For Freezer 0.5.2

.github/ISSUE_TEMPLATE/bug_report.md

@@ -1,13 +1,45 @@
 ---
 name: Bug report
-about: Create a report to help us improve
+about: Follow the instructions carefully on the next page.
 title: ''
 labels: 1 backlog, bug
 assignees: ryanheise
 
 ---
 
-<!--    ALL SECTIONS BELOW MUST BE COMPLETED   -->
+<!--
+
+        Note: Issues that don't follow these instructions will be closed,
+        therefore please read them carefully.
+
+        1. A bug report must demonstrate a bug in the plugin, and not merely a
+           bug in your app. Understand that this plugin WILL throw exceptions
+           or otherwise misbehave if not used in accordance with the
+           documentation. In order to verify that you have indeed found a bug,
+           you will need to make a reference to the documentation in order to
+           explain how the actual behaviour you experienced is different from
+           the behaviour that was documented. If the behaviour you want is
+           undocumented, please submit either a documentation request or a
+           feature request instead, whichever is more appropriate.
+
+        2. You must supply a link to a minimal reproduction project and explain
+           what steps I need to perform (as a user) in the app to reproduce the
+           bug. A minimal reproduction project can be created by forking this
+           project and making the minimal number of changes required to the
+           example to reproduce the bug. Do not post code directly into the bug
+           report, it must be a link to a git repo that I can clone and then
+           immediately run.
+
+        3. Leave all markdown formatting in this template intact. Do not modify
+           the section headings in any way, and insert your answers below each
+           section heading. Use code markdown (3 backticks) when inserting
+           errors and logs, not only for readability, but also to avoid issue
+           reference spamming using the # symbol.
+
+        THANK YOU :-D
+
+
+-->
 **Which API doesn't behave as documented, and how does it misbehave?**
 Name here the specific methods or fields that are not behaving as documented, and explain clearly what is happening.
 

.github/ISSUE_TEMPLATE/config.yml

@@ -1,8 +1,8 @@
 blank_issues_enabled: false
 contact_links:
-  - name: Community Support
+  - name: Stack Overflow
     url: https://stackoverflow.com/search?q=audio_service
-    about: Ask for help on Stack Overflow.
+    about: Ask here if it's not a bug report, documentation request or feature request.
-  - name: New to Flutter?
+  - name: Gitter
     url: https://gitter.im/flutter/flutter
-    about: Chat with other Flutter developers on Gitter.
+    about: Ask here if you want to have a live chat with other Flutter developers.

.github/ISSUE_TEMPLATE/documentation-request.md

@@ -1,6 +1,6 @@
 ---
 name: Documentation request
-about: Suggest an improvement to the documentation
+about: Follow the instructions carefully on the next page.
 title: ''
 labels: 1 backlog, documentation
 assignees: ryanheise
@@ -9,15 +9,19 @@ assignees: ryanheise
 
 <!--
 
-        PLEASE READ CAREFULLY!
+        Note: Issues that don't follow these instructions will be closed,
+        therefore please read them carefully.
 
+        1. This form is not intended for asking questions or asking for
+           support. For that, you are advised to ask your question on
+           StackOverflow or Gitter. Instead, this form is intended for people
+           who wish to help improve this plugin's documentation in a concrete
+           way.
 
-
+        2. To that end, it is required that you link to the specific
-
+           page/section, and quote the words that are unclear (unless you are
-
+           proposing an entirely new section), and describe how you would like
-        FOR YOUR DOCUMENTATION REQUEST TO BE PROCESSED, YOU WILL NEED
+           it to be improved.
-        TO FILL IN ALL SECTIONS BELOW. DON'T DELETE THE HEADINGS.
-
 
         THANK YOU :-D
 

.github/ISSUE_TEMPLATE/feature_request.md

@@ -1,6 +1,6 @@
 ---
 name: Feature request
-about: Suggest an idea for this project
+about: Follow the instructions carefully on the next page.
 title: ''
 labels: 1 backlog, enhancement
 assignees: ryanheise
@@ -9,15 +9,26 @@ assignees: ryanheise
 
 <!--
 
-        PLEASE READ CAREFULLY!
+        Note: Issues that don't follow these instructions will be closed,
+        therefore please read them carefully.
 
+        1. A prerequisite before requesting a feature is that you familiarise
+           yourself with the existing features by reading the API
+           documentation.
 
+        2. If it is unclear from the documentation whether an existing feature
+           is the one you want, this is a shortcoming of the documentation. In
+           this case, please submit a documentation request instead.
 
+        3. Do not use this form for asking questions. My goal is to provide
+           good documentation that answers your questions, and if the
+           documentation isn't doing its job, please submit a documentation
+           request to help me to improve it. Remember that the purpose of this
+           GitHub issues page is for plugin development and not for support
+           (community support is available via StackOverflow and Gitter).
 
-
+        4. You must complete at least the first 3 sections below. Leave the
-        FOR YOUR FEATURE REQUEST TO BE PROCESSED, YOU WILL NEED
+           section headings intact, and insert your answers below each heading.
-        TO FILL IN ALL SECTIONS BELOW. DON'T DELETE THE HEADINGS.
-
 
         THANK YOU :-D
 
@@ -26,13 +37,13 @@ assignees: ryanheise
 
 
 **Is your feature request related to a problem? Please describe.**
-A clear and concise description of what the problem is. Ex. I'm always frustrated when [...]
+<!-- A clear and concise description of what the problem is. Ex. I'm always frustrated when [...] -->
 
 **Describe the solution you'd like**
-A clear and concise description of what you want to happen.
+<!-- A clear and concise description of what you want to happen. -->
 
 **Describe alternatives you've considered**
-A clear and concise description of any alternative solutions or features you've considered.
+<!-- A clear and concise description of any alternative solutions or features you've considered. -->
 
 **Additional context**
-Add any other context or screenshots about the feature request here.
+<!-- Add any other context or screenshots about the feature request here. -->

CHANGELOG.md

@@ -1,3 +1,9 @@
+## 0.15.1
+
+* Fix loading of file:// artUri values.
+* Allow booleans/doubles in MediaItems.
+* Silently ignore duplicate onStop requests.
+
 ## 0.15.0
 
 * Web support (@keaganhilliard)

android/src/main/java/com/ryanheise/audioservice/AudioService.java

@@ -15,8 +15,6 @@ import android.graphics.BitmapFactory;
 import android.media.AudioAttributes;
 import android.media.AudioFocusRequest;
 import android.media.AudioManager;
-import android.media.MediaDescription;
-import android.media.MediaMetadata;
 import android.os.Build;
 import android.os.Bundle;
 import android.os.Handler;
@@ -29,7 +27,6 @@ import android.support.v4.media.RatingCompat;
 import android.support.v4.media.session.MediaControllerCompat;
 import android.support.v4.media.session.MediaSessionCompat;
 import android.support.v4.media.session.PlaybackStateCompat;
-import android.util.Log;
 import android.util.LruCache;
 import android.view.KeyEvent;
 
@@ -161,8 +158,13 @@ public class AudioService extends MediaBrowserServiceCompat {
 		mediaSession.setActive(false);
 		releaseWakeLock();
 		stopForeground(true);
-		notificationCreated = false;
 		stopSelf();
+		// This still does not solve the Android 11 problem.
+		// if (notificationCreated) {
+		// 	NotificationManager notificationManager = (NotificationManager)getSystemService(Context.NOTIFICATION_SERVICE);
+		// 	notificationManager.cancel(NOTIFICATION_ID);
+		// }
+		notificationCreated = false;
 	}
 
 	public static boolean isRunning() {
@@ -377,7 +379,7 @@ public class AudioService extends MediaBrowserServiceCompat {
 			wakeLock.release();
 	}
 
-	static MediaMetadataCompat createMediaMetadata(String mediaId, String album, String title, String artist, String genre, Long duration, String artUri, String displayTitle, String displaySubtitle, String displayDescription, RatingCompat rating, Map<?, ?> extras) {
+	static MediaMetadataCompat createMediaMetadata(String mediaId, String album, String title, String artist, String genre, Long duration, String artUri, Boolean playable, String displayTitle, String displaySubtitle, String displayDescription, RatingCompat rating, Map<?, ?> extras) {
 		MediaMetadataCompat.Builder builder = new MediaMetadataCompat.Builder()
 				.putString(MediaMetadataCompat.METADATA_KEY_MEDIA_ID, mediaId)
 				.putString(MediaMetadataCompat.METADATA_KEY_ALBUM, album)
@@ -402,7 +404,8 @@ public class AudioService extends MediaBrowserServiceCompat {
 				}
 			}
 		}
-
+		if (playable != null)
+			builder.putLong("playable_long", playable ? 1 : 0);
 		if (displayTitle != null)
 			builder.putString(MediaMetadataCompat.METADATA_KEY_DISPLAY_TITLE, displayTitle);
 		if (displaySubtitle != null)
@@ -422,6 +425,10 @@ public class AudioService extends MediaBrowserServiceCompat {
 					builder.putLong("extra_long_" + key, (Integer)value);
 				} else if (value instanceof String) {
 					builder.putString("extra_string_" + key, (String)value);
+				} else if (value instanceof Boolean) {
+					builder.putLong("extra_boolean_" + key, (Boolean)value ? 1 : 0);
+				} else if (value instanceof Double) {
+					builder.putString("extra_double_" + key, value.toString());
 				}
 			}
 		}
@@ -554,7 +561,6 @@ public class AudioService extends MediaBrowserServiceCompat {
 	}
 
 	public class MediaSessionCallback extends MediaSessionCompat.Callback {
-
 		@Override
 		public void onAddQueueItem(MediaDescriptionCompat description) {
 			if (listener == null) return;

android/src/main/java/com/ryanheise/audioservice/AudioServicePlugin.java

@@ -60,7 +60,6 @@ import io.flutter.embedding.engine.dart.DartExecutor;
 import io.flutter.embedding.engine.dart.DartExecutor.DartCallback;
 
 import android.content.res.AssetManager;
-import android.util.Log;
 
 import io.flutter.view.FlutterNativeView;
 import io.flutter.view.FlutterRunArguments;
@@ -997,6 +996,7 @@ public class AudioServicePlugin implements FlutterPlugin, ActivityAware {
 		raw.put("genre", metadataToString(mediaMetadata, MediaMetadataCompat.METADATA_KEY_GENRE));
 		if (mediaMetadata.containsKey(MediaMetadataCompat.METADATA_KEY_DURATION))
 			raw.put("duration", mediaMetadata.getLong(MediaMetadataCompat.METADATA_KEY_DURATION));
+		raw.put("playable", mediaMetadata.getLong("playable_long") != 0);
 		raw.put("displayTitle", metadataToString(mediaMetadata, MediaMetadataCompat.METADATA_KEY_DISPLAY_TITLE));
 		raw.put("displaySubtitle", metadataToString(mediaMetadata, MediaMetadataCompat.METADATA_KEY_DISPLAY_SUBTITLE));
 		raw.put("displayDescription", metadataToString(mediaMetadata, MediaMetadataCompat.METADATA_KEY_DISPLAY_DESCRIPTION));
@@ -1011,6 +1011,12 @@ public class AudioServicePlugin implements FlutterPlugin, ActivityAware {
 			} else if (key.startsWith("extra_string_")) {
 				String rawKey = key.substring("extra_string_".length());
 				extras.put(rawKey, mediaMetadata.getString(key));
+			} else if (key.startsWith("extra_boolean_")) {
+				String rawKey = key.substring("extra_boolean_".length());
+				extras.put(rawKey, mediaMetadata.getLong(key) != 0);
+			} else if (key.startsWith("extra_double_")) {
+				String rawKey = key.substring("extra_double_".length());
+				extras.put(rawKey, new Double(mediaMetadata.getString(key)));
 			}
 		}
 		if (extras.size() > 0) {
@@ -1028,6 +1034,7 @@ public class AudioServicePlugin implements FlutterPlugin, ActivityAware {
 				(String)rawMediaItem.get("genre"),
 				getLong(rawMediaItem.get("duration")),
 				(String)rawMediaItem.get("artUri"),
+				(Boolean)rawMediaItem.get("playable"),
 				(String)rawMediaItem.get("displayTitle"),
 				(String)rawMediaItem.get("displaySubtitle"),
 				(String)rawMediaItem.get("displayDescription"),

audio_service.iml

@@ -12,6 +12,7 @@
       <excludeFolder url="file://$MODULE_DIR$/example/build" />
     </content>
     <orderEntry type="sourceFolder" forTests="false" />
+    <orderEntry type="library" name="Dart Packages" level="project" />
     <orderEntry type="library" name="Dart SDK" level="project" />
     <orderEntry type="library" name="Flutter Plugins" level="project" />
   </component>

lib/audio_service.dart

@@ -329,8 +329,8 @@ class MediaItem {
         duration: raw['duration'] != null
             ? Duration(milliseconds: raw['duration'])
             : null,
-        playable: raw['playable']??true,
         artUri: raw['artUri'],
+        playable: raw['playable'],
         displayTitle: raw['displayTitle'],
         displaySubtitle: raw['displaySubtitle'],
         displayDescription: raw['displayDescription'],
@@ -592,6 +592,16 @@ class AudioService {
   static ReceivePort _customEventReceivePort;
   static StreamSubscription _customEventSubscription;
 
+  /// A queue of tasks to be processed serially. Tasks that are processed on
+  /// this queue:
+  ///
+  /// - [connect]
+  /// - [disconnect]
+  /// - [start]
+  ///
+  /// TODO: Queue other tasks? Note, only short-running tasks should be queued.
+  static final _asyncTaskQueue = _AsyncTaskQueue();
+
   /// Connects to the service from your UI so that audio playback can be
   /// controlled.
   ///
@@ -600,93 +610,95 @@ class AudioService {
   /// other methods in this class will work only while connected.
   ///
   /// Use [AudioServiceWidget] to handle this automatically.
-  static Future<void> connect() async {
+  static Future<void> connect() => _asyncTaskQueue.schedule(() async {
-    _channel.setMethodCallHandler((MethodCall call) async {
+        if (_connected) return;
-      switch (call.method) {
+        _channel.setMethodCallHandler((MethodCall call) async {
-        case 'onChildrenLoaded':
+          switch (call.method) {
-          final List<Map> args = List<Map>.from(call.arguments[0]);
+            case 'onChildrenLoaded':
-          _browseMediaChildren =
+              final List<Map> args = List<Map>.from(call.arguments[0]);
-              args.map((raw) => MediaItem.fromJson(raw)).toList();
+              _browseMediaChildren =
-          _browseMediaChildrenSubject.add(_browseMediaChildren);
+                  args.map((raw) => MediaItem.fromJson(raw)).toList();
-          break;
+              _browseMediaChildrenSubject.add(_browseMediaChildren);
-        case 'onPlaybackStateChanged':
+              break;
-          // If this event arrives too late, ignore it.
+            case 'onPlaybackStateChanged':
-          if (_afterStop) return;
+              // If this event arrives too late, ignore it.
-          final List args = call.arguments;
+              if (_afterStop) return;
-          int actionBits = args[2];
+              final List args = call.arguments;
-          _playbackState = PlaybackState(
+              int actionBits = args[2];
-            processingState: AudioProcessingState.values[args[0]],
+              _playbackState = PlaybackState(
-            playing: args[1],
+                processingState: AudioProcessingState.values[args[0]],
-            actions: MediaAction.values
+                playing: args[1],
-                .where((action) => (actionBits & (1 << action.index)) != 0)
+                actions: MediaAction.values
-                .toSet(),
+                    .where((action) => (actionBits & (1 << action.index)) != 0)
-            position: Duration(milliseconds: args[3]),
+                    .toSet(),
-            bufferedPosition: Duration(milliseconds: args[4]),
+                position: Duration(milliseconds: args[3]),
-            speed: args[5],
+                bufferedPosition: Duration(milliseconds: args[4]),
-            updateTime: Duration(milliseconds: args[6]),
+                speed: args[5],
-            repeatMode: AudioServiceRepeatMode.values[args[7]],
+                updateTime: Duration(milliseconds: args[6]),
-            shuffleMode: AudioServiceShuffleMode.values[args[8]],
+                repeatMode: AudioServiceRepeatMode.values[args[7]],
-          );
+                shuffleMode: AudioServiceShuffleMode.values[args[8]],
-          _playbackStateSubject.add(_playbackState);
+              );
-          break;
+              _playbackStateSubject.add(_playbackState);
-        case 'onMediaChanged':
+              break;
-          _currentMediaItem = call.arguments[0] != null
+            case 'onMediaChanged':
-              ? MediaItem.fromJson(call.arguments[0])
+              _currentMediaItem = call.arguments[0] != null
-              : null;
+                  ? MediaItem.fromJson(call.arguments[0])
-          _currentMediaItemSubject.add(_currentMediaItem);
+                  : null;
-          break;
+              _currentMediaItemSubject.add(_currentMediaItem);
-        case 'onQueueChanged':
+              break;
-          final List<Map> args = call.arguments[0] != null
+            case 'onQueueChanged':
-              ? List<Map>.from(call.arguments[0])
+              final List<Map> args = call.arguments[0] != null
-              : null;
+                  ? List<Map>.from(call.arguments[0])
-          _queue = args?.map((raw) => MediaItem.fromJson(raw))?.toList();
+                  : null;
-          _queueSubject.add(_queue);
+              _queue = args?.map((raw) => MediaItem.fromJson(raw))?.toList();
-          break;
+              _queueSubject.add(_queue);
-        case 'onStopped':
+              break;
-          _browseMediaChildren = null;
+            case 'onStopped':
-          _browseMediaChildrenSubject.add(null);
+              _browseMediaChildren = null;
-          _playbackState = null;
+              _browseMediaChildrenSubject.add(null);
-          _playbackStateSubject.add(null);
+              _playbackState = null;
-          _currentMediaItem = null;
+              _playbackStateSubject.add(null);
-          _currentMediaItemSubject.add(null);
+              _currentMediaItem = null;
-          _queue = null;
+              _currentMediaItemSubject.add(null);
-          _queueSubject.add(null);
+              _queue = null;
-          _notificationSubject.add(false);
+              _queueSubject.add(null);
-          _running = false;
+              _notificationSubject.add(false);
-          _afterStop = true;
+              _running = false;
-          break;
+              _afterStop = true;
-        case 'notificationClicked':
+              break;
-          _notificationSubject.add(call.arguments[0]);
+            case 'notificationClicked':
-          break;
+              _notificationSubject.add(call.arguments[0]);
-      }
+              break;
-    });
+          }
-    if (AudioService.usesIsolate) {
+        });
-      _customEventReceivePort = ReceivePort();
+        if (AudioService.usesIsolate) {
-      _customEventSubscription = _customEventReceivePort.listen((event) {
+          _customEventReceivePort = ReceivePort();
-        _customEventSubject.add(event);
+          _customEventSubscription = _customEventReceivePort.listen((event) {
+            _customEventSubject.add(event);
+          });
+          IsolateNameServer.removePortNameMapping(_CUSTOM_EVENT_PORT_NAME);
+          IsolateNameServer.registerPortWithName(
+              _customEventReceivePort.sendPort, _CUSTOM_EVENT_PORT_NAME);
+        }
+        await _channel.invokeMethod("connect");
+        _running = await _channel.invokeMethod("isRunning");
+        _connected = true;
       });
-      IsolateNameServer.removePortNameMapping(_CUSTOM_EVENT_PORT_NAME);
-      IsolateNameServer.registerPortWithName(
-          _customEventReceivePort.sendPort, _CUSTOM_EVENT_PORT_NAME);
-    }
-    await _channel.invokeMethod("connect");
-    _running = await _channel.invokeMethod("isRunning");
-    _connected = true;
-  }
 
   /// Disconnects your UI from the service.
   ///
   /// This method should be called when the UI is no longer visible.
   ///
   /// Use [AudioServiceWidget] to handle this automatically.
-  static Future<void> disconnect() async {
+  static Future<void> disconnect() => _asyncTaskQueue.schedule(() async {
-    _channel.setMethodCallHandler(null);
+        if (!_connected) return;
-    _customEventSubscription?.cancel();
+        _channel.setMethodCallHandler(null);
-    _customEventSubscription = null;
+        _customEventSubscription?.cancel();
-    _customEventReceivePort = null;
+        _customEventSubscription = null;
-    await _channel.invokeMethod("disconnect");
+        _customEventReceivePort = null;
-    _connected = false;
+        await _channel.invokeMethod("disconnect");
-  }
+        _connected = false;
+      });
 
   /// True if the UI is connected.
   static bool get connected => _connected;
@@ -738,6 +750,12 @@ class AudioService {
   /// Android. If your app will run on Android and has a queue, you should set
   /// this to true.
   ///
+  /// [androidStopForegroundOnPause] will switch the Android service to a lower
+  /// priority state when playback is paused allowing the user to swipe away the
+  /// notification. Note that while in this lower priority state, the operating
+  /// system will also be able to kill your service at any time to reclaim
+  /// resources.
+  ///
   /// This method waits for [BackgroundAudioTask.onStart] to complete, and
   /// completes with true if the task was successfully started, or false
   /// otherwise.
@@ -757,59 +775,62 @@ class AudioService {
     Duration fastForwardInterval = const Duration(seconds: 10),
     Duration rewindInterval = const Duration(seconds: 10),
   }) async {
-    if (_running) return false;
+    return await _asyncTaskQueue.schedule(() async {
-    _running = true;
+      if (!_connected) throw Exception("Not connected");
-    _afterStop = false;
+      if (_running) return false;
-    ui.CallbackHandle handle;
+      _running = true;
-    if (AudioService.usesIsolate) {
+      _afterStop = false;
-      handle = ui.PluginUtilities.getCallbackHandle(backgroundTaskEntrypoint);
+      ui.CallbackHandle handle;
-      if (handle == null) {
+      if (AudioService.usesIsolate) {
-        return false;
+        handle = ui.PluginUtilities.getCallbackHandle(backgroundTaskEntrypoint);
+        if (handle == null) {
+          return false;
+        }
       }
-    }
 
-    var callbackHandle = handle?.toRawHandle();
+      var callbackHandle = handle?.toRawHandle();
-    if (kIsWeb) {
+      if (kIsWeb) {
-      // Platform throws runtime exceptions on web
+        // Platform throws runtime exceptions on web
-    } else if (Platform.isIOS) {
+      } else if (Platform.isIOS) {
-      // NOTE: to maintain compatibility between the Android and iOS
+        // NOTE: to maintain compatibility between the Android and iOS
-      // implementations, we ensure that the iOS background task also runs in
+        // implementations, we ensure that the iOS background task also runs in
-      // an isolate. Currently, the standard Isolate API does not allow
+        // an isolate. Currently, the standard Isolate API does not allow
-      // isolates to invoke methods on method channels. That may be fixed in
+        // isolates to invoke methods on method channels. That may be fixed in
-      // the future, but until then, we use the flutter_isolate plugin which
+        // the future, but until then, we use the flutter_isolate plugin which
-      // creates a FlutterNativeView for us, similar to what the Android
+        // creates a FlutterNativeView for us, similar to what the Android
-      // implementation does.
+        // implementation does.
-      // TODO: remove dependency on flutter_isolate by either using the
+        // TODO: remove dependency on flutter_isolate by either using the
-      // FlutterNativeView API directly or by waiting until Flutter allows
+        // FlutterNativeView API directly or by waiting until Flutter allows
-      // regular isolates to use method channels.
+        // regular isolates to use method channels.
-      await FlutterIsolate.spawn(_iosIsolateEntrypoint, callbackHandle);
+        await FlutterIsolate.spawn(_iosIsolateEntrypoint, callbackHandle);
-    }
+      }
-    final success = await _channel.invokeMethod('start', {
+      final success = await _channel.invokeMethod('start', {
-      'callbackHandle': callbackHandle,
+        'callbackHandle': callbackHandle,
-      'params': params,
+        'params': params,
-      'androidNotificationChannelName': androidNotificationChannelName,
+        'androidNotificationChannelName': androidNotificationChannelName,
-      'androidNotificationChannelDescription':
+        'androidNotificationChannelDescription':
-          androidNotificationChannelDescription,
+            androidNotificationChannelDescription,
-      'androidNotificationColor': androidNotificationColor,
+        'androidNotificationColor': androidNotificationColor,
-      'androidNotificationIcon': androidNotificationIcon,
+        'androidNotificationIcon': androidNotificationIcon,
-      'androidNotificationClickStartsActivity':
+        'androidNotificationClickStartsActivity':
-          androidNotificationClickStartsActivity,
+            androidNotificationClickStartsActivity,
-      'androidNotificationOngoing': androidNotificationOngoing,
+        'androidNotificationOngoing': androidNotificationOngoing,
-      'androidResumeOnClick': androidResumeOnClick,
+        'androidResumeOnClick': androidResumeOnClick,
-      'androidStopForegroundOnPause': androidStopForegroundOnPause,
+        'androidStopForegroundOnPause': androidStopForegroundOnPause,
-      'androidEnableQueue': androidEnableQueue,
+        'androidEnableQueue': androidEnableQueue,
-      'androidArtDownscaleSize': androidArtDownscaleSize != null
+        'androidArtDownscaleSize': androidArtDownscaleSize != null
-          ? {
+            ? {
-              'width': androidArtDownscaleSize.width,
+                'width': androidArtDownscaleSize.width,
-              'height': androidArtDownscaleSize.height
+                'height': androidArtDownscaleSize.height
-            }
+              }
-          : null,
+            : null,
-      'fastForwardInterval': fastForwardInterval.inMilliseconds,
+        'fastForwardInterval': fastForwardInterval.inMilliseconds,
-      'rewindInterval': rewindInterval.inMilliseconds,
+        'rewindInterval': rewindInterval.inMilliseconds,
+      });
+      _running = await _channel.invokeMethod("isRunning");
+      if (!AudioService.usesIsolate) backgroundTaskEntrypoint();
+      return success;
     });
-    _running = await _channel.invokeMethod("isRunning");
-    if (!AudioService.usesIsolate) backgroundTaskEntrypoint();
-    return success;
   }
 
   /// Sets the parent of the children that [browseMediaChildrenStream] broadcasts.
@@ -1050,6 +1071,7 @@ class AudioServiceBackground {
   static List<MediaItem> _queue;
   static BaseCacheManager _cacheManager;
   static BackgroundAudioTask _task;
+  static bool _running = false;
 
   /// The current media playback state.
   ///
@@ -1075,6 +1097,7 @@ class AudioServiceBackground {
   /// any requests by the client to play, pause and otherwise control audio
   /// playback.
   static Future<void> run(BackgroundAudioTask taskBuilder()) async {
+    _running = true;
     _backgroundChannel =
         const MethodChannel('ryanheise.com/audioServiceBackground');
     WidgetsFlutterBinding.ensureInitialized();
@@ -1234,6 +1257,10 @@ class AudioServiceBackground {
 
   /// Shuts down the background audio task within the background isolate.
   static Future<void> _shutdown() async {
+    if (!_running) return;
+    // Set this to false immediately so that if duplicate shutdown requests come
+    // through, they are ignored.
+    _running = false;
     final audioSession = await AudioSession.instance;
     try {
       await audioSession.setActive(false);
@@ -1343,15 +1370,15 @@ class AudioServiceBackground {
     await _backgroundChannel.invokeMethod('setState', [
       rawControls,
       rawSystemActions,
-      processingState.index,
+      processingState?.index ?? AudioProcessingState.none.index,
-      playing,
+      playing ?? false,
-      position.inMilliseconds,
+      position?.inMilliseconds ?? 0,
-      bufferedPosition.inMilliseconds,
+      bufferedPosition?.inMilliseconds ?? 0,
-      speed,
+      speed ?? 1.0,
       updateTime?.inMilliseconds,
       androidCompactActions,
-      repeatMode.index,
+      repeatMode?.index ?? AudioServiceRepeatMode.none.index,
-      shuffleMode.index,
+      shuffleMode?.index ?? AudioServiceShuffleMode.none.index,
     ]);
   }
 
@@ -1371,19 +1398,22 @@ class AudioServiceBackground {
     _mediaItem = mediaItem;
     if (mediaItem.artUri != null) {
       // We potentially need to fetch the art.
-      final fileInfo = _cacheManager.getFileFromMemory(mediaItem.artUri);
+      String filePath = _getLocalPath(mediaItem.artUri);
-      String filePath = fileInfo?.file?.path;
       if (filePath == null) {
-        // We haven't fetched the art yet, so show the metadata now, and again
+        final fileInfo = _cacheManager.getFileFromMemory(mediaItem.artUri);
-        // after we load the art.
+        filePath = fileInfo?.file?.path;
-        await _backgroundChannel.invokeMethod(
+        if (filePath == null) {
-            'setMediaItem', mediaItem.toJson());
+          // We haven't fetched the art yet, so show the metadata now, and again
-        // Load the art
+          // after we load the art.
-        filePath = await _loadArtwork(mediaItem);
+          await _backgroundChannel.invokeMethod(
-        // If we failed to download the art, abort.
+              'setMediaItem', mediaItem.toJson());
-        if (filePath == null) return;
+          // Load the art
-        // If we've already set a new media item, cancel this request.
+          filePath = await _loadArtwork(mediaItem);
-        if (mediaItem != _mediaItem) return;
+          // If we failed to download the art, abort.
+          if (filePath == null) return;
+          // If we've already set a new media item, cancel this request.
+          if (mediaItem != _mediaItem) return;
+        }
       }
       final extras = Map.of(mediaItem.extras ?? <String, dynamic>{});
       extras['artCacheFile'] = filePath;
@@ -1406,9 +1436,9 @@ class AudioServiceBackground {
     try {
       final artUri = mediaItem.artUri;
       if (artUri != null) {
-        const prefix = 'file://';
+        String local = _getLocalPath(artUri);
-        if (artUri.toLowerCase().startsWith(prefix)) {
+        if (local != null) {
-          return artUri.substring(prefix.length);
+          return local;
         } else {
           final file = await _cacheManager.getSingleFile(mediaItem.artUri);
           return file.path;
@@ -1418,6 +1448,14 @@ class AudioServiceBackground {
     return null;
   }
 
+  static String _getLocalPath(String artUri) {
+    const prefix = "file://";
+    if (artUri.toLowerCase().startsWith(prefix)) {
+      return artUri.substring(prefix.length);
+    }
+    return null;
+  }
+
   /// Notifies clients that the child media items of [parentMediaId] have
   /// changed.
   ///
@@ -1668,7 +1706,16 @@ abstract class BackgroundAudioTask {
   Future<void> onTaskRemoved() async {}
 
   /// Called on Android when the user swipes away the notification. The default
-  /// implementation (which you may override) calls [onStop].
+  /// implementation (which you may override) calls [onStop]. Note that by
+  /// default, the service runs in the foreground state which (despite the name)
+  /// allows the service to run at a high priority in the background without the
+  /// operating system killing it. While in the foreground state, the
+  /// notification cannot be swiped away. You can pass a parameter value of
+  /// `true` for `androidStopForegroundOnPause` in the [AudioService.start]
+  /// method if you would like the service to exit the foreground state when
+  /// playback is paused. This will allow the user to swipe the notification
+  /// away while playback is paused (but it will also allow the operating system
+  /// to kill your service at any time to free up resources).
   Future<void> onClose() => onStop();
 
   void _setParams({
@@ -1686,7 +1733,8 @@ abstract class BackgroundAudioTask {
     int i = queue.indexOf(mediaItem);
     if (i == -1) return;
     int newIndex = i + offset;
-    if (newIndex < queue.length) await onSkipToQueueItem(queue[newIndex]?.id);
+    if (newIndex >= 0 && newIndex < queue.length)
+      await onSkipToQueueItem(queue[newIndex]?.id);
   }
 }
 
@@ -1763,3 +1811,37 @@ class _AudioServiceWidgetState extends State<AudioServiceWidget>
 enum AudioServiceShuffleMode { none, all, group }
 
 enum AudioServiceRepeatMode { none, one, all, group }
+
+class _AsyncTaskQueue {
+  final _queuedAsyncTaskController = StreamController<_AsyncTaskQueueEntry>();
+
+  _AsyncTaskQueue() {
+    _process();
+  }
+
+  Future<void> _process() async {
+    await for (var entry in _queuedAsyncTaskController.stream) {
+      try {
+        final result = await entry.asyncTask();
+        entry.completer.complete(result);
+      } catch (e, stacktrace) {
+        entry.completer.completeError(e, stacktrace);
+      }
+    }
+  }
+
+  Future<dynamic> schedule(_AsyncTask asyncTask) async {
+    final completer = Completer<dynamic>();
+    _queuedAsyncTaskController.add(_AsyncTaskQueueEntry(asyncTask, completer));
+    return completer.future;
+  }
+}
+
+class _AsyncTaskQueueEntry {
+  final _AsyncTask asyncTask;
+  final Completer completer;
+
+  _AsyncTaskQueueEntry(this.asyncTask, this.completer);
+}
+
+typedef _AsyncTask = Future<dynamic> Function();

pubspec.yaml

@@ -1,6 +1,6 @@
 name: audio_service
 description: Flutter plugin to play audio in the background while the screen is off.
-version: 0.15.0
+version: 0.15.1
 homepage: https://github.com/ryanheise/audio_service
 
 environment: