update media notification when toggling track favorite status

- fixes #989

lib/services/favorite_provider.dart

@@ -1,3 +1,5 @@
+import 'package:finamp/services/music_player_background_task.dart';
+import 'package:finamp/services/queue_service.dart';
 import 'package:flutter_gen/gen_l10n/app_localizations.dart';
 import 'package:flutter_vibrate/flutter_vibrate.dart';
 import 'package:get_it/get_it.dart';
@@ -77,6 +79,8 @@ class IsFavorite extends _$IsFavorite {
     assert(value.item != null);
     final isOffline = FinampSettingsHelper.finampSettings.isOffline;
     final jellyfinApiHelper = GetIt.instance<JellyfinApiHelper>();
+    final audioHandler = GetIt.instance<MusicPlayerBackgroundTask>();
+    final queueService = GetIt.instance<QueueService>();
     if (isOffline) {
       FeedbackHelper.feedback(FeedbackType.error);
       GlobalSnackbar.message(
@@ -108,6 +112,10 @@ class IsFavorite extends _$IsFavorite {
       }
     });
     state = isFavorite;
+    // If the current track is the one being toggled, update the playback state (and media notification)
+    if (value.item!.id == queueService.getCurrentTrack()?.baseItem?.id) {
+      audioHandler.refreshPlaybackStateAndMediaNotification();
+    }
     return state;
   }
 

lib/services/music_player_background_task.dart

@@ -694,9 +694,7 @@ class MusicPlayerBackgroundTask extends BaseAudioHandler {
               },
             ));
           }
-          // re-trigger the playbackState update to update the notification
-          final event = _transformEvent(_player.playbackEvent);
-          return playbackState.add(event);
+          return refreshPlaybackStateAndMediaNotification();
         default:
         // NOP, handled below
       }
@@ -709,6 +707,12 @@ class MusicPlayerBackgroundTask extends BaseAudioHandler {
     return await super.customAction(name, extras);
   }
 
+  Future<void> refreshPlaybackStateAndMediaNotification() async {
+    // re-trigger the playbackState update to update the notification
+    final event = _transformEvent(_player.playbackEvent);
+    return playbackState.add(event);
+  }
+
   // triggers when skipping to specific item in android auto queue
   @override
   Future<void> skipToQueueItem(int index) async {