Fix AA disconnect: detect via display removal, prevent auto-resume

Android Auto on projection-mode devices (com.google.android.projection.gearhead)
doesn't trigger ACTION_EXIT_CAR_MODE, so the disconnect was never detected.

- Add DisplayManager.DisplayListener to detect AA disconnect when virtual
  displays are removed (projection mode)
- Add bidirectional method channel so Dart notifies native of AA connection
- Add onAADisconnected callback that force-pauses (not toggles) the player
- Suppress Sendspin stream/start for 2s after disconnect to handle the race
  where the server sends audio before processing our pause command
- Guard interruption begin handler to only pause/toggle when actually playing,
  preventing the interrupted-while-paused -> accidental resume bug

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: CollotsSpot

android/app/src/main/kotlin/com/collotsspot/ensemble/MainActivity.kt

@@ -5,13 +5,15 @@ import android.content.Context
 import android.content.Intent
 import android.content.IntentFilter
 import android.database.ContentObserver
+import android.hardware.display.DisplayManager
 import android.media.AudioManager
 import android.os.Build
 import android.os.Handler
 import android.os.Looper
 import android.provider.Settings
 import android.app.UiModeManager
 import android.util.Log
+import android.view.Display
 import android.view.KeyEvent
 import com.ryanheise.audioservice.AudioServiceActivity
 import io.flutter.embedding.engine.FlutterEngine
@@ -38,6 +40,10 @@ class MainActivity: AudioServiceActivity() {
     // Guard flag to ignore volume changes triggered by our own setStreamVolume calls
     private var ignoringVolumeChange = false
 
+    // Android Auto projection tracking via display listener
+    private var isAATracked = false
+    private var displayListener: DisplayManager.DisplayListener? = null
+
     override fun configureFlutterEngine(flutterEngine: FlutterEngine) {
         super.configureFlutterEngine(flutterEngine)
         Log.d(TAG, "Configuring Flutter engine, setting up MethodChannel")
@@ -85,11 +91,25 @@ class MainActivity: AudioServiceActivity() {
 
         // Android Auto / car mode detection
         aaChannel = MethodChannel(flutterEngine.dartExecutor.binaryMessenger, AA_CHANNEL)
+
+        // Receive AA connection signal from Dart side
+        aaChannel?.setMethodCallHandler { call, result ->
+            when (call.method) {
+                "notifyAAConnected" -> {
+                    Log.d(TAG, "AA tracked via Dart notifyAAConnected")
+                    isAATracked = true
+                    result.success(null)
+                }
+                else -> result.notImplemented()
+            }
+        }
+
         carModeReceiver = object : BroadcastReceiver() {
             override fun onReceive(context: Context, intent: Intent) {
                 when (intent.action) {
                     UiModeManager.ACTION_ENTER_CAR_MODE -> {
                         Log.d(TAG, "Car mode ENTERED")
+                        isAATracked = true
                         aaChannel?.invokeMethod("onAndroidAutoConnected", null)
                     }
                     UiModeManager.ACTION_EXIT_CAR_MODE -> {
@@ -108,6 +128,25 @@ class MainActivity: AudioServiceActivity() {
         } else {
             applicationContext.registerReceiver(carModeReceiver, carModeFilter)
         }
+
+        // Detect AA disconnect via display removal (projection mode)
+        val dm = getSystemService(Context.DISPLAY_SERVICE) as DisplayManager
+        displayListener = object : DisplayManager.DisplayListener {
+            override fun onDisplayAdded(displayId: Int) {}
+            override fun onDisplayChanged(displayId: Int) {}
+            override fun onDisplayRemoved(displayId: Int) {
+                if (!isAATracked) return
+                val hasExtraDisplay = dm.displays.any {
+                    it.displayId != Display.DEFAULT_DISPLAY
+                }
+                if (!hasExtraDisplay) {
+                    Log.d(TAG, "AA projection ended (all extra displays removed)")
+                    isAATracked = false
+                    aaChannel?.invokeMethod("onAndroidAutoDisconnected", null)
+                }
+            }
+        }
+        dm.registerDisplayListener(displayListener, Handler(Looper.getMainLooper()))
     }
 
     /// Start observing system STREAM_MUSIC volume changes.
@@ -261,6 +300,10 @@ class MainActivity: AudioServiceActivity() {
         carModeReceiver?.let {
             try { applicationContext.unregisterReceiver(it) } catch (_: Exception) {}
         }
+        displayListener?.let {
+            val dm = getSystemService(Context.DISPLAY_SERVICE) as DisplayManager
+            dm.unregisterDisplayListener(it)
+        }
         super.onDestroy()
     }
 }

lib/providers/music_assistant_provider.dart

@@ -2130,6 +2130,13 @@ class MusicAssistantProvider with ChangeNotifier {
     audioHandler.onBrowseActivity = () {
       _cancelIdleServiceTimer();
     };
+    audioHandler.onAADisconnected = () {
+      _logger.log('🎵 AA disconnected: force-pausing player');
+      final player = _selectedPlayer;
+      if (player != null) {
+        pausePlayer(player.playerId);
+      }
+    };
 
     // Player registration is now handled in _initializeAfterConnection()
     // which runs after authentication completes (when auth is required)
@@ -2557,6 +2564,11 @@ class MusicAssistantProvider with ChangeNotifier {
   /// 2. Start the foreground service to prevent background throttling
   /// 3. Reset position for new track and start position timer
   void _handleSendspinStreamStart(Map<String, dynamic>? trackInfo) async {
+    final aaDisc = audioHandler.aaDisconnectedAt;
+    if (aaDisc != null && DateTime.now().difference(aaDisc).inSeconds < 2) {
+      _logger.log('🎵 Sendspin: Ignoring stream/start (AA disconnected ${DateTime.now().difference(aaDisc).inMilliseconds}ms ago)');
+      return;
+    }
     _logger.log('🎵 Sendspin: Stream starting');
 
     // Ensure PCM player is initialized and ready

lib/services/audio/massiv_audio_handler.dart

@@ -37,6 +37,7 @@ class MassivAudioHandler extends BaseAudioHandler with QueueHandler, SeekHandler
   Function()? onPause;
   Function()? onSwitchPlayer;
   Function()? onBrowseActivity;
+  Function()? onAADisconnected;
 
   // Track whether we're in remote control mode (controlling MA player, not playing locally)
   bool _isRemoteMode = false;
@@ -65,6 +66,15 @@ class MassivAudioHandler extends BaseAudioHandler with QueueHandler, SeekHandler
   // Suppress auto-resume after audio route changes (e.g. BT/AA disconnect)
   bool _suppressResume = false;
 
+  // Track whether music was actually playing before an interruption
+  bool _wasPlayingBeforeInterruption = false;
+
+  // Timestamp of last AA disconnect — used to suppress stream/start race condition
+  DateTime? aaDisconnectedAt;
+
+  // Android Auto method channel (Dart ↔ Native)
+  static const _aaChannel = MethodChannel('com.collotsspot.ensemble/android_auto');
+
   // Custom control for switching players
   static final _switchPlayerControl = MediaControl.custom(
     androidIcon: 'drawable/ic_switch_player',
@@ -94,8 +104,11 @@ class MassivAudioHandler extends BaseAudioHandler with QueueHandler, SeekHandler
             break;
           case AudioInterruptionType.pause:
           case AudioInterruptionType.unknown:
-            _player.pause();
-            onPause?.call();
+            _wasPlayingBeforeInterruption = playbackState.value.playing;
+            if (_wasPlayingBeforeInterruption) {
+              _player.pause();
+              onPause?.call();
+            }
             break;
         }
       } else {
@@ -109,6 +122,10 @@ class MassivAudioHandler extends BaseAudioHandler with QueueHandler, SeekHandler
               _suppressResume = false;
               break;
             }
+            if (!_wasPlayingBeforeInterruption) {
+              _logger.log('🔊 Audio interruption ended but was not playing before');
+              break;
+            }
             _player.play();
             onPlay?.call();
             break;
@@ -138,17 +155,19 @@ class MassivAudioHandler extends BaseAudioHandler with QueueHandler, SeekHandler
     });
 
     // Listen for Android Auto connection events from native side
-    const aaChannel = MethodChannel('com.collotsspot.ensemble/android_auto');
-    aaChannel.setMethodCallHandler((call) async {
+    _aaChannel.setMethodCallHandler((call) async {
       switch (call.method) {
         case 'onAndroidAutoConnected':
           _logger.log('AndroidAuto: car mode connected (broadcast)');
           _isAndroidAutoConnected = true;
+          _aaChannel.invokeMethod('notifyAAConnected', null);
           _refreshPlaybackState();
         case 'onAndroidAutoDisconnected':
           _logger.log('AndroidAuto: car mode disconnected (broadcast)');
           _isAndroidAutoConnected = false;
           _suppressResume = true;
+          aaDisconnectedAt = DateTime.now();
+          onAADisconnected?.call();
           _refreshPlaybackState();
       }
     });
@@ -203,7 +222,6 @@ class MassivAudioHandler extends BaseAudioHandler with QueueHandler, SeekHandler
 
   @override
   Future<void> play() async {
-    _suppressResume = false;
     // Always prefer callbacks — they handle both remote players and
     // Sendspin PCM (which uses local mode but delegates playback to MA server)
     if (onPlay != null) {
@@ -349,6 +367,12 @@ class MassivAudioHandler extends BaseAudioHandler with QueueHandler, SeekHandler
     final current = playbackState.value;
     playbackState.add(current.copyWith(
       controls: _controls,
+      systemActions: const {
+        MediaAction.play,
+        MediaAction.pause,
+        MediaAction.skipToNext,
+        MediaAction.skipToPrevious,
+      },
     ));
   }
 
@@ -676,6 +700,7 @@ class MassivAudioHandler extends BaseAudioHandler with QueueHandler, SeekHandler
       if (!_isAndroidAutoConnected) {
         _logger.log('AndroidAuto: detected AA connection via getChildren');
         _isAndroidAutoConnected = true;
+        _aaChannel.invokeMethod('notifyAAConnected', null);
         _refreshPlaybackState();
       }
       final playerId = await SettingsService.getBuiltinPlayerId();