.value = Prompt.NONE
+        CarToasts.show(this, appContext?.getString(message) ?: return, CarToast.LENGTH_LONG)
+    }
+
+    private fun stopWatching() {
+        val r = receiver ?: return
+        receiver = null
+        runCatching { appContext?.unregisterReceiver(r) }
+    }
+
+    /** The car as a Bluetooth device, or null (and logged) when Gearslip can't reach Bluetooth. */
+    private fun device(): BluetoothDevice? {
+        val context = appContext ?: return null
+        val address = car?.service?.carAddress ?: return null
+        if (context.checkSelfPermission(Manifest.permission.BLUETOOTH_CONNECT) != PackageManager.PERMISSION_GRANTED) {
+            log.i("can't check pairing: the Bluetooth permission isn't granted")
+            return null
+        }
+        val adapter = context.getSystemService(BluetoothManager::class.java)?.adapter
+        if (adapter == null || !adapter.isEnabled) {
+            log.i("can't check pairing: Bluetooth is off")
+            return null
+        }
+        if (!BluetoothAdapter.checkBluetoothAddress(address)) {
+            log.w("the car sent an address that isn't one")
+            return null
+        }
+        return adapter.getRemoteDevice(address)
+    }
+
+    /** Apps get 02:00:00:00:00:00 here, not the real address. Sent anyway, as the field is required. */
+    @SuppressLint("MissingPermission", "HardwareIds")
+    private fun phoneAddress(): String =
+        runCatching { appContext?.getSystemService(BluetoothManager::class.java)?.adapter?.address }.getOrNull()
+            ?: "02:00:00:00:00:00"
+
+    private fun declined(address: String): Boolean {
+        val context = appContext ?: return false
+        return hash(address) in AppSettings.getString(context, KEY_DECLINED, "").split(",")
+    }
+
+    /** Settings keep a short hash, not the car's address. */
+    private fun hash(address: String): String =
+        MessageDigest.getInstance("SHA-256").digest(address.uppercase().toByteArray())
+            .take(8).joinToString("") { "%02x".format(it) }
+
+    private const val KEY_DECLINED = "bluetooth_pair_declined"
+    private const val CAR_REPLY_WAIT_MS = 5_000L
+    private const val CAR_BOND_WAIT_MS = 3_000L
+    private const val GIVE_UP_MS = 90_000L
+    private const val METHOD_NUMERIC_COMPARISON = 2
+    private const val MSG_CHANNEL_OPEN_RESPONSE = 8
+    private const val MSG_PAIRING_REQUEST = 32769
+    private const val MSG_PAIRING_RESPONSE = 32770
+    private const val MSG_AUTHENTICATION_DATA = 32771
+}

gearslip/src/main/java/app/seb3thehacker/gearslip/car/CarDashboardScreen.kt

@@ -1,5 +1,7 @@
 package app.seb3thehacker.gearslip.car
 
+import androidx.compose.ui.res.stringResource
+import app.seb3thehacker.gearslip.R
 import android.Manifest
 import android.content.Context
 import android.content.pm.PackageManager
@@ -60,7 +62,7 @@ fun CarDashboardScreen() {
             .padding(horizontal = 24.dp, vertical = 16.dp),
         verticalArrangement = Arrangement.spacedBy(24.dp),
     ) {
-        Text("Today", style = MaterialTheme.typography.headlineMedium, fontWeight = FontWeight.Bold)
+        ScreenHeader(stringResource(R.string.dash_today))
         WeatherCard(context)
         AgendaCard(context)
         NotificationsSection()
@@ -84,9 +86,9 @@ private fun WeatherCard(context: Context) {
             horizontalArrangement = Arrangement.spacedBy(16.dp),
         ) {
             when (val s = state) {
-                WeatherState.Loading -> Text("Getting weather…", style = MaterialTheme.typography.bodyLarge)
+                WeatherState.Loading -> Text(stringResource(R.string.dash_getting_weather), style = MaterialTheme.typography.bodyLarge)
                 is WeatherState.Unavailable -> Text(
-                    s.reason, style = MaterialTheme.typography.bodyLarge,
+                    stringResource(s.reason), style = MaterialTheme.typography.bodyLarge,
                     color = MaterialTheme.colorScheme.onSurfaceVariant,
                 )
                 is WeatherState.Ready -> {
@@ -94,7 +96,7 @@ private fun WeatherCard(context: Context) {
                     WeatherIcon(w.code, w.isDay, size = 44.dp)
                     Column {
                         Text(
-                            "${w.temp}${w.tempUnit}  ·  ${Weather.describe(w.code)}",
+                            "${w.temp}${w.tempUnit}  ·  ${Weather.condition(w.code)}",
                             style = MaterialTheme.typography.titleLarge, fontWeight = FontWeight.SemiBold,
                         )
                         Text(w.place, style = MaterialTheme.typography.bodyMedium, color = MaterialTheme.colorScheme.onSurfaceVariant)
@@ -112,12 +114,12 @@ private fun AgendaCard(context: Context) {
     }
 
     Column(verticalArrangement = Arrangement.spacedBy(12.dp)) {
-        Text("Coming up", style = MaterialTheme.typography.titleMedium, color = MaterialTheme.colorScheme.primary)
+        Text(stringResource(R.string.dash_coming_up), style = MaterialTheme.typography.titleMedium, color = MaterialTheme.colorScheme.primary)
         val list = events
         when {
-            list == null -> Text("Loading calendar…", style = MaterialTheme.typography.bodyMedium)
+            list == null -> Text(stringResource(R.string.dash_loading_calendar), style = MaterialTheme.typography.bodyMedium)
             list.isEmpty() -> Text(
-                "Nothing in the next week.",
+                stringResource(R.string.dash_nothing_week),
                 style = MaterialTheme.typography.bodyMedium,
                 color = MaterialTheme.colorScheme.onSurfaceVariant,
             )
@@ -135,7 +137,7 @@ private fun EventRow(event: AgendaEvent) {
             verticalAlignment = Alignment.CenterVertically,
         ) {
             Text(
-                eventWhen(event),
+                eventWhen(event, stringResource(R.string.dash_all_day)),
                 style = MaterialTheme.typography.bodyLarge,
                 fontWeight = FontWeight.SemiBold,
             )
@@ -149,14 +151,14 @@ private fun EventRow(event: AgendaEvent) {
     }
 }
 
-/** "Today" events show just a time; later days get a weekday so a week's list stays readable. */
-private fun eventWhen(event: AgendaEvent): String {
+/** stringResource(R.string.dash_today) events show just a time; later days get a weekday so a week's list stays readable. */
+private fun eventWhen(event: AgendaEvent, allDay: String): String {
     val zone = if (event.allDay) TimeZone.getTimeZone("UTC") else TimeZone.getDefault()
     val start = Calendar.getInstance(zone).apply { timeInMillis = event.startMillis }
     val today = Calendar.getInstance()
     val sameDay = start.get(Calendar.YEAR) == today.get(Calendar.YEAR) &&
         start.get(Calendar.DAY_OF_YEAR) == today.get(Calendar.DAY_OF_YEAR)
-    val time = if (event.allDay) "All day" else DateFormat.getTimeInstance(DateFormat.SHORT).format(Date(event.startMillis))
+    val time = if (event.allDay) allDay else DateFormat.getTimeInstance(DateFormat.SHORT).format(Date(event.startMillis))
     if (sameDay || (event.allDay && start.before(today))) return time
     return SimpleDateFormat("EEE", Locale.getDefault()).apply { timeZone = zone }.format(Date(event.startMillis)) + " " + time
 }

gearslip/src/main/java/app/seb3thehacker/gearslip/car/CarData.kt

@@ -0,0 +1,110 @@
+package app.seb3thehacker.gearslip.car
+
+import app.seb3thehacker.gearslip.Wire
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+
+/**
+ * The car's sensors, read into real values for the car apps that ask (a map's speed, an EV app's
+ * range). [CarSensors] keeps the raw readings for the Vehicle data screen; this keeps the few with
+ * a known meaning, decoded the way Android Auto's SensorBatch scales them:
+ *
+ *   gps_location = 1 { latitude_e7 = 2; longitude_e7 = 3; accuracy_e3 = 4; altitude_e2 = 5;
+ *                      speed_e3 = 6; bearing_e6 = 7 }
+ *   compass = 2 { bearing_e6 = 1 }      speed = 3 { speed_e3 = 1 }  (metres per second)
+ *   odometer = 5 { kms_e1 = 1 }         fuel = 6 { level = 1 (percent); range = 2 (km); low = 3 }
+ *
+ * Each value is null until the car first sends it, and the whole lot clears when it disconnects.
+ */
+object CarData {
+
+    class Location(
+        val latitude: Double,
+        val longitude: Double,
+        val accuracyMeters: Float?,
+        val altitudeMeters: Double?,
+        val speedMps: Float?,
+        val bearingDegrees: Float?,
+    )
+
+    data class Snapshot(
+        val speedMps: Float? = null,
+        val odometerKm: Float? = null,
+        val fuelPercent: Int? = null,
+        val rangeKm: Int? = null,
+        val fuelLow: Boolean? = null,
+        val compassDegrees: Float? = null,
+        val location: Location? = null,
+        /** When each kind last changed, by its SensorBatch field number. */
+        val updatedAt: Map<Int, Long> = emptyMap(),
+    )
+
+    /** What the car says it is, from its service discovery: model and year. It names no maker. */
+    class Model(val name: String, val year: Int?)
+
+    private val flow = MutableStateFlow(Snapshot())
+    val state: StateFlow<Snapshot> = flow
+
+    @Volatile var model: Model? = null
+        private set
+
+    fun onModel(name: String, year: String) {
+        model = name.takeIf { it.isNotBlank() }?.let { Model(it, year.toIntOrNull()?.takeIf { y -> y > 0 }) }
+    }
+
+    fun onEvent(body: ByteArray) {
+        val now = System.currentTimeMillis()
+        val batch = Wire.fields(body)
+        var s = flow.value
+        val touched = HashSet<Int>()
+        // Each kind may come several times in one batch: the last is the newest.
+        Wire.allBytes(batch, LOCATION).lastOrNull()?.let { bytes ->
+            val f = Wire.fields(bytes)
+            val lat = Wire.varint(f, 2)?.toInt()
+            val lon = Wire.varint(f, 3)?.toInt()
+            if (lat != null && lon != null) {
+                s = s.copy(
+                    location = Location(
+                        lat / 1e7, lon / 1e7,
+                        Wire.varint(f, 4)?.let { it / 1e3f },
+                        Wire.varint(f, 5)?.let { it.toInt() / 1e2 },
+                        Wire.varint(f, 6)?.let { it.toInt() / 1e3f },
+                        Wire.varint(f, 7)?.let { it.toInt() / 1e6f },
+                    ),
+                )
+                touched += LOCATION
+            }
+        }
+        Wire.allBytes(batch, COMPASS).lastOrNull()?.let { bytes ->
+            Wire.varint(Wire.fields(bytes), 1)?.let { s = s.copy(compassDegrees = it.toInt() / 1e6f); touched += COMPASS }
+        }
+        Wire.allBytes(batch, SPEED).lastOrNull()?.let { bytes ->
+            Wire.varint(Wire.fields(bytes), 1)?.let { s = s.copy(speedMps = it.toInt() / 1e3f); touched += SPEED }
+        }
+        Wire.allBytes(batch, ODOMETER).lastOrNull()?.let { bytes ->
+            Wire.varint(Wire.fields(bytes), 1)?.let { s = s.copy(odometerKm = it.toInt() / 10f); touched += ODOMETER }
+        }
+        Wire.allBytes(batch, FUEL).lastOrNull()?.let { bytes ->
+            val f = Wire.fields(bytes)
+            s = s.copy(
+                fuelPercent = Wire.varint(f, 1)?.toInt() ?: s.fuelPercent,
+                rangeKm = Wire.varint(f, 2)?.toInt() ?: s.rangeKm,
+                fuelLow = Wire.varint(f, 3)?.let { it != 0L } ?: s.fuelLow,
+            )
+            touched += FUEL
+        }
+        if (touched.isEmpty()) return
+        flow.value = s.copy(updatedAt = s.updatedAt + touched.associateWith { now })
+    }
+
+    fun clear() {
+        flow.value = Snapshot()
+        model = null
+    }
+
+    const val LOCATION = 1
+    const val COMPASS = 2
+    const val SPEED = 3
+    const val ODOMETER = 5
+    const val FUEL = 6
+}

gearslip/src/main/java/app/seb3thehacker/gearslip/car/CarEnvironment.kt

@@ -64,7 +64,9 @@ object CarEnvironment {
     }
 
     @Volatile private var sensorNight: Boolean? = null
-    private var appContext: Context? = null
+    /** Set once the car UI starts; the cluster screen draws with it too. */
+    var appContext: Context? = null
+        private set
     private var running = false
 
     private val handler = Handler(Looper.getMainLooper())

gearslip/src/main/java/app/seb3thehacker/gearslip/car/CarFullscreen.kt

@@ -0,0 +1,51 @@
+package app.seb3thehacker.gearslip.car
+
+import android.os.SystemClock
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.setValue
+
+/**
+ * Full screen for the screen that asks for it (the browser, or a video in it): no header and no
+ * nav bar. A swipe in from the top or bottom edge brings the nav bar back for a few seconds,
+ * with a button to leave full screen; [revealed] says when.
+ */
+object CarFullscreen {
+
+    var active by mutableStateOf(false)
+        private set
+
+    var revealed by mutableStateOf(false)
+        private set
+
+    private var lastTouch = 0L
+
+    fun enter() {
+        active = true
+        revealed = false
+    }
+
+    fun exit() {
+        active = false
+        revealed = false
+    }
+
+    /** A swipe in from an edge: show the nav bar and the way out. */
+    fun reveal() {
+        if (!active) return
+        lastTouch = SystemClock.uptimeMillis()
+        revealed = true
+    }
+
+    /** Any touch keeps a revealed bar up, so it doesn't slide away under a finger reaching for it. */
+    fun touch() {
+        if (revealed) lastTouch = SystemClock.uptimeMillis()
+    }
+
+    /** Called on a timer; hides the bar again after [REVEAL_MS] without a touch. */
+    fun tick() {
+        if (revealed && SystemClock.uptimeMillis() - lastTouch >= REVEAL_MS) revealed = false
+    }
+
+    private const val REVEAL_MS = 4_000L
+}

gearslip/src/main/java/app/seb3thehacker/gearslip/car/CarHomeScreen.kt

@@ -1,5 +1,6 @@
 package app.seb3thehacker.gearslip.car
 
+import androidx.compose.ui.res.stringResource
 import app.seb3thehacker.gearslip.car.theme.*
 import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Box
@@ -12,6 +13,8 @@ import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.height
 import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.layout.width
+import app.seb3thehacker.gearslip.car.theme.gsPanelShadow
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.filled.Close
 import androidx.compose.material.icons.filled.PlayArrow
@@ -64,7 +67,9 @@ import app.seb3thehacker.gearslip.media.NowPlaying
 import kotlinx.coroutines.launch
 
 /**
- * The home screen: the map on the left, the docked player on the right when asked for.
+ * The home screen: the map, with the docked player floating over one side of it when asked for.
+ * With the player on the left, the map app's cards move to the map's far edge, so the player, the
+ * map and the cards each keep their own space.
  *
  * The map is whatever navigation app was used last, brought back on its own. The player sits in
  * the nav bar's pill until its dock button moves it here; the column closes itself back to a
@@ -93,27 +98,57 @@ fun CarHome() {
         if (onHome) seenHome[0] = true
     }
     val splitScreen = phase == CarMedia.Phase.READY && now.isActive && panel != SidePanel.NONE
+    val playerLeft by CarSettings.playerLeft.collectAsStateWithLifecycle()
+    // What the card showed last, so it still has something to show while it slides away.
+    val shown = remember { androidx.compose.runtime.mutableStateOf(SidePanel.CONTROLS) }
+    if (panel != SidePanel.NONE) shown.value = panel
 
-    // No outer padding on any side, split screen or not - only the gap between the two panes
-    // when the player is sharing the screen with the map.
-    Row(
-        Modifier.fillMaxSize(),
-        horizontalArrangement = Arrangement.spacedBy(8.dp),
-    ) {
-        Box(
-            Modifier
-                .weight(if (splitScreen) 2.1f else 1f)
-                .fillMaxHeight(),
+    // The map runs edge to edge underneath; the player floats over one side of it as a card, with
+    // a gap all round. The map's surface keeps its size when the card comes and goes, so the app
+    // only re-centres its map instead of drawing onto a new surface.
+    BoxWithConstraints(Modifier.fillMaxSize()) {
+        val column = (maxWidth / PLAYER_SHARE).coerceIn(PLAYER_MIN_WIDTH, PLAYER_MAX_WIDTH)
+        androidx.compose.runtime.CompositionLocalProvider(
+            LocalCardsAtEnd provides (splitScreen && playerLeft),
+            LocalSidePanelInset provides if (splitScreen) column else 0.dp,
         ) {
             MapPane(navStatus, frame)
         }
-        if (splitScreen) {
-            val side = Modifier.weight(1f).fillMaxHeight()
-            if (panel == SidePanel.LYRICS) SideLyrics(now, side) else DockedPlayer(now, side)
+        androidx.compose.animation.AnimatedVisibility(
+            splitScreen,
+            Modifier.align(if (playerLeft) Alignment.CenterStart else Alignment.CenterEnd),
+            enter = androidx.compose.animation.slideInHorizontally(tween(220)) { if (playerLeft) -it / 3 else it / 3 } +
+                androidx.compose.animation.fadeIn(tween(180)),
+            exit = androidx.compose.animation.slideOutHorizontally(tween(180)) { if (playerLeft) -it / 3 else it / 3 } +
+                androidx.compose.animation.fadeOut(tween(140)),
+        ) {
+            val card = Modifier
+                .width(column)
+                .fillMaxHeight()
+                .padding(
+                    start = if (playerLeft) CARD_GAP else 0.dp,
+                    end = if (playerLeft) 0.dp else CARD_GAP,
+                    top = CARD_GAP,
+                    bottom = LocalNavBarInset.current + CARD_GAP,
+                )
+            if (shown.value == SidePanel.LYRICS) SideLyrics(now, card) else DockedPlayer(now, card)
         }
     }
 }
 
+/** The player takes one part in this many of the screen's width. */
+private const val PLAYER_SHARE = 3.6f
+
+/** Narrow enough to leave the map most of a small screen; on a wide one the map gets the extra room. */
+private val PLAYER_MIN_WIDTH = 240.dp
+private val PLAYER_MAX_WIDTH = 340.dp
+
+/** Between the player card and the screen's edges, and the map's own cards beside it. */
+private val CARD_GAP = 12.dp
+
+/** The card's corners: rounder than a button's, as the map app's own cards are. */
+private val CARD_SHAPE = RoundedCornerShape(24.dp)
+
 @Composable
 private fun MapPane(status: CarAppConnection.Status, frame: CarEnvironment.Frame) {
     val navigator = LocalCarNavigator.current
@@ -123,8 +158,11 @@ private fun MapPane(status: CarAppConnection.Status, frame: CarEnvironment.Frame
     }
 
     Column(
-        Modifier.fillMaxSize().padding(24.dp),
-        verticalArrangement = Arrangement.Center,
+        Modifier.fillMaxSize().padding(
+            start = if (LocalCardsAtEnd.current) LocalSidePanelInset.current else 0.dp,
+            end = if (LocalCardsAtEnd.current) 0.dp else LocalSidePanelInset.current,
+        ).padding(24.dp),
+        verticalArrangement = Arrangement.spacedBy(10.dp, Alignment.CenterVertically),
         horizontalAlignment = Alignment.CenterHorizontally,
     ) {
         val hasLast = CarSettings.lastNav.value != null
@@ -132,18 +170,19 @@ private fun MapPane(status: CarAppConnection.Status, frame: CarEnvironment.Frame
         val scope = androidx.compose.runtime.rememberCoroutineScope()
         when (status.phase) {
             CarAppConnection.Phase.BINDING, CarAppConnection.Phase.HANDSHAKE ->
-                Text("Starting ${status.app ?: "the map"}…", style = MaterialTheme.typography.titleMedium)
+                Text(status.app?.let { stringResource(R.string.home_starting, it) } ?: stringResource(R.string.home_starting_map), style = MaterialTheme.typography.titleMedium)
             CarAppConnection.Phase.REJECTED, CarAppConnection.Phase.FAILED -> {
-                Text("${status.app ?: "The map app"} would not start.", style = MaterialTheme.typography.titleMedium)
+                Text(status.app?.let { stringResource(R.string.home_failed, it) } ?: stringResource(R.string.home_failed_map), style = MaterialTheme.typography.titleMedium)
                 status.detail?.let { Text(it, style = MaterialTheme.typography.bodyMedium, color = MaterialTheme.colorScheme.onSurfaceVariant) }
-                GsButton(onClick = navigator::apps, tone = GsTone.Tonal) { Text("Choose another app") }
+                Spacer(Modifier.height(8.dp))
+                StatusButton(stringResource(R.string.home_choose_app), GsTone.Primary, navigator::apps)
             }
             else -> if (!hasNavApps) {
                 // Nothing to auto-select and nothing to pick from Car apps either - this is the
                 // only case worth a distinct screen, since every other IDLE case resolves itself.
-                Text("No mapping apps found.", style = MaterialTheme.typography.titleMedium)
+                Text(stringResource(R.string.home_no_maps), style = MaterialTheme.typography.titleMedium)
                 Text(
-                    "Install a navigation app that supports Android Auto and it will start here on its own.",
+                    stringResource(R.string.home_no_maps_body),
                     style = MaterialTheme.typography.bodyMedium,
                     color = MaterialTheme.colorScheme.onSurfaceVariant,
                 )
@@ -151,9 +190,18 @@ private fun MapPane(status: CarAppConnection.Status, frame: CarEnvironment.Frame
                 // IDLE with a last app on record means the driver stopped it themselves - it will
                 // not come back on its own, so the screen must offer a way to bring it back rather
                 // than sit on a "starting" message that never resolves.
-                Text("Map stopped.", style = MaterialTheme.typography.titleMedium)
-                GsButton(onClick = { scope.launch { CarServices.reconnectNav(frame) } }, tone = GsTone.Tonal) { Text("Reopen") }
-                GsButton(onClick = { navigator.apps() }, tone = GsTone.Tonal) { Text("Car apps") }
+                Text(stringResource(R.string.home_map_stopped), style = MaterialTheme.typography.headlineSmall, fontWeight = FontWeight.Bold)
+                Text(
+                    stringResource(R.string.home_map_stopped_body),
+                    style = MaterialTheme.typography.bodyLarge,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant,
+                )
+                Spacer(Modifier.height(8.dp))
+                // Side by side, the same size, the likely one lit: one clear choice, not a stack.
+                Row(horizontalArrangement = Arrangement.spacedBy(14.dp)) {
+                    StatusButton(stringResource(R.string.home_reopen_map), GsTone.Primary) { scope.launch { CarServices.reconnectNav(frame) } }
+                    StatusButton(stringResource(R.string.home_car_apps), GsTone.Tonal) { navigator.apps() }
+                }
             } else {
                 // Autostart is still picking one - a navigation app is installed, so this resolves
                 // to a "Starting..." state itself, in the next frame or two.
@@ -162,9 +210,17 @@ private fun MapPane(status: CarAppConnection.Status, frame: CarEnvironment.Frame
     }
 }
 
+/** A big, even button for the map pane's few choices. */
+@Composable
+private fun StatusButton(label: String, tone: GsTone, onClick: () -> Unit) {
+    GsButton(onClick = onClick, tone = tone, modifier = Modifier.width(220.dp).height(64.dp)) {
+        Text(label, style = MaterialTheme.typography.titleMedium, fontWeight = FontWeight.SemiBold)
+    }
+}
+
 /**
- * The player, docked beside the map: art, title, progress, transport, then like, shuffle, repeat
- * and lyrics. While it's here the nav bar's pill steps aside on Home, so the controls never show
+ * The player, docked beside the map: the art as large as it fits, then title, progress, transport,
+ * and like, shuffle, repeat and lyrics along the bottom. While it's here the nav bar's pill steps aside on Home, so the controls never show
  * twice. The X sends it back to the nav bar.
  */
 @Composable
@@ -175,28 +231,31 @@ private fun DockedPlayer(now: NowPlaying, modifier: Modifier) {
     val scheme = MaterialTheme.colorScheme
     val art by produceState(now.art, now.art, now.artUri) { value = now.art ?: MediaArt.load(context, now.artUri) }
 
-    Surface(modifier = modifier, color = rememberArtColor(art, MaterialTheme.colorScheme.surfaceVariant)) {
-        BoxWithConstraints(Modifier.fillMaxSize().padding(12.dp)) {
-            // Whatever height the controls below leave over, so the art grows on a taller
-            // screen and shrinks rather than pushing the buttons off a short one.
-            val artSize = minOf(maxWidth - 44.dp, maxHeight - 250.dp).coerceIn(56.dp, 200.dp)
+    // The theme's surface, with a faint wash of the cover's colours behind the top of it. A solid
+    // slab of album colour beside the map fought it for attention; this only hints at the song.
+    Surface(modifier = modifier.gsPanelShadow(CARD_SHAPE), shape = CARD_SHAPE, color = scheme.surfaceContainer) {
+        AlbumGlow(art, Modifier.fillMaxSize())
+        Box(Modifier.fillMaxSize().padding(12.dp)) {
             Column(Modifier.fillMaxSize(), horizontalAlignment = Alignment.CenterHorizontally) {
-                Box(Modifier.fillMaxWidth()) {
+                // The cover gets everything the controls leave, as big a square as fits, sitting
+                // right on top of the title; the controls stay pinned to the bottom.
+                BoxWithConstraints(Modifier.weight(1f).fillMaxWidth(), contentAlignment = Alignment.BottomCenter) {
+                    val artSize = minOf(maxWidth, maxHeight).coerceAtLeast(0.dp)
                     // Art opens the full media screen, same as on the pill.
+                    val coverShape = RoundedCornerShape(16.dp)
                     Box(
                         Modifier
-                            .align(Alignment.TopCenter)
                             .size(artSize)
-                            .clip(RoundedCornerShape(12.dp))
+                            .gsPanelShadow(coverShape)
+                            .clip(coverShape)
                             .background(scheme.surface)
                             .clickable { navigator.media() },
                     ) {
-                        art?.let { Image(it.asImageBitmap(), null, Modifier.fillMaxSize(), contentScale = ContentScale.Crop) }
+                        // A new song's cover fades in over the old one instead of cutting to it.
+                        androidx.compose.animation.Crossfade(art, animationSpec = tween(350), label = "cover") { shown ->
+                            shown?.let { Image(it.asImageBitmap(), null, Modifier.fillMaxSize(), contentScale = ContentScale.Crop) }
+                        }
                     }
-                    GsIconButton(
-                        Icons.Filled.Close, "Back to the nav bar", navigator::closeSidePanel,
-                        Modifier.align(Alignment.TopEnd), size = 36.dp, iconSize = 20.dp,
-                    )
                 }
                 Spacer(Modifier.height(10.dp))
                 Text(
@@ -212,46 +271,53 @@ private fun DockedPlayer(now: NowPlaying, modifier: Modifier) {
                 } else {
                     Spacer(Modifier.height(10.dp))
                 }
-                TransportRow(now, media, skip = 48.dp, modifier = Modifier.fillMaxWidth())
+                TransportRow(now, media, skip = 56.dp, modifier = Modifier.fillMaxWidth())
                 Spacer(Modifier.height(10.dp))
-                PlayModeRow(now, media, size = 42.dp, modifier = Modifier.fillMaxWidth()) {
+                PlayModeRow(now, media, size = 50.dp, modifier = Modifier.fillMaxWidth()) {
                     GsIconButton(
-                        ImageVector.vectorResource(R.drawable.lyrics_24), "Lyrics", navigator::showSideLyrics,
-                        size = 42.dp, iconSize = 22.dp,
+                        ImageVector.vectorResource(R.drawable.lyrics_24), stringResource(R.string.storage_lyrics), navigator::showSideLyrics,
+                        size = 50.dp, iconSize = 26.dp,
                     )
                 }
             }
+            GsIconButton(
+                Icons.Filled.Close, stringResource(R.string.home_back_nav), navigator::closeSidePanel,
+                Modifier.align(Alignment.TopEnd), size = 36.dp, iconSize = 20.dp,
+            )
         }
     }
 }
 
 /**
- * Lyrics alone beside the map, big enough to read at a glance. No art: that space goes to a
- * larger title and artist instead. The player goes back to the nav bar meanwhile, whose dock
- * button swaps these back out for the controls.
+ * Lyrics alone beside the map, big enough to read at a glance. The header is slim, since the
+ * player goes back to the nav bar meanwhile and names the song there. Its note button swaps the
+ * lyrics back for the player; the X closes the panel.
  */
 @Composable
 private fun SideLyrics(now: NowPlaying, modifier: Modifier) {
     val navigator = LocalCarNavigator.current
     val context = LocalContext.current
+    val scheme = MaterialTheme.colorScheme
     val art by produceState(now.art, now.art, now.artUri) { value = now.art ?: MediaArt.load(context, now.artUri) }
-    Surface(modifier = modifier, color = rememberArtColor(art, MaterialTheme.colorScheme.surfaceVariant)) {
-        Column(Modifier.fillMaxSize().padding(16.dp)) {
-            Row(verticalAlignment = Alignment.Top) {
-                Column(Modifier.weight(1f)) {
-                    Text(
-                        now.title, style = MaterialTheme.typography.headlineSmall, fontWeight = FontWeight.Bold,
-                        maxLines = 2, overflow = TextOverflow.Ellipsis,
-                    )
-                    Text(
-                        now.artist, style = MaterialTheme.typography.titleMedium,
-                        color = MaterialTheme.colorScheme.onSurfaceVariant,
-                        maxLines = 1, overflow = TextOverflow.Ellipsis,
-                    )
+    Surface(modifier = modifier.gsPanelShadow(CARD_SHAPE), shape = CARD_SHAPE, color = scheme.surfaceContainer) {
+        Column(Modifier.fillMaxSize().padding(start = 18.dp, end = 12.dp, top = 12.dp, bottom = 8.dp)) {
+            Row(verticalAlignment = Alignment.CenterVertically) {
+                Box(Modifier.size(36.dp).clip(RoundedCornerShape(8.dp)).background(scheme.surface)) {
+                    art?.let { Image(it.asImageBitmap(), null, Modifier.fillMaxSize(), contentScale = ContentScale.Crop) }
                 }
-                GsIconButton(Icons.Filled.Close, "Hide lyrics", navigator::closeSidePanel, size = 36.dp, iconSize = 20.dp)
+                Spacer(Modifier.size(10.dp))
+                Text(
+                    listOf(now.title, now.artist).filter { it.isNotEmpty() }.joinToString(" · "),
+                    Modifier.weight(1f),
+                    style = MaterialTheme.typography.bodyMedium,
+                    color = scheme.onSurfaceVariant,
+                    maxLines = 1, overflow = TextOverflow.Ellipsis,
+                )
+                // The way back to the player, as the player's own Lyrics button is the way here.
+                GsIconButton(MediaIcons.MusicNote, stringResource(R.string.home_show_player), navigator::showSidePlayer, size = 36.dp, iconSize = 20.dp)
+                Spacer(Modifier.size(6.dp))
+                GsIconButton(Icons.Filled.Close, stringResource(R.string.home_hide_lyrics), navigator::closeSidePanel, size = 36.dp, iconSize = 20.dp)
             }
-            Spacer(Modifier.height(12.dp))
             LyricsPanel(now, Modifier.weight(1f).fillMaxWidth(), lineStyle = MaterialTheme.typography.headlineSmall)
         }
     }

gearslip/src/main/java/app/seb3thehacker/gearslip/car/CarKeyboard.kt

@@ -1,5 +1,7 @@
 package app.seb3thehacker.gearslip.car
 
+import androidx.compose.ui.res.stringResource
+import app.seb3thehacker.gearslip.R
 import app.seb3thehacker.gearslip.car.theme.*
 import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Column
@@ -27,6 +29,13 @@ import androidx.compose.ui.graphics.vector.ImageVector
 import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.unit.dp
 import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.runtime.CompositionLocalProvider
+import androidx.compose.runtime.compositionLocalOf
+import androidx.compose.ui.platform.LocalConfiguration
+import androidx.compose.ui.unit.Dp
+import androidx.compose.ui.unit.coerceIn
+import androidx.compose.runtime.rememberUpdatedState
+import androidx.compose.runtime.LaunchedEffect
 
 /**
  * Whether a [CarKeyboard] is on screen right now, so [CarUi] can give it the row of height the
@@ -37,6 +46,12 @@ object CarKeyboardVisibility {
     val state = mutableStateOf(false)
 }
 
+/**
+ * True for the car UI the phone's own car preview draws. The phone is in hand there, so a
+ * [CarKeyboard] draws nothing and the phone's keyboard does the typing instead (see [PhoneTyping]).
+ */
+val LocalCarPreview = compositionLocalOf { false }
+
 /**
  * A keyboard the host draws itself.
  *
@@ -66,70 +81,85 @@ fun CarKeyboard(
 ) {
     var symbols by remember { mutableStateOf(false) }
     var shifted by remember { mutableStateOf(false) }
+    val preview = LocalCarPreview.current
 
-    DisposableEffect(Unit) {
-        CarKeyboardVisibility.state.value = true
-        onDispose { CarKeyboardVisibility.state.value = false }
+    DisposableEffect(preview) {
+        if (!preview) CarKeyboardVisibility.state.value = true
+        onDispose { if (!preview) CarKeyboardVisibility.state.value = false }
     }
 
-    val rows = if (symbols) SYMBOL_ROWS else LETTER_ROWS
+    // The same field on the phone, for typing on its own keyboard: see [PhoneTyping].
+    val latestChange by rememberUpdatedState(onTextChange)
+    val latestSubmit by rememberUpdatedState(onSubmit)
+    val latestDismiss by rememberUpdatedState(onDismiss)
+    val phoneField = remember {
+        PhoneTyping.open(text, { latestChange(it) }, { latestSubmit() }, onDismiss?.let { { latestDismiss?.invoke() } })
+    }
+    DisposableEffect(phoneField) { onDispose { PhoneTyping.close(phoneField) } }
+    LaunchedEffect(text) { PhoneTyping.carText(phoneField, text) }
+    if (preview) return
 
-    Surface(
-        color = MaterialTheme.colorScheme.surfaceContainerHigh,
-        modifier = modifier.fillMaxWidth(),
-    ) {
-        Column(
-            Modifier.padding(horizontal = 6.dp, vertical = 4.dp),
-            verticalArrangement = Arrangement.spacedBy(4.dp),
+    val rows = if (symbols) SYMBOL_ROWS else LETTER_ROWS
+    val keyHeight = keyHeight(LocalConfiguration.current.screenHeightDp)
+
+    CompositionLocalProvider(LocalKeyHeight provides keyHeight) {
+        Surface(
+            color = MaterialTheme.colorScheme.surfaceContainerHigh,
+            modifier = modifier.fillMaxWidth(),
         ) {
-            rows.dropLast(1).forEach { row ->
+            Column(
+                Modifier.padding(horizontal = 6.dp, vertical = 4.dp),
+                verticalArrangement = Arrangement.spacedBy(4.dp),
+            ) {
+                rows.dropLast(1).forEach { row ->
+                    Row(
+                        Modifier.fillMaxWidth(),
+                        horizontalArrangement = Arrangement.spacedBy(4.dp),
+                    ) {
+                        row.forEach { key ->
+                            val label = if (shifted && !symbols) key.uppercase() else key
+                            Key(label, Modifier.weight(1f)) {
+                                onTextChange(text + label)
+                                shifted = false
+                            }
+                        }
+                    }
+                }
+
+                // The bottom letter row: shift and backspace bookend it, exactly where a physical
+                // keyboard puts them relative to the letter block, not down beside the space bar.
                 Row(
                     Modifier.fillMaxWidth(),
                     horizontalArrangement = Arrangement.spacedBy(4.dp),
                 ) {
-                    row.forEach { key ->
+                    if (!symbols) {
+                        Key(if (shifted) "SHIFT" else "shift", Modifier.weight(1.6f)) { shifted = !shifted }
+                    }
+                    rows.last().forEach { key ->
                         val label = if (shifted && !symbols) key.uppercase() else key
                         Key(label, Modifier.weight(1f)) {
                             onTextChange(text + label)
                             shifted = false
                         }
                     }
-                }
-            }
-
-            // The bottom letter row: shift and backspace bookend it, exactly where a physical
-            // keyboard puts them relative to the letter block, not down beside the space bar.
-            Row(
-                Modifier.fillMaxWidth(),
-                horizontalArrangement = Arrangement.spacedBy(4.dp),
-            ) {
-                if (!symbols) {
-                    Key(if (shifted) "SHIFT" else "shift", Modifier.weight(1.6f)) { shifted = !shifted }
-                }
-                rows.last().forEach { key ->
-                    val label = if (shifted && !symbols) key.uppercase() else key
-                    Key(label, Modifier.weight(1f)) {
-                        onTextChange(text + label)
-                        shifted = false
+                    Key("⌫", Modifier.weight(1.6f)) {
+                        if (text.isNotEmpty()) onTextChange(text.dropLast(1))
                     }
                 }
-                Key("⌫", Modifier.weight(1.6f)) {
-                    if (text.isNotEmpty()) onTextChange(text.dropLast(1))
-                }
-            }
 
-            // Control row: no backspace here - it stays with the letters above, not next to the
-            // key most likely to be hit right after it by mistake. Dismiss (when offered) is the
-            // last key, bottom-right corner of the keyboard.
-            Row(
-                Modifier.fillMaxWidth(),
-                horizontalArrangement = Arrangement.spacedBy(4.dp),
-            ) {
-                Key(if (symbols) "abc" else "?123", Modifier.weight(1.4f)) { symbols = !symbols }
-                Key("space", Modifier.weight(if (onDismiss != null) 3.2f else 4f)) { onTextChange("$text ") }
-                SubmitKey(Modifier.weight(1.6f), submitIcon, submitImage, onSubmit)
-                if (onDismiss != null) {
-                    DismissKey(onDismiss, Modifier.weight(1.4f))
+                // Control row: no backspace here - it stays with the letters above, not next to the
+                // key most likely to be hit right after it by mistake. Search/enter takes the
+                // bottom-right corner, where a thumb expects it; dismiss (when offered) sits left of it.
+                Row(
+                    Modifier.fillMaxWidth(),
+                    horizontalArrangement = Arrangement.spacedBy(4.dp),
+                ) {
+                    Key(if (symbols) "abc" else "?123", Modifier.weight(1.4f)) { symbols = !symbols }
+                    Key(stringResource(R.string.keyboard_space), Modifier.weight(if (onDismiss != null) 3.2f else 4f)) { onTextChange("$text ") }
+                    if (onDismiss != null) {
+                        DismissKey(onDismiss, Modifier.weight(1.4f))
+                    }
+                    SubmitKey(Modifier.weight(1.6f), submitIcon, submitImage, onSubmit)
                 }
             }
         }
@@ -140,7 +170,7 @@ fun CarKeyboard(
 private fun Key(label: String, modifier: Modifier = Modifier, onClick: () -> Unit) {
     GsIconBox(
         onClick = onClick,
-        modifier = modifier.height(KEY_HEIGHT),
+        modifier = modifier.height(LocalKeyHeight.current),
         colors = GsColors(MaterialTheme.colorScheme.surfaceContainerHighest, MaterialTheme.colorScheme.onSurface),
         shape = RoundedCornerShape(8.dp),
     ) {
@@ -163,7 +193,7 @@ private fun Key(label: String, modifier: Modifier = Modifier, onClick: () -> Uni
 private fun DismissKey(onClick: () -> Unit, modifier: Modifier = Modifier) {
     GsIconBox(
         onClick = onClick,
-        modifier = modifier.height(KEY_HEIGHT),
+        modifier = modifier.height(LocalKeyHeight.current),
         colors = GsColors(MaterialTheme.colorScheme.surfaceContainerHighest, MaterialTheme.colorScheme.onSurfaceVariant),
         shape = RoundedCornerShape(8.dp),
     ) {
@@ -172,7 +202,7 @@ private fun DismissKey(onClick: () -> Unit, modifier: Modifier = Modifier) {
             horizontalArrangement = Arrangement.Center,
             verticalAlignment = Alignment.CenterVertically,
         ) {
-            Icon(Icons.Filled.Close, contentDescription = "Hide keyboard")
+            Icon(Icons.Filled.Close, contentDescription = stringResource(R.string.keyboard_hide))
         }
     }
 }
@@ -181,7 +211,7 @@ private fun DismissKey(onClick: () -> Unit, modifier: Modifier = Modifier) {
 private fun SubmitKey(modifier: Modifier, search: Boolean, image: ImageVector?, onClick: () -> Unit) {
     GsIconBox(
         onClick = onClick,
-        modifier = modifier.height(KEY_HEIGHT),
+        modifier = modifier.height(LocalKeyHeight.current),
         colors = GsColors(MaterialTheme.colorScheme.primary, MaterialTheme.colorScheme.onPrimary),
         shape = RoundedCornerShape(8.dp),
     ) {
@@ -192,17 +222,19 @@ private fun SubmitKey(modifier: Modifier, search: Boolean, image: ImageVector?,
         ) {
             Icon(
                 image ?: if (search) Icons.Filled.Search else Icons.Filled.ArrowBack,
-                contentDescription = "Submit",
+                contentDescription = stringResource(R.string.keyboard_submit),
             )
         }
     }
 }
 
 /**
- * Big enough to hit on a bumpy road, small enough that four rows plus a field plus a few
- * results all fit a 480px-tall screen - which is the real constraint here, not the key size.
+ * Big enough to hit on a bumpy road, small enough that four rows plus a field plus a few results
+ * still fit. A 480-tall screen sets the floor; a taller one (LIVI's 1280x720) gets bigger keys.
  */
-private val KEY_HEIGHT = 34.dp
+private fun keyHeight(screenHeightDp: Int): Dp = (screenHeightDp * 0.09f).dp.coerceIn(44.dp, 64.dp)
+
+private val LocalKeyHeight = compositionLocalOf { 44.dp }
 
 private val LETTER_ROWS = listOf(
     "qwertyuiop".map { it.toString() },

gearslip/src/main/java/app/seb3thehacker/gearslip/car/CarKeys.kt

@@ -27,6 +27,11 @@ object CarKeys {
     private val _screenKeys = MutableSharedFlow<ScreenKey>(extraBufferCapacity = 8)
     val screenKeys: SharedFlow<ScreenKey> = _screenKeys
 
+    private val _focusMoves = MutableSharedFlow<Unit>(extraBufferCapacity = 1)
+
+    /** A knob turn or D-pad press, so controls that hide when left alone can come back. */
+    val focusMoves: SharedFlow<Unit> = _focusMoves
+
     /** Delivers an Android key event to the car display; set while the car UI is showing. */
     @Volatile var focusSink: ((keyCode: Int, down: Boolean) -> Unit)? = null
 
@@ -58,6 +63,7 @@ object CarKeys {
      */
     fun onKey(keyCode: Int, down: Boolean, longPress: Boolean): Boolean {
         if (keyCode in FOCUS_KEYS) {
+            _focusMoves.tryEmit(Unit)
             focusSink?.invoke(keyCode, down)
             return true
         }
@@ -86,6 +92,7 @@ object CarKeys {
     /** A turn of the rotary knob: each click moves focus one step, like Tab or Shift+Tab. */
     fun onRotate(delta: Int) {
         val sink = focusSink ?: return
+        _focusMoves.tryEmit(Unit)
         val code = if (delta > 0) KeyEvent.KEYCODE_TAB else KEYCODE_SHIFT_TAB
         repeat(kotlin.math.abs(delta).coerceAtMost(MAX_ROTARY_STEPS)) {
             sink(code, true)
@@ -95,15 +102,10 @@ object CarKeys {
 
     /**
      * The voice key: answers the message on screen if there is one, otherwise starts the
-     * assistant when it's turned on.
+     * assistant.
      */
     private fun voice() = main.post {
-        if (VoiceReply.onVoiceKey()) return@post
-        if (CarSettings.experimentalFeaturesEnabled.value && CarSettings.voiceAssistantEnabled.value) {
-            CarAssistant.start()
-        } else {
-            GearslipLog.i("keys: voice pressed, but the assistant is off in settings")
-        }
+        if (!VoiceReply.onVoiceKey()) CarAssistant.start()
     }
 
     /** Answers a ringing call; with nothing ringing, opens the phone screen. */

gearslip/src/main/java/app/seb3thehacker/gearslip/car/CarLauncher.kt

@@ -1,5 +1,7 @@
 package app.seb3thehacker.gearslip.car
 
+import androidx.compose.ui.res.stringResource
+import app.seb3thehacker.gearslip.R
 import app.seb3thehacker.gearslip.car.theme.*
 import androidx.compose.foundation.Image
 import androidx.compose.foundation.ExperimentalFoundationApi
@@ -16,6 +18,7 @@ import androidx.compose.foundation.lazy.grid.LazyVerticalGrid
 import androidx.compose.foundation.lazy.grid.items
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.filled.Info
+import androidx.compose.material.icons.filled.KeyboardArrowDown
 import androidx.compose.material3.Icon
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Text
@@ -47,6 +50,8 @@ import androidx.compose.foundation.layout.width
 import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.background
+import androidx.compose.foundation.layout.offset
+import androidx.compose.foundation.border
 import androidx.compose.foundation.shape.CircleShape
 import androidx.compose.foundation.lazy.grid.GridItemSpan
 import androidx.compose.material.icons.filled.Check
@@ -67,12 +72,8 @@ private class Tile(
     val label: String,
     val icon: ImageBitmap? = null,
     val glyph: ImageVector? = null,
-    /** Tested from start to finish with Gearslip; drawn with a check mark. */
-    val verified: Boolean = false,
     /** Known not to work; drawn with a red X instead of being left off the launcher. */
     val broken: Boolean = false,
-    /** Starts and can be used, but rough enough not to call working; drawn with a yellow mark. */
-    val partial: Boolean = false,
     val onLongClick: (() -> Unit)? = null,
     val onClick: () -> Unit,
 )
@@ -120,35 +121,62 @@ internal object LauncherCache {
             context.packageManager.getApplicationIcon(pkg).toBitmap(128, 128).asImageBitmap()
         }.getOrNull()
 
-        val navApps = CarAppCatalog.installed(context)
-        val mediaApps = MediaCatalog.installed(context)
-        // Some apps (Spotify among them) ship both a Car App Library template and a legacy
-        // MediaBrowserService, which otherwise land as two identically-labeled tiles with no
-        // way to tell them apart. They're genuinely different screens - browsing versus Now
-        // Playing - so only the label needs disambiguating, not the tile itself.
-        val mediaPackages = mediaApps.map { it.component.packageName }.toSet()
+        val carApps = CarAppCatalog.installed(context).associateBy { it.component.packageName }
+        val mediaApps = MediaCatalog.installed(context).associateBy { it.component.packageName }
+        val messagingApps = MessagingCatalog.installed(context).associateBy { it.packageName }
 
-        val messagingApps = MessagingCatalog.installed(context)
-        // Google Messages ships its own car app, which won't start under Gearslip. Gearslip's
-        // own Messages screen does the same job, so a messenger gets only that tile.
-        val messagingPackages = messagingApps.map { it.packageName }.toSet()
-
-        val nav = navApps
-            .filter { it.component.packageName !in messagingPackages }
-            // An app whose template screen is rejected but whose player works through Gearslip
-            // (Spotify) shows only its player tile - a "· Browse" tile beside it would just report
-            // that the car screen isn't supported.
-            .filter { !(KnownApps.screenBroken(it.component.packageName) && KnownApps.playerWorks(it.component.packageName)) }
-            .map {
-                val label = if (it.component.packageName in mediaPackages) "${it.label} · Browse" else it.label
-                Entry(label, iconOf(it.component.packageName), template = it)
+        // One decision per app over everything it offers a car - a car screen, a player, car
+        // notifications - rather than a filter per kind that has to know about the others.
+        val tiles = (carApps.keys + mediaApps.keys + messagingApps.keys).flatMap { pkg ->
+            val icon by lazy { iconOf(pkg) }
+            tilesFor(carApps[pkg], mediaApps[pkg], messagingApps[pkg], context.getString(R.string.media_browse)).map { tile ->
+                when (tile) {
+                    is AppTile.Screen -> Entry(tile.label, icon, template = tile.app)
+                    is AppTile.Player -> Entry(tile.app.label, icon, media = tile.app)
+                    is AppTile.Messages -> Entry(tile.app.label, icon, messaging = tile.app)
+                }
             }
-        val media = mediaApps.map { Entry(it.label, iconOf(it.component.packageName), media = it) }
-        // A messenger that is also a car media app keeps only its player tile.
-        val messaging = messagingApps
-            .filter { it.packageName !in mediaPackages }
-            .map { Entry(it.label, iconOf(it.packageName), messaging = it) }
-        return (nav + media + messaging).sortedBy { it.label.lowercase() }.also { flow.value = it }
+        }
+        return tiles.sortedBy { it.label.lowercase() }.also { flow.value = it }
+    }
+}
+
+/** What one app gets on the launcher. */
+private sealed interface AppTile {
+    class Screen(val app: TemplateApp, val label: String) : AppTile
+    class Player(val app: app.seb3thehacker.gearslip.media.MediaApp) : AppTile
+    class Messages(val app: app.seb3thehacker.gearslip.notify.MessagingApp) : AppTile
+}
+
+/**
+ * The tiles for one app, from what it offers.
+ *
+ * - A car screen that is something other than media or messaging (RF Sentinel's POI screen) is
+ *   the app: its media service only makes sound, and its notifications are alerts, so it gets the
+ *   one tile under its own name.
+ * - A media app with both a car screen and a player (Spotify) gets both, the screen labelled
+ *   "· Browse", since they really are different screens - unless the screen is known to refuse
+ *   Gearslip while the player works, when the Browse tile would only report that.
+ * - A messenger's own car screen (Google Messages) won't start under Gearslip, and Gearslip's
+ *   Messages screen does the job, so it gets only that - and a messenger that is also a media
+ *   app keeps only its player.
+ */
+private fun tilesFor(
+    car: TemplateApp?,
+    media: app.seb3thehacker.gearslip.media.MediaApp?,
+    messaging: app.seb3thehacker.gearslip.notify.MessagingApp?,
+    browse: String,
+): List<AppTile> {
+    if (car != null && !car.isMediaScreen && car.kind != "messaging") return listOf(AppTile.Screen(car, car.label))
+    val pkg = car?.component?.packageName ?: media?.component?.packageName ?: messaging?.packageName ?: return emptyList()
+    return buildList {
+        val screenRefused = KnownApps.screenBroken(pkg) && KnownApps.playerWorks(pkg)
+        val messengerScreen = messaging != null && (car?.kind == "messaging" || car?.kind == "app")
+        if (car != null && !messengerScreen && !(media != null && screenRefused)) {
+            add(AppTile.Screen(car, if (media != null) "${car.label} · $browse" else car.label))
+        }
+        if (media != null) add(AppTile.Player(media))
+        else if (messaging != null) add(AppTile.Messages(messaging))
     }
 }
 
@@ -164,7 +192,7 @@ internal fun rememberAllEntries(): List<Entry> {
 }
 
 /** The launcher's groups, in the order they're laid out. */
-private enum class AppGroup { PHONE, MAPS, MUSIC, MESSAGING, WEB, SCREEN_SHARING, OTHER, SETTINGS }
+private enum class AppGroup { PHONE, MAPS, MUSIC, MESSAGING, WEB, SCREEN_SHARING, OTHER, SETTINGS, EXIT }
 
 private fun groupOf(entry: Entry, mediaPackages: Set<String>): AppGroup {
     entry.builtIn?.let {
@@ -172,6 +200,7 @@ private fun groupOf(entry: Entry, mediaPackages: Set<String>): AppGroup {
             BuiltInApps.Phone -> AppGroup.PHONE
             BuiltInApps.Web -> AppGroup.WEB
             BuiltInApps.ScreenSharing -> AppGroup.SCREEN_SHARING
+            BuiltInApps.Exit -> AppGroup.EXIT
             else -> AppGroup.SETTINGS
         }
     }
@@ -183,6 +212,8 @@ private fun groupOf(entry: Entry, mediaPackages: Set<String>): AppGroup {
     return when (app.kind) {
         "calling" -> AppGroup.PHONE
         "navigation", "poi", "parking", "charging" -> AppGroup.MAPS
+        // Template-only media apps may have no legacy browser/player tile to identify them.
+        "media" -> AppGroup.MUSIC
         "messaging" -> AppGroup.MESSAGING
         "settings" -> AppGroup.SETTINGS
         else -> AppGroup.OTHER
@@ -237,6 +268,7 @@ internal fun launchEntry(entry: Entry, navigator: CarNavigator, frame: CarEnviro
 /** The app launcher: every app as an icon grid, grouped Phone, Maps, Music, Messaging, Web, Screen sharing, Settings. */
 @Composable
 fun CarLauncher() {
+    val context = LocalContext.current
     val navigator = LocalCarNavigator.current
     val frame by CarEnvironment.frame.collectAsState()
 
@@ -244,18 +276,15 @@ fun CarLauncher() {
     val all = rememberAllEntries()
     val running = rememberRunningApps()
     val showVehicleData = rememberVehicleDataShown()
-    var showBadgeKey by remember { mutableStateOf(false) }
 
     fun tileOf(entry: Entry): Tile {
-        // The badges rate an app's own car screens; a messenger shown on Gearslip's own Messages
-        // screen has none, so it gets no badge.
+        // Only apps that don't work get a mark. The X rates an app's own car screens; a messenger
+        // shown on Gearslip's own Messages screen has none, so it never gets one.
         val pkg = entry.packageName?.takeIf { entry.messaging == null }
         val id = entry.componentId
         return Tile(
-            entry.label, entry.icon, entry.builtIn?.glyph,
-            verified = pkg != null && (KnownApps.works(pkg) || (entry.media != null && KnownApps.playerWorks(pkg))),
-            broken = pkg != null && (KnownApps.isBroken(pkg) || (entry.template != null && KnownApps.screenBroken(pkg))),
-            partial = pkg != null && KnownApps.isPartial(pkg),
+            entry.builtIn?.let { context.getString(it.labelRes) } ?: entry.label, entry.icon, entry.builtIn?.glyph,
+            broken = pkg != null && (KnownApps.isBroken(context, pkg) || (entry.template != null && KnownApps.screenBroken(pkg))),
             onLongClick = id?.let { { navigator.showAppMenu(it) } },
         ) { openApp(entry, id?.let { running[it] }, navigator, frame) }
     }
@@ -271,60 +300,6 @@ fun CarLauncher() {
         verticalArrangement = Arrangement.spacedBy(12.dp),
     ) {
         items(tiles) { AppTile(it) }
-        if (tiles.any { it.verified || it.broken || it.partial }) {
-            // Folded away behind one button: it's reference, read once, not something every
-            // visit to the launcher needs spelled out under the grid.
-            item(span = { GridItemSpan(maxLineSpan) }) {
-                Column(horizontalAlignment = Alignment.CenterHorizontally) {
-                    GsButton(onClick = { showBadgeKey = !showBadgeKey }, tone = GsTone.Neutral) {
-                        Icon(Icons.Filled.Info, contentDescription = null, modifier = Modifier.size(18.dp))
-                        Spacer(Modifier.width(8.dp))
-                        Text(if (showBadgeKey) "Hide badge key" else "What the badges mean")
-                    }
-                    if (showBadgeKey) {
-                        BadgeLegend(
-                            verified = tiles.any { it.verified },
-                            partial = tiles.any { it.partial },
-                            broken = tiles.any { it.broken },
-                        )
-                    }
-                }
-            }
-        }
-    }
-}
-
-/** Says what each badge on a tile means, once, under the grid - only the ones actually in use. */
-@Composable
-private fun BadgeLegend(verified: Boolean, partial: Boolean, broken: Boolean) {
-    Column(
-        Modifier.fillMaxWidth().padding(top = 4.dp),
-        horizontalAlignment = Alignment.CenterHorizontally,
-        verticalArrangement = Arrangement.spacedBy(4.dp),
-    ) {
-        if (verified) LegendRow(size = 16.dp, badge = { VerifiedBadge(it) }, text = "Tested and working with Gearslip")
-        if (partial) LegendRow(size = 16.dp, badge = { PartialBadge(it) }, text = "Runs, but not cleanly, with Gearslip")
-        if (broken) LegendRow(size = 16.dp, badge = { BrokenBadge(it) }, text = "Doesn't work with Gearslip yet")
-    }
-}
-
-@Composable
-private fun LegendRow(size: androidx.compose.ui.unit.Dp, badge: @Composable (androidx.compose.ui.unit.Dp) -> Unit, text: String) {
-    Row(horizontalArrangement = Arrangement.Center, verticalAlignment = Alignment.CenterVertically) {
-        badge(size)
-        Spacer(Modifier.width(8.dp))
-        Text(text, style = MaterialTheme.typography.bodyMedium, color = MaterialTheme.colorScheme.onSurfaceVariant)
-    }
-}
-
-/** A green disc with a white check: the same mark on every tile and in the legend. */
-@Composable
-private fun VerifiedBadge(size: androidx.compose.ui.unit.Dp, modifier: Modifier = Modifier) {
-    Box(
-        modifier.size(size).background(Color(0xFF43A047), CircleShape),
-        contentAlignment = Alignment.Center,
-    ) {
-        Icon(Icons.Filled.Check, contentDescription = "Tested and working", tint = Color.White, modifier = Modifier.size(size * 0.66f))
     }
 }
 
@@ -335,18 +310,7 @@ private fun BrokenBadge(size: androidx.compose.ui.unit.Dp, modifier: Modifier =
         modifier.size(size).background(Color(0xFFD32F2F), CircleShape),
         contentAlignment = Alignment.Center,
     ) {
-        Icon(Icons.Filled.Close, contentDescription = "Doesn't work with Gearslip", tint = Color.White, modifier = Modifier.size(size * 0.66f))
-    }
-}
-
-/** A yellow disc with a warning mark: neither the check nor the X, since this app runs but isn't clean about it. */
-@Composable
-private fun PartialBadge(size: androidx.compose.ui.unit.Dp, modifier: Modifier = Modifier) {
-    Box(
-        modifier.size(size).background(Color(0xFFF9A825), CircleShape),
-        contentAlignment = Alignment.Center,
-    ) {
-        Icon(Icons.Filled.Warning, contentDescription = "Works, but not cleanly, with Gearslip", tint = Color.White, modifier = Modifier.size(size * 0.6f))
+        Icon(Icons.Filled.Close, contentDescription = stringResource(R.string.launcher_broken), tint = Color.White, modifier = Modifier.size(size * 0.66f))
     }
 }
 
@@ -355,7 +319,7 @@ private fun PartialBadge(size: androidx.compose.ui.unit.Dp, modifier: Modifier =
 private fun AppTile(tile: Tile) {
     val shape = MaterialTheme.shapes.extraLarge
     // A long press opens the app's menu (pin, close) - the same gesture everywhere apps are
-    // shown, here and on the nav bar.
+    // shown, here and on the nav bar. GsIconBox marks it in the theme's style.
     GsIconBox(
         onClick = tile.onClick,
         onLongClick = tile.onLongClick,
@@ -369,29 +333,42 @@ private fun AppTile(tile: Tile) {
                 horizontalAlignment = Alignment.CenterHorizontally,
                 verticalArrangement = Arrangement.Center,
             ) {
-                when {
-                    tile.icon != null -> Image(tile.icon, contentDescription = null, modifier = Modifier.size(52.dp))
-                    tile.glyph != null -> Icon(tile.glyph, contentDescription = null, modifier = Modifier.size(52.dp))
+                Box {
+                    TileIcon(tile)
+                    if (tile.broken) {
+                        // Pinned to the icon's lower corner, ringed in the tile's colour so it
+                        // reads as sitting on top of the icon.
+                        BrokenBadge(
+                            22.dp,
+                            Modifier.align(Alignment.BottomEnd).offset(x = 6.dp, y = 4.dp)
+                                .border(2.dp, MaterialTheme.colorScheme.surfaceVariant, CircleShape),
+                        )
+                    }
                 }
                 Spacer(Modifier.height(8.dp))
-                Text(
-                    tile.label,
-                    style = MaterialTheme.typography.labelLarge,
-                    fontWeight = FontWeight.SemiBold,
-                    textAlign = TextAlign.Center,
-                    maxLines = 2,
-                    overflow = TextOverflow.Ellipsis,
-                )
-            }
-            if (tile.verified) {
-                VerifiedBadge(24.dp, Modifier.align(Alignment.TopEnd).padding(8.dp))
-            }
-            if (tile.broken) {
-                BrokenBadge(24.dp, Modifier.align(Alignment.TopEnd).padding(8.dp))
-            }
-            if (tile.partial) {
-                PartialBadge(24.dp, Modifier.align(Alignment.TopEnd).padding(8.dp))
+                TileLabel(tile)
             }
         }
     }
 }
+
+@Composable
+private fun TileIcon(tile: Tile) {
+    when {
+        tile.icon != null -> Image(tile.icon, contentDescription = null, modifier = Modifier.size(52.dp))
+        tile.glyph != null -> Icon(tile.glyph, contentDescription = null, modifier = Modifier.size(52.dp))
+    }
+}
+
+@Composable
+private fun TileLabel(tile: Tile, maxLines: Int = 2, modifier: Modifier = Modifier) {
+    Text(
+        tile.label,
+        modifier = modifier,
+        style = MaterialTheme.typography.labelLarge,
+        fontWeight = FontWeight.SemiBold,
+        textAlign = TextAlign.Center,
+        maxLines = maxLines,
+        overflow = TextOverflow.Ellipsis,
+    )
+}

gearslip/src/main/java/app/seb3thehacker/gearslip/car/CarNavBar.kt

@@ -0,0 +1,680 @@
+package app.seb3thehacker.gearslip.car
+
+import androidx.compose.ui.res.stringResource
+import androidx.compose.material.icons.filled.Call
+import app.seb3thehacker.gearslip.call.CarCalls
+import app.seb3thehacker.gearslip.call.CallUiState
+import androidx.compose.foundation.Image
+import androidx.compose.foundation.clickable
+import androidx.compose.foundation.LocalIndication
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.BoxWithConstraints
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.PaddingValues
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.offset
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.layout.width
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.foundation.background
+import androidx.compose.foundation.gestures.detectTapGestures
+import androidx.compose.ui.graphics.lerp
+import androidx.compose.ui.graphics.Brush
+import androidx.compose.foundation.layout.widthIn
+import androidx.compose.foundation.layout.fillMaxHeight
+import androidx.compose.foundation.border
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.automirrored.filled.ArrowBack
+import androidx.compose.foundation.layout.BoxScope
+import androidx.car.app.model.CarIcon
+import androidx.car.app.navigation.model.NavigationTemplate
+import androidx.car.app.navigation.model.RoutingInfo
+import app.seb3thehacker.gearslip.host.CarAppConnection
+import app.seb3thehacker.gearslip.host.display
+import app.seb3thehacker.gearslip.host.text
+import androidx.compose.foundation.shape.CircleShape
+import androidx.compose.material.icons.filled.PlayArrow
+import androidx.compose.material3.Icon
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Surface
+import androidx.compose.material3.Text
+import androidx.compose.material3.dynamicDarkColorScheme
+import androidx.compose.material3.dynamicLightColorScheme
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.CompositionLocalProvider
+import androidx.compose.ui.hapticfeedback.HapticFeedback
+import androidx.compose.ui.hapticfeedback.HapticFeedbackType
+import androidx.compose.ui.platform.LocalHapticFeedback
+import androidx.compose.ui.platform.LocalView
+import androidx.compose.runtime.State
+import androidx.compose.runtime.collectAsState
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.produceState
+import androidx.compose.runtime.DisposableEffect
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.setValue
+import androidx.compose.animation.animateContentSize
+import android.media.session.PlaybackState
+import androidx.compose.runtime.remember
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.clip
+import androidx.compose.ui.input.pointer.PointerEventPass
+import androidx.compose.ui.input.pointer.pointerInput
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.graphics.asImageBitmap
+import androidx.compose.ui.graphics.vector.ImageVector
+import androidx.compose.ui.layout.ContentScale
+import androidx.compose.ui.res.vectorResource
+import androidx.compose.ui.text.style.TextOverflow
+import app.seb3thehacker.gearslip.R
+import app.seb3thehacker.gearslip.car.theme.GsColors
+import app.seb3thehacker.gearslip.car.theme.withTintedSurfaces
+import app.seb3thehacker.gearslip.car.theme.GsIconBox
+import app.seb3thehacker.gearslip.car.theme.GsIconButton
+import app.seb3thehacker.gearslip.car.theme.GsButton
+import app.seb3thehacker.gearslip.car.theme.GsTone
+import app.seb3thehacker.gearslip.car.theme.gsColors
+import app.seb3thehacker.gearslip.car.theme.GsThemes
+import app.seb3thehacker.gearslip.car.theme.LocalGsTheme
+import app.seb3thehacker.gearslip.media.CarMedia
+import app.seb3thehacker.gearslip.media.MediaArt
+import androidx.compose.ui.platform.LocalContext
+import androidx.compose.ui.platform.LocalDensity
+import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.unit.Density
+import androidx.compose.ui.unit.dp
+import app.seb3thehacker.gearslip.notify.CarNotifications
+import androidx.core.graphics.drawable.toBitmap
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.withContext
+import java.text.DateFormat
+import java.util.Date
+
+// The nav bar along the bottom of the car screen: home, apps, the assistant, running apps,
+// the next turn or a call, the player, and the clock. Split out of CarUi.kt.
+
+/**
+ * "Home > Apps > Settings", like a file manager's address bar: hidden at Home itself (nothing to
+ * show yet), and grows by one crumb for every screen pushed from there. The back arrow undoes one
+ * step; a crumb jumps straight to it, dropping everything after - this is the only on-screen way
+ * back at all, since a car touchscreen has no hardware button for it.
+ */
+@Composable
+private fun BreadcrumbBar(navigator: CarNavigator) {
+    val trail = navigator.trail
+    if (trail.size <= 1) return
+    Row(
+        Modifier.fillMaxWidth().height(40.dp).padding(start = 2.dp, end = 10.dp),
+        verticalAlignment = Alignment.CenterVertically,
+    ) {
+        GsIconButton(Icons.AutoMirrored.Filled.ArrowBack, stringResource(R.string.back), navigator::back, size = 32.dp, iconSize = 20.dp)
+        Spacer(Modifier.width(2.dp))
+        trail.forEachIndexed { index, crumb ->
+            val isLast = index == trail.lastIndex
+            Text(
+                crumb.shown(),
+                style = MaterialTheme.typography.labelLarge,
+                fontWeight = if (isLast) FontWeight.SemiBold else FontWeight.Normal,
+                color = if (isLast) MaterialTheme.colorScheme.onSurface else MaterialTheme.colorScheme.onSurfaceVariant,
+                maxLines = 1,
+                overflow = TextOverflow.Ellipsis,
+                modifier = if (isLast) Modifier else Modifier
+                    .clip(RoundedCornerShape(6.dp))
+                    .clickable { navigator.jumpTo(index) }
+                    .padding(horizontal = 4.dp, vertical = 2.dp),
+            )
+            if (!isLast) {
+                Text(
+                    "›",
+                    style = MaterialTheme.typography.labelLarge,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant,
+                    modifier = Modifier.padding(horizontal = 2.dp),
+                )
+            }
+        }
+    }
+}
+
+/**
+ * Apps and open/pinned shortcuts on the left; now-playing pill against them; clock (tap for
+ * calendar and weather), phone battery and the darkness signal on the right. Icon-only: a driver
+ * reads a glyph faster than a label, and it keeps the bar short enough to leave the app underneath
+ * more room.
+ */
+@Composable
+internal fun CarNavBar(navigator: CarNavigator) {
+    val battery by CarEnvironment.battery.collectAsState()
+    val now by rememberNow()
+    val weather by Weather.state.collectAsState()
+    val weatherData = (weather as? WeatherState.Ready)?.data
+
+    val pinnedIds by CarSettings.pinnedApps.collectAsState()
+    val entries = rememberAllEntries()
+    val pinnedEntries = remember(entries, pinnedIds) {
+        pinnedIds.mapNotNull { id -> entries.find { it.componentId == id } }
+    }
+    val frame by CarEnvironment.frame.collectAsState()
+    val running = rememberRunningApps()
+
+    // A full-width strip along the bottom in the screens' own background, so it reads as part of
+    // the screen above rather than a panel on it. Over the player it's see-through, so the
+    // cover's glow carries on behind it.
+    val overPlayer = navigator.current == CarScreen.Media
+    Surface(color = if (overPlayer) androidx.compose.ui.graphics.Color.Transparent else MaterialTheme.colorScheme.background) {
+        BoxWithConstraints(Modifier.fillMaxWidth().height(NAV_BAR_HEIGHT).padding(horizontal = 10.dp)) {
+            Row(Modifier.fillMaxSize(), verticalAlignment = Alignment.CenterVertically) {
+                // Home and Apps are two different places now, not a toggle on one button - the
+                // breadcrumb trail is how you retrace your steps, but reaching for either of
+                // these two from three screens deep in a media app shouldn't mean reading it
+                // first.
+                NavHomeButton(navigator, entries, running)
+                Spacer(Modifier.width(6.dp))
+                NavItem(MediaIcons.Apps, navigator.current == CarScreen.Apps) { navigator.apps() }
+                Spacer(Modifier.width(6.dp))
+                NavAssistantIcon()
+
+                // Pinned shortcuts, then whatever else is open right now. A pinned app that's also
+                // open stays in its pinned spot, marked with a dot, instead of showing up twice.
+                // The map app lives on the Home button, so it never gets a second icon here.
+                val runningEntries = running.keys
+                    .filter { it !in pinnedIds && running[it] != RunningSlot.NAV }
+                    .mapNotNull { id -> entries.find { it.componentId == id } }
+                val shownPins = pinnedEntries.filter { running[it.componentId] != RunningSlot.NAV }
+                if (shownPins.isNotEmpty() || runningEntries.isNotEmpty()) NavDivider()
+                shownPins.forEach { entry -> NavEntryIcon(entry, running, navigator, frame) }
+                if (shownPins.isNotEmpty() && runningEntries.isNotEmpty()) NavDivider()
+                runningEntries.forEach { entry -> NavEntryIcon(entry, running, navigator, frame) }
+
+                // Next turn first, off the map only; the player shares the space when it fits,
+                // and gives way to the turn when it doesn't.
+                // A call takes the player's place until it ends.
+                val turn = rememberNextTurn().takeIf { navigator.current != CarScreen.Home }
+                val call = CarCalls.state.collectAsState().value as? CallUiState.Active
+                BoxWithConstraints(Modifier.weight(1f).padding(horizontal = 16.dp), contentAlignment = Alignment.Center) {
+                    val roomForBoth = maxWidth >= TURN_AND_PLAYER_MIN_WIDTH
+                    Row(verticalAlignment = Alignment.CenterVertically, horizontalArrangement = Arrangement.spacedBy(10.dp)) {
+                        if (call == null || roomForBoth) turn?.let { NavTurnPill(it) { navigator.home() } }
+                        if (call != null) {
+                            NavCallPill(call, Modifier.weight(1f, fill = false))
+                        } else if (turn == null || roomForBoth) {
+                            NavNowPlaying(navigator, selected = navigator.current == CarScreen.Media, modifier = Modifier.weight(1f, fill = false))
+                        }
+                    }
+                }
+
+                // Weather no longer has its own chip - the temperature alone (no icon, no room
+                // for one) sits where "Night"/"Day" used to, freeing a whole chip's width for the
+                // Home button above.
+                // The clock is also the notifications button: the dashboard lists them under the
+                // calendar and weather, and a dot here marks anything unread.
+                val unread by CarNotifications.unread.collectAsState()
+                NavChip(
+                    navigator.current == CarScreen.Dashboard || navigator.current is CarScreen.Notifications,
+                    { navigator.dashboard() },
+                ) {
+                    if (unread > 0) {
+                        Box(
+                            Modifier
+                                .align(Alignment.TopEnd)
+                                .offset(x = 8.dp, y = (-2).dp)
+                                .size(8.dp)
+                                .clip(CircleShape)
+                                .background(MaterialTheme.colorScheme.primary),
+                        )
+                    }
+                    Column(horizontalAlignment = Alignment.End) {
+                        Text(
+                            DateFormat.getTimeInstance(DateFormat.SHORT).format(Date(now)),
+                            style = MaterialTheme.typography.titleMedium,
+                            fontWeight = FontWeight.SemiBold,
+                        )
+                        Row(verticalAlignment = Alignment.CenterVertically, horizontalArrangement = Arrangement.spacedBy(3.dp)) {
+                            if (battery.percent >= 0) {
+                                Text(
+                                    "${battery.percent}%",
+                                    style = MaterialTheme.typography.labelMedium,
+                                    color = MaterialTheme.colorScheme.onSurfaceVariant,
+                                )
+                                if (battery.charging) {
+                                    ChargingGlyph(Modifier.size(13.dp))
+                                }
+                            }
+                            weatherData?.let { w ->
+                                Text(
+                                    "  ·  ${w.temp}°",
+                                    style = MaterialTheme.typography.labelMedium,
+                                    color = MaterialTheme.colorScheme.onSurfaceVariant,
+                                )
+                            }
+                        }
+                    }
+                }
+            }
+        }
+    }
+}
+
+/**
+ * Home: the map, with the player or lyrics beside it. While a map app runs, the button wears that
+ * app's icon and a long press offers to close it, so the app needs no icon of its own on the bar.
+ */
+@Composable
+private fun NavHomeButton(navigator: CarNavigator, entries: List<Entry>, running: Map<String, RunningSlot>) {
+    val selected = navigator.current == CarScreen.Home
+    val navId = running.entries.firstOrNull { it.value == RunningSlot.NAV }?.key
+    val navEntry = navId?.let { id -> entries.find { it.componentId == id } }
+    GsIconBox(
+        { navigator.home() },
+        colors = navColors(selected),
+        latched = selected,
+        onLongClick = navId?.let { id -> { navigator.showAppMenu(id) } },
+    ) {
+        val icon = navEntry?.icon
+        if (icon != null) {
+            Box(Modifier.padding(NAV_ITEM_PADDING).size(28.dp), contentAlignment = Alignment.Center) {
+                Image(icon, navEntry.label, Modifier.size(28.dp).clip(RoundedCornerShape(7.dp)))
+            }
+        } else {
+            Icon(
+                ImageVector.vectorResource(R.drawable.navigation_24), contentDescription = stringResource(R.string.crumb_home),
+                modifier = Modifier.padding(NAV_ITEM_PADDING).size(28.dp),
+            )
+        }
+    }
+}
+
+/** Splits the nav bar's sections: Home and Apps, pinned apps, open apps. */
+@Composable
+private fun NavDivider() {
+    Box(
+        Modifier
+            .padding(horizontal = 10.dp)
+            .width(1.dp)
+            .height(28.dp)
+            .background(MaterialTheme.colorScheme.outlineVariant),
+    )
+}
+
+/**
+ * A pinned or open app on the nav bar. Tapping brings it back without reconnecting if it's
+ * already open; a long press opens its menu (pin, unpin, close).
+ */
+@Composable
+private fun NavEntryIcon(
+    entry: Entry,
+    running: Map<String, RunningSlot>,
+    navigator: CarNavigator,
+    frame: CarEnvironment.Frame,
+) {
+    val id = entry.componentId ?: return
+    val slot = running[id]
+    Box(Modifier.padding(horizontal = 3.dp)) {
+        NavAppIcon(
+            entry,
+            open = slot != null,
+            showing = slot != null && slot.isShowing(navigator.current),
+            onLongClick = { navigator.showAppMenu(id) },
+        ) { openApp(entry, slot, navigator, frame) }
+    }
+}
+
+/** One open or pinned app's icon on the nav bar - the same fixed size and shape either way. */
+@Composable
+private fun NavAppIcon(
+    entry: Entry,
+    open: Boolean,
+    showing: Boolean,
+    onLongClick: () -> Unit,
+    onClick: () -> Unit,
+) {
+    val scheme = MaterialTheme.colorScheme
+    GsIconBox(
+        onClick,
+        Modifier.size(44.dp),
+        colors = if (showing) GsColors(scheme.secondaryContainer, scheme.onSecondaryContainer)
+        else GsColors(scheme.surfaceVariant, scheme.onSurfaceVariant),
+        latched = showing,
+        onLongClick = onLongClick,
+    ) {
+        entry.icon?.let { Image(it, entry.label, Modifier.size(30.dp).clip(RoundedCornerShape(8.dp))) }
+        entry.builtIn?.let { Icon(it.glyph, entry.shownLabel(), Modifier.size(26.dp)) }
+        // Only running apps get the line along the bottom edge, the usual taskbar mark for it.
+        if (open) {
+            Box(
+                Modifier
+                    .align(Alignment.BottomCenter)
+                    .padding(bottom = 2.dp)
+                    .size(width = 12.dp, height = 3.dp)
+                    .clip(RoundedCornerShape(50))
+                    .background(scheme.primary),
+            )
+        }
+    }
+}
+
+/** A tappable group in the bar that stays highlighted while its screen is open, like [NavItem]. */
+@Composable
+private fun NavChip(selected: Boolean, onClick: () -> Unit, content: @Composable BoxScope.() -> Unit) {
+    GsIconBox(onClick, colors = navColors(selected), latched = selected) {
+        Box(Modifier.padding(horizontal = 10.dp, vertical = 2.dp)) { content() }
+    }
+}
+
+/** Every nav bar item is raised, so it reads as pressable; the current screen's takes the accent colour. */
+@Composable
+private fun navColors(selected: Boolean): GsColors {
+    val s = MaterialTheme.colorScheme
+    return if (selected) GsColors(s.secondaryContainer, s.onSecondaryContainer)
+    else GsColors(s.surfaceContainerHighest, s.onSurface)
+}
+
+/**
+ * Between Apps and whatever's actually open, not with the clock/battery group on the right - a
+ * driver reaches for it right after deciding "not a tap for this", same gesture family as the
+ * two buttons beside it.
+ */
+@Composable
+private fun NavAssistantIcon() {
+    val state by CarAssistant.state.collectAsState()
+    val active = state.phase != CarAssistant.Phase.IDLE
+    GsIconBox({ CarAssistant.start() }, colors = navColors(active), latched = active) {
+        MicGlyph(Modifier.padding(NAV_ITEM_PADDING).size(28.dp))
+    }
+}
+
+/** Inner padding of every icon on the nav bar, leaving each button room inside the 56dp bar. */
+private val NAV_ITEM_PADDING = 8.dp
+
+@Composable
+private fun NavItem(icon: ImageVector, selected: Boolean, onClick: () -> Unit) {
+    GsIconBox(onClick, colors = navColors(selected), latched = selected) {
+        Icon(icon, contentDescription = null, modifier = Modifier.padding(NAV_ITEM_PADDING).size(28.dp))
+    }
+}
+
+/** Wall-clock time, ticking on the minute: no reason to redraw (and re-encode) more often. */
+@Composable
+internal fun rememberNow(): State<Long> = produceState(System.currentTimeMillis()) {
+    while (true) {
+        value = System.currentTimeMillis()
+        delay(60_000 - value % 60_000)
+    }
+}
+
+/** How long the pill shows a new song's title before settling to just the controls. */
+private const val TITLE_SHOWN_MS = 3_000L
+
+/** Below this, the nav bar's middle only has room for the turn, not the player beside it. */
+private val TURN_AND_PLAYER_MIN_WIDTH = 520.dp
+
+/** The next manoeuvre, as the running nav app last described it. */
+private class NextTurn(val icon: CarIcon?, val distance: String, val road: String)
+
+/**
+ * Read straight off the nav app's own template: a navigation app keeps sending its routing card
+ * while it's running, whether or not the map is the screen being shown.
+ */
+@Composable
+private fun rememberNextTurn(): NextTurn? {
+    val status by CarServices.nav.status.collectAsState()
+    val template by CarServices.nav.template.collectAsState()
+    // Read so a change of units redraws the distance straight away, not at the next update.
+    CarSettings.units.collectAsState().value
+    if (status.phase != CarAppConnection.Phase.RUNNING) return null
+    val routing = (template as? NavigationTemplate)?.navigationInfo as? RoutingInfo ?: return null
+    if (routing.isLoading) return null
+    val step = routing.currentStep ?: return null
+    return NextTurn(
+        icon = step.maneuver?.icon,
+        distance = routing.currentDistance.display(),
+        road = step.road.text().ifEmpty { step.cue.text() },
+    )
+}
+
+/** The next turn in the nav bar: arrow, how far, onto what. Tapping goes back to the map. */
+@Composable
+private fun NavTurnPill(turn: NextTurn, onClick: () -> Unit) {
+    // Same finish as every other button on the bar, in the accent colour; the text runs a step
+    // bigger than anything else there, since it's the one thing worth a glance mid-drive.
+    GsIconBox(
+        onClick,
+        Modifier.widthIn(max = 340.dp).height(44.dp),
+        colors = gsColors(GsTone.Primary),
+    ) {
+        Row(
+            Modifier.padding(NAV_ITEM_PADDING),
+            verticalAlignment = Alignment.CenterVertically,
+            horizontalArrangement = Arrangement.spacedBy(8.dp),
+        ) {
+            CarGlyph(turn.icon, Modifier.size(28.dp))
+            if (turn.distance.isNotEmpty()) {
+                Text(turn.distance, style = MaterialTheme.typography.titleLarge, fontWeight = FontWeight.Bold, maxLines = 1)
+            }
+            if (turn.road.isNotEmpty()) {
+                Text(
+                    turn.road,
+                    style = MaterialTheme.typography.titleMedium,
+                    fontWeight = FontWeight.SemiBold,
+                    maxLines = 1,
+                    overflow = TextOverflow.Ellipsis,
+                )
+            }
+        }
+    }
+}
+
+/** The call under way: who, how long, and Mute and End right here. Ringing has its own screen. */
+@Composable
+private fun NavCallPill(call: CallUiState.Active, modifier: Modifier = Modifier) {
+    val context = LocalContext.current.applicationContext
+    val muted by CarCalls.muted.collectAsState()
+    val elapsed by produceState(0L, call.since) {
+        while (true) {
+            value = (android.os.SystemClock.uptimeMillis() - call.since) / 1000
+            delay(1000 - (android.os.SystemClock.uptimeMillis() - call.since) % 1000)
+        }
+    }
+    val scheme = MaterialTheme.colorScheme
+    Surface(
+        modifier = modifier.height(44.dp),
+        shape = RoundedCornerShape(14.dp),
+        color = scheme.secondaryContainer,
+        contentColor = scheme.onSecondaryContainer,
+    ) {
+        Row(
+            Modifier.fillMaxHeight().padding(start = 12.dp, end = 4.dp),
+            verticalAlignment = Alignment.CenterVertically,
+            horizontalArrangement = Arrangement.spacedBy(6.dp),
+        ) {
+            Icon(Icons.Filled.Call, contentDescription = null, modifier = Modifier.size(20.dp))
+            Text(
+                call.caller?.label ?: stringResource(R.string.navbar_on_call),
+                style = MaterialTheme.typography.titleSmall,
+                fontWeight = FontWeight.SemiBold,
+                maxLines = 1,
+                overflow = TextOverflow.Ellipsis,
+                modifier = Modifier.weight(1f, fill = false),
+            )
+            Text(
+                "%d:%02d".format(elapsed / 60, elapsed % 60),
+                style = MaterialTheme.typography.titleSmall,
+                maxLines = 1,
+            )
+            Spacer(Modifier.width(2.dp))
+            GsIconButton(
+                if (muted) MediaIcons.MicOff else MediaIcons.Mic,
+                stringResource(if (muted) R.string.navbar_unmute else R.string.navbar_mute),
+                CarCalls::toggleMute,
+                tone = if (muted) GsTone.Primary else GsTone.Neutral, size = 36.dp, iconSize = 22.dp,
+            )
+            GsIconButton(
+                MediaIcons.CallEnd, stringResource(R.string.navbar_end_call), { CarCalls.end(context) },
+                colors = GsColors(scheme.error, scheme.onError), size = 36.dp, iconSize = 22.dp,
+            )
+        }
+    }
+}
+
+/** "Title - Artist" on one line. The text itself cuts it off, and only where the pill runs out of room. */
+@Composable
+private fun nowPlayingLabel(title: String, artist: String): String =
+    listOf(title.trim(), artist.trim()).filter { it.isNotEmpty() }.joinToString(" - ")
+        .ifEmpty { stringResource(R.string.media_nothing_playing) }
+
+/**
+ * The player in the nav bar, on every screen. Art and title open the full media screen;
+ * play/pause and skip work right here. The dock button moves the player into the column beside
+ * the map on Home (see [CarHome]), and the pill steps aside there while it's docked - unless the
+ * column is showing lyrics instead, when the pill stays and its dock button closes them.
+ */
+@Composable
+private fun NavNowPlaying(navigator: CarNavigator, selected: Boolean, modifier: Modifier = Modifier) {
+    val media = CarServices.media
+    val phase by media.phase.collectAsState()
+    val now by media.now.collectAsState()
+    if (phase != CarMedia.Phase.READY || !now.isActive) return
+    // Docked beside the map, the player is already on screen - the pill steps aside for it.
+    if (navigator.sidePanel == SidePanel.CONTROLS && navigator.current == CarScreen.Home) return
+    // The media screen is the full player already; the pill would only repeat its controls.
+    if (navigator.current == CarScreen.Media) return
+    val context = LocalContext.current
+    val art by produceState(now.art, now.art, now.artUri) { value = now.art ?: MediaArt.load(context, now.artUri) }
+    val position by produceState(now.currentPosition(), now) {
+        while (true) {
+            value = now.currentPosition()
+            if (!now.playing) break
+            delay(1000)
+        }
+    }
+
+    // A new song announces itself: title, play/pause and dock for a few seconds, then the title
+    // goes and the pill settles to just the controls - unless the driver keeps the title up.
+    val keepTitle by CarSettings.playerTitle.collectAsState()
+    var announcing by remember { mutableStateOf(true) }
+    LaunchedEffect(now.title, now.artist) {
+        announcing = true
+        delay(TITLE_SHOWN_MS)
+        announcing = false
+    }
+    val showTitle = keepTitle || announcing
+
+    val scheme = MaterialTheme.colorScheme
+    val onPill = if (selected) scheme.onPrimaryContainer else scheme.onSecondaryContainer
+    Surface(
+        modifier = modifier
+            .animateContentSize()
+            // With the title up, all the room the bar has, so as much of it shows as can.
+            .then(if (showTitle) Modifier.fillMaxWidth() else Modifier)
+            .height(44.dp),
+        shape = RoundedCornerShape(14.dp),
+        color = if (selected) scheme.primaryContainer else scheme.secondaryContainer,
+        contentColor = onPill,
+    ) {
+        Box {
+            Row(
+                Modifier.fillMaxHeight().padding(horizontal = 4.dp),
+                verticalAlignment = Alignment.CenterVertically,
+                horizontalArrangement = Arrangement.spacedBy(6.dp),
+            ) {
+                // Art (and the title while it shows) opens the full media screen.
+                Row(
+                    Modifier
+                        .then(if (showTitle) Modifier.weight(1f) else Modifier)
+                        .fillMaxHeight()
+                        .clip(RoundedCornerShape(10.dp))
+                        .clickable { navigator.media() },
+                    verticalAlignment = Alignment.CenterVertically,
+                    horizontalArrangement = Arrangement.spacedBy(8.dp),
+                ) {
+                    Box(Modifier.size(34.dp).clip(RoundedCornerShape(8.dp)).background(scheme.surfaceVariant)) {
+                        art?.let { Image(it.asImageBitmap(), null, Modifier.fillMaxSize(), contentScale = ContentScale.Crop) }
+                    }
+                    if (showTitle) {
+                        Text(
+                            nowPlayingLabel(now.title, now.artist),
+                            style = MaterialTheme.typography.titleSmall,
+                            fontWeight = FontWeight.SemiBold,
+                            maxLines = 1,
+                            overflow = TextOverflow.Ellipsis,
+                        )
+                    }
+                }
+                if (!showTitle) {
+                    GsIconButton(
+                        MediaIcons.Previous, stringResource(R.string.player_previous), media::previous,
+                        enabled = now.canDo(PlaybackState.ACTION_SKIP_TO_PREVIOUS), size = 36.dp, iconSize = 22.dp,
+                    )
+                }
+                GsIconButton(
+                    if (now.playing) MediaIcons.Pause else Icons.Filled.PlayArrow,
+                    stringResource(if (now.playing) R.string.player_pause else R.string.media_play),
+                    media::togglePlay,
+                    tone = GsTone.Primary, size = 36.dp, iconSize = 22.dp,
+                )
+                if (!showTitle) {
+                    GsIconButton(
+                        MediaIcons.Next, stringResource(R.string.player_next), media::next,
+                        enabled = now.canDo(PlaybackState.ACTION_SKIP_TO_NEXT), size = 36.dp, iconSize = 22.dp,
+                    )
+                }
+                // Drawn on the side the panel opens on, and filled in while it's open.
+                val playerLeft by CarSettings.playerLeft.collectAsState()
+                val docked = navigator.current == CarScreen.Home && navigator.sidePanel != SidePanel.NONE
+                GsIconButton(
+                    when {
+                        playerLeft && docked -> MediaIcons.DockLeftOpen
+                        playerLeft -> MediaIcons.DockLeft
+                        docked -> MediaIcons.DockRightOpen
+                        else -> MediaIcons.DockRight
+                    },
+                    stringResource(if (docked) R.string.navbar_close_panel else R.string.navbar_dock_player),
+                    navigator::togglePlayerDock,
+                    size = 36.dp, iconSize = 22.dp,
+                )
+            }
+            if (now.durationMs > 0) {
+                // matchParentSize, so the line follows the pill's width rather than widening it.
+                Box(Modifier.matchParentSize(), contentAlignment = Alignment.BottomStart) {
+                    Box(
+                        Modifier
+                            .fillMaxWidth((position.toFloat() / now.durationMs).coerceIn(0f, 1f))
+                            .height(2.dp)
+                            .background(onPill.copy(alpha = 0.7f)),
+                    )
+                }
+            }
+        }
+    }
+}
+
+/**
+ * A filled lightning bolt, next to the battery percentage instead of the word "charging" - the
+ * core Material icon set this project ships (no extended pack, to keep the app small) has no
+ * bolt, so this is drawn rather than a vector asset.
+ */
+@Composable
+private fun ChargingGlyph(modifier: Modifier = Modifier, tint: Color = MaterialTheme.colorScheme.onSurfaceVariant) {
+    androidx.compose.foundation.Canvas(modifier) {
+        val w = size.width
+        val h = size.height
+        val bolt = androidx.compose.ui.graphics.Path().apply {
+            moveTo(w * 0.58f, 0f)
+            lineTo(w * 0.12f, h * 0.58f)
+            lineTo(w * 0.46f, h * 0.58f)
+            lineTo(w * 0.42f, h)
+            lineTo(w * 0.88f, h * 0.40f)
+            lineTo(w * 0.54f, h * 0.40f)
+            close()
+        }
+        drawPath(bolt, tint)
+    }
+}

gearslip/src/main/java/app/seb3thehacker/gearslip/car/CarNavigator.kt

@@ -1,5 +1,9 @@
 package app.seb3thehacker.gearslip.car
 
+import androidx.compose.runtime.Composable
+import androidx.annotation.StringRes
+import androidx.compose.ui.res.stringResource
+import app.seb3thehacker.gearslip.R
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateListOf
 import androidx.compose.runtime.mutableStateOf
@@ -41,7 +45,11 @@ sealed interface CarScreen {
 enum class SidePanel { NONE, CONTROLS, LYRICS }
 
 /** One step on the breadcrumb trail: the screen it shows and the word for it in the trail. */
-data class Crumb(val screen: CarScreen, val label: String)
+data class Crumb(val screen: CarScreen, val label: String, @param:StringRes val labelRes: Int = 0) {
+    /** [labelRes] when the step is one of Gearslip's own, translated; [label] for an app's own name. */
+    @Composable
+    fun shown(): String = if (labelRes != 0) stringResource(labelRes) else label
+}
 
 /**
  * Where the car UI is, and how it got there. A car touchscreen has no hardware back button, so
@@ -57,6 +65,7 @@ class CarNavigator(startId: String) {
         Crumb(
             if (CarApps.find(startId) != null) CarScreen.App(startId) else CarScreen.Home,
             "Home",
+            R.string.crumb_home,
         ),
     )
 
@@ -69,15 +78,15 @@ class CarNavigator(startId: String) {
 
     /** Pushes a new step, unless it's the same screen already on top - tapping the button for
      * where you already are shouldn't grow the trail. */
-    private fun push(screen: CarScreen, label: String) {
+    private fun push(screen: CarScreen, label: String, @StringRes labelRes: Int = 0) {
         if (stack.last().screen == screen) return
-        stack.add(Crumb(screen, label))
+        stack.add(Crumb(screen, label, labelRes))
     }
 
     /** The one way back to a clean slate: resets the whole trail to just Home. */
     fun home() {
         stack.clear()
-        stack.add(Crumb(CarScreen.Home, "Home"))
+        stack.add(Crumb(CarScreen.Home, "Home", R.string.crumb_home))
     }
 
     /**
@@ -90,8 +99,9 @@ class CarNavigator(startId: String) {
         private set
 
     /**
-     * The pill's dock button: moves the player beside the map, going Home first if need be. With
-     * lyrics already there it swaps them for the controls; with the controls there it closes.
+     * The pill's dock button, an open/close switch for the panel: moves the player beside the map,
+     * going Home first if need be, or closes the panel when something is already there. Switching
+     * between the player and lyrics is done inside the panel itself.
      */
     fun togglePlayerDock() {
         if (current != CarScreen.Home) {
@@ -99,9 +109,11 @@ class CarNavigator(startId: String) {
             home()
             return
         }
-        sidePanel = if (sidePanel == SidePanel.CONTROLS) SidePanel.NONE else SidePanel.CONTROLS
+        sidePanel = if (sidePanel == SidePanel.NONE) SidePanel.CONTROLS else SidePanel.NONE
     }
 
+    fun showSidePlayer() { sidePanel = SidePanel.CONTROLS }
+
     fun showSideLyrics() { sidePanel = SidePanel.LYRICS }
 
     fun closeSidePanel() { sidePanel = SidePanel.NONE }
@@ -114,17 +126,17 @@ class CarNavigator(startId: String) {
 
     fun dismissAppMenu() { appMenu = null }
 
-    fun media() { push(CarScreen.Media, "Media") }
+    fun media() { push(CarScreen.Media, "Media", R.string.crumb_media) }
 
     fun browse(label: String) { push(CarScreen.Browse, label) }
 
-    fun apps() { push(CarScreen.Apps, "Apps") }
+    fun apps() { push(CarScreen.Apps, "Apps", R.string.crumb_apps) }
 
-    fun settings() { push(CarScreen.Settings, "Settings") }
+    fun settings() { push(CarScreen.Settings, "Settings", R.string.settings_title) }
 
-    fun dashboard() { push(CarScreen.Dashboard, "Dashboard") }
+    fun dashboard() { push(CarScreen.Dashboard, "Dashboard", R.string.crumb_dashboard) }
 
-    fun weather() { push(CarScreen.Weather, "Weather") }
+    fun weather() { push(CarScreen.Weather, "Weather", R.string.crumb_weather) }
 
     fun vehicleData() { push(CarScreen.VehicleData, "Vehicle data") }
 
@@ -132,10 +144,10 @@ class CarNavigator(startId: String) {
 
     /** The list lives on the dashboard; only a reply gets a screen of its own. */
     fun notifications(replyTo: String? = null) {
-        if (replyTo == null) dashboard() else push(CarScreen.Notifications(replyTo), "Reply")
+        if (replyTo == null) dashboard() else push(CarScreen.Notifications(replyTo), "Reply", R.string.crumb_reply)
     }
 
-    fun open(id: String) { push(CarScreen.App(id), CarApps.find(id)?.label ?: id) }
+    fun open(id: String) { push(CarScreen.App(id), CarApps.find(id)?.label ?: id, CarApps.find(id)?.labelRes ?: 0) }
 
     /** Jumps straight to a step already on the trail, dropping everything after it - what
      * tapping a breadcrumb does. Index 0 (Home) is always on the trail, so this always succeeds. */

gearslip/src/main/java/app/seb3thehacker/gearslip/car/CarSensors.kt

@@ -5,16 +5,7 @@ import app.seb3thehacker.gearslip.Wire
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.StateFlow
 
-/**
- * Everything the head unit's sensor channel has offered and sent, for the "Vehicle data" screen.
- *
- * [ServiceDiscovery.findSensorService] tells us which numeric sensor types this head unit is
- * willing to stream; [SensorType] names the ones publicly documented by other AA reverse-engineering
- * projects (aasdk, openauto). That mapping is carried over from other projects, not verified
- * against this exact unit, so it's a label, not a guarantee - the raw field dump next to it is
- * the ground truth. Once [onEvent] starts decoding real traffic from the 2018 Uconnect, correct
- * any type that turns out to be mislabeled.
- */
+/** Raw sensor readings, keyed by SensorBatch field number, which matches the sensor type id. */
 object CarSensors {
 
     data class Reading(val typeId: Int, val typeName: String, val raw: String, val updatedAtMs: Long)
@@ -30,16 +21,10 @@ object CarSensors {
         }
     }
 
-    /**
-     * One SensorEventIndication. Every reverse-engineered version of this message multiplexes
-     * every sensor type into one shared set of message-level field numbers (field N = "the data
-     * for sensor type N", roughly) rather than tagging events with the type id from
-     * SensorType.type - so field number is read here as a best-effort type id, same as the
-     * other services in this file.
-     */
+    /** Each SensorBatch field contains repeated readings of one sensor type. */
     fun onEvent(body: ByteArray) {
         val now = System.currentTimeMillis()
-        val fields = Wire.fields(body)
+        val fields = Wire.fields(body).filter { it.wireType == 2 }
         val byType = fields.groupBy { it.number }
         val updated = byType.mapValues { (number, group) ->
             Reading(
@@ -61,10 +46,7 @@ object CarSensors {
     }
 }
 
-/**
- * Sensor type ids as named across public Android Auto reverse-engineering references. Treated as
- * a label, not a fact - see [CarSensors] doc.
- */
+/** Sensor type values shared by the discovery service and SensorBatch. */
 object SensorType {
     private val NAMES = mapOf(
         1 to "Location (GPS)",
@@ -87,8 +69,12 @@ object SensorType {
         18 to "Tire pressure",
         19 to "Accelerometer",
         20 to "Gyroscope",
-        21 to "Gravity",
-        22 to "Wheel tick / distance",
+        21 to "GPS satellites",
+        22 to "Toll card",
+        23 to "Vehicle energy model",
+        24 to "Trailer",
+        25 to "Raw vehicle energy model",
+        26 to "Raw EV trip settings",
     )
 
     fun name(id: Int): String = NAMES[id]?.let { "$it (#$id)" } ?: "Sensor #$id"

gearslip/src/main/java/app/seb3thehacker/gearslip/car/CarServices.kt

@@ -33,6 +33,12 @@ object CarServices {
     val nav: CarAppConnection by lazy { CarAppConnection(requireNotNull(context)) }
     val media: CarMedia by lazy { CarMedia(requireNotNull(context)) }
 
+    /** [nav], or null before the car screen has set things up. */
+    fun navOrNull(): CarAppConnection? = if (context != null) nav else null
+
+    /** [media], or null before the car screen has set things up: for code outside the car UI. */
+    fun mediaOrNull(): CarMedia? = if (context != null) media else null
+
     /**
      * A second, independent connection for templated apps that aren't navigation apps - Spotify's
      * own Car App Library service is the first of these. Kept apart from [nav] so opening one
@@ -54,11 +60,22 @@ object CarServices {
     private var navStopped = false
     private var autoplayPending = false
 
+    /**
+     * The app that was playing when the driver opened another one. Opening an app is only a look
+     * at its library: until something plays there, the music carries on in this one, so leaving
+     * the new app's screen goes back to it, as Android Auto does.
+     */
+    private var stillPlaying: MediaApp? = null
+
     fun init(appContext: Context) {
         context = appContext.applicationContext
         app.seb3thehacker.gearslip.notify.CarMotion.start(appContext)
         app.seb3thehacker.gearslip.call.CarCalls.start(appContext)
         CarAssistant.init(appContext)
+        DirectionsVoice.init(appContext)
+        CarBluetooth.init(appContext)
+        BluetoothAudioCheck.init(appContext)
+        LocationCheck.init(appContext)
         CarKeys.init(appContext)
         VoiceReply.init(appContext)
         // Loaded now, while nothing's waiting on it, so the first reply isn't slower than the rest.
@@ -79,15 +96,22 @@ object CarServices {
         if (destination != null && nav.connectedComponent == app.component) {
             nav.navigateTo(destination)
         } else {
+            // Another map app taking over ends the old one's route, or it keeps guiding unseen.
+            if (nav.connectedComponent != app.component) endRoute()
             nav.connect(app, frame.width, frame.height, frame.densityDpi, destination)
         }
     }
 
     fun stopNav() {
         navStopped = true
+        endRoute()
         nav.disconnect()
     }
 
+    private fun endRoute() {
+        if (nav.navigating) nav.stopNavigating()
+    }
+
     /** Undoes [stopNav]'s hold so the last map app comes back, same as it would after a restart. */
     suspend fun reconnectNav(frame: CarEnvironment.Frame) {
         navStopped = false
@@ -113,6 +137,8 @@ object CarServices {
         val live = phase == CarMedia.Phase.READY || phase == CarMedia.Phase.CONNECTING
         if (_mediaApp.value?.component == app.component && live) return
 
+        val previous = _mediaApp.value
+        stillPlaying = previous?.takeIf { it.component != app.component && media.now.value.playing && !autoplay }
         _mediaApp.value = app
         autoplayPending = autoplay
         media.connect(app)
@@ -121,12 +147,39 @@ object CarServices {
         if (CarSettings.pipeAudio.value) CarAudio.request()
     }
 
+    /**
+     * Reopens the media app used last, for the car's media button when nothing is open. False
+     * when there's none on record or it's been uninstalled since.
+     */
+    suspend fun reopenLastMedia(): Boolean {
+        val ctx = context ?: return false
+        val last = CarSettings.lastMedia.value?.let(ComponentName::unflattenFromString) ?: return false
+        val app = withContext(Dispatchers.IO) { MediaCatalog.installed(ctx) }
+            .firstOrNull { it.component == last } ?: return false
+        openMedia(app)
+        return true
+    }
+
+    /**
+     * The media screen closed. If nothing started in the app it showed, go back to the one that
+     * kept playing meanwhile, so the player and its buttons follow the music you can hear.
+     */
+    fun mediaScreenClosed() {
+        val back = stillPlaying ?: return
+        stillPlaying = null
+        // A track loaded here, even one paused since, means the driver used this app.
+        if (media.now.value.playing || media.now.value.title.isNotEmpty()) return
+        app.seb3thehacker.gearslip.GearslipLog.i("media: nothing played in ${_mediaApp.value?.label}, back to ${back.label}")
+        openMedia(back)
+    }
+
     /** Closes the media app from the car: stops what it's playing and drops the connection. */
     fun closeMedia() {
         if (media.now.value.playing) media.togglePlay()
         media.disconnect()
         _mediaApp.value = null
         autoplayPending = false
+        stillPlaying = null
     }
 
     /** Called once the media app is connected: starts playback if that was asked for. */
@@ -148,7 +201,7 @@ object CarServices {
             _hasNavApps.value = navApps.isNotEmpty()
             // Never auto-pick one already known to fail outright - a driver who plugs in should
             // land on a map, not on the one tile marked with a red X.
-            val candidates = navApps.filterNot { KnownApps.isBroken(it.component.packageName) }
+            val candidates = navApps.filterNot { KnownApps.isBroken(ctx, it.component.packageName) }
             val last = CarSettings.lastNav.value
             // The one used last, or - first run, nothing on record yet - whichever comes first:
             // a driver who plugs in for the first time shouldn't have to go pick one by hand
@@ -194,6 +247,32 @@ object CarServices {
         return playingPackages.firstNotNullOfOrNull { pkg -> catalog.firstOrNull { it.component.packageName == pkg } }
     }
 
+    /**
+     * The car went away mid-song: pause it, as Android Auto does, so it doesn't carry on out of
+     * the phone's speaker. Unplugging a USB accessory isn't "audio becoming noisy" the way
+     * headphones are, so the apps won't pause themselves. Every playing session is paused, not
+     * just the one Gearslip opened: anything the car was playing was going through the car.
+     */
+    fun pausePhoneMedia(why: String = "the car left") {
+        val ctx = context ?: return
+        val manager = ctx.getSystemService(MediaSessionManager::class.java)
+        val listener = ComponentName(ctx, GearslipNotificationListener::class.java)
+        val playing = try {
+            manager.getActiveSessions(listener).filter { it.playbackState?.state == PlaybackState.STATE_PLAYING }
+        } catch (e: SecurityException) {
+            null
+        }
+        if (playing == null) {
+            // No notification access: the app Gearslip itself is driving is all it can reach.
+            mediaOrNull()?.let { if (it.now.value.playing) it.togglePlay() }
+            return
+        }
+        playing.forEach { runCatching { it.transportControls.pause() } }
+        if (playing.isNotEmpty()) {
+            app.seb3thehacker.gearslip.GearslipLog.i("media: paused ${playing.joinToString { it.packageName }}: $why")
+        }
+    }
+
     /** The car went away: nothing should keep running for a screen that no longer exists. */
     fun shutdown() {
         context?.let { app.seb3thehacker.gearslip.notify.CarMotion.stop(it) }
@@ -202,6 +281,8 @@ object CarServices {
         runCatching { media.disconnect() }
         runCatching { browse.disconnect() }
         CarAssistant.cancel()
+        // About 900 MB that nothing needs once the car's gone.
+        app.seb3thehacker.gearslip.speech.SpeechEngine.unload()
         CarAudio.release()
         _mediaApp.value = null
         navStopped = false

gearslip/src/main/java/app/seb3thehacker/gearslip/car/CarSettings.kt

@@ -1,7 +1,9 @@
 package app.seb3thehacker.gearslip.car
 
+import app.seb3thehacker.gearslip.car.theme.DarkStyle
 import android.content.Context
 import app.seb3thehacker.gearslip.AppSettings
+import app.seb3thehacker.gearslip.audio.CarAudio
 import app.seb3thehacker.gearslip.car.theme.GsTheme
 import app.seb3thehacker.gearslip.car.theme.GsThemes
 import kotlinx.coroutines.flow.MutableStateFlow
@@ -17,6 +19,33 @@ enum class Units { AUTO, IMPERIAL, METRIC }
 /** The car UI's own colours. Separate from [NightMode], which is about the light outside (the map). */
 enum class AppTheme { PHONE, LIGHT, DARK }
 
+/** A screen's width and height in pixels, as someone typed it: "1280x480". */
+data class ScreenSize(val width: Int, val height: Int) {
+    override fun toString() = "${width}x$height"
+
+    companion object {
+        fun parse(text: String?): ScreenSize? {
+            val parts = text?.lowercase()?.split('x', '×', ' ')?.filter { it.isNotBlank() } ?: return null
+            if (parts.size != 2) return null
+            val w = parts[0].trim().toIntOrNull() ?: return null
+            val h = parts[1].trim().toIntOrNull() ?: return null
+            return if (w in 100..8000 && h in 100..8000) ScreenSize(w, h) else null
+        }
+    }
+}
+
+/**
+ * How a head unit puts our frame on a screen of another shape. [CROP] cuts the edges off, as
+ * a car's own margins do; [SQUASH] shrinks the whole frame to fit, stretching everything.
+ */
+enum class ScreenFit { CROP, SQUASH }
+
+/** What size the phone's car preview draws: the last car's, this device's whole screen, or one typed in. */
+enum class PreviewSize { LAST_CAR, FILL, CUSTOM }
+
+/** When the nav bar gets out of the way: never, during a route, or whenever the map is up. */
+enum class NavBarMode { SHOW, HIDE_NAVIGATING, HIDE }
+
 /**
  * Settings changed from the car screen itself. Held as flows so the car UI reacts the moment a
  * button is tapped, and persisted through [AppSettings] so they survive the next connection.
@@ -27,19 +56,34 @@ object CarSettings {
     private const val KEY_OPEN = "car_open_on_connect"
     private const val KEY_NIGHT = "car_night_mode"
     private const val KEY_PIPE_AUDIO = "car_pipe_audio"
+private const val KEY_SPEAK_DIRECTIONS = "car_speak_directions"
+private const val KEY_BLUETOOTH_WARNING = "car_bluetooth_warning"
+private const val KEY_LOCATION_WARNING = "car_location_warning"
+    private const val KEY_AUDIO_CHOICE_ASKED = "car_audio_choice_asked"
     private const val KEY_LAST_NAV = "car_last_nav"
     private const val KEY_LAST_MEDIA = "car_last_media"
     private const val KEY_AUTOPLAY = "car_autoplay"
     private const val KEY_PLAYER_TITLE = "car_player_title"
+    private const val KEY_PLAYER_LEFT = "car_player_left"
+    private const val KEY_MORE_LYRICS = "car_more_lyrics"
     private const val KEY_THEME = "car_app_theme"
     private const val KEY_UI_THEME = "car_ui_theme"
+    private const val KEY_DARK_STYLE = "car_dark_style"
     private const val KEY_PINNED = "car_pinned_apps"
     private const val KEY_APP_ORDER = "car_app_order"
     private const val KEY_EXPERIMENTAL_FEATURES = "car_experimental_features"
-    private const val KEY_VOICE_ASSISTANT = "car_voice_assistant"
+    private const val KEY_SYSTEM_SPEECH = "car_system_speech"
     private const val KEY_CAR_SENSORS = "car_sensors_enabled"
+    private const val KEY_ADAPTIVE_VIDEO = "adaptive_video_enabled"
+private const val KEY_CLUSTER_VIDEO = "cluster_video_enabled"
+    private const val KEY_DEBUG_BADGE = "debug_badge"
     private const val KEY_SEEN_SAFETY_WARNING = "car_seen_safety_warning"
     private const val KEY_UNITS = "car_units"
+    private const val KEY_NAV_BAR = "car_nav_bar"
+    private const val KEY_SCREEN_SIZE = "car_screen_size"
+    private const val KEY_SCREEN_FIT = "car_screen_fit"
+    private const val KEY_PREVIEW_SIZE = "preview_size"
+    private const val KEY_PREVIEW_CUSTOM = "preview_custom_size"
     private const val KEY_WHATS_NEW = "car_whats_new_after_updates"
     private const val KEY_WHATS_NEW_SEEN = "car_whats_new_seen_code"
 
@@ -56,12 +100,21 @@ object CarSettings {
     private val openFlow = MutableStateFlow(HOME)
     private val nightFlow = MutableStateFlow(NightMode.AUTO)
     private val pipeAudioFlow = MutableStateFlow(true)
+    private val speakDirectionsFlow = MutableStateFlow(true)
+    private val bluetoothWarningFlow = MutableStateFlow(true)
+    private val locationWarningFlow = MutableStateFlow(true)
     private val lastNavFlow = MutableStateFlow<String?>(null)
     private val lastMediaFlow = MutableStateFlow<String?>(null)
     private val autoplayFlow = MutableStateFlow(false)
     private val playerTitleFlow = MutableStateFlow(false)
+    private val playerLeftFlow = MutableStateFlow(false)
+    private val moreLyricsFlow = MutableStateFlow(true)
     private val themeFlow = MutableStateFlow(AppTheme.PHONE)
     val appTheme: StateFlow<AppTheme> = themeFlow
+    private val darkStyleFlow = MutableStateFlow(DarkStyle.BLACK)
+
+    /** How dark the car's dark mode goes; black until the driver picks another. */
+    val darkStyle: StateFlow<DarkStyle> = darkStyleFlow
     private val uiThemeFlow = MutableStateFlow(GsThemes.default.id)
 
     /** Id of the [GsTheme] controls are drawn in; an unknown id falls back to the default. */
@@ -69,13 +122,53 @@ object CarSettings {
     private val pinnedFlow = MutableStateFlow<Set<String>>(emptySet())
     private val appOrderFlow = MutableStateFlow<List<String>>(emptyList())
     private val experimentalFeaturesFlow = MutableStateFlow(false)
-    private val voiceAssistantFlow = MutableStateFlow(false)
+    private val systemSpeechFlow = MutableStateFlow(false)
     private val carSensorsFlow = MutableStateFlow(false)
+    private val adaptiveVideoFlow = MutableStateFlow(false)
+    private val clusterVideoFlow = MutableStateFlow(false)
+    private val debugBadgeFlow = MutableStateFlow(true)
     private val seenSafetyWarningFlow = MutableStateFlow(false)
     private val unitsFlow = MutableStateFlow(Units.AUTO)
 
     val units: StateFlow<Units> = unitsFlow
 
+    private val screenSizeFlow = MutableStateFlow<ScreenSize?>(null)
+    private val screenFitFlow = MutableStateFlow(ScreenFit.CROP)
+    private val previewSizeFlow = MutableStateFlow(PreviewSize.LAST_CAR)
+    private val previewCustomFlow = MutableStateFlow<ScreenSize?>(null)
+
+    /** The car screen's real size, when the head unit gets it wrong; null trusts the head unit. */
+    val screenSize: StateFlow<ScreenSize?> = screenSizeFlow
+    val screenFit: StateFlow<ScreenFit> = screenFitFlow
+    val previewSize: StateFlow<PreviewSize> = previewSizeFlow
+    val previewCustom: StateFlow<ScreenSize?> = previewCustomFlow
+
+    /** Takes effect the next time the car connects: the video size is agreed at the start. */
+    fun setScreenSize(size: ScreenSize?) {
+        screenSizeFlow.value = size
+        AppSettings.putString(app, KEY_SCREEN_SIZE, size?.toString().orEmpty())
+    }
+
+    fun setScreenFit(fit: ScreenFit) {
+        screenFitFlow.value = fit
+        AppSettings.putString(app, KEY_SCREEN_FIT, fit.name)
+    }
+
+    fun setPreviewSize(size: PreviewSize, custom: ScreenSize? = previewCustomFlow.value) {
+        previewSizeFlow.value = size
+        previewCustomFlow.value = custom
+        AppSettings.putString(app, KEY_PREVIEW_SIZE, size.name)
+        AppSettings.putString(app, KEY_PREVIEW_CUSTOM, custom?.toString().orEmpty())
+    }
+
+    private val navBarFlow = MutableStateFlow(NavBarMode.SHOW)
+    val navBarMode: StateFlow<NavBarMode> = navBarFlow
+
+    fun setNavBarMode(mode: NavBarMode) {
+        navBarFlow.value = mode
+        AppSettings.putString(app, KEY_NAV_BAR, mode.name)
+    }
+
 
     private val whatsNewFlow = MutableStateFlow(true)
     private val whatsNewSeenFlow = MutableStateFlow(0)
@@ -138,6 +231,12 @@ object CarSettings {
      */
     val playerTitle: StateFlow<Boolean> = playerTitleFlow
 
+    /** The home screen's player sits left of the map instead of right of it. */
+    val playerLeft: StateFlow<Boolean> = playerLeftFlow
+
+    /** Lyrics from BetterLyrics and KuGou as well as LRCLIB; off sends song details to LRCLIB only. */
+    val moreLyrics: StateFlow<Boolean> = moreLyricsFlow
+
     val scale: StateFlow<Float> = scaleFlow
     val openOnConnect: StateFlow<String> = openFlow
     val nightMode: StateFlow<NightMode> = nightFlow
@@ -146,22 +245,41 @@ object CarSettings {
      * Whether a media app's sound is captured and sent over the car link. On by default, since
      * sound in the car is the point of the exercise; the platform allows the capture only behind a
      * consent dialog, which [app.seb3thehacker.gearslip.audio.CarAudio] raises once the car has
-     * somewhere to play it. Turned off, the app plays through the phone's normal output instead.
+     * somewhere to play it. Turned off ("Bluetooth" in the settings), the app plays through the
+     * phone's normal output instead, and Android never asks.
      */
     val pipeAudio: StateFlow<Boolean> = pipeAudioFlow
 
+    /** Gearslip reads the map app's turns aloud on the car's directions channel; see DirectionsVoice. */
+    val speakDirections: StateFlow<Boolean> = speakDirectionsFlow
+
+    /** With Bluetooth audio, warn when the phone isn't connected to the car; see BluetoothAudioCheck. */
+    val bluetoothWarning: StateFlow<Boolean> = bluetoothWarningFlow
+
+    /** Warn on the car when the phone's location is off; see LocationCheck. */
+    val locationWarning: StateFlow<Boolean> = locationWarningFlow
+
+    /**
+     * Whether the driver has already been offered Bluetooth after turning down the capture
+     * dialog. Offered once only: someone who chose to keep the USB route shouldn't be nagged.
+     */
+    /** False until the driver picks USB or Bluetooth, in setup or in settings. */
+    val pipeAudioChosen: Boolean
+        get() = AppSettings.getString(app, KEY_PIPE_AUDIO, "") != ""
+
+    val audioChoiceAsked: Boolean
+        get() = AppSettings.getString(app, KEY_AUDIO_CHOICE_ASKED, "false") == "true"
+
+    fun markAudioChoiceAsked() = AppSettings.putString(app, KEY_AUDIO_CHOICE_ASKED, "true")
+
     /**
      * Off by default: a driver has to opt into experimental features as a whole before any of
      * them - the voice assistant included - show up to turn on individually.
      */
     val experimentalFeaturesEnabled: StateFlow<Boolean> = experimentalFeaturesFlow
 
-    /**
-     * The voice assistant is experimental and off by default; a driver has to turn it on
-     * knowingly, from the settings screen, after reading the warning shown there. This flag
-     * alone does not run the assistant - [experimentalFeaturesEnabled] must also be on.
-     */
-    val voiceAssistantEnabled: StateFlow<Boolean> = voiceAssistantFlow
+    /** Listen with the phone's own speech service instead of Gearslip's on-device model. */
+    val systemSpeech: StateFlow<Boolean> = systemSpeechFlow
 
     /**
      * Vehicle data is experimental and off by default: the launcher's tile for it, and the
@@ -171,6 +289,27 @@ object CarSettings {
      */
     val carSensorsEnabled: StateFlow<Boolean> = carSensorsFlow
 
+    /**
+     * Video bitrate that backs off when the car, or the Wi-Fi to it, falls behind. Takes effect
+     * only while [experimentalFeaturesEnabled] is on too; untested in a car so far.
+     */
+    val adaptiveVideoEnabled: StateFlow<Boolean> = adaptiveVideoFlow
+
+    /**
+     * Gearslip's turn card on a car's instrument-cluster screen, for a car that offers one as a
+     * second video sink. Applies only while [experimentalFeaturesEnabled] is on too, and from the
+     * next connection; untested in a car so far.
+     */
+    val clusterVideoEnabled: StateFlow<Boolean> = clusterVideoFlow
+
+    /** Debug builds only: the car screen's DEBUG BUILD badge, which screenshots for the README leave out. */
+    val debugBadge: StateFlow<Boolean> = debugBadgeFlow
+
+    fun setDebugBadge(on: Boolean) {
+        debugBadgeFlow.value = on
+        AppSettings.putString(app, KEY_DEBUG_BADGE, on.toString())
+    }
+
     /**
      * Whether the car screen's own "drive safely" warning has already been shown and dismissed
      * once, from this same install. Separate from the phone side's own compat/safety dialogs -
@@ -193,10 +332,20 @@ object CarSettings {
         themeFlow.value = runCatching {
             AppTheme.valueOf(AppSettings.getString(app, KEY_THEME, AppTheme.PHONE.name))
         }.getOrDefault(AppTheme.PHONE)
+        darkStyleFlow.value = runCatching {
+            DarkStyle.valueOf(AppSettings.getString(app, KEY_DARK_STYLE, DarkStyle.BLACK.name))
+        }.getOrDefault(DarkStyle.BLACK)
         uiThemeFlow.value = AppSettings.getString(app, KEY_UI_THEME, GsThemes.default.id)
         autoplayFlow.value = AppSettings.getString(app, KEY_AUTOPLAY, "false") == "true"
         playerTitleFlow.value = AppSettings.getString(app, KEY_PLAYER_TITLE, "false") == "true"
+        playerLeftFlow.value = AppSettings.getString(app, KEY_PLAYER_LEFT, "false") == "true"
+        moreLyricsFlow.value = AppSettings.getString(app, KEY_MORE_LYRICS, "true") == "true"
         pipeAudioFlow.value = AppSettings.getString(app, KEY_PIPE_AUDIO, "true") == "true"
+        // Until the driver sets it, on for USB audio and off for Bluetooth, where the map app's
+        // own voice already reaches the car.
+        speakDirectionsFlow.value = AppSettings.getString(app, KEY_SPEAK_DIRECTIONS, pipeAudioFlow.value.toString()) == "true"
+        bluetoothWarningFlow.value = AppSettings.getString(app, KEY_BLUETOOTH_WARNING, "true") == "true"
+        locationWarningFlow.value = AppSettings.getString(app, KEY_LOCATION_WARNING, "true") == "true"
         nightFlow.value = runCatching {
             NightMode.valueOf(AppSettings.getString(app, KEY_NIGHT, NightMode.AUTO.name))
         }.getOrDefault(NightMode.AUTO)
@@ -205,12 +354,26 @@ object CarSettings {
         appOrderFlow.value = AppSettings.getString(app, KEY_APP_ORDER, "")
             .split(",").filter { it.isNotEmpty() }
         experimentalFeaturesFlow.value = AppSettings.getString(app, KEY_EXPERIMENTAL_FEATURES, "false") == "true"
-        voiceAssistantFlow.value = AppSettings.getString(app, KEY_VOICE_ASSISTANT, "false") == "true"
+        systemSpeechFlow.value = AppSettings.getString(app, KEY_SYSTEM_SPEECH, "false") == "true"
         carSensorsFlow.value = AppSettings.getString(app, KEY_CAR_SENSORS, "false") == "true"
+        adaptiveVideoFlow.value = AppSettings.getString(app, KEY_ADAPTIVE_VIDEO, "false") == "true"
+        clusterVideoFlow.value = AppSettings.getString(app, KEY_CLUSTER_VIDEO, "false") == "true"
+        debugBadgeFlow.value = AppSettings.getString(app, KEY_DEBUG_BADGE, "true") == "true"
         seenSafetyWarningFlow.value = AppSettings.getString(app, KEY_SEEN_SAFETY_WARNING, "false") == "true"
         unitsFlow.value = runCatching {
             Units.valueOf(AppSettings.getString(app, KEY_UNITS, Units.AUTO.name))
         }.getOrDefault(Units.AUTO)
+        screenSizeFlow.value = ScreenSize.parse(AppSettings.getString(app, KEY_SCREEN_SIZE, ""))
+        screenFitFlow.value = runCatching {
+            ScreenFit.valueOf(AppSettings.getString(app, KEY_SCREEN_FIT, ScreenFit.CROP.name))
+        }.getOrDefault(ScreenFit.CROP)
+        previewSizeFlow.value = runCatching {
+            PreviewSize.valueOf(AppSettings.getString(app, KEY_PREVIEW_SIZE, PreviewSize.LAST_CAR.name))
+        }.getOrDefault(PreviewSize.LAST_CAR)
+        previewCustomFlow.value = ScreenSize.parse(AppSettings.getString(app, KEY_PREVIEW_CUSTOM, ""))
+        navBarFlow.value = runCatching {
+            NavBarMode.valueOf(AppSettings.getString(app, KEY_NAV_BAR, NavBarMode.SHOW.name))
+        }.getOrDefault(NavBarMode.SHOW)
         whatsNewFlow.value = AppSettings.getString(app, KEY_WHATS_NEW, "true") == "true"
         whatsNewSeenFlow.value = AppSettings.getString(app, KEY_WHATS_NEW_SEEN, "0").toIntOrNull() ?: 0
     }
@@ -240,6 +403,11 @@ object CarSettings {
         AppSettings.putString(app, KEY_THEME, theme.name)
     }
 
+    fun setDarkStyle(style: DarkStyle) {
+        darkStyleFlow.value = style
+        AppSettings.putString(app, KEY_DARK_STYLE, style.name)
+    }
+
     fun setUiTheme(id: String) {
         uiThemeFlow.value = id
         AppSettings.putString(app, KEY_UI_THEME, id)
@@ -250,14 +418,47 @@ object CarSettings {
         AppSettings.putString(app, KEY_PLAYER_TITLE, on.toString())
     }
 
+    fun setPlayerLeft(on: Boolean) {
+        playerLeftFlow.value = on
+        AppSettings.putString(app, KEY_PLAYER_LEFT, on.toString())
+    }
+
+    fun setMoreLyrics(on: Boolean) {
+        moreLyricsFlow.value = on
+        AppSettings.putString(app, KEY_MORE_LYRICS, on.toString())
+    }
+
     fun setAutoplay(on: Boolean) {
         autoplayFlow.value = on
         AppSettings.putString(app, KEY_AUTOPLAY, on.toString())
     }
 
+    /**
+     * Takes effect at once: switching to Bluetooth mid-drive stops the capture, and switching
+     * back asks for it again (or waits for the car, if none is connected).
+     */
     fun setPipeAudio(on: Boolean) {
-        pipeAudioFlow.value = on
+        // Saved even when unchanged, so picking the default still counts as a choice.
         AppSettings.putString(app, KEY_PIPE_AUDIO, on.toString())
+        if (pipeAudioFlow.value == on) return
+        pipeAudioFlow.value = on
+        if (AppSettings.getString(app, KEY_SPEAK_DIRECTIONS, "") == "") speakDirectionsFlow.value = on
+        if (on) CarAudio.request() else CarAudio.release()
+    }
+
+    fun setSpeakDirections(on: Boolean) {
+        speakDirectionsFlow.value = on
+        AppSettings.putString(app, KEY_SPEAK_DIRECTIONS, on.toString())
+    }
+
+    fun setBluetoothWarning(on: Boolean) {
+        bluetoothWarningFlow.value = on
+        AppSettings.putString(app, KEY_BLUETOOTH_WARNING, on.toString())
+    }
+
+    fun setLocationWarning(on: Boolean) {
+        locationWarningFlow.value = on
+        AppSettings.putString(app, KEY_LOCATION_WARNING, on.toString())
     }
 
     fun setExperimentalFeaturesEnabled(on: Boolean) {
@@ -265,9 +466,19 @@ object CarSettings {
         AppSettings.putString(app, KEY_EXPERIMENTAL_FEATURES, on.toString())
     }
 
-    fun setVoiceAssistantEnabled(on: Boolean) {
-        voiceAssistantFlow.value = on
-        AppSettings.putString(app, KEY_VOICE_ASSISTANT, on.toString())
+    fun setSystemSpeech(on: Boolean) {
+        systemSpeechFlow.value = on
+        AppSettings.putString(app, KEY_SYSTEM_SPEECH, on.toString())
+    }
+
+    fun setAdaptiveVideoEnabled(on: Boolean) {
+        adaptiveVideoFlow.value = on
+        AppSettings.putString(app, KEY_ADAPTIVE_VIDEO, on.toString())
+    }
+
+    fun setClusterVideoEnabled(on: Boolean) {
+        clusterVideoFlow.value = on
+        AppSettings.putString(app, KEY_CLUSTER_VIDEO, on.toString())
     }
 
     fun setCarSensorsEnabled(on: Boolean) {

gearslip/src/main/java/app/seb3thehacker/gearslip/car/CarSettingsScreen.kt

@@ -1,16 +1,25 @@
 package app.seb3thehacker.gearslip.car
 
+import androidx.compose.ui.res.stringResource
+import app.seb3thehacker.gearslip.R
 
+import app.seb3thehacker.gearslip.car.theme.DarkStyle
 import app.seb3thehacker.gearslip.car.theme.*
 import android.os.Build
 import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.PaddingValues
+import androidx.compose.foundation.lazy.LazyColumn
 import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.fillMaxHeight
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.ui.graphics.Color
 import androidx.compose.foundation.layout.Spacer
 import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.height
 import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.width
 import androidx.compose.foundation.rememberScrollState
 import androidx.compose.foundation.verticalScroll
@@ -51,15 +60,26 @@ fun CarSettingsScreen() {
     val open by CarSettings.openOnConnect.collectAsState()
     val night by CarSettings.nightMode.collectAsState()
     val units by CarSettings.units.collectAsState()
+    val navBar by CarSettings.navBarMode.collectAsState()
+    val screenSize by CarSettings.screenSize.collectAsState()
+    val screenFit by CarSettings.screenFit.collectAsState()
     val whatsNew by CarSettings.whatsNewAfterUpdates.collectAsState()
     val pipeAudio by CarSettings.pipeAudio.collectAsState()
+    val speakDirections by CarSettings.speakDirections.collectAsState()
+    val bluetoothWarning by CarSettings.bluetoothWarning.collectAsState()
+    val locationWarning by CarSettings.locationWarning.collectAsState()
     val autoplay by CarSettings.autoplay.collectAsState()
     val playerTitle by CarSettings.playerTitle.collectAsState()
+    val playerLeft by CarSettings.playerLeft.collectAsState()
+    val moreLyrics by CarSettings.moreLyrics.collectAsState()
     val theme by CarSettings.appTheme.collectAsState()
     val uiTheme by CarSettings.uiTheme.collectAsState()
+    val darkStyle by CarSettings.darkStyle.collectAsState()
     val experimentalFeatures by CarSettings.experimentalFeaturesEnabled.collectAsState()
-    val voiceAssistant by CarSettings.voiceAssistantEnabled.collectAsState()
     val carSensors by CarSettings.carSensorsEnabled.collectAsState()
+    val adaptiveVideo by CarSettings.adaptiveVideoEnabled.collectAsState()
+    val clusterVideo by CarSettings.clusterVideoEnabled.collectAsState()
+    val systemSpeech by CarSettings.systemSpeech.collectAsState()
     val display by CarEnvironment.display.collectAsState()
     val vehicle by CarEnvironment.vehicle.collectAsState()
     val context = LocalContext.current
@@ -67,109 +87,260 @@ fun CarSettingsScreen() {
         value = withContext(Dispatchers.Default) { CertSummary.read(context) }
     }
 
-    Column(
-        Modifier
-            .fillMaxSize()
-            .verticalScroll(rememberScrollState())
-            .padding(horizontal = 24.dp, vertical = 16.dp),
-        verticalArrangement = Arrangement.spacedBy(20.dp),
-    ) {
-        Text("Settings", style = MaterialTheme.typography.headlineMedium, fontWeight = FontWeight.Bold)
+    // A rail of the groups down the left, and the chosen group's settings beside it: five short
+    // lists instead of one long scroll.
+    var chosen by androidx.compose.runtime.saveable.rememberSaveable { androidx.compose.runtime.mutableIntStateOf(0) }
+    val listState = androidx.compose.foundation.lazy.rememberLazyListState()
+    androidx.compose.runtime.LaunchedEffect(chosen) { listState.scrollToItem(0) }
+    Row(Modifier.fillMaxSize().padding(start = 16.dp, top = 12.dp)) {
+    SettingsRail(listOf(stringResource(R.string.car_group_screen), stringResource(R.string.car_group_nav_bar), stringResource(R.string.car_group_sound), stringResource(R.string.car_group_warnings), stringResource(R.string.car_group_more)), chosen) { chosen = it }
+        LazyColumn(
+            Modifier.weight(1f).fillMaxHeight(),
+            state = listState,
+            // Built as it scrolls into view rather than all at once: every row here is a set of
+            // buttons, and building the whole screen made opening Settings visibly slow.
+            contentPadding = PaddingValues(horizontal = 24.dp, vertical = 16.dp),
+            verticalArrangement = Arrangement.spacedBy(20.dp),
+        ) {
+            var section: Int
+            section = 0
+            if (section == chosen) item { Group(stringResource(R.string.car_group_screen)) }
 
-        ChoiceRow(
-            "Open on connect",
-            listOf(CarSettings.HOME to "Home") + CarApps.all.filter { it.id != "settings" }.map { it.id to it.label },
-            open,
-        ) { CarSettings.setOpenOnConnect(it) }
+            if (section == chosen) item {
+                ChoiceRow(
+                    stringResource(R.string.car_open_on_connect),
+                    listOf(CarSettings.HOME to stringResource(R.string.choice_open_home)) + CarApps.all.filter { it.id != "settings" }.map { it.id to stringResource(it.labelRes) },
+                    open,
+                ) { CarSettings.setOpenOnConnect(it) }
+            }
 
-        ChoiceRow(
-            "Size",
-            listOf(1f to "Normal", 1.25f to "Large", 1.5f to "Extra large"),
-            scale,
-        ) { CarSettings.setScale(it) }
+            if (section == chosen) item {
+                ChoiceRow(
+                    stringResource(R.string.car_size),
+                    listOf(1f to stringResource(R.string.choice_size_normal), 1.25f to stringResource(R.string.choice_size_large), 1.5f to stringResource(R.string.choice_size_xlarge)),
+                    scale,
+                ) { CarSettings.setScale(it) }
+            }
 
-        ChoiceRow(
-            "App theme",
-            listOf(AppTheme.PHONE to "Follow phone", AppTheme.LIGHT to "Light", AppTheme.DARK to "Dark"),
-            theme,
-        ) { CarSettings.setAppTheme(it) }
+            if (section == chosen) item {
+                ChoiceRow(
+                    stringResource(R.string.car_app_theme),
+                    listOf(AppTheme.PHONE to stringResource(R.string.choice_theme_phone), AppTheme.LIGHT to stringResource(R.string.choice_theme_light), AppTheme.DARK to stringResource(R.string.choice_theme_dark)),
+                    theme,
+                ) { CarSettings.setAppTheme(it) }
+            }
 
-        ChoiceRow(
-            "Theme",
-            GsThemes.builtIn.map { it.id to it.name },
-            uiTheme,
-        ) { CarSettings.setUiTheme(it) }
+            if (section == chosen && theme != AppTheme.LIGHT) item {
+                ChoiceRow(
+                    stringResource(R.string.car_dark_mode),
+                    listOf(
+                        DarkStyle.BLACK to stringResource(R.string.choice_dark_black),
+                        DarkStyle.BLACK_COLOUR to stringResource(R.string.choice_dark_black_colour),
+                        DarkStyle.DEEP_COLOUR to stringResource(R.string.choice_dark_deep_colour),
+                        DarkStyle.GREY to stringResource(R.string.choice_dark_grey),
+                    ),
+                    darkStyle,
+                ) { CarSettings.setDarkStyle(it) }
+            }
 
-        ChoiceRow(
-            "Map day/night",
-            listOf(NightMode.AUTO to "Auto", NightMode.DAY to "Day", NightMode.NIGHT to "Night"),
-            night,
-        ) { CarSettings.setNightMode(it) }
+            if (section == chosen) item {
+                ChoiceRow(
+                    stringResource(R.string.carset_theme),
+                    GsThemes.builtIn.map { it.id to it.name },
+                    uiTheme,
+                ) { CarSettings.setUiTheme(it) }
+            }
 
-        ChoiceRow(
-            "Units",
-            listOf(Units.AUTO to "Auto", Units.IMPERIAL to "Imperial (mi, ft, °F)", Units.METRIC to "Metric (km, m, °C)"),
-            units,
-        ) { CarSettings.setUnits(it) }
+            if (section == chosen) item {
+                ChoiceRow(
+                    stringResource(R.string.car_map_day_night),
+                    listOf(NightMode.AUTO to stringResource(R.string.choice_auto), NightMode.DAY to stringResource(R.string.choice_night_day), NightMode.NIGHT to stringResource(R.string.choice_night_night)),
+                    night,
+                ) { CarSettings.setNightMode(it) }
+            }
 
-        ChoiceRow(
-            "Player in the nav bar",
-            listOf(false to "Skip buttons", true to "Song title"),
-            playerTitle,
-        ) { CarSettings.setPlayerTitle(it) }
+            if (section == chosen) item {
+                ChoiceRow(
+                    stringResource(R.string.car_units),
+                    listOf(Units.AUTO to stringResource(R.string.choice_auto), Units.IMPERIAL to stringResource(R.string.carset_imperial), Units.METRIC to stringResource(R.string.carset_metric)),
+                    units,
+                ) { CarSettings.setUnits(it) }
+            }
 
-        ChoiceRow(
-            "Autoplay on connect",
-            listOf(false to "Off", true to "On"),
-            autoplay,
-        ) { CarSettings.setAutoplay(it) }
+            // For a head unit that reports the wrong size and stretches the picture (issue #12).
+            if (section == chosen) item {
+                ChoiceRow(
+                    stringResource(R.string.carset_screen_size),
+                    listOf<ScreenSize?>(null).plus(SCREEN_PRESETS).plus(screenSize).distinct()
+                        .map { it to (it?.toString() ?: stringResource(R.string.screen_from_car)) },
+                    screenSize,
+                ) { CarSettings.setScreenSize(it) }
+            }
 
-        ChoiceRow(
-            "Media audio",
-            listOf(false to "Phone output", true to "Through Gearslip"),
-            pipeAudio,
-        ) { CarSettings.setPipeAudio(it) }
-        Text(
-            "Through Gearslip sends the sound over the USB link. Android asks for consent the " +
-                "first time a media app plays in the car, and some apps refuse to be captured at " +
-                "all. Phone output needs no permission: the app plays as it normally would, for " +
-                "example over Bluetooth to the car.",
-            style = MaterialTheme.typography.bodySmall,
-            color = MaterialTheme.colorScheme.onSurfaceVariant,
-        )
+            if (section == chosen && screenSize != null) item {
+                ChoiceRow(
+                    stringResource(R.string.carset_fit),
+                    listOf(ScreenFit.CROP to stringResource(R.string.screen_crop), ScreenFit.SQUASH to stringResource(R.string.screen_squash)),
+                    screenFit,
+                ) { CarSettings.setScreenFit(it) }
+            }
 
-        WebPageSetting()
+            section = 1
+            if (section == chosen) item { Group(stringResource(R.string.car_group_nav_bar)) }
 
-        ScreenFit(vehicle)
+            if (section == chosen) item {
+                ChoiceRow(
+                    stringResource(R.string.car_nav_bar),
+                    listOf(
+                        NavBarMode.SHOW to stringResource(R.string.choice_nav_show),
+                        NavBarMode.HIDE_NAVIGATING to stringResource(R.string.choice_nav_hide_navigating),
+                        NavBarMode.HIDE to stringResource(R.string.choice_nav_hide),
+                    ),
+                    navBar,
+                ) { CarSettings.setNavBarMode(it) }
+            }
 
-        ChoiceRow(
-            "Experimental features",
-            listOf(false to "Hide", true to "Show"),
-            experimentalFeatures,
-        ) { CarSettings.setExperimentalFeaturesEnabled(it) }
-        if (experimentalFeatures) {
-            ExperimentalFeaturesList(voiceAssistant, carSensors)
-        }
+            if (section == chosen) item {
+                ChoiceRow(
+                    stringResource(R.string.car_player_nav_bar),
+                    listOf(false to stringResource(R.string.car_skip_buttons), true to stringResource(R.string.car_song_title)),
+                    playerTitle,
+                ) { CarSettings.setPlayerTitle(it) }
+            }
 
-        Column(verticalArrangement = Arrangement.spacedBy(8.dp)) {
-            Text("Connection", style = MaterialTheme.typography.titleMedium, color = MaterialTheme.colorScheme.primary)
-            Info("Phone", "${Build.MANUFACTURER} ${Build.MODEL}")
-            Info("Vehicle", vehicle.ifEmpty { "-" })
-            Info("Video", display.ifEmpty { "-" })
-            Info("Certificate", cert?.headline ?: "Checking…")
-        }
+            if (section == chosen) item {
+                ChoiceRow(
+                    stringResource(R.string.car_player_beside_map),
+                    listOf(false to stringResource(R.string.car_right), true to stringResource(R.string.car_left)),
+                    playerLeft,
+                ) { CarSettings.setPlayerLeft(it) }
+            }
 
-        Column(verticalArrangement = Arrangement.spacedBy(8.dp)) {
-            Text("About", style = MaterialTheme.typography.titleMedium, color = MaterialTheme.colorScheme.primary)
-            Info("Version", app.seb3thehacker.gearslip.BuildConfig.VERSION_NAME)
-            Info("Build", app.seb3thehacker.gearslip.BuildConfig.VERSION_CODE.toString())
-            ExperimentalFeatureRow(
-                "What's new after updates",
-                "Show the list of changes once, the first time the car connects after an update.",
-                whatsNew,
-            ) { CarSettings.setWhatsNewAfterUpdates(it) }
-            GsButton(onClick = CarSettings::openWhatsNew, tone = GsTone.Tonal, modifier = Modifier.height(56.dp)) {
-                Text("What's new", style = MaterialTheme.typography.titleMedium)
+            if (section == chosen) item {
+                ChoiceRow(
+                    stringResource(R.string.car_autoplay),
+                    listOf(false to stringResource(R.string.off), true to stringResource(R.string.on)),
+                    autoplay,
+                ) { CarSettings.setAutoplay(it) }
+            }
+
+            if (section == chosen) item {
+                ChoiceRow(
+                    stringResource(R.string.carset_lyrics_from),
+                    listOf(false to "LRCLIB", true to stringResource(R.string.carset_more_sources)),
+                    moreLyrics,
+                ) { CarSettings.setMoreLyrics(it) }
+            }
+
+            section = 2
+            if (section == chosen) item { Group(stringResource(R.string.car_group_sound)) }
+
+            if (section == chosen) item {
+                ChoiceRow(
+                    stringResource(R.string.car_audio),
+                    listOf(false to stringResource(R.string.guide_audio_bluetooth), true to stringResource(R.string.guide_audio_usb)),
+                    pipeAudio,
+                ) { CarSettings.setPipeAudio(it) }
+            }
+
+            if (section == chosen) item {
+                Text(
+                    stringResource(R.string.carset_audio_note),
+                    style = MaterialTheme.typography.bodySmall,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant,
+                )
+            }
+
+            section = 3
+            if (section == chosen) item { Group(stringResource(R.string.car_group_warnings)) }
+
+            if (section == chosen && !pipeAudio) item {
+                ChoiceRow(
+                    stringResource(R.string.car_warn_bluetooth),
+                    listOf(false to stringResource(R.string.off), true to stringResource(R.string.on)),
+                    bluetoothWarning,
+                ) { CarSettings.setBluetoothWarning(it) }
+            }
+
+            if (section == chosen) item {
+                ChoiceRow(
+                    stringResource(R.string.car_warn_location),
+                    listOf(false to stringResource(R.string.off), true to stringResource(R.string.on)),
+                    locationWarning,
+                ) { CarSettings.setLocationWarning(it) }
+            }
+
+            if (section == chosen) item {
+                ChoiceRow(
+                    stringResource(R.string.car_spoken_directions),
+                    listOf(false to stringResource(R.string.off), true to stringResource(R.string.on)),
+                    speakDirections,
+                ) { CarSettings.setSpeakDirections(it) }
+            }
+
+            if (section == chosen) item {
+                Text(
+                    stringResource(R.string.carset_directions_note),
+                    style = MaterialTheme.typography.bodySmall,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant,
+                )
+            }
+
+            if (section == chosen) item {
+                ExperimentalFeatureRow(
+                    title = stringResource(R.string.car_phone_speech),
+                    description = stringResource(R.string.carset_phone_speech_note),
+                    checked = systemSpeech,
+                ) { CarSettings.setSystemSpeech(it) }
+            }
+
+            section = 4
+            if (section == chosen) item { Group(stringResource(R.string.car_group_more)) }
+
+            if (section == chosen) item {
+                WebPageSetting()
+            }
+
+            if (section == chosen) item {
+                ScreenFit(vehicle)
+            }
+
+            if (section == chosen) item {
+                ChoiceRow(
+                    stringResource(R.string.car_experimental),
+                    listOf(false to stringResource(R.string.carset_hide), true to stringResource(R.string.carset_show)),
+                    experimentalFeatures,
+                ) { CarSettings.setExperimentalFeaturesEnabled(it) }
+            }
+
+            if (section == chosen && experimentalFeatures) item {
+                ExperimentalFeaturesList(carSensors, adaptiveVideo, clusterVideo)
+            }
+
+            if (section == chosen) item {
+                Column(verticalArrangement = Arrangement.spacedBy(8.dp)) {
+                    Text(stringResource(R.string.settings_connection), style = MaterialTheme.typography.titleMedium, color = MaterialTheme.colorScheme.primary)
+                    Info(stringResource(R.string.carset_phone), "${Build.MANUFACTURER} ${Build.MODEL}")
+                    Info(stringResource(R.string.carset_vehicle), vehicle.ifEmpty { "-" })
+                    Info(stringResource(R.string.carset_video), display.ifEmpty { "-" })
+                    Info(stringResource(R.string.settings_certificate), cert?.headline ?: stringResource(R.string.cert_checking))
+                }
+            }
+
+            if (section == chosen) item {
+                Column(verticalArrangement = Arrangement.spacedBy(8.dp)) {
+                    Text(stringResource(R.string.settings_about), style = MaterialTheme.typography.titleMedium, color = MaterialTheme.colorScheme.primary)
+                    Info(stringResource(R.string.carset_version), app.seb3thehacker.gearslip.BuildConfig.VERSION_NAME)
+                    Info(stringResource(R.string.carset_build), app.seb3thehacker.gearslip.BuildConfig.VERSION_CODE.toString())
+                    ExperimentalFeatureRow(
+                        stringResource(R.string.carset_whats_new_after),
+                        stringResource(R.string.carset_whats_new_after_sub),
+                        whatsNew,
+                    ) { CarSettings.setWhatsNewAfterUpdates(it) }
+                    GsButton(onClick = CarSettings::openWhatsNew, tone = GsTone.Tonal, modifier = Modifier.height(56.dp)) {
+                        Text(stringResource(R.string.settings_whats_new), style = MaterialTheme.typography.titleMedium)
+                    }
+                }
             }
         }
     }
@@ -177,8 +348,78 @@ fun CarSettingsScreen() {
 
 @Composable
 private fun <T> ChoiceRow(title: String, options: List<Pair<T, String>>, selected: T, onSelect: (T) -> Unit) {
-    Column(verticalArrangement = Arrangement.spacedBy(8.dp)) {
-        Text(title, style = MaterialTheme.typography.titleMedium, color = MaterialTheme.colorScheme.primary)
+    // On a wide screen the name sits beside its choices, which halves how far there is to scroll.
+    androidx.compose.foundation.layout.BoxWithConstraints(Modifier.fillMaxWidth()) {
+        if (maxWidth >= 720.dp && options.size <= 4) {
+            Row(verticalAlignment = Alignment.CenterVertically, horizontalArrangement = Arrangement.spacedBy(16.dp)) {
+                Text(title, style = MaterialTheme.typography.titleMedium, modifier = Modifier.weight(0.3f))
+                Box(Modifier.weight(0.7f)) { ChoiceButtons(options, selected, onSelect) }
+            }
+        } else {
+            Column(verticalArrangement = Arrangement.spacedBy(8.dp)) {
+                Text(title, style = MaterialTheme.typography.titleMedium)
+                ChoiceButtons(options, selected, onSelect)
+            }
+        }
+    }
+}
+
+/** The groups, with the chosen one lit: a card down the left of Settings. */
+@Composable
+private fun SettingsRail(groups: List<String>, chosen: Int, onChoose: (Int) -> Unit) {
+    val scheme = MaterialTheme.colorScheme
+    val shape = RoundedCornerShape(24.dp)
+    Surface(
+        Modifier.width(250.dp).padding(bottom = 12.dp).fillMaxHeight().gsPanelShadow(shape),
+        shape = shape,
+        color = scheme.surfaceContainer,
+    ) {
+        Column(
+            Modifier.padding(10.dp).verticalScroll(androidx.compose.foundation.rememberScrollState()),
+            verticalArrangement = Arrangement.spacedBy(4.dp),
+        ) {
+            Text(
+                stringResource(R.string.settings_title),
+                style = MaterialTheme.typography.headlineSmall,
+                fontWeight = FontWeight.Bold,
+                modifier = Modifier.padding(start = 14.dp, top = 6.dp, bottom = 10.dp),
+            )
+            groups.forEachIndexed { i, name ->
+                val on = i == chosen
+                GsIconBox(
+                    onClick = { onChoose(i) },
+                    modifier = Modifier.fillMaxWidth().height(56.dp),
+                    colors = if (on) GsColors(scheme.primaryContainer, scheme.onPrimaryContainer)
+                    else GsColors(Color.Transparent, scheme.onSurface),
+                    latched = on,
+                ) {
+                    Text(
+                        name,
+                        style = MaterialTheme.typography.titleMedium,
+                        fontWeight = if (on) FontWeight.Bold else FontWeight.Normal,
+                        modifier = Modifier.fillMaxWidth().padding(horizontal = 16.dp),
+                    )
+                }
+            }
+        }
+    }
+}
+
+/** A group of settings: a heading, so a long list reads as a few short ones. */
+@Composable
+private fun Group(title: String) {
+    Text(
+        title,
+        style = MaterialTheme.typography.titleLarge,
+        fontWeight = FontWeight.Bold,
+        color = MaterialTheme.colorScheme.primary,
+        modifier = Modifier.padding(top = 12.dp),
+    )
+}
+
+@Composable
+private fun <T> ChoiceButtons(options: List<Pair<T, String>>, selected: T, onSelect: (T) -> Unit) {
+    run {
         Row(Modifier.fillMaxWidth(), horizontalArrangement = Arrangement.spacedBy(12.dp)) {
             options.forEach { (value, label) ->
                 val on = value == selected
@@ -205,29 +446,26 @@ private fun <T> ChoiceRow(title: String, options: List<Pair<T, String>>, selecte
  * so the list reads fine whether there's one entry or several.
  */
 @Composable
-private fun ExperimentalFeaturesList(voiceAssistant: Boolean, carSensors: Boolean) {
+private fun ExperimentalFeaturesList(carSensors: Boolean, adaptiveVideo: Boolean, clusterVideo: Boolean) {
     Column(
         Modifier.fillMaxWidth(),
         verticalArrangement = Arrangement.spacedBy(10.dp),
     ) {
         ExperimentalFeatureRow(
-            title = "Voice assistant",
-            description = "Push-to-talk and the car's voice button start listening: navigate, " +
-                "play media, call, or open an app by saying so. Can mishear you or act on the " +
-                "wrong command - keep your eyes on the road, and confirm anything it does " +
-                "before you rely on it.",
-            warning = true,
-            checked = voiceAssistant,
-        ) { CarSettings.setVoiceAssistantEnabled(it) }
-
-        ExperimentalFeatureRow(
-            title = "Vehicle data",
-            description = "Adds a Vehicle data tile: a live, raw dump of the head unit's sensor " +
-                "channel. Field labels (speed, RPM, fuel...) are carried over from other " +
-                "reverse-engineering projects and unverified against this car - treat them as a " +
-                "guess, not a fact, until you've watched one change for yourself.",
+            title = stringResource(R.string.car_vehicle_data),
+            description = stringResource(R.string.carset_vehicle_data_note),
             checked = carSensors,
         ) { CarSettings.setCarSensorsEnabled(it) }
+        ExperimentalFeatureRow(
+            title = stringResource(R.string.car_adaptive_video),
+            description = stringResource(R.string.carset_adaptive_note),
+            checked = adaptiveVideo,
+        ) { CarSettings.setAdaptiveVideoEnabled(it) }
+        ExperimentalFeatureRow(
+            title = stringResource(R.string.car_cluster_video),
+            description = stringResource(R.string.car_cluster_video_note),
+            checked = clusterVideo,
+        ) { CarSettings.setClusterVideoEnabled(it) }
     }
 }
 
@@ -265,7 +503,7 @@ private fun ExperimentalFeatureRow(
     }
 }
 
-/** The URL (or raw HTML) the Web app shows. Edited with [CarKeyboard] - no phone in hand needed. */
+/** The URL (or raw HTML) the Browser app shows. Edited with [CarKeyboard] - no phone in hand needed. */
 @Composable
 private fun WebPageSetting() {
     val context = LocalContext.current
@@ -273,7 +511,7 @@ private fun WebPageSetting() {
     var url by remember { mutableStateOf(AppSettings.startupUrl(context)) }
 
     Column(verticalArrangement = Arrangement.spacedBy(8.dp)) {
-        Text("Web page", style = MaterialTheme.typography.titleMedium, color = MaterialTheme.colorScheme.primary)
+        Text(stringResource(R.string.web_page), style = MaterialTheme.typography.titleMedium, color = MaterialTheme.colorScheme.primary)
         Surface(
             onClick = { editing = !editing },
             shape = MaterialTheme.shapes.large,
@@ -281,7 +519,7 @@ private fun WebPageSetting() {
             modifier = Modifier.fillMaxWidth(),
         ) {
             Text(
-                url.ifEmpty { "DuckDuckGo (default) - tap to set a different page" },
+                url.ifEmpty { stringResource(R.string.carset_web_default) },
                 style = MaterialTheme.typography.bodyLarge,
                 color = if (url.isEmpty()) MaterialTheme.colorScheme.onSurfaceVariant else MaterialTheme.colorScheme.onSurface,
                 maxLines = 1,
@@ -290,7 +528,7 @@ private fun WebPageSetting() {
             )
         }
         Text(
-            "Shown by the Web app on the launcher. Applies on the next connection.",
+            stringResource(R.string.carset_web_note),
             style = MaterialTheme.typography.bodySmall,
             color = MaterialTheme.colorScheme.onSurfaceVariant,
         )
@@ -333,22 +571,22 @@ private fun ScreenFit(vehicle: String) {
     }
 
     Column(verticalArrangement = Arrangement.spacedBy(8.dp)) {
-        Text("Screen fit", style = MaterialTheme.typography.titleMedium, color = MaterialTheme.colorScheme.primary)
-        Stepper("Top", insets.top) { change(insets.copy(top = (insets.top + it).coerceAtLeast(0))) }
-        Stepper("Bottom", insets.bottom) { change(insets.copy(bottom = (insets.bottom + it).coerceAtLeast(0))) }
+        Text(stringResource(R.string.carset_screen_fit), style = MaterialTheme.typography.titleMedium, color = MaterialTheme.colorScheme.primary)
+        Stepper(stringResource(R.string.carset_top), insets.top) { change(insets.copy(top = (insets.top + it).coerceAtLeast(0))) }
+        Stepper(stringResource(R.string.carset_bottom), insets.bottom) { change(insets.copy(bottom = (insets.bottom + it).coerceAtLeast(0))) }
         Text(
-            "Usable height ${480 - insets.top - insets.bottom}px of 480",
+            stringResource(R.string.carset_usable_height, 480 - insets.top - insets.bottom),
             style = MaterialTheme.typography.bodyMedium,
             color = MaterialTheme.colorScheme.onSurfaceVariant,
         )
         GsButton(
             onClick = {
                 val ok = app.seb3thehacker.gearslip.VehicleProfiles.saveInsets(context, vehicle, insets)
-                saved = if (ok) "Saved to $vehicle" else "Could not save"
+                saved = if (ok) context.getString(R.string.carset_saved_to, vehicle) else context.getString(R.string.carset_save_failed)
             },
             enabled = known,
             modifier = Modifier.fillMaxWidth().height(56.dp),
-        ) { Text(if (known) "Save for this vehicle" else "No vehicle profile matched") }
+        ) { Text(if (known) stringResource(R.string.carset_save_vehicle) else stringResource(R.string.carset_no_profile)) }
         saved?.let { Text(it, style = MaterialTheme.typography.bodyMedium) }
     }
 }
@@ -360,7 +598,7 @@ private fun Stepper(label: String, value: Int, onStep: (Int) -> Unit) {
         StepButton("−5", Modifier.weight(1f)) { onStep(-5) }
         StepButton("−1", Modifier.weight(1f)) { onStep(-1) }
         Text(
-            "${value}px",
+            stringResource(R.string.carset_px, value),
             style = MaterialTheme.typography.titleLarge,
             modifier = Modifier.weight(1.3f),
             textAlign = androidx.compose.ui.text.style.TextAlign.Center,
@@ -382,3 +620,8 @@ private fun StepButton(text: String, modifier: Modifier, onClick: () -> Unit) {
     }
 }
 
+/** Common car screen sizes; Settings on the phone takes any other. */
+private val SCREEN_PRESETS = listOf(
+    ScreenSize(800, 480), ScreenSize(1024, 600), ScreenSize(1280, 480), ScreenSize(1280, 720),
+    ScreenSize(1440, 540), ScreenSize(1920, 720), ScreenSize(1920, 1080),
+)

gearslip/src/main/java/app/seb3thehacker/gearslip/car/CarToastOverlay.kt

@@ -0,0 +1,62 @@
+package app.seb3thehacker.gearslip.car
+
+import androidx.compose.foundation.background
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.widthIn
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.collectAsState
+import androidx.compose.runtime.getValue
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.clip
+import androidx.compose.ui.platform.LocalAccessibilityManager
+import androidx.compose.ui.semantics.LiveRegionMode
+import androidx.compose.ui.semantics.liveRegion
+import androidx.compose.ui.semantics.semantics
+import androidx.compose.ui.text.style.TextOverflow
+import androidx.compose.ui.unit.dp
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.flow.first
+import kotlinx.coroutines.withTimeoutOrNull
+
+/** Draw inside the encoded car display; a normal Android Toast would appear on the phone. */
+@Composable
+internal fun CarToastOverlay(modifier: Modifier = Modifier) {
+    val current by CarToasts.message.collectAsState()
+    val message = current ?: return
+    val accessibility = LocalAccessibilityManager.current
+    LaunchedEffect(message, accessibility) {
+        val timeout = accessibility?.calculateRecommendedTimeoutMillis(
+            message.durationMs, containsIcons = false, containsText = true, containsControls = false,
+        ) ?: message.durationMs
+        // The full time, unless another toast is waiting: then it gives way after the minimum.
+        delay(minOf(timeout, CarToasts.MIN_SHOWN_MS))
+        withTimeoutOrNull((timeout - CarToasts.MIN_SHOWN_MS).coerceAtLeast(0)) {
+            CarToasts.waiting.first { it > 0 }
+        }
+        CarToasts.dismiss(message)
+    }
+
+    // A non-interactive overlay leaves the map's touch handling and focus intact.
+    Box(
+        modifier
+            .padding(horizontal = 24.dp, vertical = 16.dp)
+            .widthIn(max = 560.dp)
+            .clip(RoundedCornerShape(20.dp))
+            .background(MaterialTheme.colorScheme.surfaceContainerHigh)
+            .semantics { liveRegion = LiveRegionMode.Polite },
+    ) {
+        Text(
+            message.text,
+            modifier = Modifier.padding(horizontal = 20.dp, vertical = 12.dp),
+            color = MaterialTheme.colorScheme.onSurface,
+            style = MaterialTheme.typography.titleMedium,
+            maxLines = 3,
+            overflow = TextOverflow.Ellipsis,
+        )
+    }
+}

gearslip/src/main/java/app/seb3thehacker/gearslip/car/CarToasts.kt

@@ -0,0 +1,65 @@
+package app.seb3thehacker.gearslip.car
+
+import androidx.annotation.MainThread
+import androidx.car.app.CarToast
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.asStateFlow
+
+/**
+ * One toast at a time across navigation and browse apps. A newer one waits its turn instead of
+ * replacing the one on screen, which gets at least [MIN_SHOWN_MS] before it gives way.
+ */
+@MainThread
+internal object CarToasts {
+    // Identity matters: repeating identical text must restart its display timer.
+    class Message(val owner: Any, val text: String, val durationMs: Long)
+
+    /** Long enough to read a short toast at a glance; a waiting toast cuts the rest short. */
+    const val MIN_SHOWN_MS = 2_000L
+
+    /** A burst beyond this many is stale by the time it would show; the oldest waiting go first. */
+    private const val MAX_WAITING = 3
+
+    private val current = MutableStateFlow<Message?>(null)
+    val message: StateFlow<Message?> = current.asStateFlow()
+
+    private val queue = ArrayDeque<Message>()
+    private val _waiting = MutableStateFlow(0)
+    val waiting: StateFlow<Int> = _waiting.asStateFlow()
+
+    fun show(owner: Any, text: String, duration: Int) {
+        if (text.isBlank()) return
+        // Longer than a phone toast: the driver only glances at the screen now and then.
+        val durationMs = if (duration == CarToast.LENGTH_LONG) 7_000L else 4_000L
+        val next = Message(owner, text, durationMs)
+        val shown = current.value
+        when {
+            shown == null -> current.value = next
+            // The same words again restart the one on screen rather than queueing a copy.
+            shown.text == text -> current.value = next
+            queue.lastOrNull()?.text == text -> Unit
+            else -> {
+                queue.addLast(next)
+                while (queue.size > MAX_WAITING) queue.removeFirst()
+            }
+        }
+        _waiting.value = queue.size
+    }
+
+    fun dismiss(message: Message) {
+        // An old timer must not dismiss a newer toast, even if its text is identical.
+        if (current.value === message) advance()
+    }
+
+    fun clear(owner: Any) {
+        // Disconnecting the map must not clear a toast belonging to the browse app.
+        queue.removeAll { it.owner === owner }
+        if (current.value?.owner === owner) advance() else _waiting.value = queue.size
+    }
+
+    private fun advance() {
+        current.value = queue.removeFirstOrNull()
+        _waiting.value = queue.size
+    }
+}

gearslip/src/main/java/app/seb3thehacker/gearslip/car/CarUi.kt

@@ -1,7 +1,12 @@
 package app.seb3thehacker.gearslip.car
 
+import androidx.compose.ui.res.stringResource
+import androidx.compose.material.icons.filled.Call
+import app.seb3thehacker.gearslip.call.CarCalls
+import app.seb3thehacker.gearslip.call.CallUiState
 import androidx.compose.foundation.Image
 import androidx.compose.foundation.clickable
+import androidx.compose.foundation.LocalIndication
 import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.BoxWithConstraints
@@ -43,6 +48,10 @@ import androidx.compose.material3.dynamicDarkColorScheme
 import androidx.compose.material3.dynamicLightColorScheme
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.CompositionLocalProvider
+import androidx.compose.ui.hapticfeedback.HapticFeedback
+import androidx.compose.ui.hapticfeedback.HapticFeedbackType
+import androidx.compose.ui.platform.LocalHapticFeedback
+import androidx.compose.ui.platform.LocalView
 import androidx.compose.runtime.State
 import androidx.compose.runtime.collectAsState
 import androidx.compose.runtime.getValue
@@ -54,6 +63,8 @@ import androidx.compose.runtime.setValue
 import androidx.compose.animation.animateContentSize
 import android.media.session.PlaybackState
 import androidx.compose.runtime.remember
+import androidx.compose.runtime.SideEffect
+import androidx.compose.ui.graphics.graphicsLayer
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.clip
@@ -67,6 +78,7 @@ import androidx.compose.ui.res.vectorResource
 import androidx.compose.ui.text.style.TextOverflow
 import app.seb3thehacker.gearslip.R
 import app.seb3thehacker.gearslip.car.theme.GsColors
+import app.seb3thehacker.gearslip.car.theme.withTintedSurfaces
 import app.seb3thehacker.gearslip.car.theme.GsIconBox
 import app.seb3thehacker.gearslip.car.theme.GsIconButton
 import app.seb3thehacker.gearslip.car.theme.GsButton
@@ -101,6 +113,7 @@ fun CarUi() {
     val phoneDark by CarEnvironment.phoneDark.collectAsState()
     val appTheme by CarSettings.appTheme.collectAsState()
     val uiThemeId by CarSettings.uiTheme.collectAsState()
+    val darkStyle by CarSettings.darkStyle.collectAsState()
     val mediaApp by CarServices.mediaApp.collectAsState()
     val darkOutside by CarEnvironment.darkOutside.collectAsState()
     val appContext = LocalContext.current.applicationContext
@@ -109,7 +122,7 @@ fun CarUi() {
         AppTheme.LIGHT -> false
         AppTheme.DARK -> true
     }
-    val colors = if (dark) dynamicDarkColorScheme(appContext) else dynamicLightColorScheme(appContext)
+    val colors = (if (dark) dynamicDarkColorScheme(appContext) else dynamicLightColorScheme(appContext)).withTintedSurfaces(dark, darkStyle)
     val base = LocalDensity.current
     val insets by CarEnvironment.insets.collectAsState()
     val navigator = remember { CarNavigator(CarSettings.openOnConnect.value) }
@@ -118,10 +131,19 @@ fun CarUi() {
         while (true) {
             delay(250)
             controlsWake.tick()
+            CarFullscreen.tick()
         }
     }
+    // The knob counts as a touch: the map's buttons can't be found while they're faded out.
+    LaunchedEffect(controlsWake) { CarKeys.focusMoves.collect { controlsWake.touch() } }
     remember(appContext) { Prefetch.warm(appContext, force = true); CarServices.init(appContext) }
     DisposableEffect(Unit) { onDispose { CarServices.shutdown() } }
+    // Ask for the phone's sound as soon as the car connects, not only when a media app opens:
+    // a video in the web browser or a map's voice needs it too. Asks once, after the car offers
+    // somewhere to play it.
+    LaunchedEffect(Unit) { if (CarSettings.pipeAudio.value) app.seb3thehacker.gearslip.audio.CarAudio.request() }
+    // A new version gets one card in the top right, a few seconds in and only while parked.
+    LaunchedEffect(Unit) { app.seb3thehacker.gearslip.update.UpdateChecker.onCarConnected(appContext) }
     // The map follows the light outside, whatever the app's own theme is set to.
     LaunchedEffect(darkOutside) { CarServices.nav.pushConfiguration() }
 
@@ -146,14 +168,27 @@ fun CarUi() {
                     VoiceReply.state.value.phase != VoiceReply.Phase.IDLE -> VoiceReply.cancel()
                     else -> navigator.back()
                 }
-                CarKeys.ScreenKey.HOME, CarKeys.ScreenKey.MAP -> navigator.home()
-                CarKeys.ScreenKey.MEDIA -> if (CarServices.mediaApp.value != null) navigator.media() else navigator.apps()
+                // Home is the dashboard, over the map, so Back from it lands on the map.
+                CarKeys.ScreenKey.HOME -> { navigator.home(); navigator.dashboard() }
+                CarKeys.ScreenKey.MAP -> navigator.home()
+                CarKeys.ScreenKey.MEDIA ->
+                    if (CarServices.mediaApp.value != null || CarServices.reopenLastMedia()) navigator.media()
+                    else navigator.apps()
                 CarKeys.ScreenKey.PHONE -> BuiltInApps.Phone.open(navigator)
             }
         }
     }
 
+    // The car screen is drawn on the phone, so every long press or text-handle drag would buzz
+    // the phone in its mount. Nobody feels that while driving; it's only noise.
+    val view = LocalView.current
+    DisposableEffect(view) {
+        view.isHapticFeedbackEnabled = false
+        onDispose { }
+    }
+
     CompositionLocalProvider(
+        LocalHapticFeedback provides NoHaptics,
         LocalDensity provides Density(base.density * scale, base.fontScale),
         LocalCarNavigator provides navigator,
         LocalDarkOutside provides darkOutside,
@@ -161,22 +196,40 @@ fun CarUi() {
         LocalGsTheme provides GsThemes.byId(uiThemeId),
     ) {
         MaterialTheme(colorScheme = colors) {
+          CompositionLocalProvider(LocalIndication provides FocusRingIndication(MaterialTheme.colorScheme.primary)) {
             Surface(
                 Modifier
                     .fillMaxSize()
                     // Watches every touch without taking any: first in line, consumes nothing.
                     .pointerInput(controlsWake) {
+                        // In full screen, a swipe that starts at the top or bottom edge brings the
+                        // nav bar back. Only from the very edge, so scrolling a page still scrolls.
+                        val edge = 32.dp.toPx()
+                        val slop = 24.dp.toPx()
+                        var startY = -1f
                         awaitPointerEventScope {
                             while (true) {
-                                awaitPointerEvent(PointerEventPass.Initial)
+                                val event = awaitPointerEvent(PointerEventPass.Initial)
                                 controlsWake.touch()
+                                CarFullscreen.touch()
+                                val change = event.changes.firstOrNull() ?: continue
+                                if (!CarFullscreen.active) continue
+                                if (change.pressed && !change.previousPressed) {
+                                    val y = change.position.y
+                                    startY = if (y < edge || y > size.height - edge) y else -1f
+                                } else if (startY >= 0f && change.pressed && kotlin.math.abs(change.position.y - startY) > slop) {
+                                    CarFullscreen.reveal()
+                                    startY = -1f
+                                }
                             }
                         }
                     },
                 color = MaterialTheme.colorScheme.background,
             ) {
-                // Insets are in video-frame pixels, so convert with the un-scaled density.
-                val pad = with(base) {
+                // Insets are video-frame pixels. Resolve them with the live (size-scaled) density,
+                // which padding() also uses, so the safe-area margin stays one fixed physical size
+                // at every size setting instead of growing with it and eating the screen's sides.
+                val pad = with(LocalDensity.current) {
                     PaddingValues(
                         start = insets.left.toDp(), top = insets.top.toDp(),
                         end = insets.right.toDp(), bottom = insets.bottom.toDp(),
@@ -184,6 +237,26 @@ fun CarUi() {
                 }
                 val screen = navigator.current
                 val safetyWarningSeen by CarSettings.hasSeenSafetyWarning.collectAsState()
+                val keyboardVisible by CarKeyboardVisibility.state
+                // The bar always lies over the map and every other screen rather than taking a row
+                // of its own: hiding it then leaves the map's surface the size it was.
+                // Resizing it would hand the map app a new surface each time, and some go black on that.
+                val navBarMode by CarSettings.navBarMode.collectAsState()
+                val appTemplate by CarServices.nav.template.collectAsState()
+                val barMayHide = screen == CarScreen.Home && when (navBarMode) {
+                    NavBarMode.SHOW -> false
+                    NavBarMode.HIDE_NAVIGATING -> appTemplate is androidx.car.app.navigation.model.NavigationTemplate
+                    NavBarMode.HIDE -> true
+                }
+                // A full wait from when hiding becomes possible, not from whenever the last touch was.
+                LaunchedEffect(barMayHide) { if (barMayHide) controlsWake.touch() }
+                // A call keeps the bar up whatever the setting: End and Mute live on it.
+                val onCall = CarCalls.state.collectAsState().value is CallUiState.Active
+                val barShown = !keyboardVisible && (!barMayHide || controlsWake.navBarAwake || onCall)
+                // Up to the bar's top edge, so the map's cards and the player end above it.
+                val homeInset = if (barShown) NAV_BAR_HEIGHT else 0.dp
+                // Only the screen that asked: going Home or anywhere else ends it.
+                val fullscreen = CarFullscreen.active && screen != CarScreen.Home
                 Box(Modifier.fillMaxSize().padding(pad)) {
                 Column(Modifier.fillMaxSize()) {
                     if (!safetyWarningSeen) {
@@ -196,30 +269,64 @@ fun CarUi() {
                         // Home never leaves the composition; other screens cover it. Dropping it
                         // would tear down the map's surface, and coming back would then show black
                         // while the nav app redrew on a new one.
-                        CarHome()
+                        CompositionLocalProvider(LocalNavBarInset provides homeInset) { CarHome() }
+                    }
+                    // The keyboard takes the nav bar's row instead of squeezing in above it -
+                    // nothing on the nav bar is useful mid-type, and the screen is too small to
+                    // show both.
+                }
+                // Every other screen, and everything that pops up, in a layer over Home rather
+                // than inside its area: full screen grows this layer over the nav bar's row while
+                // Home, and the map's surface in it, keeps its size.
+                // Each new screen fades in while rising a little, once, over a fifth of a second.
+                // Coming from Home the backdrop fades in with it, over the map; between two other
+                // screens it stays put, so the map never flashes through.
+                val lastScreen = remember { arrayOf<CarScreen>(CarScreen.Home) }
+                val fromHome = remember(screen) { lastScreen[0] == CarScreen.Home }
+                SideEffect { lastScreen[0] = screen }
+                val enter = remember(screen) { androidx.compose.animation.core.Animatable(0f) }
+                LaunchedEffect(screen) { enter.animateTo(1f, androidx.compose.animation.core.tween(180)) }
+                if (safetyWarningSeen) {
+                    Box(Modifier.fillMaxSize()) {
                         if (screen != CarScreen.Home) {
                             Box(
                                 Modifier
                                     .fillMaxSize()
+                                    .graphicsLayer { if (fromHome) alpha = enter.value }
                                     .background(MaterialTheme.colorScheme.background)
+                                    // The bar never hides here, so keep the screen clear of it. The
+                                    // player runs on under the see-through bar and keeps clear itself.
+                                    .padding(bottom = if (!keyboardVisible && !fullscreen && screen != CarScreen.Media) NAV_BAR_HEIGHT else 0.dp)
                                     // Keeps touches that miss this screen's controls off the map.
                                     .pointerInput(Unit) { detectTapGestures { } },
                             ) {
-                                when (screen) {
-                                    CarScreen.Home -> Unit
-                                    CarScreen.Apps -> CarLauncher()
-                                    CarScreen.Media -> mediaApp?.let { MediaScreen(it) { navigator.back() } }
-                                    CarScreen.Browse -> BrowseAppScreen(navigator)
-                                    CarScreen.Settings -> CarSettingsScreen()
-                                    CarScreen.Dashboard -> CarDashboardScreen()
-                                    CarScreen.Weather -> WeatherScreen()
-                                    CarScreen.VehicleData -> VehicleDataScreen()
-                                    is CarScreen.Notifications -> NotificationsScreen(screen.replyTo)
-                                    is CarScreen.Messages -> MessagesScreen(screen.packageName)
-                                    is CarScreen.App -> CarApps.find(screen.id)?.content?.invoke()
+                                Box(
+                                    Modifier.fillMaxSize().graphicsLayer {
+                                        if (!fromHome) alpha = enter.value
+                                        translationY = (1f - enter.value) * 16.dp.toPx()
+                                    },
+                                ) {
+                                    when (screen) {
+                                        CarScreen.Home -> Unit
+                                        CarScreen.Apps -> CarLauncher()
+                                        CarScreen.Media -> CompositionLocalProvider(
+                                            LocalNavBarInset provides if (!keyboardVisible && !fullscreen) NAV_BAR_HEIGHT else 0.dp,
+                                        ) { mediaApp?.let { MediaScreen(it) { navigator.back() } } }
+                                        CarScreen.Browse -> BrowseAppScreen(navigator)
+                                        CarScreen.Settings -> CarSettingsScreen()
+                                        CarScreen.Dashboard -> CarDashboardScreen()
+                                        CarScreen.Weather -> WeatherScreen()
+                                        CarScreen.VehicleData -> VehicleDataScreen()
+                                        is CarScreen.Notifications -> NotificationsScreen(screen.replyTo)
+                                        is CarScreen.Messages -> MessagesScreen(screen.packageName)
+                                        is CarScreen.App -> CarApps.find(screen.id)?.content?.invoke()
+                                    }
                                 }
                             }
                         }
+                        CarToastOverlay(Modifier.align(Alignment.BottomCenter).padding(bottom = homeInset))
+                        CallPromptOverlay()
+                        BluetoothPairOverlay()
                         PopupTimer()
                         // The dashboard is already listing them, so it needs no popup.
                         NotificationPopup(
@@ -227,31 +334,59 @@ fun CarUi() {
                             modifier = Modifier.align(Alignment.TopEnd),
                         )
                         // Above the popup: a call is more urgent than any notification.
-                        CallOverlay(Modifier.align(Alignment.TopCenter))
-                        AssistantOverlay(Modifier.align(Alignment.TopCenter))
-                        if (app.seb3thehacker.gearslip.BuildConfig.DEBUG) {
+                        VoiceHelpOverlay(Modifier.align(Alignment.Center))
+                        CallOverlay()
+                        AssistantOverlay(Modifier.align(Alignment.BottomCenter).padding(bottom = homeInset))
+                        val badge by CarSettings.debugBadge.collectAsState()
+                        if (app.seb3thehacker.gearslip.BuildConfig.DEBUG && badge) {
                             // Bottom corner, not top: a screen's own header almost always puts
                             // something in the top-right (settings, search, a Liked Songs
                             // shortcut) and this badge used to sit right on top of it, hiding
                             // whatever the screen drew there.
-                            DevBuildBadge(Modifier.align(Alignment.BottomEnd))
+                            DebugBuildBadge(Modifier.align(Alignment.BottomEnd).padding(bottom = homeInset))
+                        }
+                        run {
+                            androidx.compose.animation.AnimatedVisibility(
+                                if (fullscreen) CarFullscreen.revealed || onCall else barShown,
+                                Modifier.align(Alignment.BottomCenter),
+                                enter = androidx.compose.animation.slideInVertically { it },
+                                exit = androidx.compose.animation.slideOutVertically { it },
+                            ) { CarNavBar(navigator) }
+                        }
+                        if (fullscreen) {
+                            androidx.compose.animation.AnimatedVisibility(
+                                CarFullscreen.revealed,
+                                Modifier.align(Alignment.TopCenter).padding(top = 12.dp),
+                                enter = androidx.compose.animation.slideInVertically { -it },
+                                exit = androidx.compose.animation.slideOutVertically { -it },
+                            ) {
+                                GsButton(onClick = CarFullscreen::exit, modifier = Modifier.height(48.dp)) {
+                                    Icon(MediaIcons.FullscreenExit, contentDescription = null, modifier = Modifier.size(22.dp))
+                                    Spacer(Modifier.width(8.dp))
+                                    Text(stringResource(R.string.carui_exit_fullscreen), style = MaterialTheme.typography.titleMedium)
+                                }
+                            }
                         }
                     }
-                    // The keyboard takes the nav bar's row instead of squeezing in above it -
-                    // nothing on the nav bar is useful mid-type, and the screen is too small to
-                    // show both.
-                    val keyboardVisible by CarKeyboardVisibility.state
-                    if (!keyboardVisible) CarNavBar(navigator)
                 }
                 // Over everything, nav bar included: a long press on an app, anywhere.
                 AppMenu(navigator, rememberRunningApps())
                 if (safetyWarningSeen) CarWhatsNew()
                 }
             }
+          }
         }
     }
 }
 
+internal val NAV_BAR_HEIGHT = 56.dp
+
+/**
+ * How much of the bottom of Home the floating nav bar covers right now: its height while it shows,
+ * zero while it's hidden or when it has a row of its own.
+ */
+internal val LocalNavBarInset = androidx.compose.runtime.compositionLocalOf { 0.dp }
+
 /**
  * A single blocking screen, shown once per install before anything else the car screen can show -
  * Home included. The phone's own setup guide carries the same warning, but a driver who plugs in
@@ -262,31 +397,31 @@ fun CarUi() {
 @Composable
 private fun CarSafetyWizard(onDone: () -> Unit) {
     Box(Modifier.fillMaxSize(), contentAlignment = Alignment.Center) {
+        // The card and its button share one width, capped so neither sprawls across a wide screen.
         Column(
-            Modifier.fillMaxWidth().padding(24.dp),
+            Modifier.widthIn(max = 640.dp).fillMaxWidth().padding(24.dp),
             horizontalAlignment = Alignment.CenterHorizontally,
         ) {
             Surface(
                 color = MaterialTheme.colorScheme.surfaceContainerLow,
                 shape = MaterialTheme.shapes.extraLarge,
+                modifier = Modifier.fillMaxWidth(),
             ) {
                 Column(Modifier.padding(24.dp), verticalArrangement = Arrangement.spacedBy(12.dp)) {
-                    Text("Drive safely", style = ChromeType.headline, fontWeight = FontWeight.Bold)
+                    Text(stringResource(R.string.carui_drive_safely), style = ChromeType.headline, fontWeight = FontWeight.Bold)
                     Text(
-                        "Gearslip is unofficial software: it is not made or reviewed by any " +
-                            "carmaker, and it can fail without warning.",
+                        stringResource(R.string.carui_unofficial),
                         style = ChromeType.body,
                     )
                     Text(
-                        "Never interact with this screen while driving. Set the route or the " +
-                            "song before you go, then keep your attention on the road.",
+                        stringResource(R.string.carui_never_interact),
                         style = ChromeType.body,
                     )
                 }
             }
             Spacer(Modifier.height(24.dp))
             GsButton(onClick = onDone, modifier = Modifier.fillMaxWidth().height(56.dp)) {
-                Text("I understand", style = ChromeType.body)
+                Text(stringResource(R.string.carui_understand), style = ChromeType.body)
             }
         }
     }
@@ -317,7 +452,7 @@ private fun BrowseAppScreen(navigator: CarNavigator) {
     }
     val failed = status.phase == CarAppConnection.Phase.REJECTED || status.phase == CarAppConnection.Phase.FAILED
     if (failed || timedOut) {
-        AppWontStart(status.app ?: "This app", leave)
+        AppWontStart(status.app ?: stringResource(R.string.carui_this_app), leave)
         return
     }
     CarAppStage(CarServices.browse, status, frame, onDisconnect = leave)
@@ -333,13 +468,13 @@ private fun AppWontStart(app: String, onBack: () -> Unit) {
         verticalArrangement = Arrangement.spacedBy(12.dp, Alignment.CenterVertically),
         horizontalAlignment = Alignment.CenterHorizontally,
     ) {
-        Text("$app doesn't work with Gearslip yet.", style = MaterialTheme.typography.titleLarge, fontWeight = FontWeight.SemiBold)
+        Text(stringResource(R.string.carui_app_unsupported, app), style = MaterialTheme.typography.titleLarge, fontWeight = FontWeight.SemiBold)
         Text(
-            "It didn't start. Some apps only run on Google's Android Auto.",
+            stringResource(R.string.carui_app_unsupported_body),
             style = MaterialTheme.typography.bodyLarge,
             color = MaterialTheme.colorScheme.onSurfaceVariant,
         )
-        GsButton(onClick = onBack, tone = GsTone.Tonal) { Text("Back") }
+        GsButton(onClick = onBack, tone = GsTone.Tonal) { Text(stringResource(R.string.back)) }
     }
 }
 
@@ -348,7 +483,7 @@ private fun AppWontStart(app: String, onBack: () -> Unit) {
  * that matters while driving, since a debug build is slower and less tested than what ships.
  */
 @Composable
-private fun DevBuildBadge(modifier: Modifier = Modifier) {
+private fun DebugBuildBadge(modifier: Modifier = Modifier) {
     Surface(
         modifier = modifier.padding(6.dp),
         color = MaterialTheme.colorScheme.error,
@@ -356,7 +491,7 @@ private fun DevBuildBadge(modifier: Modifier = Modifier) {
         shape = MaterialTheme.shapes.small,
     ) {
         Text(
-            "DEV BUILD",
+            "DEBUG BUILD",
             style = MaterialTheme.typography.labelSmall,
             fontWeight = FontWeight.Bold,
             modifier = Modifier.padding(horizontal = 8.dp, vertical = 3.dp),
@@ -364,512 +499,7 @@ private fun DevBuildBadge(modifier: Modifier = Modifier) {
     }
 }
 
-/**
- * "Home > Apps > Settings", like a file manager's address bar: hidden at Home itself (nothing to
- * show yet), and grows by one crumb for every screen pushed from there. The back arrow undoes one
- * step; a crumb jumps straight to it, dropping everything after - this is the only on-screen way
- * back at all, since a car touchscreen has no hardware button for it.
- */
-@Composable
-private fun BreadcrumbBar(navigator: CarNavigator) {
-    val trail = navigator.trail
-    if (trail.size <= 1) return
-    Row(
-        Modifier.fillMaxWidth().height(40.dp).padding(start = 2.dp, end = 10.dp),
-        verticalAlignment = Alignment.CenterVertically,
-    ) {
-        GsIconButton(Icons.AutoMirrored.Filled.ArrowBack, "Back", navigator::back, size = 32.dp, iconSize = 20.dp)
-        Spacer(Modifier.width(2.dp))
-        trail.forEachIndexed { index, crumb ->
-            val isLast = index == trail.lastIndex
-            Text(
-                crumb.label,
-                style = MaterialTheme.typography.labelLarge,
-                fontWeight = if (isLast) FontWeight.SemiBold else FontWeight.Normal,
-                color = if (isLast) MaterialTheme.colorScheme.onSurface else MaterialTheme.colorScheme.onSurfaceVariant,
-                maxLines = 1,
-                overflow = TextOverflow.Ellipsis,
-                modifier = if (isLast) Modifier else Modifier
-                    .clip(RoundedCornerShape(6.dp))
-                    .clickable { navigator.jumpTo(index) }
-                    .padding(horizontal = 4.dp, vertical = 2.dp),
-            )
-            if (!isLast) {
-                Text(
-                    "›",
-                    style = MaterialTheme.typography.labelLarge,
-                    color = MaterialTheme.colorScheme.onSurfaceVariant,
-                    modifier = Modifier.padding(horizontal = 2.dp),
-                )
-            }
-        }
-    }
-}
-
-/**
- * Apps and open/pinned shortcuts on the left; now-playing pill against them; clock (tap for
- * calendar and weather), phone battery and the darkness signal on the right. Icon-only: a driver
- * reads a glyph faster than a label, and it keeps the bar short enough to leave the app underneath
- * more room.
- */
-@Composable
-private fun CarNavBar(navigator: CarNavigator) {
-    val battery by CarEnvironment.battery.collectAsState()
-    val now by rememberNow()
-    val weather by Weather.state.collectAsState()
-    val weatherData = (weather as? WeatherState.Ready)?.data
-
-    val pinnedIds by CarSettings.pinnedApps.collectAsState()
-    val entries = rememberAllEntries()
-    val pinnedEntries = remember(entries, pinnedIds) {
-        pinnedIds.mapNotNull { id -> entries.find { it.componentId == id } }
-    }
-    val frame by CarEnvironment.frame.collectAsState()
-    val running = rememberRunningApps()
-
-    Surface(color = MaterialTheme.colorScheme.surfaceContainer) {
-        BoxWithConstraints(Modifier.fillMaxWidth().height(56.dp).padding(horizontal = 10.dp)) {
-            Row(Modifier.fillMaxSize(), verticalAlignment = Alignment.CenterVertically) {
-                // Home and Apps are two different places now, not a toggle on one button - the
-                // breadcrumb trail is how you retrace your steps, but reaching for either of
-                // these two from three screens deep in a media app shouldn't mean reading it
-                // first.
-                NavHomeButton(navigator, entries, running)
-                Spacer(Modifier.width(6.dp))
-                NavItem(MediaIcons.Apps, navigator.current == CarScreen.Apps) { navigator.apps() }
-                val experimentalFeatures by CarSettings.experimentalFeaturesEnabled.collectAsState()
-                val voiceEnabled by CarSettings.voiceAssistantEnabled.collectAsState()
-                if (experimentalFeatures && voiceEnabled) {
-                    Spacer(Modifier.width(6.dp))
-                    NavAssistantIcon()
-                }
-
-                // Pinned shortcuts, then whatever else is open right now. A pinned app that's also
-                // open stays in its pinned spot, marked with a dot, instead of showing up twice.
-                // The map app lives on the Home button, so it never gets a second icon here.
-                val runningEntries = running.keys
-                    .filter { it !in pinnedIds && running[it] != RunningSlot.NAV }
-                    .mapNotNull { id -> entries.find { it.componentId == id } }
-                val shownPins = pinnedEntries.filter { running[it.componentId] != RunningSlot.NAV }
-                if (shownPins.isNotEmpty() || runningEntries.isNotEmpty()) NavDivider()
-                shownPins.forEach { entry -> NavEntryIcon(entry, running, navigator, frame) }
-                if (shownPins.isNotEmpty() && runningEntries.isNotEmpty()) NavDivider()
-                runningEntries.forEach { entry -> NavEntryIcon(entry, running, navigator, frame) }
-
-                // Next turn first, off the map only; the player shares the space when it fits,
-                // and gives way to the turn when it doesn't.
-                val turn = rememberNextTurn().takeIf { navigator.current != CarScreen.Home }
-                BoxWithConstraints(Modifier.weight(1f).padding(horizontal = 16.dp), contentAlignment = Alignment.Center) {
-                    val roomForBoth = maxWidth >= TURN_AND_PLAYER_MIN_WIDTH
-                    Row(verticalAlignment = Alignment.CenterVertically, horizontalArrangement = Arrangement.spacedBy(10.dp)) {
-                        turn?.let { NavTurnPill(it) { navigator.home() } }
-                        if (turn == null || roomForBoth) {
-                            NavNowPlaying(navigator, selected = navigator.current == CarScreen.Media, modifier = Modifier.weight(1f, fill = false))
-                        }
-                    }
-                }
-
-                // Weather no longer has its own chip - the temperature alone (no icon, no room
-                // for one) sits where "Night"/"Day" used to, freeing a whole chip's width for the
-                // Home button above.
-                // The clock is also the notifications button: the dashboard lists them under the
-                // calendar and weather, and a dot here marks anything unread.
-                val unread by CarNotifications.unread.collectAsState()
-                NavChip(
-                    navigator.current == CarScreen.Dashboard || navigator.current is CarScreen.Notifications,
-                    { navigator.dashboard() },
-                ) {
-                    if (unread > 0) {
-                        Box(
-                            Modifier
-                                .align(Alignment.TopEnd)
-                                .offset(x = 8.dp, y = (-2).dp)
-                                .size(8.dp)
-                                .clip(CircleShape)
-                                .background(MaterialTheme.colorScheme.primary),
-                        )
-                    }
-                    Column(horizontalAlignment = Alignment.End) {
-                        Text(
-                            DateFormat.getTimeInstance(DateFormat.SHORT).format(Date(now)),
-                            style = MaterialTheme.typography.titleMedium,
-                            fontWeight = FontWeight.SemiBold,
-                        )
-                        Row(verticalAlignment = Alignment.CenterVertically, horizontalArrangement = Arrangement.spacedBy(3.dp)) {
-                            if (battery.percent >= 0) {
-                                Text(
-                                    "${battery.percent}%",
-                                    style = MaterialTheme.typography.labelMedium,
-                                    color = MaterialTheme.colorScheme.onSurfaceVariant,
-                                )
-                                if (battery.charging) {
-                                    ChargingGlyph(Modifier.size(13.dp))
-                                }
-                            }
-                            weatherData?.let { w ->
-                                Text(
-                                    "  ·  ${w.temp}°",
-                                    style = MaterialTheme.typography.labelMedium,
-                                    color = MaterialTheme.colorScheme.onSurfaceVariant,
-                                )
-                            }
-                        }
-                    }
-                }
-            }
-        }
-    }
-}
-
-/**
- * Home: the map, with the player or lyrics beside it. While a map app runs, the button wears that
- * app's icon and a long press offers to close it, so the app needs no icon of its own on the bar.
- */
-@Composable
-private fun NavHomeButton(navigator: CarNavigator, entries: List<Entry>, running: Map<String, RunningSlot>) {
-    val selected = navigator.current == CarScreen.Home
-    val navId = running.entries.firstOrNull { it.value == RunningSlot.NAV }?.key
-    val navEntry = navId?.let { id -> entries.find { it.componentId == id } }
-    GsIconBox(
-        { navigator.home() },
-        colors = navColors(selected),
-        latched = selected,
-        onLongClick = navId?.let { id -> { navigator.showAppMenu(id) } },
-    ) {
-        val icon = navEntry?.icon
-        if (icon != null) {
-            Box(Modifier.padding(NAV_ITEM_PADDING).size(28.dp), contentAlignment = Alignment.Center) {
-                Image(icon, navEntry.label, Modifier.size(28.dp).clip(RoundedCornerShape(7.dp)))
-            }
-        } else {
-            Icon(
-                ImageVector.vectorResource(R.drawable.navigation_24), contentDescription = "Home",
-                modifier = Modifier.padding(NAV_ITEM_PADDING).size(28.dp),
-            )
-        }
-    }
-}
-
-/** Splits the nav bar's sections: Home and Apps, pinned apps, open apps. */
-@Composable
-private fun NavDivider() {
-    Box(
-        Modifier
-            .padding(horizontal = 10.dp)
-            .width(1.dp)
-            .height(28.dp)
-            .background(MaterialTheme.colorScheme.outlineVariant),
-    )
-}
-
-/**
- * A pinned or open app on the nav bar. Tapping brings it back without reconnecting if it's
- * already open; a long press opens its menu (pin, unpin, close).
- */
-@Composable
-private fun NavEntryIcon(
-    entry: Entry,
-    running: Map<String, RunningSlot>,
-    navigator: CarNavigator,
-    frame: CarEnvironment.Frame,
-) {
-    val id = entry.componentId ?: return
-    val slot = running[id]
-    Box(Modifier.padding(horizontal = 3.dp)) {
-        NavAppIcon(
-            entry,
-            open = slot != null,
-            showing = slot != null && slot.isShowing(navigator.current),
-            onLongClick = { navigator.showAppMenu(id) },
-        ) { openApp(entry, slot, navigator, frame) }
-    }
-}
-
-/** One open or pinned app's icon on the nav bar - the same fixed size and shape either way. */
-@Composable
-private fun NavAppIcon(
-    entry: Entry,
-    open: Boolean,
-    showing: Boolean,
-    onLongClick: () -> Unit,
-    onClick: () -> Unit,
-) {
-    val scheme = MaterialTheme.colorScheme
-    GsIconBox(
-        onClick,
-        Modifier.size(44.dp),
-        colors = if (showing) GsColors(scheme.secondaryContainer, scheme.onSecondaryContainer)
-        else GsColors(scheme.surfaceVariant, scheme.onSurfaceVariant),
-        latched = showing,
-        onLongClick = onLongClick,
-    ) {
-        entry.icon?.let { Image(it, entry.label, Modifier.size(30.dp).clip(RoundedCornerShape(8.dp))) }
-        entry.builtIn?.let { Icon(it.glyph, entry.label, Modifier.size(26.dp)) }
-        // Only running apps get the line along the bottom edge, the usual taskbar mark for it.
-        if (open) {
-            Box(
-                Modifier
-                    .align(Alignment.BottomCenter)
-                    .padding(bottom = 2.dp)
-                    .size(width = 12.dp, height = 3.dp)
-                    .clip(RoundedCornerShape(50))
-                    .background(scheme.primary),
-            )
-        }
-    }
-}
-
-/** A tappable group in the bar that stays highlighted while its screen is open, like [NavItem]. */
-@Composable
-private fun NavChip(selected: Boolean, onClick: () -> Unit, content: @Composable BoxScope.() -> Unit) {
-    GsIconBox(onClick, colors = navColors(selected), latched = selected) {
-        Box(Modifier.padding(horizontal = 10.dp, vertical = 2.dp)) { content() }
-    }
-}
-
-/** Every nav bar item is raised, so it reads as pressable; the current screen's takes the accent colour. */
-@Composable
-private fun navColors(selected: Boolean): GsColors {
-    val s = MaterialTheme.colorScheme
-    return if (selected) GsColors(s.secondaryContainer, s.onSecondaryContainer)
-    else GsColors(s.surfaceContainerHighest, s.onSurface)
-}
-
-/**
- * Between Apps and whatever's actually open, not with the clock/battery group on the right - a
- * driver reaches for it right after deciding "not a tap for this", same gesture family as the
- * two buttons beside it.
- */
-@Composable
-private fun NavAssistantIcon() {
-    val state by CarAssistant.state.collectAsState()
-    val active = state.phase != CarAssistant.Phase.IDLE
-    GsIconBox({ CarAssistant.start() }, colors = navColors(active), latched = active) {
-        MicGlyph(Modifier.padding(NAV_ITEM_PADDING).size(28.dp))
-    }
-}
-
-/** Inner padding of every icon on the nav bar, leaving each button room inside the 56dp bar. */
-private val NAV_ITEM_PADDING = 8.dp
-
-@Composable
-private fun NavItem(icon: ImageVector, selected: Boolean, onClick: () -> Unit) {
-    GsIconBox(onClick, colors = navColors(selected), latched = selected) {
-        Icon(icon, contentDescription = null, modifier = Modifier.padding(NAV_ITEM_PADDING).size(28.dp))
-    }
-}
-
-/** Wall-clock time, ticking on the minute: no reason to redraw (and re-encode) more often. */
-@Composable
-internal fun rememberNow(): State<Long> = produceState(System.currentTimeMillis()) {
-    while (true) {
-        value = System.currentTimeMillis()
-        delay(60_000 - value % 60_000)
-    }
-}
-
-/** How long the pill shows a new song's title before settling to just the controls. */
-private const val TITLE_SHOWN_MS = 3_000L
-
-/** Below this, the nav bar's middle only has room for the turn, not the player beside it. */
-private val TURN_AND_PLAYER_MIN_WIDTH = 520.dp
-
-/** The next manoeuvre, as the running nav app last described it. */
-private class NextTurn(val icon: CarIcon?, val distance: String, val road: String)
-
-/**
- * Read straight off the nav app's own template: a navigation app keeps sending its routing card
- * while it's running, whether or not the map is the screen being shown.
- */
-@Composable
-private fun rememberNextTurn(): NextTurn? {
-    val status by CarServices.nav.status.collectAsState()
-    val template by CarServices.nav.template.collectAsState()
-    // Read so a change of units redraws the distance straight away, not at the next update.
-    CarSettings.units.collectAsState().value
-    if (status.phase != CarAppConnection.Phase.RUNNING) return null
-    val routing = (template as? NavigationTemplate)?.navigationInfo as? RoutingInfo ?: return null
-    if (routing.isLoading) return null
-    val step = routing.currentStep ?: return null
-    return NextTurn(
-        icon = step.maneuver?.icon,
-        distance = routing.currentDistance.display(),
-        road = step.road.text().ifEmpty { step.cue.text() },
-    )
-}
-
-/** The next turn in the nav bar: arrow, how far, onto what. Tapping goes back to the map. */
-@Composable
-private fun NavTurnPill(turn: NextTurn, onClick: () -> Unit) {
-    // Same finish as every other button on the bar, in the accent colour; the text runs a step
-    // bigger than anything else there, since it's the one thing worth a glance mid-drive.
-    GsIconBox(
-        onClick,
-        Modifier.widthIn(max = 340.dp).height(44.dp),
-        colors = gsColors(GsTone.Primary),
-    ) {
-        Row(
-            Modifier.padding(NAV_ITEM_PADDING),
-            verticalAlignment = Alignment.CenterVertically,
-            horizontalArrangement = Arrangement.spacedBy(8.dp),
-        ) {
-            CarGlyph(turn.icon, Modifier.size(28.dp))
-            if (turn.distance.isNotEmpty()) {
-                Text(turn.distance, style = MaterialTheme.typography.titleLarge, fontWeight = FontWeight.Bold, maxLines = 1)
-            }
-            if (turn.road.isNotEmpty()) {
-                Text(
-                    turn.road,
-                    style = MaterialTheme.typography.titleMedium,
-                    fontWeight = FontWeight.SemiBold,
-                    maxLines = 1,
-                    overflow = TextOverflow.Ellipsis,
-                )
-            }
-        }
-    }
-}
-
-/** "Title - Artist" on one line. The text itself cuts it off, and only where the pill runs out of room. */
-private fun nowPlayingLabel(title: String, artist: String): String =
-    listOf(title.trim(), artist.trim()).filter { it.isNotEmpty() }.joinToString(" - ")
-        .ifEmpty { "Nothing playing" }
-
-/**
- * The player in the nav bar, on every screen. Art and title open the full media screen;
- * play/pause and skip work right here. The dock button moves the player into the column beside
- * the map on Home (see [CarHome]), and the pill steps aside there while it's docked - unless the
- * column is showing lyrics instead, when the pill stays and its dock button swaps them back.
- */
-@Composable
-private fun NavNowPlaying(navigator: CarNavigator, selected: Boolean, modifier: Modifier = Modifier) {
-    val media = CarServices.media
-    val phase by media.phase.collectAsState()
-    val now by media.now.collectAsState()
-    if (phase != CarMedia.Phase.READY || !now.isActive) return
-    // Docked beside the map, the player is already on screen - the pill steps aside for it.
-    if (navigator.sidePanel == SidePanel.CONTROLS && navigator.current == CarScreen.Home) return
-    // The media screen is the full player already; the pill would only repeat its controls.
-    if (navigator.current == CarScreen.Media) return
-    val context = LocalContext.current
-    val art by produceState(now.art, now.art, now.artUri) { value = now.art ?: MediaArt.load(context, now.artUri) }
-    val position by produceState(now.currentPosition(), now) {
-        while (true) {
-            value = now.currentPosition()
-            if (!now.playing) break
-            delay(1000)
-        }
-    }
-
-    // A new song announces itself: title, play/pause and dock for a few seconds, then the title
-    // goes and the pill settles to just the controls - unless the driver keeps the title up.
-    val keepTitle by CarSettings.playerTitle.collectAsState()
-    var announcing by remember { mutableStateOf(true) }
-    LaunchedEffect(now.title, now.artist) {
-        announcing = true
-        delay(TITLE_SHOWN_MS)
-        announcing = false
-    }
-    val showTitle = keepTitle || announcing
-
-    val scheme = MaterialTheme.colorScheme
-    val onPill = if (selected) scheme.onPrimaryContainer else scheme.onSecondaryContainer
-    Surface(
-        modifier = modifier
-            .animateContentSize()
-            // With the title up, all the room the bar has, so as much of it shows as can.
-            .then(if (showTitle) Modifier.fillMaxWidth() else Modifier)
-            .height(44.dp),
-        shape = RoundedCornerShape(14.dp),
-        color = if (selected) scheme.primaryContainer else scheme.secondaryContainer,
-        contentColor = onPill,
-    ) {
-        Box {
-            Row(
-                Modifier.fillMaxHeight().padding(horizontal = 4.dp),
-                verticalAlignment = Alignment.CenterVertically,
-                horizontalArrangement = Arrangement.spacedBy(6.dp),
-            ) {
-                // Art (and the title while it shows) opens the full media screen.
-                Row(
-                    Modifier
-                        .then(if (showTitle) Modifier.weight(1f) else Modifier)
-                        .fillMaxHeight()
-                        .clip(RoundedCornerShape(10.dp))
-                        .clickable { navigator.media() },
-                    verticalAlignment = Alignment.CenterVertically,
-                    horizontalArrangement = Arrangement.spacedBy(8.dp),
-                ) {
-                    Box(Modifier.size(34.dp).clip(RoundedCornerShape(8.dp)).background(scheme.surfaceVariant)) {
-                        art?.let { Image(it.asImageBitmap(), null, Modifier.fillMaxSize(), contentScale = ContentScale.Crop) }
-                    }
-                    if (showTitle) {
-                        Text(
-                            nowPlayingLabel(now.title, now.artist),
-                            style = MaterialTheme.typography.titleSmall,
-                            fontWeight = FontWeight.SemiBold,
-                            maxLines = 1,
-                            overflow = TextOverflow.Ellipsis,
-                        )
-                    }
-                }
-                if (!showTitle) {
-                    GsIconButton(
-                        MediaIcons.Previous, "Previous", media::previous,
-                        enabled = now.canDo(PlaybackState.ACTION_SKIP_TO_PREVIOUS), size = 36.dp, iconSize = 22.dp,
-                    )
-                }
-                GsIconButton(
-                    if (now.playing) MediaIcons.Pause else Icons.Filled.PlayArrow,
-                    if (now.playing) "Pause" else "Play",
-                    media::togglePlay,
-                    tone = GsTone.Primary, size = 36.dp, iconSize = 22.dp,
-                )
-                if (!showTitle) {
-                    GsIconButton(
-                        MediaIcons.Next, "Next", media::next,
-                        enabled = now.canDo(PlaybackState.ACTION_SKIP_TO_NEXT), size = 36.dp, iconSize = 22.dp,
-                    )
-                }
-                GsIconButton(
-                    MediaIcons.DockRight, "Move the player beside the map", navigator::togglePlayerDock,
-                    size = 36.dp, iconSize = 22.dp,
-                )
-            }
-            if (now.durationMs > 0) {
-                // matchParentSize, so the line follows the pill's width rather than widening it.
-                Box(Modifier.matchParentSize(), contentAlignment = Alignment.BottomStart) {
-                    Box(
-                        Modifier
-                            .fillMaxWidth((position.toFloat() / now.durationMs).coerceIn(0f, 1f))
-                            .height(2.dp)
-                            .background(onPill.copy(alpha = 0.7f)),
-                    )
-                }
-            }
-        }
-    }
-}
-
-/**
- * A filled lightning bolt, next to the battery percentage instead of the word "charging" - the
- * core Material icon set this project ships (no extended pack, to keep the app small) has no
- * bolt, so this is drawn rather than a vector asset.
- */
-@Composable
-private fun ChargingGlyph(modifier: Modifier = Modifier, tint: Color = MaterialTheme.colorScheme.onSurfaceVariant) {
-    androidx.compose.foundation.Canvas(modifier) {
-        val w = size.width
-        val h = size.height
-        val bolt = androidx.compose.ui.graphics.Path().apply {
-            moveTo(w * 0.58f, 0f)
-            lineTo(w * 0.12f, h * 0.58f)
-            lineTo(w * 0.46f, h * 0.58f)
-            lineTo(w * 0.42f, h)
-            lineTo(w * 0.88f, h * 0.40f)
-            lineTo(w * 0.54f, h * 0.40f)
-            close()
-        }
-        drawPath(bolt, tint)
-    }
+/** Stands in for the phone's vibration motor on the car screen: does nothing. */
+private object NoHaptics : HapticFeedback {
+    override fun performHapticFeedback(hapticFeedbackType: HapticFeedbackType) {}
 }

gearslip/src/main/java/app/seb3thehacker/gearslip/car/CarWhatsNew.kt

@@ -1,5 +1,7 @@
 package app.seb3thehacker.gearslip.car
 
+import androidx.compose.ui.res.stringResource
+import app.seb3thehacker.gearslip.R
 import androidx.compose.foundation.background
 import androidx.compose.foundation.clickable
 import androidx.compose.foundation.interaction.MutableInteractionSource
@@ -76,7 +78,7 @@ fun CarWhatsNew() {
         ) {
             Column(Modifier.padding(20.dp), verticalArrangement = Arrangement.spacedBy(14.dp)) {
                 Text(
-                    "What's new in ${release.versionName}",
+                    stringResource(R.string.whatsnew_title, release.versionName),
                     style = MaterialTheme.typography.headlineSmall,
                     fontWeight = FontWeight.Bold,
                 )
@@ -99,12 +101,12 @@ fun CarWhatsNew() {
                 Row(verticalAlignment = Alignment.CenterVertically, horizontalArrangement = Arrangement.spacedBy(14.dp)) {
                     GsSwitch(afterUpdates, CarSettings::setWhatsNewAfterUpdates)
                     Text(
-                        "Show after updates",
+                        stringResource(R.string.whatsnew_show_after),
                         style = MaterialTheme.typography.titleMedium,
                         modifier = Modifier.weight(1f),
                     )
                     GsButton(onClick = close, modifier = Modifier.height(56.dp)) {
-                        Text("Got it", style = MaterialTheme.typography.titleMedium)
+                        Text(stringResource(R.string.whatsnew_got_it), style = MaterialTheme.typography.titleMedium)
                     }
                 }
             }

gearslip/src/main/java/app/seb3thehacker/gearslip/car/ClusterNav.kt

@@ -0,0 +1,221 @@
+package app.seb3thehacker.gearslip.car
+
+import androidx.car.app.model.CarText
+import androidx.car.app.model.Distance
+import androidx.car.app.navigation.model.Maneuver
+import androidx.car.app.navigation.model.NavigationTemplate
+import androidx.car.app.navigation.model.RoutingInfo
+import androidx.car.app.navigation.model.Step
+import app.seb3thehacker.gearslip.GearslipLog
+import app.seb3thehacker.gearslip.Protobuf
+
+/**
+ * The next turn on the car's instrument cluster, over its NavigationStatusService (Service
+ * field 8), the way Android Auto feeds it:
+ *
+ *   -> NavigationStatus         { status = 1 (1 active, 2 inactive, 3 rerouting) }
+ *   -> NavigationNextTurnEvent  { road = 1; turn_side = 2; event = 3; turn_number = 5; turn_angle = 6 }
+ *   -> NavigationNextTurnDistanceEvent { distance_meters = 1; time_to_turn_seconds = 2;
+ *                                        display_distance_e3 = 3; display_distance_unit = 4 }
+ *
+ * Newer cars also take a NavigationState message; the deprecated pair above is what a 2018
+ * Uconnect understands. The turn comes from the map app's trip (what the Car App Library hands
+ * to clusters), or from its routing card when it sends no trip.
+ */
+class ClusterNav(
+    val channelId: Int,
+    minimumIntervalMs: Long = 0,
+    private val sendOnChannel: (messageId: Int, body: ByteArray) -> Unit,
+) {
+    private val updateIntervalMs = maxOf(TICK_MS, minimumIntervalMs)
+    @Volatile private var running = false
+    private var worker: Thread? = null
+    private var updatesRequested = true
+    private var sentStatus = -1
+    private var sentTurn: String? = null
+    private var sentDistance: String? = null
+
+    @Synchronized
+    fun onMessage(messageId: Int, body: ByteArray) {
+        when (messageId) {
+            MSG_CHANNEL_OPEN_RESPONSE -> {
+                val status = Protobuf.readInt32Field(body, 1)
+                GearslipLog.i("cluster: <- ChannelOpenResponse: status=$status")
+                if (status == 0) start()
+            }
+            MSG_START -> {
+                updatesRequested = true
+                sentStatus = -1
+                sentTurn = null
+                sentDistance = null
+                GearslipLog.i("cluster: <- start")
+            }
+            MSG_STOP -> {
+                updatesRequested = false
+                GearslipLog.i("cluster: <- stop")
+            }
+            else -> GearslipLog.i("cluster: <- unhandled message id=$messageId (${body.size} bytes)")
+        }
+    }
+
+    private fun start() {
+        if (running) return
+        running = true
+        worker = Thread({
+            while (running) {
+                runCatching { tick() }.onFailure { GearslipLog.w("cluster: ${it.message}") }
+                try {
+                    Thread.sleep(updateIntervalMs)
+                } catch (_: InterruptedException) {
+                    return@Thread
+                }
+            }
+        }, "gearslip-cluster").also { it.start() }
+    }
+
+    @Synchronized
+    fun stop() {
+        running = false
+        worker?.interrupt()
+        worker = null
+    }
+
+    @Synchronized
+    private fun tick() {
+        if (!running || !updatesRequested) return
+        val turn = NavTurn.current()
+        val status = when {
+            turn == null -> STATUS_INACTIVE
+            turn.rerouting -> STATUS_REROUTING
+            else -> STATUS_ACTIVE
+        }
+        if (status != sentStatus) {
+            sendOnChannel(MSG_STATUS, Protobuf.varintField(1, status.toLong()))
+            GearslipLog.i("cluster: -> ${STATUS_NAMES[status]}")
+            sentStatus = status
+            if (status == STATUS_INACTIVE) { sentTurn = null; sentDistance = null }
+        }
+        if (turn == null || status == STATUS_REROUTING) return
+        sendTurn(turn.step)
+        turn.distance?.let { sendDistance(it, turn.seconds) }
+    }
+
+    private fun sendTurn(step: Step) {
+        val maneuver = step.maneuver
+        val (event, side) = maneuver?.let { eventFor(it.type) } ?: (EVENT_UNKNOWN to SIDE_UNSPECIFIED)
+        val road = step.road.text().ifBlank { step.cue.text() }
+        val key = "$road|$event|$side|${maneuver?.roundaboutExitNumber}|${maneuver?.roundaboutExitAngle}"
+        if (key == sentTurn) return
+        sentTurn = key
+        var body = Protobuf.stringField(1, road) +
+            Protobuf.varintField(2, side.toLong()) +
+            Protobuf.varintField(3, event.toLong())
+        maneuver?.roundaboutExitNumber?.takeIf { it > 0 }?.let { body += Protobuf.varintField(5, it.toLong()) }
+        maneuver?.roundaboutExitAngle?.takeIf { it > 0 }?.let { body += Protobuf.varintField(6, it.toLong()) }
+        sendOnChannel(MSG_TURN, body)
+        GearslipLog.i("cluster: -> turn event=$event side=$side road=\"$road\"")
+    }
+
+    /**
+     * The Car App Library's distance units use the same numbers as the protocol's (1 metres ...
+     * 7 yards), so the app's own display choice passes straight through.
+     */
+    private fun sendDistance(distance: Distance, seconds: Long?) {
+        val meters = NavTurn.toMeters(distance)
+        val key = "${distance.displayDistance}|${distance.displayUnit}|${seconds ?: -1}"
+        if (key == sentDistance) return
+        sentDistance = key
+        sendOnChannel(
+            MSG_DISTANCE,
+            Protobuf.varintField(1, meters.toLong()) +
+                Protobuf.varintField(2, (seconds ?: 0L).coerceAtLeast(0)) +
+                Protobuf.varintField(3, (distance.displayDistance * 1000).toLong()) +
+                Protobuf.varintField(4, distance.displayUnit.toLong()),
+        )
+    }
+
+    private fun CarText?.text() = this?.toString().orEmpty()
+
+    companion object {
+        private const val TICK_MS = 500L
+        private const val MSG_CHANNEL_OPEN_RESPONSE = 8
+        private const val MSG_START = 32769
+        private const val MSG_STOP = 32770
+        private const val MSG_STATUS = 32771
+        private const val MSG_TURN = 32772
+        private const val MSG_DISTANCE = 32773
+
+        private const val STATUS_ACTIVE = 1
+        private const val STATUS_INACTIVE = 2
+        private const val STATUS_REROUTING = 3
+        private val STATUS_NAMES = mapOf(1 to "navigating", 2 to "not navigating", 3 to "rerouting")
+
+        private const val SIDE_LEFT = 1
+        private const val SIDE_RIGHT = 2
+        private const val SIDE_UNSPECIFIED = 3
+
+        private const val EVENT_UNKNOWN = 0
+
+        /** The car's turn icon and side for a Car App Library manoeuvre. */
+        fun eventFor(type: Int): Pair<Int, Int> = when (type) {
+            Maneuver.TYPE_DEPART -> 1 to SIDE_UNSPECIFIED
+            Maneuver.TYPE_NAME_CHANGE -> 2 to SIDE_UNSPECIFIED
+            Maneuver.TYPE_KEEP_LEFT, Maneuver.TYPE_TURN_SLIGHT_LEFT -> 3 to SIDE_LEFT
+            Maneuver.TYPE_KEEP_RIGHT, Maneuver.TYPE_TURN_SLIGHT_RIGHT -> 3 to SIDE_RIGHT
+            Maneuver.TYPE_TURN_NORMAL_LEFT -> 4 to SIDE_LEFT
+            Maneuver.TYPE_TURN_NORMAL_RIGHT -> 4 to SIDE_RIGHT
+            Maneuver.TYPE_TURN_SHARP_LEFT -> 5 to SIDE_LEFT
+            Maneuver.TYPE_TURN_SHARP_RIGHT -> 5 to SIDE_RIGHT
+            Maneuver.TYPE_U_TURN_LEFT -> 6 to SIDE_LEFT
+            Maneuver.TYPE_U_TURN_RIGHT -> 6 to SIDE_RIGHT
+            Maneuver.TYPE_ON_RAMP_SLIGHT_LEFT, Maneuver.TYPE_ON_RAMP_NORMAL_LEFT, Maneuver.TYPE_ON_RAMP_SHARP_LEFT,
+            Maneuver.TYPE_ON_RAMP_U_TURN_LEFT -> 7 to SIDE_LEFT
+            Maneuver.TYPE_ON_RAMP_SLIGHT_RIGHT, Maneuver.TYPE_ON_RAMP_NORMAL_RIGHT, Maneuver.TYPE_ON_RAMP_SHARP_RIGHT,
+            Maneuver.TYPE_ON_RAMP_U_TURN_RIGHT -> 7 to SIDE_RIGHT
+            Maneuver.TYPE_OFF_RAMP_SLIGHT_LEFT, Maneuver.TYPE_OFF_RAMP_NORMAL_LEFT -> 8 to SIDE_LEFT
+            Maneuver.TYPE_OFF_RAMP_SLIGHT_RIGHT, Maneuver.TYPE_OFF_RAMP_NORMAL_RIGHT -> 8 to SIDE_RIGHT
+            Maneuver.TYPE_FORK_LEFT -> 9 to SIDE_LEFT
+            Maneuver.TYPE_FORK_RIGHT -> 9 to SIDE_RIGHT
+            Maneuver.TYPE_MERGE_LEFT -> 10 to SIDE_LEFT
+            Maneuver.TYPE_MERGE_RIGHT -> 10 to SIDE_RIGHT
+            Maneuver.TYPE_MERGE_SIDE_UNSPECIFIED -> 10 to SIDE_UNSPECIFIED
+            Maneuver.TYPE_ROUNDABOUT_ENTER_CW, Maneuver.TYPE_ROUNDABOUT_ENTER_CCW -> 11 to SIDE_UNSPECIFIED
+            Maneuver.TYPE_ROUNDABOUT_EXIT_CW, Maneuver.TYPE_ROUNDABOUT_EXIT_CCW -> 12 to SIDE_UNSPECIFIED
+            Maneuver.TYPE_ROUNDABOUT_ENTER_AND_EXIT_CW, Maneuver.TYPE_ROUNDABOUT_ENTER_AND_EXIT_CW_WITH_ANGLE,
+            Maneuver.TYPE_ROUNDABOUT_ENTER_AND_EXIT_CCW, Maneuver.TYPE_ROUNDABOUT_ENTER_AND_EXIT_CCW_WITH_ANGLE -> 13 to SIDE_UNSPECIFIED
+            Maneuver.TYPE_STRAIGHT -> 14 to SIDE_UNSPECIFIED
+            Maneuver.TYPE_FERRY_BOAT, Maneuver.TYPE_FERRY_BOAT_LEFT, Maneuver.TYPE_FERRY_BOAT_RIGHT -> 16 to SIDE_UNSPECIFIED
+            Maneuver.TYPE_FERRY_TRAIN, Maneuver.TYPE_FERRY_TRAIN_LEFT, Maneuver.TYPE_FERRY_TRAIN_RIGHT -> 17 to SIDE_UNSPECIFIED
+            Maneuver.TYPE_DESTINATION, Maneuver.TYPE_DESTINATION_STRAIGHT -> 19 to SIDE_UNSPECIFIED
+            Maneuver.TYPE_DESTINATION_LEFT -> 19 to SIDE_LEFT
+            Maneuver.TYPE_DESTINATION_RIGHT -> 19 to SIDE_RIGHT
+            else -> EVENT_UNKNOWN to SIDE_UNSPECIFIED
+        }
+    }
+}
+
+/** One turn as the car wants it, from whichever source the map app fills. */
+internal class NavTurn(val step: Step, val distance: Distance?, val seconds: Long?, val rerouting: Boolean) {
+    companion object {
+        /** The map app's next turn: from its trip (what clusters get), or its routing card. */
+        fun current(): NavTurn? {
+            val nav = CarServices.navOrNull() ?: return null
+            nav.trip.value?.let { trip ->
+                val step = trip.steps.firstOrNull() ?: return@let
+                val estimate = trip.stepTravelEstimates.firstOrNull()
+                return NavTurn(step, estimate?.remainingDistance, estimate?.remainingTimeSeconds?.takeIf { it >= 0 }, trip.isLoading)
+            }
+            val info = (nav.template.value as? NavigationTemplate)?.navigationInfo as? RoutingInfo ?: return null
+            val step = info.currentStep ?: return null
+            return NavTurn(step, info.currentDistance, null, info.isLoading)
+        }
+
+        fun toMeters(d: Distance): Int = (d.displayDistance * when (d.displayUnit) {
+            Distance.UNIT_KILOMETERS, Distance.UNIT_KILOMETERS_P1 -> 1000.0
+            Distance.UNIT_MILES, Distance.UNIT_MILES_P1 -> 1609.344
+            Distance.UNIT_FEET -> 0.3048
+            Distance.UNIT_YARDS -> 0.9144
+            else -> 1.0
+        }).toInt()
+    }
+}

gearslip/src/main/java/app/seb3thehacker/gearslip/car/ClusterScreen.kt

@@ -0,0 +1,140 @@
+package app.seb3thehacker.gearslip.car
+
+import androidx.compose.foundation.background
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.BoxWithConstraints
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.layout.width
+import androidx.compose.material3.LocalContentColor
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.material3.darkColorScheme
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.CompositionLocalProvider
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.produceState
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.platform.LocalDensity
+import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.text.style.TextOverflow
+import androidx.compose.ui.unit.dp
+import app.seb3thehacker.gearslip.host.clockTime
+import app.seb3thehacker.gearslip.host.display
+import app.seb3thehacker.gearslip.host.remainingTime
+import kotlinx.coroutines.delay
+
+/**
+ * The instrument-cluster screen: the next turn, big enough to read in a glance past the wheel.
+ * The arrow and the distance to it, what to do there, and the time, distance and arrival left
+ * along the bottom. With no route it shows what's playing, quietly, or nothing.
+ *
+ * Always dark, like the dials around it. [marginX] and [marginY] are the pixels the car crops off
+ * the frame, kept clear.
+ */
+@Composable
+internal fun ClusterScreen(marginX: Int, marginY: Int) {
+    // The map app's turn changes a few times a minute: read it once a second.
+    val turn by produceState<ClusterTurn?>(null) {
+        while (true) {
+            value = ClusterTurn.now()
+            delay(1_000)
+        }
+    }
+    val density = LocalDensity.current
+    MaterialTheme(colorScheme = darkColorScheme()) {
+        CompositionLocalProvider(LocalContentColor provides Color.White) {
+            BoxWithConstraints(
+                Modifier.fillMaxSize().background(Color.Black).padding(
+                    horizontal = with(density) { (marginX / 2).toDp() } + 24.dp,
+                    vertical = with(density) { (marginY / 2).toDp() } + 16.dp,
+                ),
+                contentAlignment = Alignment.CenterStart,
+            ) {
+                // Sized off the height: clusters run from short strips to near squares.
+                val unit = maxHeight / 12
+                val t = turn
+                if (t == null) {
+                    NowPlayingLine(Modifier.align(Alignment.Center))
+                    return@BoxWithConstraints
+                }
+                Column(verticalArrangement = Arrangement.spacedBy(unit * 0.4f)) {
+                    Row(verticalAlignment = Alignment.CenterVertically) {
+                        CarGlyph(t.icon, Modifier.size(unit * 3.4f))
+                        Spacer(Modifier.width(unit))
+                        Text(
+                            t.distance,
+                            fontSize = with(density) { (unit * 2.2f).toSp() },
+                            fontWeight = FontWeight.Bold,
+                            maxLines = 1,
+                        )
+                    }
+                    if (t.what.isNotEmpty()) {
+                        Text(
+                            t.what,
+                            fontSize = with(density) { (unit * 1.1f).toSp() },
+                            fontWeight = FontWeight.SemiBold,
+                            maxLines = 2,
+                            overflow = TextOverflow.Ellipsis,
+                        )
+                    }
+                    if (t.trip.isNotEmpty()) {
+                        Text(
+                            t.trip,
+                            fontSize = with(density) { (unit * 0.85f).toSp() },
+                            color = Color.White.copy(alpha = 0.7f),
+                            maxLines = 1,
+                        )
+                    }
+                }
+            }
+        }
+    }
+}
+
+@Composable
+private fun NowPlayingLine(modifier: Modifier) {
+    val now = CarServices.mediaOrNull()?.now?.value
+    if (now == null || now.title.isEmpty()) return
+    Text(
+        listOf(now.title, now.artist).filter { it.isNotEmpty() }.joinToString(" · "),
+        modifier,
+        style = MaterialTheme.typography.titleLarge,
+        color = Color.White.copy(alpha = 0.7f),
+        maxLines = 1,
+        overflow = TextOverflow.Ellipsis,
+    )
+}
+
+/** What the cluster shows of a route, read from [NavTurn] and the trip's estimate to the destination. */
+private class ClusterTurn(
+    val icon: androidx.car.app.model.CarIcon?,
+    val distance: String,
+    val what: String,
+    val trip: String,
+) {
+    companion object {
+        fun now(): ClusterTurn? {
+            val turn = NavTurn.current() ?: return null
+            if (turn.rerouting) return null
+            val step = turn.step
+            val cue = step.cue?.toString().orEmpty()
+            val what = cue.ifEmpty { step.road?.toString().orEmpty() }
+            val estimate = CarServices.navOrNull()?.trip?.value?.destinationTravelEstimates?.firstOrNull()
+            val trip = estimate?.let { e ->
+                listOf(
+                    e.remainingTimeSeconds.takeIf { it >= 0 }?.let { remainingTime(it) }.orEmpty(),
+                    e.remainingDistance.display(),
+                    e.arrivalTimeAtDestination.clockTime(),
+                ).filter { it.isNotEmpty() }.joinToString(" · ")
+            }.orEmpty()
+            return ClusterTurn(step.maneuver?.icon, turn.distance.display(), what, trip)
+        }
+    }
+}

gearslip/src/main/java/app/seb3thehacker/gearslip/car/DirectionsVoice.kt

@@ -0,0 +1,367 @@
+package app.seb3thehacker.gearslip.car
+
+import app.seb3thehacker.gearslip.R
+import android.content.Context
+import android.os.Bundle
+import android.speech.tts.TextToSpeech
+import android.speech.tts.UtteranceProgressListener
+import androidx.car.app.model.CarText
+import androidx.car.app.model.Distance
+import androidx.car.app.navigation.model.Maneuver
+import androidx.car.app.navigation.model.Step
+import app.seb3thehacker.gearslip.GearslipLog
+import app.seb3thehacker.gearslip.audio.AudioLink
+import java.io.File
+import java.nio.ByteBuffer
+import java.nio.ByteOrder
+import java.util.concurrent.ConcurrentHashMap
+import java.util.concurrent.CountDownLatch
+import java.util.concurrent.Executors
+import java.util.concurrent.TimeUnit
+import kotlin.math.roundToInt
+
+/**
+ * Spoken turn-by-turn on the car's directions channel (the GUIDANCE audio sink).
+ *
+ * A map app on the phone speaks its own prompts as navigation audio, which Android can't hand to
+ * Gearslip without root, and which the phone mutes while USB audio runs. So Gearslip reads the
+ * same turn the instrument cluster gets ([NavTurn]) and says it itself: once when the turn comes
+ * up, again a kilometre or so out on a long stretch, and once more just before it. The words are
+ * rendered with the phone's text-to-speech to a file, never played on the phone, and streamed to
+ * the car, which ducks the music under them the way it does for real Android Auto. When the music
+ * isn't Gearslip's, each announcement first asks the car for its speakers, as Android Auto does.
+ *
+ * Nothing spoken is logged: road names are where the driver is going.
+ */
+object DirectionsVoice {
+
+    private enum class Stage { FAR, PREPARED, DONE }
+
+    private var appContext: Context? = null
+    private var tts: TextToSpeech? = null
+    @Volatile private var ttsReady = false
+    private val pending = ConcurrentHashMap<String, CountDownLatch>()
+
+    @Volatile private var link: AudioLink? = null
+    @Volatile private var running = false
+    @Volatile private var musicIsOurs: () -> Boolean = { false }
+    private val speaker = Executors.newSingleThreadScheduledExecutor { Thread(it, "gearslip-directions").apply { isDaemon = true } }
+    /** Counts announcements, so a hand-back scheduled after one is dropped if another has begun. */
+    private var spoken = 0
+    @Volatile private var latest = 0
+
+    private var turnKey: String? = null
+    private var stage = Stage.DONE
+
+    fun init(context: Context) {
+        if (tts != null) return
+        appContext = context.applicationContext
+        tts = TextToSpeech(appContext) { status -> ttsReady = status == TextToSpeech.SUCCESS }.apply {
+            setOnUtteranceProgressListener(object : UtteranceProgressListener() {
+                override fun onStart(utteranceId: String?) {}
+                override fun onDone(utteranceId: String?) { pending.remove(utteranceId)?.countDown() }
+                @Deprecated("Deprecated in Java, no replacement on this API level")
+                override fun onError(utteranceId: String?) { pending.remove(utteranceId)?.countDown() }
+            })
+        }
+    }
+
+    /** The car opened its directions sink: start following the map app's turns. */
+    fun attach(link: AudioLink, musicIsOurs: () -> Boolean) {
+        this.link = link
+        this.musicIsOurs = musicIsOurs
+        GearslipLog.i("guidance: the car offered a directions sink at ${link.sampleRate}Hz x${link.channels}")
+        if (running) return
+        running = true
+        turnKey = null
+        Thread({
+            while (running) {
+                runCatching { tick() }.onFailure { GearslipLog.w("guidance: ${it.message}") }
+                Thread.sleep(TICK_MS)
+            }
+        }, "gearslip-directions-watch").apply { isDaemon = true }.start()
+    }
+
+    fun detach(link: AudioLink) {
+        if (this.link !== link) return
+        this.link = null
+        running = false
+    }
+
+    /** Why the last turn wasn't spoken, so the log says it once rather than every tick. */
+    private var silentBecause: String? = null
+
+    private fun quiet(reason: String) {
+        if (silentBecause == reason) return
+        silentBecause = reason
+        GearslipLog.i("guidance: not speaking - $reason")
+    }
+
+    private fun tick() {
+        val turn = NavTurn.current()
+        if (turn == null) {
+            turnKey = null
+            return
+        }
+        if (!CarSettings.speakDirections.value) return quiet("Spoken directions is off in the car's Settings")
+        if (turn.rerouting) return quiet("the map app is rerouting")
+        val step = turn.step
+        val instruction = instruction(step) ?: return quiet("the map app gave this turn no words")
+        silentBecause = null
+        val meters = turn.distance?.let(NavTurn::toMeters)
+        val close = (turn.seconds != null && turn.seconds <= NEAR_SECONDS) || (meters != null && meters <= NEAR_METERS)
+
+        val key = "${step.road.text()}|${step.maneuver?.type}|${step.maneuver?.roundaboutExitNumber}|${step.cue.text()}"
+        if (key != turnKey) {
+            turnKey = key
+            if (step.maneuver?.type == Maneuver.TYPE_DEPART) {
+                stage = Stage.DONE
+                return
+            }
+            if (close || turn.distance == null) {
+                say(instruction)
+                stage = Stage.DONE
+            } else {
+                say(ahead(turn.distance, instruction))
+                stage = if (meters != null && meters > PREPARE_FROM_METERS) Stage.FAR else Stage.PREPARED
+            }
+            return
+        }
+        when {
+            stage != Stage.DONE && close -> {
+                say(instruction)
+                stage = Stage.DONE
+            }
+            stage == Stage.FAR && meters != null && meters <= PREPARE_AT_METERS -> {
+                say(ahead(turn.distance, instruction))
+                stage = Stage.PREPARED
+            }
+        }
+    }
+
+    /** What to do, in words: built from the manoeuvre when the app names one, else the app's own text. */
+    private fun instruction(step: Step): String? {
+        val res = appContext?.resources ?: return null
+        val road = step.road.text()
+        // Each manoeuvre is a whole sentence, with and without the road, so a translation can
+        // put the road wherever its language wants it.
+        fun say(plain: Int, withRoad: Int) =
+            if (road.isBlank() || withRoad == 0) res.getString(plain) else res.getString(withRoad, road)
+        val maneuver = step.maneuver
+        val built = when (maneuver?.type) {
+            Maneuver.TYPE_TURN_SLIGHT_LEFT -> say(R.string.dir_slight_left, R.string.dir_slight_left_onto)
+            Maneuver.TYPE_TURN_SLIGHT_RIGHT -> say(R.string.dir_slight_right, R.string.dir_slight_right_onto)
+            Maneuver.TYPE_TURN_NORMAL_LEFT -> say(R.string.dir_left, R.string.dir_left_onto)
+            Maneuver.TYPE_TURN_NORMAL_RIGHT -> say(R.string.dir_right, R.string.dir_right_onto)
+            Maneuver.TYPE_TURN_SHARP_LEFT -> say(R.string.dir_sharp_left, R.string.dir_sharp_left_onto)
+            Maneuver.TYPE_TURN_SHARP_RIGHT -> say(R.string.dir_sharp_right, R.string.dir_sharp_right_onto)
+            Maneuver.TYPE_U_TURN_LEFT, Maneuver.TYPE_U_TURN_RIGHT -> say(R.string.dir_u_turn, 0)
+            Maneuver.TYPE_KEEP_LEFT -> say(R.string.dir_keep_left, R.string.dir_keep_left_toward)
+            Maneuver.TYPE_KEEP_RIGHT -> say(R.string.dir_keep_right, R.string.dir_keep_right_toward)
+            Maneuver.TYPE_FORK_LEFT -> say(R.string.dir_fork_left, R.string.dir_fork_left_toward)
+            Maneuver.TYPE_FORK_RIGHT -> say(R.string.dir_fork_right, R.string.dir_fork_right_toward)
+            Maneuver.TYPE_ON_RAMP_SLIGHT_LEFT, Maneuver.TYPE_ON_RAMP_NORMAL_LEFT, Maneuver.TYPE_ON_RAMP_SHARP_LEFT,
+            Maneuver.TYPE_ON_RAMP_U_TURN_LEFT -> say(R.string.dir_ramp_left, R.string.dir_ramp_left_onto)
+            Maneuver.TYPE_ON_RAMP_SLIGHT_RIGHT, Maneuver.TYPE_ON_RAMP_NORMAL_RIGHT, Maneuver.TYPE_ON_RAMP_SHARP_RIGHT,
+            Maneuver.TYPE_ON_RAMP_U_TURN_RIGHT -> say(R.string.dir_ramp_right, R.string.dir_ramp_right_onto)
+            Maneuver.TYPE_OFF_RAMP_SLIGHT_LEFT, Maneuver.TYPE_OFF_RAMP_NORMAL_LEFT -> say(R.string.dir_exit_left, R.string.dir_exit_left_toward)
+            Maneuver.TYPE_OFF_RAMP_SLIGHT_RIGHT, Maneuver.TYPE_OFF_RAMP_NORMAL_RIGHT -> say(R.string.dir_exit_right, R.string.dir_exit_right_toward)
+            Maneuver.TYPE_MERGE_LEFT -> say(R.string.dir_merge_left, R.string.dir_merge_left_onto)
+            Maneuver.TYPE_MERGE_RIGHT -> say(R.string.dir_merge_right, R.string.dir_merge_right_onto)
+            Maneuver.TYPE_MERGE_SIDE_UNSPECIFIED -> say(R.string.dir_merge, R.string.dir_merge_onto)
+            Maneuver.TYPE_ROUNDABOUT_ENTER_AND_EXIT_CW, Maneuver.TYPE_ROUNDABOUT_ENTER_AND_EXIT_CW_WITH_ANGLE,
+            Maneuver.TYPE_ROUNDABOUT_ENTER_AND_EXIT_CCW, Maneuver.TYPE_ROUNDABOUT_ENTER_AND_EXIT_CCW_WITH_ANGLE ->
+                maneuver.roundaboutExitNumber.takeIf { it in 1..ORDINALS.size }
+                    ?.let { res.getString(ORDINALS[it - 1]) }
+                    ?.let { exit ->
+                        if (road.isBlank()) res.getString(R.string.dir_roundabout_take, exit)
+                        else res.getString(R.string.dir_roundabout_take_onto, exit, road)
+                    }
+                    ?: say(R.string.dir_roundabout_through, R.string.dir_roundabout_through_onto)
+            Maneuver.TYPE_ROUNDABOUT_ENTER_CW, Maneuver.TYPE_ROUNDABOUT_ENTER_CCW -> say(R.string.dir_roundabout_enter, 0)
+            Maneuver.TYPE_ROUNDABOUT_EXIT_CW, Maneuver.TYPE_ROUNDABOUT_EXIT_CCW -> say(R.string.dir_roundabout_exit, R.string.dir_roundabout_exit_onto)
+            Maneuver.TYPE_STRAIGHT -> say(R.string.dir_straight, R.string.dir_straight_onto)
+            Maneuver.TYPE_NAME_CHANGE -> say(R.string.dir_continue, R.string.dir_continue_onto)
+            Maneuver.TYPE_FERRY_BOAT, Maneuver.TYPE_FERRY_BOAT_LEFT, Maneuver.TYPE_FERRY_BOAT_RIGHT -> say(R.string.dir_ferry, 0)
+            Maneuver.TYPE_FERRY_TRAIN, Maneuver.TYPE_FERRY_TRAIN_LEFT, Maneuver.TYPE_FERRY_TRAIN_RIGHT -> say(R.string.dir_train, 0)
+            Maneuver.TYPE_DESTINATION, Maneuver.TYPE_DESTINATION_STRAIGHT -> say(R.string.dir_destination, 0)
+            Maneuver.TYPE_DESTINATION_LEFT -> say(R.string.dir_destination_left, 0)
+            Maneuver.TYPE_DESTINATION_RIGHT -> say(R.string.dir_destination_right, 0)
+            else -> null
+        }
+        return built ?: step.cue.text().ifBlank { null }
+    }
+
+    /** "In 300 meters, turn left": the distance ahead of a turn that isn't close yet. */
+    private fun ahead(d: Distance, instruction: String): String =
+        appContext?.getString(R.string.dir_in_distance, spoken(d), instruction) ?: instruction
+
+    /** The app's own rounded distance, read the way a person would say it. */
+    private fun spoken(d: Distance): String {
+        val res = appContext?.resources ?: return ""
+        val n = d.displayDistance
+        val whole = n % 1.0 == 0.0
+        val number = if (whole) n.toInt().toString() else "%.1f".format(n)
+        return when (d.displayUnit) {
+            Distance.UNIT_KILOMETERS, Distance.UNIT_KILOMETERS_P1 ->
+                if (whole) res.getQuantityString(R.plurals.dir_km, n.toInt(), number) else res.getString(R.string.dir_km_decimal, number)
+            Distance.UNIT_MILES, Distance.UNIT_MILES_P1 -> when (n) {
+                0.25 -> res.getString(R.string.dir_quarter_mile)
+                0.5 -> res.getString(R.string.dir_half_mile)
+                0.75 -> res.getString(R.string.dir_three_quarter_mile)
+                else -> if (whole) res.getQuantityString(R.plurals.dir_miles, n.toInt(), number) else res.getString(R.string.dir_miles_decimal, number)
+            }
+            Distance.UNIT_FEET -> res.getQuantityString(R.plurals.dir_feet, n.toInt(), number)
+            Distance.UNIT_YARDS -> res.getQuantityString(R.plurals.dir_yards, n.toInt(), number)
+            else -> res.getQuantityString(R.plurals.dir_meters, n.roundToInt(), n.roundToInt())
+        }
+    }
+
+    /** Newest wins: a prompt still waiting when the next one arrives is already out of date. */
+    private fun say(text: String) {
+        val id = ++latest
+        speaker.execute {
+            if (id != latest) return@execute
+            runCatching { play(text, id) }.onFailure { GearslipLog.w("guidance: could not speak a turn: ${it.message}") }
+        }
+    }
+
+    private fun play(text: String, id: Int) {
+        val engine = tts ?: return
+        val context = appContext ?: return
+        val sink = link ?: return
+        if (!ttsReady) {
+            GearslipLog.w("guidance: text-to-speech isn't ready, a turn went unspoken")
+            return
+        }
+        val file = File(context.cacheDir, "directions.wav")
+        val utterance = "gearslip-directions-$id"
+        val done = CountDownLatch(1)
+        pending[utterance] = done
+        if (engine.synthesizeToFile(text, Bundle(), file, utterance) != TextToSpeech.SUCCESS) {
+            pending.remove(utterance)
+            return
+        }
+        if (!done.await(SYNTH_TIMEOUT_S, TimeUnit.SECONDS)) {
+            pending.remove(utterance)
+            GearslipLog.w("guidance: text-to-speech took too long, a turn went unspoken")
+            return
+        }
+        val pcm = Wav.read(file)?.let { Wav.convert(it, sink.sampleRate, sink.channels) } ?: run {
+            GearslipLog.w("guidance: text-to-speech gave audio Gearslip can't read")
+            return
+        }
+        // Logged before speaking too, so a car that dies mid-announcement shows what it was doing.
+        GearslipLog.i("guidance: speaking a turn")
+        // Held through back-to-back prompts rather than asked for and given back each time.
+        if (!musicIsOurs()) sink.askForSpeakers()
+        val turn = ++spoken
+        try {
+            stream(sink, pcm)
+        } finally {
+            speaker.schedule({ if (turn == spoken) sink.handBackSpeakers() }, HOLD_MS, TimeUnit.MILLISECONDS)
+        }
+        GearslipLog.i("guidance: spoke a turn (${pcm.size / (2 * sink.channels) * 1000 / sink.sampleRate} ms)")
+    }
+
+    /** Start, the words in 20 ms chunks at about real time, a little silence, Stop. */
+    private fun stream(sink: AudioLink, pcm: ByteArray) {
+        val frame = 2 * sink.channels
+        val chunk = sink.sampleRate / 50 * frame
+        val chunkMs = 20L
+        val padded = pcm + ByteArray(sink.sampleRate / 5 * frame) // 200 ms tail so the last word isn't clipped
+        sink.start()
+        try {
+            val began = System.currentTimeMillis()
+            var offset = 0
+            var sent = 0
+            while (offset < padded.size && link === sink) {
+                val size = minOf(chunk, padded.size - offset)
+                sink.write(padded.copyOfRange(offset, offset + size), size)
+                offset += size
+                sent++
+                val ahead = sent * chunkMs - (System.currentTimeMillis() - began)
+                if (ahead > LEAD_MS) Thread.sleep(ahead - LEAD_MS)
+            }
+            // Let the car play what it has before closing the stream on it.
+            Thread.sleep(LEAD_MS)
+        } finally {
+            sink.stop()
+        }
+    }
+
+    private fun CarText?.text() = this?.toString().orEmpty()
+
+    /** 16-bit PCM from the WAV text-to-speech writes, reshaped for the car's sink. */
+    private object Wav {
+        class Pcm(val samples: ShortArray, val rate: Int, val channels: Int)
+
+        fun read(file: File): Pcm? {
+            val bytes = file.readBytes()
+            if (bytes.size < 12 || String(bytes, 0, 4) != "RIFF" || String(bytes, 8, 4) != "WAVE") return null
+            val buf = ByteBuffer.wrap(bytes).order(ByteOrder.LITTLE_ENDIAN)
+            var pos = 12
+            var rate = 0
+            var channels = 0
+            var bits = 0
+            while (pos + 8 <= bytes.size) {
+                val name = String(bytes, pos, 4)
+                val size = buf.getInt(pos + 4)
+                val body = pos + 8
+                // Some engines write a streaming WAV with a zero or oversized data length.
+                val end = if (size <= 0 || body + size > bytes.size) bytes.size else body + size
+                when (name) {
+                    "fmt " -> {
+                        channels = buf.getShort(body + 2).toInt()
+                        rate = buf.getInt(body + 4)
+                        bits = buf.getShort(body + 14).toInt()
+                    }
+                    "data" -> {
+                        if (bits != 16 || rate <= 0 || channels <= 0) return null
+                        val samples = ShortArray((end - body) / 2)
+                        buf.position(body)
+                        buf.asShortBuffer().get(samples, 0, samples.size)
+                        return Pcm(samples, rate, channels)
+                    }
+                }
+                pos = end + (end and 1)
+            }
+            return null
+        }
+
+        /** Mixes to mono, resamples linearly, then copies to each of the car's channels. */
+        fun convert(pcm: Pcm, rate: Int, channels: Int): ByteArray {
+            val frames = pcm.samples.size / pcm.channels
+            val mono = FloatArray(frames) { f ->
+                var sum = 0f
+                for (c in 0 until pcm.channels) sum += pcm.samples[f * pcm.channels + c]
+                sum / pcm.channels
+            }
+            val outFrames = (frames.toLong() * rate / pcm.rate).toInt()
+            val out = ByteBuffer.allocate(outFrames * channels * 2).order(ByteOrder.LITTLE_ENDIAN)
+            val step = pcm.rate.toDouble() / rate
+            for (i in 0 until outFrames) {
+                val at = i * step
+                val j = at.toInt().coerceAtMost(frames - 1)
+                val next = (j + 1).coerceAtMost(frames - 1)
+                val v = mono[j] + (mono[next] - mono[j]) * (at - j).toFloat()
+                val s = v.roundToInt().coerceIn(Short.MIN_VALUE.toInt(), Short.MAX_VALUE.toInt()).toShort()
+                repeat(channels) { out.putShort(s) }
+            }
+            return out.array()
+        }
+    }
+
+    private const val TICK_MS = 500L
+    private const val NEAR_SECONDS = 12L
+    private const val NEAR_METERS = 120
+    private const val PREPARE_FROM_METERS = 2_500
+    private const val PREPARE_AT_METERS = 1_000
+    private const val LEAD_MS = 100L
+    private const val HOLD_MS = 2_000L
+    private const val SYNTH_TIMEOUT_S = 10L
+    private val ORDINALS = listOf(
+        R.string.dir_ordinal_1, R.string.dir_ordinal_2, R.string.dir_ordinal_3, R.string.dir_ordinal_4,
+        R.string.dir_ordinal_5, R.string.dir_ordinal_6, R.string.dir_ordinal_7, R.string.dir_ordinal_8,
+    )
+}

gearslip/src/main/java/app/seb3thehacker/gearslip/car/FocusRing.kt

@@ -0,0 +1,84 @@
+package app.seb3thehacker.gearslip.car
+
+import androidx.compose.foundation.IndicationNodeFactory
+import androidx.compose.foundation.interaction.FocusInteraction
+import androidx.compose.foundation.interaction.InteractionSource
+import androidx.compose.material3.ripple
+import androidx.compose.ui.geometry.CornerRadius
+import androidx.compose.ui.geometry.Offset
+import androidx.compose.ui.geometry.Size
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.graphics.drawscope.ContentDrawScope
+import androidx.compose.ui.graphics.drawscope.Stroke
+import androidx.compose.ui.node.DelegatableNode
+import androidx.compose.ui.node.DelegatingNode
+import androidx.compose.ui.node.DrawModifierNode
+import androidx.compose.ui.node.invalidateDraw
+import androidx.compose.ui.unit.dp
+import kotlinx.coroutines.launch
+
+/**
+ * What every car button shows: the usual ripple when pressed, and a ring in the accent color
+ * while the knob or D-pad is on it. Cars without a knob never see the ring, since nothing takes
+ * focus while the screen is in touch mode.
+ *
+ * It replaces the theme's ripple (LocalIndication) for the whole car UI, so any `clickable` that
+ * doesn't pass its own indication gets the ring for free.
+ */
+internal class FocusRingIndication(private val color: Color) : IndicationNodeFactory {
+    private val ripple = ripple()
+
+    override fun create(interactionSource: InteractionSource): DelegatableNode =
+        FocusRingNode(ripple.create(interactionSource), interactionSource, color)
+
+    override fun equals(other: Any?) = other is FocusRingIndication && other.color == color
+    override fun hashCode() = color.hashCode()
+}
+
+private class FocusRingNode(
+    rippleNode: DelegatableNode,
+    private val source: InteractionSource,
+    private val color: Color,
+) : DelegatingNode(), DrawModifierNode {
+    private var focused = false
+
+    init { delegate(rippleNode) }
+
+    override fun onAttach() {
+        coroutineScope.launch {
+            var holding = 0
+            source.interactions.collect {
+                when (it) {
+                    is FocusInteraction.Focus -> holding++
+                    is FocusInteraction.Unfocus -> holding--
+                }
+                val now = holding > 0
+                if (now != focused) {
+                    focused = now
+                    invalidateDraw()
+                }
+            }
+        }
+    }
+
+    override fun ContentDrawScope.draw() {
+        drawContent()
+        if (!focused) return
+        // Inside the button's bounds, since most buttons clip to their shape: drawn outside, a
+        // rounded tile would cut its own ring off.
+        val width = RING_WIDTH.toPx()
+        val radius = minOf(CORNER.toPx(), size.minDimension / 2)
+        drawRoundRect(
+            color,
+            topLeft = Offset(width / 2, width / 2),
+            size = Size(size.width - width, size.height - width),
+            cornerRadius = CornerRadius(radius),
+            style = Stroke(width),
+        )
+    }
+
+    private companion object {
+        val RING_WIDTH = 3.dp
+        val CORNER = 16.dp
+    }
+}

gearslip/src/main/java/app/seb3thehacker/gearslip/car/LocationCheck.kt

@@ -0,0 +1,93 @@
+package app.seb3thehacker.gearslip.car
+
+import android.content.BroadcastReceiver
+import android.content.Context
+import android.content.Intent
+import android.content.IntentFilter
+import android.location.LocationManager
+import android.os.Handler
+import android.os.Looper
+import app.seb3thehacker.gearslip.GearslipLog
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+
+/**
+ * Map apps can't find the car with the phone's location turned off. Ten seconds after the car
+ * shows Gearslip, this checks, and the car says so until location comes on or the drive ends.
+ */
+object LocationCheck {
+
+    private val _off = MutableStateFlow(false)
+    /** True while the phone's location is turned off during a drive. */
+    val off: StateFlow<Boolean> = _off
+
+    private val _carDismissed = MutableStateFlow(false)
+    /** The driver tapped OK on the car's card; it stays away for the rest of this drive. */
+    val carDismissed: StateFlow<Boolean> = _carDismissed
+
+    private val log = GearslipLog.tagged("location")
+    private val main = Handler(Looper.getMainLooper())
+    private var appContext: Context? = null
+    private var armed = false
+    private var receiver: BroadcastReceiver? = null
+
+    fun init(context: Context) {
+        appContext = context.applicationContext
+    }
+
+    /** The car shows Gearslip. Called again whenever the video restarts, so it arms once per drive. */
+    fun onProjecting() = main.post {
+        if (armed) return@post
+        armed = true
+        main.postDelayed(::start, WAIT_MS)
+    }
+
+    fun onCarDisconnected() = main.post {
+        armed = false
+        main.removeCallbacksAndMessages(null)
+        stopWatching()
+        _off.value = false
+        _carDismissed.value = false
+    }
+
+    fun dismissOnCar() {
+        _carDismissed.value = true
+    }
+
+    /** "Don't show again" on the car: turns the warning off in Settings, for every car. */
+    fun neverAgain() {
+        CarSettings.setLocationWarning(false)
+        log.i("location warning turned off")
+        _carDismissed.value = true
+        _off.value = false
+    }
+
+    private fun start() {
+        if (!armed) return
+        check()
+        // Turning location on clears the warning, and turning it off again brings it back.
+        val context = appContext ?: return
+        val r = object : BroadcastReceiver() {
+            override fun onReceive(context: Context, intent: Intent) = check()
+        }
+        context.registerReceiver(r, IntentFilter(LocationManager.MODE_CHANGED_ACTION), Context.RECEIVER_EXPORTED)
+        receiver = r
+    }
+
+    private fun check() {
+        if (!armed) return
+        val manager = appContext?.getSystemService(LocationManager::class.java) ?: return
+        val off = CarSettings.locationWarning.value && !manager.isLocationEnabled
+        if (_off.value == off) return
+        _off.value = off
+        log.i(if (off) "the phone's location is off" else "the phone's location is on")
+    }
+
+    private fun stopWatching() {
+        val r = receiver ?: return
+        receiver = null
+        runCatching { appContext?.unregisterReceiver(r) }
+    }
+
+    private const val WAIT_MS = 10_000L
+}

gearslip/src/main/java/app/seb3thehacker/gearslip/car/MapControlsWake.kt

@@ -11,27 +11,35 @@ import android.os.SystemClock
  *
  * They fade out after [IDLE_MS] with no touch anywhere on the car screen, to leave the map clear,
  * and any touch brings them back. [touch] is called for every pointer event and is cheap: it only
- * writes state when the buttons were actually hidden.
+ * writes state when the buttons were actually hidden. The nav bar, when set to hide, goes the
+ * same way but waits longer ([NAV_BAR_IDLE_MS]).
  */
 class MapControlsWake {
 
     var awake by mutableStateOf(true)
         private set
 
+    var navBarAwake by mutableStateOf(true)
+        private set
+
     private var lastTouch = SystemClock.uptimeMillis()
 
     fun touch() {
         lastTouch = SystemClock.uptimeMillis()
         if (!awake) awake = true
+        if (!navBarAwake) navBarAwake = true
     }
 
     /** Called on a timer; hides the buttons once nothing has touched the screen for [IDLE_MS]. */
     fun tick() {
-        if (awake && SystemClock.uptimeMillis() - lastTouch >= IDLE_MS) awake = false
+        val idle = SystemClock.uptimeMillis() - lastTouch
+        if (awake && idle >= IDLE_MS) awake = false
+        if (navBarAwake && idle >= NAV_BAR_IDLE_MS) navBarAwake = false
     }
 
     companion object {
         const val IDLE_MS = 4_000L
+        const val NAV_BAR_IDLE_MS = 8_000L
     }
 }
 

gearslip/src/main/java/app/seb3thehacker/gearslip/car/MediaBrowse.kt

@@ -0,0 +1,348 @@
+package app.seb3thehacker.gearslip.car
+
+import androidx.compose.ui.res.stringResource
+import app.seb3thehacker.gearslip.R
+import androidx.compose.foundation.shape.CircleShape
+import androidx.compose.foundation.shape.RoundedCornerShape
+import app.seb3thehacker.gearslip.car.theme.*
+import androidx.compose.foundation.Image
+import androidx.compose.foundation.background
+import androidx.compose.foundation.rememberScrollState
+import androidx.compose.foundation.verticalScroll
+import androidx.compose.foundation.layout.Arrangement
+import android.provider.Settings
+import android.content.Intent
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.aspectRatio
+import androidx.compose.foundation.layout.BoxWithConstraints
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxHeight
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.layout.width
+import androidx.compose.foundation.lazy.LazyColumn
+import androidx.compose.foundation.lazy.items
+import androidx.compose.foundation.lazy.itemsIndexed
+import androidx.compose.foundation.lazy.rememberLazyListState
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.automirrored.filled.KeyboardArrowRight
+import androidx.compose.material.icons.filled.ArrowBack
+import androidx.compose.material.icons.filled.PlayArrow
+import androidx.compose.material.icons.filled.Search
+import androidx.compose.material3.Icon
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Surface
+import androidx.compose.material3.Text
+import androidx.compose.material3.TextButton
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.collectAsState
+import androidx.compose.runtime.DisposableEffect
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableLongStateOf
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.produceState
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.clip
+import androidx.compose.ui.graphics.PathFillType
+import androidx.compose.ui.graphics.SolidColor
+import androidx.compose.foundation.layout.widthIn
+import androidx.compose.ui.graphics.asImageBitmap
+import androidx.compose.ui.graphics.vector.ImageVector
+import androidx.compose.ui.graphics.vector.addPathNodes
+import androidx.compose.ui.layout.ContentScale
+import androidx.compose.ui.platform.LocalContext
+import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.text.style.TextOverflow
+import androidx.compose.ui.unit.dp
+import androidx.lifecycle.compose.collectAsStateWithLifecycle
+import app.seb3thehacker.gearslip.media.CarMedia
+import app.seb3thehacker.gearslip.media.MediaApp
+import app.seb3thehacker.gearslip.media.MediaArt
+import app.seb3thehacker.gearslip.media.LyricsResult
+import app.seb3thehacker.gearslip.media.Lyrics
+import app.seb3thehacker.gearslip.media.MediaEntry
+import app.seb3thehacker.gearslip.media.NowPlaying
+import app.seb3thehacker.gearslip.media.QueueTrack
+import android.media.session.PlaybackState
+import kotlinx.coroutines.delay
+import androidx.compose.foundation.clickable
+import androidx.compose.foundation.layout.PaddingValues
+
+// The media screen's browse list, up-next queue, rows and icons. Split out of MediaScreen.kt.
+
+@Composable
+internal fun BrowsePanel(browse: app.seb3thehacker.gearslip.media.BrowseState, media: CarMedia, appLabel: String, modifier: Modifier) {
+    Column(modifier) {
+        // At the library root there's no trail and nowhere to go up to, so there's nothing this
+        // row could say that the app's name in the top-left corner hasn't already - showing it
+        // again here (as "Browse", or as the app's own name) was just the same label twice.
+        if (media.canGoUp || browse.trail.isNotEmpty()) {
+            Row(Modifier.padding(bottom = 12.dp), verticalAlignment = Alignment.CenterVertically) {
+                if (media.canGoUp) {
+                    GsIconButton(Icons.Filled.ArrowBack, stringResource(R.string.media_up), media::up, size = 44.dp, shape = CircleShape)
+                    Spacer(Modifier.width(14.dp))
+                }
+                browse.trail.lastOrNull()?.let {
+                    Text(
+                        it,
+                        style = MaterialTheme.typography.titleLarge, fontWeight = FontWeight.Bold,
+                        maxLines = 1, overflow = TextOverflow.Ellipsis,
+                    )
+                }
+            }
+        }
+        when {
+            browse.loading -> Notice(stringResource(R.string.media_loading), null)
+            browse.unavailable -> Notice(
+                stringResource(R.string.media_keeps_library, appLabel),
+                stringResource(R.string.media_browse_start),
+            )
+            browse.failed -> Notice(stringResource(R.string.media_load_failed), null)
+            browse.entries.isEmpty() -> Notice(stringResource(R.string.media_nothing_here), null)
+            else -> BrowseList(browse.entries, media)
+        }
+    }
+}
+
+/**
+ * A list laid out the way the app asked: under its section headings, covers where it asked for a
+ * grid and rows everywhere else. A grid section among others is a shelf that scrolls sideways; a
+ * list that is one grid and nothing else wraps into rows of covers instead.
+ */
+@Composable
+private fun BrowseList(entries: List<MediaEntry>, media: CarMedia) {
+    val sections = remember(entries) { browseSections(entries) }
+    BoxWithConstraints(Modifier.fillMaxSize()) {
+        val onlyGrid = sections.size == 1 && sections[0].grid && sections[0].heading == null
+        val columns = ((maxWidth + SHELF_GAP) / (SHELF_COVER + SHELF_GAP)).toInt().coerceAtLeast(2)
+        LazyColumn(
+            Modifier.fillMaxSize(),
+            contentPadding = PaddingValues(bottom = 8.dp),
+            verticalArrangement = Arrangement.spacedBy(10.dp),
+        ) {
+            sections.forEachIndexed { i, section ->
+                val heading = section.heading
+                if (heading != null && sections.getOrNull(i - 1)?.heading != heading) {
+                    item(key = "heading $i") {
+                        Text(
+                            heading,
+                            style = MaterialTheme.typography.titleLarge, fontWeight = FontWeight.Bold,
+                            maxLines = 1, overflow = TextOverflow.Ellipsis,
+                            modifier = Modifier.padding(top = if (i == 0) 0.dp else 8.dp),
+                        )
+                    }
+                }
+                when {
+                    !section.grid -> items(section.entries, key = { it.id }) { entry -> EntryRow(entry, media) }
+                    onlyGrid -> items(section.entries.chunked(columns)) { row ->
+                        Row(horizontalArrangement = Arrangement.spacedBy(SHELF_GAP)) {
+                            row.forEach { CoverTile(it, media, Modifier.weight(1f)) }
+                            repeat(columns - row.size) { Spacer(Modifier.weight(1f)) }
+                        }
+                    }
+                    else -> item(key = "shelf $i") {
+                        androidx.compose.foundation.lazy.LazyRow(horizontalArrangement = Arrangement.spacedBy(SHELF_GAP)) {
+                            items(section.entries, key = { it.id }) { CoverTile(it, media, Modifier.width(SHELF_COVER)) }
+                        }
+                    }
+                }
+            }
+        }
+    }
+}
+
+private val SHELF_COVER = 132.dp
+private val SHELF_GAP = 14.dp
+
+/** A run of entries under one heading that are all covers or all rows. */
+private class BrowseSection(val heading: String?, val grid: Boolean, val entries: List<MediaEntry>)
+
+private fun browseSections(entries: List<MediaEntry>): List<BrowseSection> {
+    val out = mutableListOf<BrowseSection>()
+    var run = mutableListOf<MediaEntry>()
+    for (entry in entries) {
+        val last = run.lastOrNull()
+        if (last != null && (last.group != entry.group || last.grid != entry.grid)) {
+            out += BrowseSection(last.group, last.grid, run)
+            run = mutableListOf()
+        }
+        run += entry
+    }
+    run.lastOrNull()?.let { out += BrowseSection(it.group, it.grid, run) }
+    return out
+}
+
+/** One entry as a cover with its name under it: what the app's grids are made of. */
+@Composable
+private fun CoverTile(entry: MediaEntry, media: CarMedia, modifier: Modifier) {
+    val context = LocalContext.current
+    val icon by produceState(entry.iconBitmap, entry.iconUri) {
+        value = entry.iconBitmap ?: MediaArt.load(context, entry.iconUri)
+    }
+    val shape = RoundedCornerShape(16.dp)
+    Column(modifier.clip(shape).clickable { media.select(entry) }) {
+        Box(
+            Modifier
+                .fillMaxWidth()
+                .aspectRatio(1f)
+                .gsPanelShadow(shape)
+                .clip(shape)
+                .background(MaterialTheme.colorScheme.surfaceContainerHigh),
+            contentAlignment = Alignment.Center,
+        ) {
+            icon?.let { Image(it.asImageBitmap(), null, Modifier.fillMaxSize(), contentScale = ContentScale.Crop) }
+                ?: Icon(
+                    if (entry.browsable) MediaIcons.Folder else MediaIcons.MusicNote, null,
+                    tint = MaterialTheme.colorScheme.onSurfaceVariant, modifier = Modifier.fillMaxSize(0.35f),
+                )
+        }
+        Text(
+            entry.title, style = MaterialTheme.typography.titleSmall, fontWeight = FontWeight.SemiBold,
+            maxLines = 1, overflow = TextOverflow.Ellipsis, modifier = Modifier.padding(top = 8.dp, start = 2.dp),
+        )
+        if (entry.subtitle.isNotEmpty()) {
+            Text(
+                entry.subtitle, style = MaterialTheme.typography.bodySmall, color = MaterialTheme.colorScheme.onSurfaceVariant,
+                maxLines = 1, overflow = TextOverflow.Ellipsis, modifier = Modifier.padding(start = 2.dp, bottom = 4.dp),
+            )
+        }
+    }
+}
+
+// --- up next -----------------------------------------------------------------------------------
+
+/**
+ * Whatever the app has queued up, starting right after the track that's playing now - not the
+ * whole queue from the top, which would just repeat what the player beside it already shows. Apps
+ * that never publish a queue (many don't) show an empty notice rather than a permanently blank tab.
+ */
+@Composable
+internal fun QueuePanel(queue: List<QueueTrack>, now: NowPlaying, media: CarMedia, modifier: Modifier) {
+    val upNext = remember(queue, now.activeQueueItemId) {
+        val current = queue.indexOfFirst { it.queueId == now.activeQueueItemId }
+        if (current >= 0) queue.drop(current + 1) else queue
+    }
+    Column(modifier) {
+        if (upNext.isEmpty()) {
+            Notice(
+                stringResource(R.string.media_nothing_queued),
+                stringResource(if (now.title.isEmpty()) R.string.media_queue_empty_idle else R.string.media_queue_empty_playing),
+            )
+        } else {
+            LazyColumn(
+                Modifier.fillMaxSize(),
+                contentPadding = PaddingValues(bottom = 8.dp),
+                verticalArrangement = Arrangement.spacedBy(8.dp),
+            ) {
+                items(upNext, key = { it.queueId }) { track -> QueueRow(track, media) }
+            }
+        }
+    }
+}
+
+@Composable
+private fun QueueRow(track: QueueTrack, media: CarMedia) {
+    val context = LocalContext.current
+    val icon by produceState(track.iconBitmap, track.iconUri) {
+        value = track.iconBitmap ?: MediaArt.load(context, track.iconUri)
+    }
+    Surface(
+        onClick = { media.playQueueItem(track) },
+        shape = MaterialTheme.shapes.large,
+        color = MaterialTheme.colorScheme.surfaceContainer,
+        modifier = Modifier.fillMaxWidth(),
+    ) {
+        Row(Modifier.padding(8.dp), verticalAlignment = Alignment.CenterVertically) {
+            RowArt(icon, MediaIcons.MusicNote)
+            Column(Modifier.weight(1f).padding(horizontal = 14.dp)) {
+                Text(track.title, style = MaterialTheme.typography.titleMedium, maxLines = 1, overflow = TextOverflow.Ellipsis)
+                if (track.subtitle.isNotEmpty()) {
+                    Text(track.subtitle, style = MaterialTheme.typography.bodyMedium, color = MaterialTheme.colorScheme.onSurfaceVariant, maxLines = 1, overflow = TextOverflow.Ellipsis)
+                }
+            }
+            Icon(Icons.Filled.PlayArrow, stringResource(R.string.media_play), tint = MaterialTheme.colorScheme.onSurfaceVariant)
+        }
+    }
+}
+
+@Composable
+internal fun EntryRow(entry: MediaEntry, media: CarMedia, onClick: () -> Unit = { media.select(entry) }) {
+    val context = LocalContext.current
+    val icon by produceState(entry.iconBitmap, entry.iconUri) {
+        value = entry.iconBitmap ?: MediaArt.load(context, entry.iconUri)
+    }
+    Surface(
+        onClick = onClick,
+        shape = MaterialTheme.shapes.large,
+        color = MaterialTheme.colorScheme.surfaceContainer,
+        modifier = Modifier.fillMaxWidth(),
+    ) {
+        Row(Modifier.padding(8.dp), verticalAlignment = Alignment.CenterVertically) {
+            RowArt(icon, if (entry.browsable) MediaIcons.Folder else MediaIcons.MusicNote)
+            Column(Modifier.weight(1f).padding(horizontal = 14.dp)) {
+                Text(entry.title, style = MaterialTheme.typography.titleMedium, maxLines = 1, overflow = TextOverflow.Ellipsis)
+                if (entry.subtitle.isNotEmpty()) {
+                    Text(entry.subtitle, style = MaterialTheme.typography.bodyMedium, color = MaterialTheme.colorScheme.onSurfaceVariant, maxLines = 1, overflow = TextOverflow.Ellipsis)
+                }
+            }
+            if (entry.browsable && entry.playable) {
+                GsIconButton(Icons.Filled.PlayArrow, stringResource(R.string.media_play), { media.playAll(entry) })
+            }
+            if (entry.browsable) Icon(Icons.AutoMirrored.Filled.KeyboardArrowRight, null)
+        }
+    }
+}
+
+/** A row's artwork, or a folder or note in its place when the app sends none. */
+@Composable
+private fun RowArt(icon: android.graphics.Bitmap?, fallback: ImageVector) {
+    Box(
+        Modifier.size(56.dp).clip(RoundedCornerShape(12.dp)).background(MaterialTheme.colorScheme.surfaceContainerHigh),
+        contentAlignment = Alignment.Center,
+    ) {
+        if (icon != null) Image(icon.asImageBitmap(), null, Modifier.fillMaxSize(), contentScale = ContentScale.Crop)
+        else Icon(fallback, null, tint = MaterialTheme.colorScheme.onSurfaceVariant, modifier = Modifier.size(30.dp))
+    }
+}
+
+/** Material's transport icons, from their published path data (they live in the extended set). */
+internal object MediaIcons {
+    val MusicNote = icon("MusicNote", "M12,3v10.55c-0.59,-0.34 -1.27,-0.55 -2,-0.55 -2.21,0 -4,1.79 -4,4s1.79,4 4,4 4,-1.79 4,-4V7h4V3h-6z")
+    val Folder = icon("Folder", "M10,4H4c-1.1,0 -1.99,0.9 -1.99,2L2,18c0,1.1 0.9,2 2,2h16c1.1,0 2,-0.9 2,-2V8c0,-1.1 -0.9,-2 -2,-2h-8l-2,-2z")
+    val Pause = icon("Pause", "M6,19h4L10,5L6,5v14zM14,5v14h4L18,5h-4z")
+    val Next = icon("SkipNext", "M6,18l8.5,-6L6,6v12zM16,6v12h2V6h-2z")
+    /** The 3x3 app grid; not in material-icons-core. */
+    val Apps = icon("Apps", "M4,8h4L8,4L4,4v4zM10,20h4v-4h-4v4zM4,20h4v-4L4,16v4zM4,14h4v-4L4,10v4zM10,14h4v-4h-4v4zM16,4v4h4L20,4h-4zM10,8h4L14,4h-4v4zM16,14h4v-4h-4v4zM16,20h4v-4h-4v4z")
+    val Previous = icon("SkipPrevious", "M6,6h2v12L6,18zM9.5,12l8.5,6V6z")
+    val Equalizer = icon("Equalizer", "M10,20h4L14,4h-4v16zM4,20h4v-8L4,12v8zM16,9v11h4L20,9h-4z")
+    val Shuffle = icon("Shuffle", "M10.59,9.17L5.41,4 4,5.41l5.17,5.17 1.42,-1.41zM14.5,4l2.04,2.04L4,18.59 5.41,20 17.96,7.46 20,9.5L20,4h-5.5zM14.83,13.41l-1.41,1.41 3.13,3.13L14.5,20L20,20v-5.5l-2.04,2.04 -3.13,-3.13z")
+    val Repeat = icon("Repeat", "M7,7h10v3l4,-4 -4,-4v3L5,5v6h2L7,7zM17,17L7,17v-3l-4,4 4,4v-3h12v-6h-2v4z")
+    val RepeatOne = icon("RepeatOne", "M7,7h10v3l4,-4 -4,-4v3L5,5v6h2L7,7zM17,17L7,17v-3l-4,4 4,4v-3h12v-6h-2v4zM13,15L13,9h-1l-2,1v1h1.5v4L13,15z")
+    /**
+     * A screen split into the map and a side panel: outlined while the panel is closed ("put the
+     * player beside the map"), filled in while it's open ("close it"), on the side it opens on.
+     */
+    val DockRight = icon("DockRight", "M2,4h20v16H2zM4,6h10v12H4zM16,6h4v12h-4z", PathFillType.EvenOdd)
+    val DockRightOpen = icon("DockRightOpen", "M2,4h20v16H2zM4,6h10v12H4z", PathFillType.EvenOdd)
+    val DockLeft = icon("DockLeft", "M2,4h20v16H2zM4,6h4v12H4zM10,6h10v12H10z", PathFillType.EvenOdd)
+    val DockLeftOpen = icon("DockLeftOpen", "M2,4h20v16H2zM10,6h10v12H10z", PathFillType.EvenOdd)
+    val Fullscreen = icon("Fullscreen", "M7,14L5,14v5h5v-2L7,17v-3zM5,10h2L7,7h3L10,5L5,5v5zM17,17h-3v2h5v-5h-2v3zM14,5v2h3v3h2L19,5h-5z")
+    val FullscreenExit = icon("FullscreenExit", "M5,16h3v3h2v-5L5,14v2zM8,8L5,8v2h5L10,5L8,5v3zM14,19h2v-3h3v-2h-5v5zM16,8L16,5h-2v5h5L19,8h-3z")
+
+    val CallEnd = icon("CallEnd", "M12,9c-1.6,0 -3.15,0.25 -4.6,0.72v3.1c0,0.39 -0.23,0.74 -0.56,0.9 -0.98,0.49 -1.87,1.12 -2.66,1.85 -0.18,0.18 -0.43,0.28 -0.7,0.28 -0.28,0 -0.53,-0.11 -0.71,-0.29L0.29,13.08c-0.18,-0.17 -0.29,-0.42 -0.29,-0.7 0,-0.28 0.11,-0.53 0.29,-0.71C3.34,8.78 7.46,7 12,7s8.66,1.78 11.71,4.67c0.18,0.18 0.29,0.43 0.29,0.71 0,0.28 -0.11,0.53 -0.29,0.71l-2.48,2.48c-0.18,0.18 -0.43,0.29 -0.71,0.29 -0.27,0 -0.52,-0.11 -0.7,-0.28 -0.79,-0.74 -1.69,-1.36 -2.67,-1.85 -0.33,-0.16 -0.56,-0.5 -0.56,-0.9v-3.1C15.15,9.25 13.6,9 12,9z")
+    val Mic = icon("Mic", "M12,14c1.66,0 2.99,-1.34 2.99,-3L15,5c0,-1.66 -1.34,-3 -3,-3S9,3.34 9,5v6c0,1.66 1.34,3 3,3zM17.3,11c0,3 -2.54,5.1 -5.3,5.1S6.7,14 6.7,11L5,11c0,3.41 2.72,6.23 6,6.72L11,21h2v-3.28c3.28,-0.48 6,-3.3 6,-6.72h-1.7z")
+    val MicOff = icon("MicOff", "M19,11h-1.7c0,0.74 -0.16,1.43 -0.43,2.05l1.23,1.23c0.56,-0.98 0.9,-2.09 0.9,-3.28zM14.98,11.17c0,-0.06 0.02,-0.11 0.02,-0.17L15,5c0,-1.66 -1.34,-3 -3,-3S9,3.34 9,5v0.18l5.98,5.99zM4.27,3L3,4.27l6.01,6.01L9,11c0,1.66 1.33,3 2.99,3 0.22,0 0.44,-0.03 0.65,-0.08l1.66,1.66c-0.71,0.33 -1.5,0.52 -2.31,0.52 -2.76,0 -5.3,-2.1 -5.3,-5.1L5,11c0,3.41 2.72,6.23 6,6.72L11,21h2v-3.28c0.91,-0.13 1.77,-0.45 2.54,-0.9L19.73,21 21,19.73 4.27,3z")
+
+    private fun icon(name: String, path: String, fillType: PathFillType = PathFillType.NonZero) = ImageVector.Builder(
+        name, 24.dp, 24.dp, 24f, 24f,
+    ).addPath(addPathNodes(path), pathFillType = fillType, fill = SolidColor(androidx.compose.ui.graphics.Color.Black)).build()
+}

gearslip/src/main/java/app/seb3thehacker/gearslip/car/MessagePopup.kt

@@ -1,5 +1,7 @@
 package app.seb3thehacker.gearslip.car
 
+import androidx.compose.ui.res.pluralStringResource
+import androidx.compose.ui.res.stringResource
 import android.os.SystemClock
 import androidx.compose.foundation.background
 import androidx.compose.foundation.horizontalScroll
@@ -83,9 +85,10 @@ internal fun ReplyGlyph(modifier: Modifier = Modifier) =
     Icon(ImageVector.vectorResource(R.drawable.voice_selection_24), null, modifier)
 
 /** "Alex", or "Alex · 3 new" when a burst of messages from one chat has been merged. */
+@Composable
 private fun CarNotification.heading(): String {
     val who = title.ifBlank { appLabel }
-    return if (burst > 1) "$who · $burst new" else who
+    return if (burst > 1) pluralStringResource(R.plurals.msg_burst, burst, who, burst) else who
 }
 
 /** The card. It shows the voice reply too, wherever that was started from. */
@@ -106,17 +109,17 @@ fun NotificationPopup(showNew: Boolean, modifier: Modifier = Modifier) {
                 Text(n.heading(), style = MaterialTheme.typography.titleMedium, fontWeight = FontWeight.Bold, maxLines = 1, overflow = TextOverflow.Ellipsis)
                 Text(n.text, style = MaterialTheme.typography.bodyMedium, color = MaterialTheme.colorScheme.onSurfaceVariant, maxLines = 1, overflow = TextOverflow.Ellipsis)
             }
-            GsIconButton(Icons.Filled.Close, "Dismiss", { CarNotifications.dismissPopup(n.id) }, size = 40.dp, iconSize = 20.dp)
+            GsIconButton(Icons.Filled.Close, stringResource(R.string.msg_dismiss), { CarNotifications.dismissPopup(n.id) }, size = 40.dp, iconSize = 20.dp)
         }
         Row(horizontalArrangement = Arrangement.spacedBy(10.dp)) {
             GsButton(onClick = { VoiceReply.read(n) }, tone = GsTone.Neutral, modifier = Modifier.weight(1f)) {
                 ReadGlyph(Modifier.size(20.dp))
-                Text("Read", Modifier.padding(start = 8.dp))
+                Text(stringResource(R.string.msg_read), Modifier.padding(start = 8.dp))
             }
             if (n.reply != null) {
                 GsButton(onClick = { VoiceReply.reply(n) }, modifier = Modifier.weight(1f)) {
                     ReplyGlyph(Modifier.size(20.dp))
-                    Text("Reply", Modifier.padding(start = 8.dp))
+                    Text(stringResource(R.string.crumb_reply), Modifier.padding(start = 8.dp))
                 }
             }
         }
@@ -191,36 +194,36 @@ private fun VoiceReplyBody(s: VoiceReply.State, n: CarNotification) {
         when (s.phase) {
             VoiceReply.Phase.READING, VoiceReply.Phase.READ -> {
                 GsButton(onClick = VoiceReply::cancel, tone = GsTone.Neutral, modifier = wide) {
-                    Text(if (s.phase == VoiceReply.Phase.READING) "Stop" else "Close")
+                    Text(if (s.phase == VoiceReply.Phase.READING) stringResource(R.string.msg_stop) else stringResource(R.string.close))
                 }
                 if (n.reply != null) {
                     GsButton(onClick = { VoiceReply.reply(n, readFirst = false) }, modifier = wide) {
                         ReplyGlyph(Modifier.size(20.dp))
-                        Text("Reply", Modifier.padding(start = 8.dp))
+                        Text(stringResource(R.string.crumb_reply), Modifier.padding(start = 8.dp))
                     }
                 }
             }
             VoiceReply.Phase.OFFERING -> {
-                GsButton(onClick = VoiceReply::cancel, tone = GsTone.Neutral, modifier = wide) { Text("No") }
+                GsButton(onClick = VoiceReply::cancel, tone = GsTone.Neutral, modifier = wide) { Text(stringResource(R.string.msg_no)) }
                 GsButton(onClick = { VoiceReply.reply(n, readFirst = false) }, modifier = wide) {
                     ReplyGlyph(Modifier.size(20.dp))
-                    Text("Reply", Modifier.padding(start = 8.dp))
+                    Text(stringResource(R.string.crumb_reply), Modifier.padding(start = 8.dp))
                 }
             }
             VoiceReply.Phase.ASKING, VoiceReply.Phase.LISTENING ->
-                GsButton(onClick = VoiceReply::cancel, tone = GsTone.Neutral, modifier = wide) { Text("Cancel") }
+                GsButton(onClick = VoiceReply::cancel, tone = GsTone.Neutral, modifier = wide) { Text(stringResource(R.string.cancel)) }
             VoiceReply.Phase.CONFIRMING -> {
-                GsButton(onClick = VoiceReply::cancel, tone = GsTone.Neutral, modifier = wide) { Text("Cancel") }
-                GsButton(onClick = VoiceReply::sendNow, modifier = wide) { Text("Send now") }
+                GsButton(onClick = VoiceReply::cancel, tone = GsTone.Neutral, modifier = wide) { Text(stringResource(R.string.cancel)) }
+                GsButton(onClick = VoiceReply::sendNow, modifier = wide) { Text(stringResource(R.string.msg_send_now)) }
             }
             VoiceReply.Phase.ERROR -> {
-                GsButton(onClick = VoiceReply::cancel, tone = GsTone.Neutral, modifier = wide) { Text("Close") }
+                GsButton(onClick = VoiceReply::cancel, tone = GsTone.Neutral, modifier = wide) { Text(stringResource(R.string.close)) }
                 if (n.reply != null) {
-                    GsButton(onClick = { VoiceReply.reply(n, readFirst = false) }, tone = GsTone.Tonal, modifier = wide) { Text("Try again") }
+                    GsButton(onClick = { VoiceReply.reply(n, readFirst = false) }, tone = GsTone.Tonal, modifier = wide) { Text(stringResource(R.string.update_try_again)) }
                     GsButton(
                         onClick = { VoiceReply.cancel(); navigator.notifications(replyTo = n.key) },
                         tone = GsTone.Neutral, modifier = wide,
-                    ) { Text("Type") }
+                    ) { Text(stringResource(R.string.msg_type)) }
                 }
             }
             VoiceReply.Phase.SENT, VoiceReply.Phase.IDLE -> Unit
@@ -228,13 +231,14 @@ private fun VoiceReplyBody(s: VoiceReply.State, n: CarNotification) {
     }
 }
 
+@Composable
 private fun voiceHeading(s: VoiceReply.State, who: String): String = when (s.phase) {
     VoiceReply.Phase.READING, VoiceReply.Phase.READ -> who
-    VoiceReply.Phase.OFFERING, VoiceReply.Phase.ASKING -> "Reply to $who"
-    VoiceReply.Phase.LISTENING -> "Listening"
-    VoiceReply.Phase.CONFIRMING -> "Sending to $who"
-    VoiceReply.Phase.SENT -> "Sent to $who"
-    VoiceReply.Phase.ERROR -> "Couldn't reply"
+    VoiceReply.Phase.OFFERING, VoiceReply.Phase.ASKING -> stringResource(R.string.msg_reply_to, who)
+    VoiceReply.Phase.LISTENING -> stringResource(R.string.msg_listening)
+    VoiceReply.Phase.CONFIRMING -> stringResource(R.string.msg_sending_to, who)
+    VoiceReply.Phase.SENT -> stringResource(R.string.msg_sent_to, who)
+    VoiceReply.Phase.ERROR -> stringResource(R.string.msg_reply_failed)
     VoiceReply.Phase.IDLE -> ""
 }
 

gearslip/src/main/java/app/seb3thehacker/gearslip/car/MessagesScreen.kt

@@ -1,5 +1,8 @@
 package app.seb3thehacker.gearslip.car
 
+import androidx.compose.ui.res.pluralStringResource
+import androidx.compose.ui.res.stringResource
+import app.seb3thehacker.gearslip.R
 import app.seb3thehacker.gearslip.car.theme.*
 import android.content.Intent
 import android.provider.Settings
@@ -8,6 +11,8 @@ import androidx.compose.foundation.Image
 import androidx.compose.foundation.clickable
 import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.ExperimentalLayoutApi
+import androidx.compose.foundation.layout.FlowRow
 import androidx.compose.foundation.layout.PaddingValues
 import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.layout.fillMaxSize
@@ -60,14 +65,14 @@ fun MessagesScreen(packageName: String) {
     val navigator = LocalCarNavigator.current
     val context = LocalContext.current.applicationContext
     val entry = remember(packageName) { findEntry(MESSAGING_PREFIX + packageName) }
-    val label = entry?.label ?: history.firstOrNull { it.packageName == packageName }?.appLabel ?: "Messages"
+    val label = entry?.label ?: history.firstOrNull { it.packageName == packageName }?.appLabel ?: stringResource(R.string.msg_messages)
     val threads = history.filter { it.packageName == packageName }
 
     LaunchedEffect(history) { CarNotifications.dismissPopupFrom(packageName) }
 
-    Column(Modifier.fillMaxSize().padding(16.dp), verticalArrangement = Arrangement.spacedBy(16.dp)) {
+    Column(Modifier.fillMaxSize().padding(start = 16.dp, end = 16.dp, top = 16.dp), verticalArrangement = Arrangement.spacedBy(16.dp)) {
         Row(verticalAlignment = Alignment.CenterVertically, horizontalArrangement = Arrangement.spacedBy(12.dp)) {
-            GsIconButton(Icons.AutoMirrored.Filled.ArrowBack, "Back", navigator::back)
+            GsIconButton(Icons.AutoMirrored.Filled.ArrowBack, stringResource(R.string.back), navigator::back)
             entry?.icon?.let { Image(it, contentDescription = null, modifier = Modifier.size(36.dp).clip(RoundedCornerShape(8.dp))) }
             Text(label, style = MaterialTheme.typography.headlineSmall, fontWeight = FontWeight.Bold)
         }
@@ -82,7 +87,7 @@ fun MessagesScreen(packageName: String) {
 
         if (threads.isEmpty()) {
             Text(
-                "No recent messages. New $label messages appear here as they arrive on the phone.",
+                stringResource(R.string.msg_none_recent, label),
                 style = MaterialTheme.typography.bodyLarge,
                 color = MaterialTheme.colorScheme.onSurfaceVariant,
             )
@@ -104,6 +109,7 @@ fun MessagesScreen(packageName: String) {
     }
 }
 
+@OptIn(ExperimentalLayoutApi::class)
 @Composable
 private fun ConversationCard(n: CarNotification, onRead: () -> Unit, onReply: () -> Unit, onMarkRead: () -> Unit) {
     var expanded by rememberSaveable(n.key) { mutableStateOf(false) }
@@ -143,40 +149,48 @@ private fun ConversationCard(n: CarNotification, onRead: () -> Unit, onReply: ()
                         color = MaterialTheme.colorScheme.onSurfaceVariant,
                         maxLines = 1,
                     )
+                    if (n.replied) {
+                        Icon(
+                            Icons.Filled.Check,
+                            contentDescription = stringResource(R.string.notif_replied),
+                            tint = MaterialTheme.colorScheme.primary,
+                            modifier = Modifier.padding(start = 8.dp).size(20.dp),
+                        )
+                    }
                 }
                 if (!expanded && lines.size > COLLAPSED_LINES) {
                     Text(
-                        "${lines.size - COLLAPSED_LINES} earlier",
+                        pluralStringResource(R.plurals.msg_earlier, lines.size - COLLAPSED_LINES, lines.size - COLLAPSED_LINES),
                         style = MaterialTheme.typography.labelMedium,
                         color = MaterialTheme.colorScheme.primary,
                     )
                 }
                 shown.forEach { MessageLine(it, showSender = n.isGroup) }
+                // Below the messages and side by side, so the text keeps the card's whole width.
+                FlowRow(
+                    Modifier.padding(top = 6.dp),
+                    horizontalArrangement = Arrangement.spacedBy(8.dp),
+                    verticalArrangement = Arrangement.spacedBy(8.dp),
+                ) {
+                    GsButton(onClick = onRead, tone = GsTone.Neutral) {
+                        ReadGlyph(Modifier.size(20.dp))
+                        Text(stringResource(R.string.msg_read), Modifier.padding(start = 8.dp))
+                    }
+                    if (n.reply != null) {
+                        GsButton(onClick = onReply, tone = GsTone.Tonal) {
+                            ReplyGlyph(Modifier.size(20.dp))
+                            Text(stringResource(R.string.crumb_reply), Modifier.padding(start = 8.dp))
+                        }
+                        GsButton(onClick = { quick = !quick }, tone = GsTone.Neutral) {
+                            Text(stringResource(if (quick) R.string.msg_hide_quick else R.string.msg_quick))
+                        }
+                    }
+                    if (n.markRead != null) {
+                        GsButton(onClick = onMarkRead, tone = GsTone.Neutral) { Text(stringResource(R.string.msg_mark_read)) }
+                    }
+                }
                 if (quick) QuickReplies(n, Modifier.padding(top = 6.dp))
             }
-            Column(horizontalAlignment = Alignment.End, verticalArrangement = Arrangement.spacedBy(8.dp)) {
-                if (n.replied) {
-                    Icon(Icons.Filled.Check, contentDescription = "Replied", tint = MaterialTheme.colorScheme.primary)
-                }
-                GsButton(onClick = onRead, tone = GsTone.Neutral) {
-                    ReadGlyph(Modifier.size(20.dp))
-                    Text("Read", Modifier.padding(start = 8.dp))
-                }
-                if (n.reply != null) {
-                    GsButton(onClick = onReply, tone = GsTone.Tonal) {
-                        ReplyGlyph(Modifier.size(20.dp))
-                        Text("Reply", Modifier.padding(start = 8.dp))
-                    }
-                }
-                if (n.reply != null) {
-                    GsButton(onClick = { quick = !quick }, tone = GsTone.Neutral) {
-                        Text(if (quick) "Hide quick replies" else "Quick reply")
-                    }
-                }
-                if (n.markRead != null) {
-                    GsButton(onClick = onMarkRead, tone = GsTone.Neutral) { Text("Mark read") }
-                }
-            }
         }
     }
 }
@@ -184,8 +198,8 @@ private fun ConversationCard(n: CarNotification, onRead: () -> Unit, onReply: ()
 @Composable
 private fun MessageLine(line: ChatLine, showSender: Boolean) {
     val who = when {
-        line.sender == null -> "You: "
-        showSender -> "${line.sender}: "
+        line.sender == null -> stringResource(R.string.msg_you)
+        showSender -> stringResource(R.string.msg_sender, line.sender)
         else -> ""
     }
     Text(

gearslip/src/main/java/app/seb3thehacker/gearslip/car/NavApps.kt

@@ -1,5 +1,8 @@
 package app.seb3thehacker.gearslip.car
 
+import androidx.annotation.StringRes
+import androidx.compose.ui.res.stringResource
+import app.seb3thehacker.gearslip.R
 import androidx.compose.foundation.Image
 import androidx.compose.foundation.background
 import androidx.compose.foundation.clickable
@@ -40,30 +43,57 @@ import app.seb3thehacker.gearslip.car.theme.GsButton
 import app.seb3thehacker.gearslip.car.theme.GsTone
 import app.seb3thehacker.gearslip.host.CarAppConnection
 import app.seb3thehacker.gearslip.media.CarMedia
+import app.seb3thehacker.gearslip.CarFocus
+import androidx.compose.ui.graphics.SolidColor
+import androidx.compose.ui.graphics.vector.PathParser
 
 /** What a built-in app's id carries in a pin, so it can't collide with an installed app's component. */
 internal const val BUILT_IN_PREFIX = "gearslip:"
 
-/** One of Gearslip's own apps: a screen, with nothing running behind it once you leave. */
+/** Material's "directions car", drawn here because only the core icon set is bundled. */
+private val CarGlyph: ImageVector = ImageVector.Builder("Car", 24.dp, 24.dp, 24f, 24f).addPath(
+    PathParser().parsePathString(
+        "M18.92,6.01C18.72,5.42 18.16,5 17.5,5h-11c-0.66,0 -1.21,0.42 -1.42,1.01L3,12v8c0,0.55 0.45,1 1,1h1" +
+            "c0.55,0 1,-0.45 1,-1v-1h12v1c0,0.55 0.45,1 1,1h1c0.55,0 1,-0.45 1,-1v-8l-2.08,-5.99z" +
+            "M6.5,16c-0.83,0 -1.5,-0.67 -1.5,-1.5S5.67,13 6.5,13s1.5,0.67 1.5,1.5S7.33,16 6.5,16z" +
+            "M17.5,16c-0.83,0 -1.5,-0.67 -1.5,-1.5s0.67,-1.5 1.5,-1.5 1.5,0.67 1.5,1.5 -0.67,1.5 -1.5,1.5z" +
+            "M5,11l1.5,-4.5h11L19,11L5,11z",
+    ).toNodes(),
+    fill = SolidColor(Color.Black),
+).build()
+
+/**
+ * One of Gearslip's own apps: a screen, with nothing running behind it once you leave. [screen] is
+ * null for an action like Exit, which has no screen and so never shows as open.
+ */
 internal class BuiltInApp(
     val id: String,
+    /** English, for matching what a driver says; [labelRes] is what the screen shows. */
     val label: String,
+    @param:StringRes val labelRes: Int,
     val glyph: ImageVector,
-    val screen: CarScreen,
+    val screen: CarScreen?,
     val open: (CarNavigator) -> Unit,
 )
 
 internal object BuiltInApps {
-    val Web = BuiltInApp("web", "Web", Icons.Filled.Search, CarScreen.App("web")) { it.open("web") }
-    val ScreenSharing = BuiltInApp("phone", "Screen sharing", Icons.Filled.Share, CarScreen.App("phone")) { it.open("phone") }
-    val Phone = BuiltInApp("dialer", "Phone", Icons.Filled.Call, CarScreen.App("dialer")) { it.open("dialer") }
-    val VehicleData = BuiltInApp("vehicle", "Vehicle data", Icons.Filled.Info, CarScreen.VehicleData) { it.vehicleData() }
-    val Settings = BuiltInApp("settings", "Settings", Icons.Filled.Settings, CarScreen.Settings) { it.settings() }
+    val Web = BuiltInApp("web", "Browser", R.string.app_browser, Icons.Filled.Search, CarScreen.App("web")) { it.open("web") }
+    val ScreenSharing = BuiltInApp("phone", "Screen sharing", R.string.app_screen_sharing, Icons.Filled.Share, CarScreen.App("phone")) { it.open("phone") }
+    val Phone = BuiltInApp("dialer", "Phone", R.string.carset_phone, Icons.Filled.Call, CarScreen.App("dialer")) { it.open("dialer") }
+    val VehicleData = BuiltInApp("vehicle", "Vehicle data", R.string.car_vehicle_data, Icons.Filled.Info, CarScreen.VehicleData) { it.vehicleData() }
+    val Settings = BuiltInApp("settings", "Settings", R.string.settings_title, Icons.Filled.Settings, CarScreen.Settings) { it.settings() }
 
-    val all = listOf(Web, ScreenSharing, Phone, VehicleData, Settings)
+    /** Hands the screen back to the car's own interface, like Android Auto's Exit. */
+    val Exit = BuiltInApp("exit", "Exit", R.string.app_exit, CarGlyph, screen = null) { CarFocus.exitToCar() }
+
+    val all = listOf(Web, ScreenSharing, Phone, VehicleData, Settings, Exit)
     val entries: List<Entry> = all.map { Entry(it.label, icon = null, builtIn = it) }
 }
 
+/** The name a driver sees: translated for Gearslip's own apps, the app's own name otherwise. */
+@Composable
+internal fun Entry.shownLabel(): String = builtIn?.let { stringResource(it.labelRes) } ?: label
+
 /** Vehicle data is experimental: raw, unverified sensor labels (see [CarSensors]). */
 @Composable
 internal fun rememberVehicleDataShown(): Boolean {
@@ -110,7 +140,7 @@ internal fun rememberRunningApps(): Map<String, RunningSlot> {
             else -> false
         }
         mediaApp?.component?.flattenToString()?.takeIf { mediaLive }?.let { put(it, RunningSlot.MEDIA) }
-        BuiltInApps.all.firstOrNull { it.screen == current }?.let { put(BUILT_IN_PREFIX + it.id, RunningSlot.SCREEN) }
+        BuiltInApps.all.firstOrNull { it.screen != null && it.screen == current }?.let { put(BUILT_IN_PREFIX + it.id, RunningSlot.SCREEN) }
         (current as? CarScreen.Messages)?.let { put(MESSAGING_PREFIX + it.packageName, RunningSlot.SCREEN) }
     }
 }
@@ -194,7 +224,7 @@ internal fun AppMenu(navigator: CarNavigator, running: Map<String, RunningSlot>)
                     entry.icon?.let { Image(it, null, Modifier.size(44.dp).clip(RoundedCornerShape(10.dp))) }
                     entry.builtIn?.let { Icon(it.glyph, null, Modifier.size(36.dp)) }
                     Text(
-                        entry.label,
+                        entry.shownLabel(),
                         style = MaterialTheme.typography.titleLarge,
                         fontWeight = FontWeight.SemiBold,
                         modifier = Modifier.padding(start = 14.dp),
@@ -211,9 +241,9 @@ internal fun AppMenu(navigator: CarNavigator, running: Map<String, RunningSlot>)
                 ) {
                     Text(
                         when {
-                            isPinned -> "Unpin from nav bar"
-                            barFull -> "Nav bar is full (${CarSettings.MAX_PINNED} pinned)"
-                            else -> "Pin to nav bar"
+                            isPinned -> stringResource(R.string.navapps_unpin)
+                            barFull -> stringResource(R.string.navapps_full, CarSettings.MAX_PINNED)
+                            else -> stringResource(R.string.navapps_pin)
                         },
                         style = MaterialTheme.typography.titleMedium,
                     )
@@ -227,13 +257,13 @@ internal fun AppMenu(navigator: CarNavigator, running: Map<String, RunningSlot>)
                         },
                         tone = GsTone.Danger,
                         modifier = Modifier.fillMaxWidth().height(56.dp),
-                    ) { Text("Close app", style = MaterialTheme.typography.titleMedium) }
+                    ) { Text(stringResource(R.string.navapps_close), style = MaterialTheme.typography.titleMedium) }
                 }
                 GsButton(
                     onClick = navigator::dismissAppMenu,
                     tone = GsTone.Neutral,
                     modifier = Modifier.fillMaxWidth().height(56.dp),
-                ) { Text("Cancel", style = MaterialTheme.typography.titleMedium) }
+                ) { Text(stringResource(R.string.cancel), style = MaterialTheme.typography.titleMedium) }
             }
         }
     }
@@ -260,19 +290,19 @@ private fun MoveButtons(id: String) {
             tone = GsTone.Tonal,
             enabled = index > 0,
             modifier = Modifier.weight(1f).height(56.dp),
-        ) { Text("Move left", style = MaterialTheme.typography.titleMedium) }
+        ) { Text(stringResource(R.string.navapps_move_left), style = MaterialTheme.typography.titleMedium) }
         GsButton(
             onClick = { move(1) },
             tone = GsTone.Tonal,
             enabled = index < order.lastIndex,
             modifier = Modifier.weight(1f).height(56.dp),
-        ) { Text("Move right", style = MaterialTheme.typography.titleMedium) }
+        ) { Text(stringResource(R.string.navapps_move_right), style = MaterialTheme.typography.titleMedium) }
     }
     if (custom.isNotEmpty()) {
         GsButton(
             onClick = { CarSettings.setAppOrder(emptyList()) },
             tone = GsTone.Neutral,
             modifier = Modifier.fillMaxWidth().height(56.dp),
-        ) { Text("Reset app order", style = MaterialTheme.typography.titleMedium) }
+        ) { Text(stringResource(R.string.navapps_reset), style = MaterialTheme.typography.titleMedium) }
     }
 }

gearslip/src/main/java/app/seb3thehacker/gearslip/car/NotificationsScreen.kt

@@ -1,5 +1,7 @@
 package app.seb3thehacker.gearslip.car
 
+import androidx.compose.ui.res.stringResource
+import app.seb3thehacker.gearslip.R
 import app.seb3thehacker.gearslip.car.theme.*
 import android.content.Intent
 import android.provider.Settings
@@ -79,12 +81,12 @@ fun NotificationsSection() {
     Column(verticalArrangement = Arrangement.spacedBy(8.dp)) {
         Row(verticalAlignment = Alignment.CenterVertically) {
             Text(
-                "Notifications",
+                stringResource(R.string.notif_title),
                 style = MaterialTheme.typography.titleMedium,
                 color = MaterialTheme.colorScheme.primary,
                 modifier = Modifier.weight(1f),
             )
-            if (history.isNotEmpty()) TextButton(onClick = CarNotifications::clear) { Text("Clear all") }
+            if (history.isNotEmpty()) TextButton(onClick = CarNotifications::clear) { Text(stringResource(R.string.notif_clear_all)) }
         }
 
         if (!listening) {
@@ -97,7 +99,7 @@ fun NotificationsSection() {
 
         if (history.isEmpty()) {
             Text(
-                "Nothing yet. New notifications from the phone will show up here.",
+                stringResource(R.string.notif_empty),
                 style = MaterialTheme.typography.bodyMedium,
                 color = MaterialTheme.colorScheme.onSurfaceVariant,
             )
@@ -124,11 +126,11 @@ internal fun AccessBanner(onOpen: () -> Unit) {
         ) {
             Icon(Icons.Filled.Warning, contentDescription = null)
             Text(
-                "Notifications are off. Allow Gearslip under Settings > Notifications > Notification access on the phone.",
+                stringResource(R.string.notif_off),
                 style = MaterialTheme.typography.bodyMedium,
                 modifier = Modifier.weight(1f),
             )
-            GsButton(onClick = onOpen) { Text("Open") }
+            GsButton(onClick = onOpen) { Text(stringResource(R.string.guide_open)) }
         }
     }
 }
@@ -160,10 +162,10 @@ private fun NotificationRow(n: CarNotification, onReply: (CarNotification) -> Un
                 }
             }
             when {
-                n.replied -> Icon(Icons.Filled.Check, contentDescription = "Replied", tint = MaterialTheme.colorScheme.primary)
+                n.replied -> Icon(Icons.Filled.Check, contentDescription = stringResource(R.string.notif_replied), tint = MaterialTheme.colorScheme.primary)
                 n.reply != null -> GsButton(onClick = { VoiceReply.reply(n) }, tone = GsTone.Tonal) {
                     ReplyGlyph(Modifier.size(20.dp))
-                    Text("Reply", Modifier.padding(start = 8.dp))
+                    Text(stringResource(R.string.crumb_reply), Modifier.padding(start = 8.dp))
                 }
             }
         }
@@ -198,14 +200,14 @@ private fun ReplyPane(n: CarNotification, onDone: () -> Unit) {
             verticalAlignment = Alignment.CenterVertically,
             horizontalArrangement = Arrangement.spacedBy(8.dp),
         ) {
-            GsIconButton(Icons.AutoMirrored.Filled.ArrowBack, "Back", onDone)
+            GsIconButton(Icons.AutoMirrored.Filled.ArrowBack, stringResource(R.string.back), onDone)
             Surface(
                 shape = RoundedCornerShape(24.dp),
                 color = MaterialTheme.colorScheme.surfaceContainerHighest,
                 modifier = Modifier.weight(1f),
             ) {
                 Text(
-                    if (text.isEmpty()) "Reply to ${n.title.ifBlank { n.appLabel }}" else "$text|",
+                    if (text.isEmpty()) stringResource(R.string.msg_reply_to, n.title.ifBlank { n.appLabel }) else "$text|",
                     color = if (text.isEmpty()) MaterialTheme.colorScheme.onSurfaceVariant else MaterialTheme.colorScheme.onSurface,
                     maxLines = 1,
                     overflow = TextOverflow.Ellipsis,

gearslip/src/main/java/app/seb3thehacker/gearslip/car/PhoneAppsScreen.kt

@@ -1,5 +1,7 @@
 package app.seb3thehacker.gearslip.car
 
+import androidx.compose.ui.res.stringResource
+import app.seb3thehacker.gearslip.R
 import app.seb3thehacker.gearslip.car.theme.*
 import androidx.compose.foundation.Image
 import androidx.compose.foundation.layout.Arrangement
@@ -52,7 +54,9 @@ fun PhoneAppsScreen() {
         value = PhoneApps.cached() ?: withContext(Dispatchers.IO) { PhoneApps.installed(context).also { PhoneApps.warm(context) } }
     }
 
-    Column(Modifier.fillMaxSize().padding(horizontal = 20.dp, vertical = 12.dp)) {
+    Column(Modifier.fillMaxSize().padding(start = 20.dp, end = 20.dp, top = 12.dp)) {
+        ScreenHeader(stringResource(R.string.app_screen_sharing))
+        Spacer(Modifier.height(12.dp))
         if (!TouchRelayService.enabled) {
             TouchRelayWarning()
             Spacer(Modifier.height(12.dp))
@@ -61,7 +65,7 @@ fun PhoneAppsScreen() {
         LazyVerticalGrid(
             columns = GridCells.Adaptive(minSize = 108.dp),
             modifier = Modifier.fillMaxSize(),
-            contentPadding = PaddingValues(bottom = 8.dp),
+            contentPadding = PaddingValues(bottom = 16.dp),
             horizontalArrangement = Arrangement.spacedBy(12.dp),
             verticalArrangement = Arrangement.spacedBy(12.dp),
         ) {
@@ -92,11 +96,11 @@ private fun TouchRelayWarning() {
         ) {
             Icon(Icons.Filled.Warning, contentDescription = null)
             Text(
-                "Touch is off. Enable Gearslip under Settings > Accessibility on the phone.",
+                stringResource(R.string.phoneapps_touch_off),
                 style = MaterialTheme.typography.bodyMedium,
                 modifier = Modifier.weight(1f),
             )
-            GsButton(onClick = { PhoneApps.openAccessibilitySettings(context) }) { Text("Open") }
+            GsButton(onClick = { PhoneApps.openAccessibilitySettings(context) }) { Text(stringResource(R.string.guide_open)) }
         }
     }
 }

gearslip/src/main/java/app/seb3thehacker/gearslip/car/PhoneDialerScreen.kt

@@ -1,5 +1,7 @@
 package app.seb3thehacker.gearslip.car
 
+import androidx.compose.ui.res.stringResource
+import app.seb3thehacker.gearslip.R
 import app.seb3thehacker.gearslip.car.theme.*
 import android.Manifest
 import android.content.Context
@@ -8,9 +10,11 @@ import android.content.pm.PackageManager
 import android.net.Uri
 import android.provider.ContactsContract
 import android.provider.Settings
+import app.seb3thehacker.gearslip.GearslipLog
 import androidx.compose.foundation.background
 import androidx.compose.foundation.clickable
 import androidx.compose.foundation.interaction.MutableInteractionSource
+import androidx.compose.foundation.layout.PaddingValues
 import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.Column
@@ -32,6 +36,7 @@ import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Surface
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.collectAsState
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.produceState
@@ -79,14 +84,49 @@ internal fun loadContacts(context: Context): List<Contact> {
     return out.distinctBy { it.number }
 }
 
+/**
+ * Places the call through Telecom directly. Starting ACTION_CALL from here launched the system's
+ * call activity onto the car's display, which Android refuses for another app's activity, and
+ * from the background, which it blocks too - so the call never went out.
+ */
 internal fun placeCall(context: Context, number: String) {
     if (number.isBlank()) return
-    if (context.checkSelfPermission(Manifest.permission.CALL_PHONE) != PackageManager.PERMISSION_GRANTED) return
-    runCatching {
-        context.startActivity(
-            Intent(Intent.ACTION_CALL, Uri.parse("tel:${Uri.encode(number)}")).addFlags(Intent.FLAG_ACTIVITY_NEW_TASK),
-        )
+    if (context.checkSelfPermission(Manifest.permission.CALL_PHONE) != PackageManager.PERMISSION_GRANTED) {
+        GearslipLog.w("calls: can't place a call without CALL_PHONE")
+        return
     }
+    val telecom = context.getSystemService(android.telecom.TelecomManager::class.java)
+    runCatching { telecom!!.placeCall(Uri.fromParts("tel", number, null), null) }
+        .onSuccess {
+            GearslipLog.i("calls: placing a call")
+            app.seb3thehacker.gearslip.call.CarCalls.outgoingCall(context, number)
+        }
+        .onFailure { GearslipLog.w("calls: placing a call failed: ${it.message}") }
+}
+
+/** A call another car screen wants to place - a number on a place page - waiting on the driver. */
+internal object CallPrompt {
+    val pending = kotlinx.coroutines.flow.MutableStateFlow<Contact?>(null)
+
+    fun ask(name: String, number: String) {
+        pending.value = Contact(name, number)
+    }
+}
+
+/** The dialer's own confirmation, drawn over the whole car screen for [CallPrompt]. */
+@Composable
+internal fun CallPromptOverlay() {
+    val context = LocalContext.current
+    val contact by CallPrompt.pending.collectAsState()
+    val c = contact ?: return
+    ConfirmCallOverlay(
+        c,
+        onConfirm = {
+            CallPrompt.pending.value = null
+            placeCall(context, c.number)
+        },
+        onDismiss = { CallPrompt.pending.value = null },
+    )
 }
 
 private const val TAB_CONTACTS = 0
@@ -96,51 +136,48 @@ private const val TAB_KEYPAD = 1
 @Composable
 fun PhoneDialerScreen() {
     val context = LocalContext.current
-    val hasPermissions = hasCallPermissions(context)
+    var hasPermissions by remember { mutableStateOf(hasCallPermissions(context)) }
     var tab by remember { mutableStateOf(TAB_CONTACTS) }
 
-    Column(Modifier.fillMaxSize().padding(16.dp), verticalArrangement = Arrangement.spacedBy(16.dp)) {
+    Column(Modifier.fillMaxSize().padding(start = 16.dp, end = 16.dp, top = 16.dp), verticalArrangement = Arrangement.spacedBy(16.dp)) {
         // The tabs share the title's row, so the list and keypad get the height back.
-        Row(Modifier.fillMaxWidth(), verticalAlignment = Alignment.CenterVertically) {
-            Text(
-                "Phone",
-                style = MaterialTheme.typography.headlineSmall,
-                fontWeight = FontWeight.Bold,
-                modifier = Modifier.weight(1f),
-            )
+        ScreenHeader(stringResource(R.string.carset_phone)) {
             if (hasPermissions) {
                 Row(horizontalArrangement = Arrangement.spacedBy(8.dp)) {
-                    DialerTab("Contacts", tab == TAB_CONTACTS, Modifier.width(140.dp)) { tab = TAB_CONTACTS }
-                    DialerTab("Keypad", tab == TAB_KEYPAD, Modifier.width(140.dp)) { tab = TAB_KEYPAD }
+                    DialerTab(stringResource(R.string.dialer_contacts), tab == TAB_CONTACTS, Modifier.width(140.dp)) { tab = TAB_CONTACTS }
+                    DialerTab(stringResource(R.string.dialer_keypad), tab == TAB_KEYPAD, Modifier.width(140.dp)) { tab = TAB_KEYPAD }
                 }
             }
         }
 
         if (!hasPermissions) {
-            MissingPermission(context)
+            MissingPermission(context) { hasPermissions = true }
             return@Column
         }
 
         Box(Modifier.weight(1f).fillMaxWidth()) {
-            if (tab == TAB_CONTACTS) ContactsList(context) else Keypad(context)
+            if (tab == TAB_CONTACTS) ContactsList(context) else Box(Modifier.padding(bottom = 16.dp)) { Keypad(context) }
         }
     }
 }
 
 @Composable
-private fun MissingPermission(context: Context) {
+private fun MissingPermission(context: Context, onGranted: () -> Unit) {
+    // Android's dialog can't show on the car screen, so it opens on the phone; checking again
+    // every second picks the answer up without the driver having to come back in.
+    androidx.compose.runtime.LaunchedEffect(Unit) {
+        while (!hasCallPermissions(context)) kotlinx.coroutines.delay(1_000)
+        onGranted()
+    }
     Column(verticalArrangement = Arrangement.spacedBy(12.dp)) {
         Text(
-            "Gearslip needs the Phone and Contacts permissions to dial from here. Grant them " +
-                "from the app's settings.",
+            stringResource(R.string.dialer_needs_permission),
             style = MaterialTheme.typography.bodyLarge,
             color = MaterialTheme.colorScheme.onSurfaceVariant,
         )
         GsButton(tone = GsTone.Tonal, onClick = {
-            context.startActivity(
-                Intent(Settings.ACTION_APPLICATION_DETAILS_SETTINGS, Uri.fromParts("package", context.packageName, null)),
-            )
-        }) { Text("Open app settings") }
+            app.seb3thehacker.gearslip.PermissionActivity.ask(context, CALL_PERMISSIONS)
+        }) { Text(stringResource(R.string.dialer_ask)) }
     }
 }
 
@@ -176,7 +213,7 @@ private fun Keypad(context: Context) {
 
     Column(Modifier.fillMaxSize(), verticalArrangement = Arrangement.spacedBy(12.dp)) {
         Text(
-            number.ifEmpty { "Enter a number" },
+            number.ifEmpty { stringResource(R.string.dialer_enter_number) },
             style = MaterialTheme.typography.headlineSmall,
             color = if (number.isEmpty()) MaterialTheme.colorScheme.onSurfaceVariant else MaterialTheme.colorScheme.onSurface,
             maxLines = 1,
@@ -205,7 +242,7 @@ private fun Keypad(context: Context) {
                     colors = gsColors(GsTone.Primary),
                     enabled = number.isNotEmpty(),
                     modifier = Modifier.weight(1f).fillMaxWidth(),
-                ) { Icon(Icons.Filled.Call, "Call") }
+                ) { Icon(Icons.Filled.Call, stringResource(R.string.dialer_call)) }
             }
         }
     }
@@ -247,16 +284,16 @@ private fun ContactsList(context: Context) {
         Box(Modifier.weight(1f).fillMaxWidth()) {
             when {
                 contacts.isEmpty() -> Text(
-                    "No contacts with a phone number found.",
+                    stringResource(R.string.dialer_no_contacts),
                     style = MaterialTheme.typography.bodyLarge,
                     color = MaterialTheme.colorScheme.onSurfaceVariant,
                 )
                 filtered.isEmpty() -> Text(
-                    "No contacts match \"$query\".",
+                    stringResource(R.string.dialer_no_match, query),
                     style = MaterialTheme.typography.bodyLarge,
                     color = MaterialTheme.colorScheme.onSurfaceVariant,
                 )
-                else -> LazyColumn(Modifier.fillMaxSize(), verticalArrangement = Arrangement.spacedBy(8.dp)) {
+                else -> LazyColumn(Modifier.fillMaxSize(), contentPadding = PaddingValues(bottom = 16.dp), verticalArrangement = Arrangement.spacedBy(8.dp)) {
                     items(filtered) { contact ->
                         ContactRow(contact) { pendingCall = contact }
                     }
@@ -309,14 +346,14 @@ private fun ConfirmCallOverlay(contact: Contact, onConfirm: () -> Unit, onDismis
                 verticalArrangement = Arrangement.spacedBy(20.dp),
                 horizontalAlignment = Alignment.CenterHorizontally,
             ) {
-                Text("Call ${contact.name}?", style = MaterialTheme.typography.headlineSmall, fontWeight = FontWeight.Bold)
+                Text(stringResource(R.string.dialer_call_who, contact.name), style = MaterialTheme.typography.headlineSmall, fontWeight = FontWeight.Bold)
                 Text(contact.number, style = MaterialTheme.typography.titleLarge, color = MaterialTheme.colorScheme.onSurfaceVariant)
                 Row(Modifier.fillMaxWidth(), horizontalArrangement = Arrangement.spacedBy(16.dp)) {
                     GsButton(onClick = onDismiss, tone = GsTone.Outline, modifier = Modifier.weight(1f).height(56.dp)) {
-                        Text("Cancel", style = MaterialTheme.typography.titleMedium)
+                        Text(stringResource(R.string.cancel), style = MaterialTheme.typography.titleMedium)
                     }
                     GsButton(onClick = onConfirm, modifier = Modifier.weight(1f).height(56.dp)) {
-                        Text("Call", style = MaterialTheme.typography.titleMedium)
+                        Text(stringResource(R.string.dialer_call), style = MaterialTheme.typography.titleMedium)
                     }
                 }
             }
@@ -333,7 +370,7 @@ private fun ContactSearchField(query: String, active: Boolean, onToggle: () -> U
         modifier = Modifier.fillMaxWidth(),
     ) {
         Text(
-            query.ifEmpty { "Search contacts" },
+            query.ifEmpty { stringResource(R.string.dialer_search) },
             style = MaterialTheme.typography.bodyLarge,
             color = if (query.isEmpty()) MaterialTheme.colorScheme.onSurfaceVariant else MaterialTheme.colorScheme.onSurface,
             maxLines = 1,
@@ -371,7 +408,7 @@ private fun ContactRow(contact: Contact, onClick: () -> Unit) {
                 Text(contact.name, style = MaterialTheme.typography.titleMedium, maxLines = 1, overflow = TextOverflow.Ellipsis)
                 Text(contact.number, style = MaterialTheme.typography.bodyMedium, color = MaterialTheme.colorScheme.onSurfaceVariant)
             }
-            Icon(Icons.Filled.Call, contentDescription = "Call", tint = MaterialTheme.colorScheme.primary)
+            Icon(Icons.Filled.Call, contentDescription = stringResource(R.string.dialer_call), tint = MaterialTheme.colorScheme.primary)
         }
     }
 }