corrects problem where google cast was disconnected from player state when app launched from head unit

lib/casting_business_object.dart

@@ -20,6 +20,9 @@ class CastingBusinessObject extends ChangeNotifier {
   CastingPlaybackStatus _playbackStatus = CastingPlaybackStatus.unknown;
   String? _connectedDeviceName;
   String? _lastError;
+  
+  /// Callback for when native side requests local audio to stop
+  VoidCallback? onStopLocalAudioRequested;
 
   CastingStatus get status => _status;
   CastingPlaybackStatus get playbackStatus => _playbackStatus;
@@ -55,6 +58,18 @@ class CastingBusinessObject extends ChangeNotifier {
       },
     );
 
+    // Set up handler for native method calls (e.g., stopLocalAudio)
+    _methodChannel.setMethodCallHandler(_handleMethodCall);
+
+    await refreshStatus();
+  }
+
+  Future<void> refreshStatus() async {
+    if (!isSupportedOnThisPlatform) {
+      _setStatus(CastingStatus.unavailable);
+      return;
+    }
+
     try {
       final dynamic status = await _methodChannel.invokeMethod<dynamic>(
         'getStatus',
@@ -66,7 +81,12 @@ class CastingBusinessObject extends ChangeNotifier {
     }
   }
 
-  Future<void> showDevicePicker() async {
+  Future<void> showDevicePicker({
+    bool autoplay = false,
+    String? streamUrl,
+    String? title,
+    String? subtitle,
+  }) async {
     if (!isSupportedOnThisPlatform) {
       _setStatus(CastingStatus.unavailable);
       return;
@@ -77,7 +97,12 @@ class CastingBusinessObject extends ChangeNotifier {
     }
 
     try {
-      await _methodChannel.invokeMethod<void>('showDevicePicker');
+      await _methodChannel.invokeMethod<void>('showDevicePicker', {
+        'autoplay': autoplay,
+        'streamUrl': streamUrl,
+        'title': title,
+        'subtitle': subtitle,
+      });
     } on PlatformException catch (error) {
       _lastError = error.message ?? error.code;
       _setStatus(CastingStatus.error);
@@ -102,7 +127,10 @@ class CastingBusinessObject extends ChangeNotifier {
       });
     } on PlatformException catch (error) {
       _lastError = error.message ?? error.code;
-      _setStatus(CastingStatus.error);
+      // Do NOT set status to error here — native emits its own status events.
+      // Overriding status from Dart corrupts the UI when native considers the
+      // session still connected (e.g. during a retry after a race condition).
+      rethrow;
     }
   }
 
@@ -146,6 +174,8 @@ class CastingBusinessObject extends ChangeNotifier {
 
     if (deviceName != null && deviceName.isNotEmpty) {
       _connectedDeviceName = deviceName;
+    } else if (status != 'connected') {
+      _connectedDeviceName = null;
     }
 
     if (message != null && message.isNotEmpty) {
@@ -210,4 +240,22 @@ class CastingBusinessObject extends ChangeNotifier {
     _eventSubscription?.cancel();
     super.dispose();
   }
+
+  /// Handles method calls from native code
+  Future<dynamic> _handleMethodCall(MethodCall call) async {
+    switch (call.method) {
+      case 'stopLocalAudio':
+        onStopLocalAudioRequested?.call();
+        return null;
+      case 'stopAudioService':
+        // Stop the audio service directly (called when transferring to cast)
+        onStopLocalAudioRequested?.call();
+        return null;
+      case 'resumeLocalAudio':
+        // Audio service is resuming after cast disconnect; no action needed on Flutter side
+        return null;
+      default:
+        return null;
+    }
+  }
 }