Opening a media app that can't connect no longer drops the music you were listening to

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

@@ -37,7 +37,13 @@ object CarServices {
     private const val REPAUSE_MS = 2_000L
 
     val nav: CarAppConnection by lazy { CarAppConnection(requireNotNull(context)) }
-    val media: CarMedia by lazy { CarMedia(requireNotNull(context)) }
+    val media: CarMedia by lazy {
+        CarMedia(requireNotNull(context)).also { m ->
+            // Remembered only once it connects: an app that refuses (NewPipe without Notification
+            // access) must not replace the one the driver was listening to on the next drive.
+            m.onReady = { app -> CarSettings.setLastMedia(app.component.flattenToString()) }
+        }
+    }
 
     /** [nav], or null before the car screen has set things up. */
     fun navOrNull(): CarAppConnection? = if (context != null) nav else null
@@ -67,7 +73,7 @@ object CarServices {
     private var autoplayPending = false
 
     /**
-     * The app that was playing when the driver opened another one. Opening an app is only a look
+     * The app that was playing, or paused with a track loaded, 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.
      */
@@ -138,13 +144,14 @@ object CarServices {
     // --- media ---------------------------------------------------------------------------
 
     fun openMedia(app: MediaApp, autoplay: Boolean = false) {
-        CarSettings.setLastMedia(app.component.flattenToString())
         val phase = media.phase.value
         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 }
+        // Paused counts too: a track loaded there is still the music the driver is listening to.
+        val loaded = media.now.value.let { it.playing || it.title.isNotEmpty() }
+        stillPlaying = previous?.takeIf { it.component != app.component && loaded && !autoplay }
         _mediaApp.value = app
         autoplayPending = autoplay
         media.connect(app)

gearslip/src/main/java/app/seb3thehacker/gearslip/media/CarMedia.kt

@@ -188,6 +188,9 @@ class CarMedia(private val context: Context) {
     /** The music app Gearslip is attached to, for the assistant to name; null when there's none. */
     val appLabel: String? get() = connecting?.label?.takeIf { controller != null }
 
+    /** Called once an app is connected and can be played, library or not. */
+    var onReady: ((MediaApp) -> Unit)? = null
+
     private val _phase = MutableStateFlow(Phase.IDLE)
     val phase: StateFlow<Phase> = _phase.asStateFlow()
 
@@ -354,6 +357,7 @@ class CarMedia(private val context: Context) {
         attach(session)
         _browse.value = BrowseState(loading = false, unavailable = true)
         _phase.value = Phase.READY
+        onReady?.invoke(app)
     }
 
     private fun onConnected(app: MediaApp) {
@@ -366,6 +370,7 @@ class CarMedia(private val context: Context) {
         mb.extras?.let { childStyles[mb.root] = it.getInt(STYLE_BROWSABLE, 0) to it.getInt(STYLE_PLAYABLE, 0) }
         path.clear()
         _phase.value = Phase.READY
+        onReady?.invoke(app)
         open(mb.root)
     }