First pass adding android auto and apple carplay support. Android auto tuned on emulator.

android/app/build.gradle.kts

@@ -9,6 +9,7 @@ dependencies {
     implementation("com.google.android.gms:play-services-cast-framework:22.1.0")
     implementation("androidx.mediarouter:mediarouter:1.7.0")
     implementation("androidx.appcompat:appcompat:1.7.0")
+    implementation("androidx.media:media:1.7.0")
 }
 
 android {

android/app/src/main/AndroidManifest.xml

@@ -42,12 +42,31 @@
             android:name="com.google.android.gms.cast.framework.OPTIONS_PROVIDER_CLASS_NAME"
             android:value="com.example.kryz_go_flutter.CastOptionsProvider" />
 
+        <!-- Declares this app as an Android Auto media app. -->
+        <meta-data
+            android:name="com.google.android.gms.car.application"
+            android:resource="@xml/automotive_app_desc" />
+
         <service
             android:name="com.ryanheise.audioservice.AudioService"
             android:enabled="true"
             android:exported="true"
             android:foregroundServiceType="mediaPlayback"
             tools:ignore="Instantiatable">
+        </service>
+
+        <!--
+          Dedicated MediaBrowserService for Android Auto. Android Auto connects here
+          to browse content and send transport controls. Styled with KryzAutoTheme
+          so Auto accents its media UI with the KRYZ brand orange (#E36A18).
+        -->
+        <service
+            android:name="com.example.kryz_go_flutter.KryzAutoMediaBrowserService"
+            android:enabled="true"
+            android:exported="true"
+            android:foregroundServiceType="mediaPlayback"
+            android:theme="@style/KryzAutoTheme"
+            tools:ignore="Instantiatable">
             <intent-filter>
                 <action android:name="android.media.browse.MediaBrowserService"/>
             </intent-filter>

android/app/src/main/kotlin/com/example/kryz_go_flutter/KryzAutoMediaBrowserService.kt

@@ -3,7 +3,6 @@ package com.example.kryz_go_flutter
 import android.app.Notification
 import android.app.NotificationChannel
 import android.app.NotificationManager
-import android.content.ComponentName
 import android.content.Context
 import android.media.AudioAttributes
 import android.media.AudioFocusRequest
@@ -132,39 +131,29 @@ class KryzAutoMediaBrowserService : MediaBrowserServiceCompat() {
         Log.d(TAG, "onCreate()")
         createNotificationChannel()
 
-        try {
-            mediaSession = MediaSessionCompat(
-                this,
-                TAG,
-                ComponentName(this, com.ryanheise.audioservice.MediaButtonReceiver::class.java),
-                null,
-            ).apply {
-                setCallback(mediaSessionCallback)
-                @Suppress("DEPRECATION")
-                setFlags(
-                    MediaSessionCompat.FLAG_HANDLES_MEDIA_BUTTONS or
-                        MediaSessionCompat.FLAG_HANDLES_TRANSPORT_CONTROLS
-                )
-                setPlaybackState(
-                    PlaybackStateCompat.Builder()
-                        .setActions(
-                            PlaybackStateCompat.ACTION_PLAY or
-                                PlaybackStateCompat.ACTION_STOP or
-                                PlaybackStateCompat.ACTION_PLAY_FROM_MEDIA_ID or
-                                PlaybackStateCompat.ACTION_PLAY_FROM_SEARCH
-                        )
-                        .setState(PlaybackStateCompat.STATE_STOPPED, 0, 1f)
-                        .build()
-                )
-                setMetadata(buildLiveStreamMetadata())
-                isActive = true
-            }
-
-            sessionToken = mediaSession.sessionToken
-            Log.d(TAG, "MediaSession created, sessionToken set")
-        } catch (e: Exception) {
-            Log.e(TAG, "Failed to create MediaSession", e)
+        mediaSession = MediaSessionCompat(this, TAG).apply {
+            setCallback(mediaSessionCallback)
+            @Suppress("DEPRECATION")
+            setFlags(
+                MediaSessionCompat.FLAG_HANDLES_MEDIA_BUTTONS or
+                    MediaSessionCompat.FLAG_HANDLES_TRANSPORT_CONTROLS
+            )
+            setPlaybackState(
+                PlaybackStateCompat.Builder()
+                    .setActions(
+                        PlaybackStateCompat.ACTION_PLAY or
+                            PlaybackStateCompat.ACTION_STOP or
+                            PlaybackStateCompat.ACTION_PLAY_FROM_MEDIA_ID or
+                            PlaybackStateCompat.ACTION_PLAY_FROM_SEARCH
+                    )
+                    .setState(PlaybackStateCompat.STATE_STOPPED, 0, 1f)
+                    .build()
+            )
+            setMetadata(buildLiveStreamMetadata())
+            isActive = true
         }
+        sessionToken = mediaSession.sessionToken
+        Log.d(TAG, "MediaSession created, sessionToken set")
     }
 
     override fun onGetRoot(

android/app/src/main/kotlin/com/example/kryz_go_flutter/MainActivity.kt

@@ -1,5 +1,6 @@
 package com.example.kryz_go_flutter
 
+import android.content.Intent
 import android.os.Handler
 import android.os.Looper
 import androidx.appcompat.view.ContextThemeWrapper
@@ -26,6 +27,7 @@ class MainActivity : AudioServiceActivity(), MethodChannel.MethodCallHandler, Ev
 	companion object {
 		private const val METHOD_CHANNEL = "kryz_go_flutter/casting/methods"
 		private const val EVENT_CHANNEL = "kryz_go_flutter/casting/events"
+		private const val PLAYBACK_METHOD_CHANNEL = "kryz_go_flutter/playback/methods"
 	}
 
 	private var castContext: CastContext? = null
@@ -33,6 +35,9 @@ class MainActivity : AudioServiceActivity(), MethodChannel.MethodCallHandler, Ev
 	private var chooserDialog: MediaRouteChooserDialog? = null
 	private val mainHandler = Handler(Looper.getMainLooper())
     private var activeRemoteMediaClient: RemoteMediaClient? = null
+	private var playbackMethodChannel: MethodChannel? = null
+	private var flutterReady = false
+	private var pendingAutoPlay = false
 
 	private var statusPayload: MutableMap<String, Any?> = mutableMapOf(
 		"status" to "idle",
@@ -101,9 +106,46 @@ class MainActivity : AudioServiceActivity(), MethodChannel.MethodCallHandler, Ev
 		EventChannel(flutterEngine.dartExecutor.binaryMessenger, EVENT_CHANNEL)
 			.setStreamHandler(this)
 
+		playbackMethodChannel = MethodChannel(
+			flutterEngine.dartExecutor.binaryMessenger,
+			PLAYBACK_METHOD_CHANNEL,
+		)
+
+		playbackMethodChannel?.setMethodCallHandler { call, result ->
+			when (call.method) {
+				"flutterReady" -> {
+					flutterReady = true
+					// Stop the service's MediaPlayer and hand off to Flutter.
+					val wasServicePlaying = KryzAutoMediaBrowserService.isServicePlaying()
+					KryzAutoMediaBrowserService.stopServicePlayer()
+					KryzAutoMediaBrowserService.registerDirectCallbacks(
+						play = { mainHandler.post { invokeFlutterPlay() } },
+						stop = { mainHandler.post { playbackMethodChannel?.invokeMethod("stop", null) } },
+					)
+					if (pendingAutoPlay || wasServicePlaying) {
+						pendingAutoPlay = false
+						invokeFlutterPlay()
+					}
+					result.success(null)
+				}
+				"updatePlaybackState" -> {
+					val isPlaying = call.argument<Boolean>("isPlaying") ?: false
+					val isBuffering = call.argument<Boolean>("isBuffering") ?: false
+					KryzAutoMediaBrowserService.updatePlaybackState(isPlaying, isBuffering)
+					result.success(null)
+				}
+				else -> result.notImplemented()
+			}
+		}
+
 		initializeCastContext()
 	}
 
+	override fun onNewIntent(intent: Intent) {
+		super.onNewIntent(intent)
+		setIntent(intent)
+	}
+
 	override fun onMethodCall(call: MethodCall, result: MethodChannel.Result) {
 		when (call.method) {
 			"getStatus" -> result.success(statusPayload)
@@ -139,6 +181,8 @@ class MainActivity : AudioServiceActivity(), MethodChannel.MethodCallHandler, Ev
 		chooserDialog?.dismiss()
 		chooserDialog = null
 
+		KryzAutoMediaBrowserService.unregisterDirectCallbacks()
+
 		castContext?.sessionManager?.removeSessionManagerListener(
 			castSessionManagerListener,
 			CastSession::class.java,
@@ -148,6 +192,16 @@ class MainActivity : AudioServiceActivity(), MethodChannel.MethodCallHandler, Ev
 		super.onDestroy()
 	}
 
+	private fun invokeFlutterPlay() {
+		if (!flutterReady) {
+			pendingAutoPlay = true
+			return
+		}
+		mainHandler.post {
+			playbackMethodChannel?.invokeMethod("play", null)
+		}
+	}
+
 	private fun initializeCastContext() {
 		try {
 			castContext = CastContext.getSharedInstance(this)

android/app/src/main/res/values/automotive_colors.xml

@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+  Brand colors exposed to Android Auto. Android Auto's media UI reads colorPrimary
+  from the app theme to accent its browsing and now-playing screens.
+  #E36A18 matches AppThemeBusinessObject.lightColors.primarySeed (brand orange).
+-->
+<resources>
+    <color name="kryz_primary">#E36A18</color>
+    <color name="kryz_primary_dark">#B84E08</color>
+    <color name="kryz_accent">#1663C7</color>
+</resources>

android/app/src/main/res/values/styles.xml

@@ -16,4 +16,14 @@
         <item name="android:windowBackground">@android:color/white</item>
         <item name="android:windowIsTranslucent">false</item>
     </style>
+
+    <!--
+      Theme used by KryzAutoMediaBrowserService. Android Auto reads colorPrimary
+      from the service's theme to accent its media browsing UI with the KRYZ brand orange.
+    -->
+    <style name="KryzAutoTheme" parent="Theme.AppCompat">
+        <item name="colorPrimary">@color/kryz_primary</item>
+        <item name="colorPrimaryDark">@color/kryz_primary_dark</item>
+        <item name="colorAccent">@color/kryz_accent</item>
+    </style>
 </resources>

android/app/src/main/res/xml/automotive_app_desc.xml

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="utf-8"?>
+<automotiveApp>
+    <uses name="media"/>
+</automotiveApp>