One navigation card: turn, lanes, a clearer next turn and the trip, with the app's own stop button when it has one

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

@@ -17,7 +17,6 @@ import androidx.compose.ui.graphics.Path
 import androidx.compose.ui.graphics.PathEffect
 import androidx.compose.ui.graphics.StrokeCap
 import androidx.compose.ui.graphics.StrokeJoin
-import androidx.compose.ui.graphics.drawscope.DrawScope
 import androidx.compose.ui.graphics.drawscope.Stroke
 import androidx.compose.ui.graphics.lerp
 import androidx.compose.ui.platform.LocalContext
@@ -112,98 +111,44 @@ internal fun LaneRoad(lanes: List<Lane>, modifier: Modifier, fill: Color, onFill
             drawLine(lerp(ground, line, 0.7f), Offset(x(i.toFloat(), 0f), 0f), Offset(x(i.toFloat(), h), h), edge, pathEffect = dashes)
         }
 
-        val top = h * 0.1f
+        val top = h * 0.12f
         val bottom = h * 0.9f
-        val half = minOf(bottomWidth / n * 0.34f, h * 0.4f)
+        // Half the room across a lane the arrows may use, as at the bottom: well inside the lines
+        // even where the lane narrows at the top.
+        val room = bottomWidth / n * 0.31f
         lanes.forEachIndexed { i, lane ->
-            // A point [u] across from the lane's middle, measured as at the bottom, at height [y].
-            val onRoad = { u: Float, y: Float -> Offset(x(i + 0.5f, y) + u * width(y) / bottomWidth, y) }
-            val stroke = half * 0.24f * width((top + bottom) / 2) / bottomWidth
             val directions = lane.directions.orEmpty().ifEmpty { listOf(null) }
+            // Faded first, so the one to take draws on top where they share a stem.
+            val arrows = directions.sortedBy { it?.isRecommended == true }
+                .map { it to laneArrow(it?.shape ?: LaneDirection.SHAPE_STRAIGHT, top, bottom) }
+            // The lane's arrows as one shape: centred in the lane, and shrunk toward the stem's
+            // foot when they'd reach past [room].
+            val xs = arrows.flatMap { (_, a) -> a.line.map { it.x } + a.head.map { it.x } }
+            val shift = -(xs.min() + xs.max()) / 2
+            val scale = minOf(1f, room / ((xs.max() - xs.min()) / 2))
+            val lift = (bottom - top) * (1 - scale) / 2
+            // Flat to the road: centred, scaled, then narrowed with the lane toward the top.
+            val onRoad = { p: Offset ->
+                val y = bottom - (bottom - p.y) * scale - lift
+                Offset(x(i + 0.5f, y) + (p.x + shift) * scale * width(y) / bottomWidth, y)
+            }
+            val stroke = (bottom - top) * 0.085f * scale * width((top + bottom) / 2) / bottomWidth
             val behind = if (lane.recommended()) fill else ground
             val on = if (lane.recommended()) onFill else line
-            // Solid colours, faded by mixing rather than transparency, so where a stem and a head
+            arrows.forEach { (d, arrow) ->
-            // overlap nothing shows through twice. Faded first, so the one to take draws on top.
+                // Solid colours, faded by mixing rather than transparency, so where a stem runs
-            directions.sortedBy { it?.isRecommended == true }.forEach { d ->
+                // into its head nothing shows through twice.
                 val color = if (d?.isRecommended == true) on else lerp(behind, on, 0.38f)
-                laneArrow(d?.shape ?: LaneDirection.SHAPE_STRAIGHT, onRoad, top, bottom, half, stroke, color)
+                val points = arrow.line.map(onRoad)
-            }
+                drawPath(
-        }
+                    Path().apply {
-    }
+                        moveTo(points[0].x, points[0].y)
-}
+                        points.drop(1).forEach { lineTo(it.x, it.y) }
-
+                    },
-/**
+                    color,
- * One direction's arrow inside a lane: a stem up from [bottom] that carries on straight, bends
+                    style = Stroke(stroke, cap = StrokeCap.Round, join = StrokeJoin.Round),
- * off to a side, or loops back for a U-turn, with a head at the end. Laid out flat, [half] being
+                )
- * half the room across the lane, then put on the road by [onRoad]. A lane's arrows share a stem.
+                val corners = arrow.head.map(onRoad)
- */
-private fun DrawScope.laneArrow(
-    shape: Int,
-    onRoad: (Float, Float) -> Offset,
-    top: Float,
-    bottom: Float,
-    half: Float,
-    stroke: Float,
-    color: Color,
-) {
-    val head = half * 0.24f * 1.9f
-    val path = Path()
-    fun Path.to(p: Offset) = onRoad(p.x, p.y).let { lineTo(it.x, it.y) }
-    fun Path.curve(c: Offset, p: Offset) {
-        val a = onRoad(c.x, c.y)
-        val b = onRoad(p.x, p.y)
-        quadraticTo(a.x, a.y, b.x, b.y)
-    }
-    onRoad(0f, bottom).let { path.moveTo(it.x, it.y) }
-    val tip: Offset
-    val dir: Offset
-    val degrees = when (shape) {
-        LaneDirection.SHAPE_SLIGHT_LEFT -> -40f
-        LaneDirection.SHAPE_SLIGHT_RIGHT -> 40f
-        LaneDirection.SHAPE_NORMAL_LEFT -> -90f
-        LaneDirection.SHAPE_NORMAL_RIGHT -> 90f
-        LaneDirection.SHAPE_SHARP_LEFT -> -135f
-        LaneDirection.SHAPE_SHARP_RIGHT -> 135f
-        LaneDirection.SHAPE_U_TURN_LEFT -> -180f
-        LaneDirection.SHAPE_U_TURN_RIGHT -> 180f
-        else -> 0f
-    }
-    val side = if (degrees < 0) -1f else 1f
-    when {
-        degrees == 0f -> {
-            path.to(Offset(0f, top + head))
-            tip = Offset(0f, top)
-            dir = Offset(0f, -1f)
-        }
-        abs(degrees) == 180f -> {
-            // Up, over the top and back down beside the stem.
-            val r = half * 0.45f
-            val back = side * 2 * r
-            path.to(Offset(0f, top + r))
-            path.curve(Offset(0f, top), Offset(side * r, top))
-            path.curve(Offset(back, top), Offset(back, top + r))
-            val end = top + (bottom - top) * 0.55f
-            path.to(Offset(back, end))
-            tip = Offset(back, end + head)
-            dir = Offset(0f, 1f)
-        }
-        else -> {
-            val rad = degrees / 180f * PI.toFloat()
-            val d = Offset(sin(rad), -cos(rad))
-            val fork = top + (bottom - top) * 0.5f
-            val length = minOf((bottom - top) * 0.42f, (half - head) / abs(d.x))
-            val bend = Offset(0f, fork - length * 0.45f)
-            val end = bend + d * length
-            path.to(Offset(0f, fork))
-            path.curve(bend, end)
-            tip = end + d * head
-            dir = d
-        }
-    }
-    drawPath(path, color, style = Stroke(stroke, cap = StrokeCap.Round, join = StrokeJoin.Round))
-    val across = Offset(-dir.y, dir.x) * (head * 0.85f)
-    val base = tip - dir * (head * 1.6f)
-    val corners = listOf(tip, base + across, base - across).map { onRoad(it.x, it.y) }
                 drawPath(
                     Path().apply {
                         moveTo(corners[0].x, corners[0].y)
@@ -213,6 +158,76 @@ private fun DrawScope.laneArrow(
                     },
                     color,
                 )
+            }
+        }
+    }
+}
+
+/** An arrow laid out flat: the stem as points, and the head's tip and two back corners. */
+private class LaneArrow(val line: List<Offset>, val head: List<Offset>)
+
+/**
+ * One direction's arrow, flat, its stem rising from x 0 at [bottom]: on straight to [top], bending
+ * off to a side from a little above the middle, or looping back for a U-turn. A lane's arrows
+ * share the stem, so a straight-and-right lane reads as one fork.
+ */
+private fun laneArrow(shape: Int, top: Float, bottom: Float): LaneArrow {
+    val tall = bottom - top
+    val head = tall * 0.17f
+    val start = Offset(0f, bottom)
+    val degrees = when (shape) {
+        LaneDirection.SHAPE_SLIGHT_LEFT -> -45f
+        LaneDirection.SHAPE_SLIGHT_RIGHT -> 45f
+        LaneDirection.SHAPE_NORMAL_LEFT -> -90f
+        LaneDirection.SHAPE_NORMAL_RIGHT -> 90f
+        LaneDirection.SHAPE_SHARP_LEFT -> -135f
+        LaneDirection.SHAPE_SHARP_RIGHT -> 135f
+        LaneDirection.SHAPE_U_TURN_LEFT -> -180f
+        LaneDirection.SHAPE_U_TURN_RIGHT -> 180f
+        else -> 0f
+    }
+    val side = if (degrees < 0) -1f else 1f
+    val line = mutableListOf(start)
+    val end: Offset
+    val dir: Offset
+    when {
+        degrees == 0f -> {
+            end = Offset(0f, top + head)
+            line += end
+            dir = Offset(0f, -1f)
+        }
+        abs(degrees) == 180f -> {
+            // Up, over the top and back down beside the stem.
+            val r = tall * 0.2f
+            line += Offset(0f, top + r)
+            line += curve(Offset(0f, top + r), Offset(0f, top), Offset(side * r, top))
+            line += curve(Offset(side * r, top), Offset(side * 2 * r, top), Offset(side * 2 * r, top + r))
+            end = Offset(side * 2 * r, top + tall * 0.5f)
+            line += end
+            dir = Offset(0f, 1f)
+        }
+        else -> {
+            val rad = degrees / 180f * PI.toFloat()
+            val d = Offset(sin(rad), -cos(rad))
+            val length = tall * 0.32f
+            val fork = Offset(0f, top + tall * 0.6f)
+            val bend = Offset(0f, fork.y - length * 0.45f)
+            end = bend + d * length
+            line += fork
+            line += curve(fork, bend, end)
+            dir = d
+        }
+    }
+    val tip = end + dir * head
+    val base = tip - dir * (head * 1.5f)
+    val across = Offset(-dir.y, dir.x) * (head * 0.9f)
+    return LaneArrow(line, listOf(tip, base + across, base - across))
+}
+
+/** Points along a quadratic curve from [a] to [c] bending toward [b], [a] itself left out. */
+private fun curve(a: Offset, b: Offset, c: Offset): List<Offset> = (1..10).map { k ->
+    val t = k / 10f
+    a * ((1 - t) * (1 - t)) + b * (2 * (1 - t) * t) + c * (t * t)
 }
 
 /**

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

@@ -38,6 +38,9 @@ import androidx.compose.runtime.getValue
 import androidx.compose.runtime.collectAsState
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.unit.sp
+import androidx.compose.runtime.setValue
 import androidx.compose.ui.layout.layoutId
 import androidx.compose.ui.draw.clip
 import androidx.compose.ui.graphics.Color
@@ -200,8 +203,7 @@ private fun NavigationChrome(template: NavigationTemplate, modifier: Modifier) {
 }
 
 /**
- * Cards down the left, map on the right: the turn on top, the trip along the bottom, the map
+ * The drive's card down the left, map on the right, the map buttons at the right edge. The whole column counts as covered, so the app centres its map in
- * buttons at the right edge. The whole column counts as covered, so the app centres its map in
  * what is left over and the car sits right of the cards rather than under them. Pan mode drops
  * the cards and gives the map the whole width.
  */
@@ -221,16 +223,14 @@ private fun NavigationBars(
         val column = cardColumnWidth(maxWidth)
         val cards = @Composable {
             if (routing != null || estimate != null) {
-                Column(
+                Column(Modifier.width(column).fillMaxHeight().covers("nav-cards", cardEdge).padding(12.dp)) {
-                    Modifier.width(column).fillMaxHeight().covers("nav-cards", cardEdge).padding(12.dp),
+                    // As tall as what it holds, up to the column's height.
-                    verticalArrangement = Arrangement.spacedBy(12.dp),
+                    NavigationCard(
-                ) {
+                        routing,
-                    // The estimate always gets its full height; the turn card has what's left and
+                        estimate,
-                    // keeps its top, the part that matters, if it ever runs out of room.
+                        showStop = !template.actionStrip.hasStop(),
-                    Box(Modifier.weight(1f).fillMaxWidth().clip(RoundedCornerShape(16.dp))) {
+                        Modifier.fillMaxWidth().weight(1f, fill = false),
-                        routing?.let { RoutingCard(it, Modifier.fillMaxWidth()) }
+                    )
-                    }
-                    estimate?.let { TravelEstimateCard(it, Modifier.fillMaxWidth()) }
                 }
             }
         }
@@ -252,25 +252,42 @@ private fun NavigationBars(
 }
 
 /**
- * The manoeuvre, big enough to read at a glance: the arrow and the distance to it, what to do
+ * The drive in one card, top to bottom: the manoeuvre big enough to read at a glance, the lanes
- * and onto which road, the lanes to be in, and the turn after it along the bottom.
+ * to be in, the turn after it, and the trip. On a short screen parts drop out whole, the lanes'
+ * words first, then the next turn, then the lanes; the manoeuvre and the trip always stay.
  */
 @Composable
-private fun RoutingCard(info: RoutingInfo, modifier: Modifier = Modifier) {
+private fun NavigationCard(info: RoutingInfo?, estimate: TravelEstimate?, showStop: Boolean, modifier: Modifier) {
-    if (info.isLoading) {
+    val step = info?.currentStep?.takeUnless { info.isLoading }
     ChromeSurface(modifier) {
-            Text(stringResource(R.string.nav_finding_route), Modifier.padding(horizontal = 18.dp, vertical = 16.dp), style = ChromeType.title)
-        }
-        return
-    }
-
-    val step = info.currentStep ?: return
-    val scheme = MaterialTheme.colorScheme
-    ChromeSurface(modifier) {
-        // On a short screen the hint goes first, then the next turn, then the lanes; never the turn.
         FitColumn {
+            if (info?.isLoading == true) {
+                Text(
+                    stringResource(R.string.nav_finding_route),
+                    Modifier.layoutId(0).padding(horizontal = 18.dp, vertical = 16.dp),
+                    style = ChromeType.title,
+                )
+            }
+            if (info != null && step != null) {
+                ManeuverHeader(info, step, Modifier.layoutId(0).fillMaxWidth())
+                // Drawn from the lane data whenever there is some, even beside the app's own picture.
+                step.lanes.orEmpty().takeIf { it.isNotEmpty() }?.let {
+                    LaneBand(it, Modifier.layoutId(2).fillMaxWidth())
+                    LaneHintLine(it, Modifier.layoutId(4).fillMaxWidth())
+                }
+                info.nextStep?.let { NextTurn(it, Modifier.layoutId(3).fillMaxWidth()) }
+            }
+            estimate?.let { TripRow(it, showStop, Modifier.layoutId(1).fillMaxWidth()) }
+        }
+    }
+}
+
+/** The manoeuvre on the theme's colour: the arrow and the distance to it, what to do, onto which road. */
+@Composable
+private fun ManeuverHeader(info: RoutingInfo, step: Step, modifier: Modifier) {
+    val scheme = MaterialTheme.colorScheme
     Column(
-                Modifier.layoutId(0).fillMaxWidth().background(scheme.primaryContainer).padding(16.dp),
+        modifier.background(scheme.primaryContainer).padding(16.dp),
         verticalArrangement = Arrangement.spacedBy(8.dp),
     ) {
         androidx.compose.runtime.CompositionLocalProvider(
@@ -283,7 +300,7 @@ private fun RoutingCard(info: RoutingInfo, modifier: Modifier = Modifier) {
                 if (distance.isNotEmpty()) {
                     Text(
                         distance,
-                                style = MaterialTheme.typography.displaySmall.copy(fontWeight = androidx.compose.ui.text.font.FontWeight.Bold),
+                        style = MaterialTheme.typography.displaySmall.copy(fontWeight = FontWeight.Bold),
                         maxLines = 1,
                     )
                 }
@@ -311,25 +328,36 @@ private fun RoutingCard(info: RoutingInfo, modifier: Modifier = Modifier) {
             info.junctionImage?.let { JunctionImage(it) }
         }
     }
-            // Drawn from the lane data whenever there is some, even beside the app's own picture.
+}
-            step.lanes.orEmpty().takeIf { it.isNotEmpty() }?.let {
+
-                LaneBand(it, Modifier.layoutId(1).fillMaxWidth())
+/**
-                LaneHintLine(it, Modifier.layoutId(3).fillMaxWidth())
+ * The turn after this one, as large as the instruction above it and wrapping rather than cut
-            }
+ * short: leaving a motorway, the next move comes quickly and has to read in a glance.
-            info.nextStep?.let { next ->
+ */
+@Composable
+private fun NextTurn(next: Step, modifier: Modifier) {
+    val scheme = MaterialTheme.colorScheme
+    // A shade apart from the trip below, so the two never read as one block of text.
     Row(
-                    Modifier.layoutId(2).fillMaxWidth().padding(horizontal = 16.dp, vertical = 10.dp),
+        modifier.background(scheme.surfaceContainerHighest).padding(horizontal = 16.dp, vertical = 12.dp),
         verticalAlignment = Alignment.CenterVertically,
     ) {
-                    Text(stringResource(R.string.nav_then), style = ChromeType.label, color = scheme.onSurfaceVariant)
+        CarGlyph(next.maneuver?.icon, Modifier.size(40.dp))
-                    Spacer(Modifier.width(10.dp))
+        Spacer(Modifier.width(14.dp))
-                    CarGlyph(next.maneuver?.icon, Modifier.size(28.dp))
+        Column {
-                    val nextText = next.cue.text().ifEmpty { next.road.text() }
+            Text(
-                    if (nextText.isNotEmpty()) {
+                stringResource(R.string.nav_then).uppercase(java.util.Locale.getDefault()),
-                        Spacer(Modifier.width(10.dp))
+                style = ChromeType.label.copy(fontWeight = FontWeight.Bold, letterSpacing = 1.2.sp),
-                        Text(nextText, style = ChromeType.body, maxLines = 1, overflow = TextOverflow.Ellipsis)
+                color = scheme.primary,
-                    }
+            )
-                }
+            val text = next.cue.text().ifEmpty { next.road.text() }
+            if (text.isNotEmpty()) {
+                Text(
+                    text,
+                    style = ChromeType.body.copy(fontWeight = FontWeight.SemiBold),
+                    maxLines = 2,
+                    overflow = TextOverflow.Ellipsis,
+                )
             }
         }
     }
@@ -381,63 +409,95 @@ private fun JunctionImage(icon: CarIcon, modifier: Modifier = Modifier) {
 }
 
 /**
- * The trip at a glance, stacked: time left on top, then the clock time it ends at and the
+ * The trip along the bottom of the card: time left, coloured as the app colours it (by traffic,
- * distance, with Gearslip's own stop button beside them. The close button is Gearslip's, not the
+ * in Vela), then the arrival and the distance, each with what it is under it. Gearslip's stop
- * app's: an actionStrip's actions carry no flag saying which one (if any) means "stop
+ * button sits at the end unless the app shows its own ([hasStop]). It ends navigation the way
- * navigating" - the first button turned out to be a mute toggle, not an exit - so this ends
+ * going Home does: the connection stays up and the app decides its own next screen.
- * navigation the way going Home already does rather than guess at the app's own controls.
  */
 @Composable
-private fun TravelEstimateCard(estimate: TravelEstimate, modifier: Modifier = Modifier) {
+private fun TripRow(estimate: TravelEstimate, showStop: Boolean, modifier: Modifier) {
     val connection = LocalCarAppConnection.current
+    val scheme = MaterialTheme.colorScheme
     val time = remainingTime(estimate.remainingTimeSeconds)
     val distance = estimate.remainingDistance.display()
     val arrival = estimate.arrivalTimeAtDestination.clockTime()
     val trip = estimate.tripText.text()
     if (time.isEmpty() && distance.isEmpty() && arrival.isEmpty() && trip.isEmpty()) return
-
+    val dark = scheme.surface.luminanceIsDark()
-    ChromeSurface(modifier) {
+    Column(modifier.padding(start = 18.dp, end = 12.dp, top = 12.dp, bottom = 12.dp)) {
-        val dark = MaterialTheme.colorScheme.surface.luminanceIsDark()
+        Row(Modifier.height(androidx.compose.foundation.layout.IntrinsicSize.Min), verticalAlignment = Alignment.CenterVertically) {
-        Row(
+            // The time leads, large and coloured; arrival and distance are smaller, each in its
-            Modifier.padding(start = 18.dp, end = 12.dp, top = 12.dp, bottom = 12.dp),
+            // own column behind a thin rule, with what it is under it.
-            verticalAlignment = Alignment.CenterVertically,
+            TripFigure(time, null, estimate.remainingTimeColor.color(dark, scheme.onSurface), ChromeType.headline, Modifier.weight(1.1f))
-        ) {
+            TripRule()
-            Column(Modifier.weight(1f)) {
+            TripFigure(arrival, stringResource(R.string.nav_arrival), scheme.onSurface, ChromeType.body, Modifier.weight(1f))
-                if (time.isNotEmpty()) {
+            TripRule()
-                    Text(
+            TripFigure(distance, stringResource(R.string.nav_to_go), scheme.onSurface, ChromeType.body, Modifier.weight(1f))
-                        time,
+            if (showStop) {
-                        style = ChromeType.headline,
-                        color = estimate.remainingTimeColor.color(dark, MaterialTheme.colorScheme.onSurface),
-                        maxLines = 1,
-                    )
-                }
-                val detail = listOfNotNull(
-                    arrival.takeIf { it.isNotEmpty() }?.let { stringResource(R.string.nav_arrive, it) },
-                    distance.takeIf { it.isNotEmpty() },
-                ).joinToString("  •  ")
-                if (detail.isNotEmpty()) {
-                    Text(detail, style = ChromeType.body, color = MaterialTheme.colorScheme.onSurfaceVariant, maxLines = 1, overflow = TextOverflow.Ellipsis)
-                }
-                if (trip.isNotEmpty()) {
-                    Text(trip, style = ChromeType.body, color = MaterialTheme.colorScheme.onSurfaceVariant, maxLines = 1, overflow = TextOverflow.Ellipsis)
-                }
-            }
-            // Not a disconnect: the connection stays up and the app decides its own next screen.
-            // Ending navigation is its own call, separate from a back press - a back press only
-            // pops the on-screen card, leaving the app still believing it is navigating.
                 GsIconButton(
                     Icons.Filled.Close,
                     stringResource(R.string.nav_stop),
                     { connection.stopNavigating() },
-                colors = GsColors(MaterialTheme.colorScheme.surfaceContainerHighest, MaterialTheme.colorScheme.onSurface),
+                    colors = GsColors(scheme.surfaceContainerHighest, scheme.onSurface),
                     size = 52.dp,
                     iconSize = 26.dp,
                     shape = CircleShape,
                 )
             }
         }
+        if (trip.isNotEmpty()) {
+            Text(
+                trip,
+                Modifier.padding(top = 6.dp),
+                style = ChromeType.body,
+                color = scheme.onSurfaceVariant,
+                maxLines = 1,
+                overflow = TextOverflow.Ellipsis,
+            )
+        }
+    }
 }
 
+@Composable
+private fun TripRule() {
+    Box(
+        Modifier.padding(horizontal = 12.dp, vertical = 4.dp).width(1.dp).fillMaxHeight()
+            .background(MaterialTheme.colorScheme.outlineVariant),
+    )
+}
+
+/** One of the trip's figures with its label under it, shrinking to stay on one line in a narrow column. */
+@Composable
+private fun TripFigure(value: String, label: String?, color: Color, style: androidx.compose.ui.text.TextStyle, modifier: Modifier) {
+    Column(modifier) {
+        if (value.isEmpty()) return@Column
+        var size by androidx.compose.runtime.remember(value, style) { androidx.compose.runtime.mutableStateOf(style.fontSize) }
+        Text(
+            value,
+            style = style.copy(fontSize = size, fontWeight = FontWeight.Bold),
+            color = color,
+            maxLines = 1,
+            softWrap = false,
+            onTextLayout = { if (it.hasVisualOverflow && size.value > 12f) size *= 0.9f },
+        )
+        if (label != null) {
+            Text(label, style = ChromeType.label, color = MaterialTheme.colorScheme.onSurfaceVariant, maxLines = 1, overflow = TextOverflow.Ellipsis)
+        }
+    }
+}
+
+/**
+ * Whether the app's own buttons include one that ends the drive: a red primary button, as
+ * Vela's is, or one named for it. Actions carry no flag that says so, so this is the best sign.
+ */
+private fun androidx.car.app.model.ActionStrip?.hasStop(): Boolean = this?.actions.orEmpty().any { action ->
+    val red = action.flags and androidx.car.app.model.Action.FLAG_PRIMARY != 0 &&
+        action.backgroundColor?.type == androidx.car.app.model.CarColor.TYPE_RED
+    red || action.title?.toString()?.let { STOP_WORDS.containsMatchIn(it) } == true
+}
+
+private val STOP_WORDS = Regex("\\b(stop|end|exit|quit|cancel)\\b", RegexOption.IGNORE_CASE)
+
 // --- map with a side pane ----------------------------------------------------------------------
 
 /**

gearslip/src/main/res/values/strings.xml

@@ -751,6 +751,10 @@
     <string name="nav_lane_from_right">Use lane %1$d from the right</string>
     <string name="nav_lane_any">Any lane</string>
     <string name="nav_arrive">Arrive %1$s</string>
+    <!-- Under the arrival time on the trip line: "4:30 p.m. / arrival" -->
+    <string name="nav_arrival">arrival</string>
+    <!-- Under the distance left on the trip line: "2.7 km / to go" -->
+    <string name="nav_to_go">to go</string>
 
     <!-- Car app screens -->
     <string name="template_nothing_playing">Nothing playing yet.</string>