Update just_audio dart code to use platform interface.

just_audio/example/pubspec.lock

@@ -113,7 +113,14 @@ packages:
       path: ".."
       relative: true
     source: path
-    version: "0.4.4"
+    version: "0.4.5"
+  just_audio_platform_interface:
+    dependency: transitive
+    description:
+      path: "../../just_audio_platform_interface"
+      relative: true
+    source: path
+    version: "0.0.1"
   matcher:
     dependency: transitive
     description:

just_audio/lib/just_audio.dart

@@ -6,6 +6,7 @@ import 'package:audio_session/audio_session.dart';
 import 'package:flutter/foundation.dart';
 import 'package:flutter/services.dart';
 import 'package:flutter/widgets.dart';
+import 'package:just_audio_platform_interface/just_audio_platform_interface.dart';
 import 'package:path/path.dart' as p;
 import 'package:path_provider/path_provider.dart';
 import 'package:rxdart/rxdart.dart';
@@ -32,22 +33,17 @@ final _uuid = Uuid();
 /// You must call [dispose] to release the resources used by this player,
 /// including any temporary files created to cache assets.
 class AudioPlayer {
-  static final _mainChannel = MethodChannel('com.ryanheise.just_audio.methods');
+  static Future<AudioPlayerPlatform> _init(String id) async {
-
+    return await JustAudioPlatform.instance.init(InitRequest(id: id));
-  static Future<MethodChannel> _init(String id) async {
-    await _mainChannel.invokeMethod('init', [id]);
-    return MethodChannel('com.ryanheise.just_audio.methods.$id');
   }
 
-  final Future<MethodChannel> _channel;
+  final Future<AudioPlayerPlatform> _platform;
   final String _id;
   _ProxyHttpServer _proxy;
-  Stream<PlaybackEvent> _eventChannelStream;
   AudioSource _audioSource;
   Map<String, AudioSource> _audioSources = {};
 
   PlaybackEvent _playbackEvent;
-  StreamSubscription<PlaybackEvent> _eventChannelStreamSubscription;
   final _playbackEventSubject = BehaviorSubject<PlaybackEvent>();
   Future<Duration> _durationFuture;
   final _durationSubject = BehaviorSubject<Duration>();
@@ -78,7 +74,7 @@ class AudioPlayer {
       AudioPlayer._internal(_uuid.v4(), handleInterruptions);
 
   AudioPlayer._internal(this._id, bool handleInterruptions)
-      : _channel = _init(_id) {
+      : _platform = _init(_id) {
     _playbackEvent = PlaybackEvent(
       processingState: ProcessingState.none,
       updatePosition: Duration.zero,
@@ -90,38 +86,6 @@ class AudioPlayer {
       androidAudioSessionId: null,
     );
     _playbackEventSubject.add(_playbackEvent);
-    _eventChannelStream = EventChannel('com.ryanheise.just_audio.events.$_id')
-        .receiveBroadcastStream()
-        .map((data) {
-      try {
-        //print("received raw event: $data");
-        final duration = (data['duration'] ?? -1) < 0
-            ? null
-            : Duration(milliseconds: data['duration']);
-        _durationFuture = Future.value(duration);
-        if (duration != _playbackEvent.duration) {
-          _durationSubject.add(duration);
-        }
-        _playbackEvent = PlaybackEvent(
-          processingState: ProcessingState.values[data['processingState']],
-          updatePosition: Duration(milliseconds: data['updatePosition']),
-          updateTime: DateTime.fromMillisecondsSinceEpoch(data['updateTime']),
-          bufferedPosition: Duration(milliseconds: data['bufferedPosition']),
-          duration: duration,
-          icyMetadata: data['icyMetadata'] == null
-              ? null
-              : IcyMetadata.fromJson(data['icyMetadata']),
-          currentIndex: data['currentIndex'],
-          androidAudioSessionId: data['androidAudioSessionId'],
-        );
-        //print("created event object with state: ${_playbackEvent.state}");
-        return _playbackEvent;
-      } catch (e, stacktrace) {
-        print("Error parsing event: $e");
-        print("$stacktrace");
-        rethrow;
-      }
-    });
     _processingStateSubject.addStream(playbackEventStream
         .map((event) => event.processingState)
         .distinct()
@@ -160,10 +124,34 @@ class AudioPlayer {
                 (playing, event) => PlayerState(playing, event.processingState))
             .distinct()
             .handleError((err, stack) {/* noop */}));
-    _eventChannelStreamSubscription = _eventChannelStream.listen(
+    _platform.then((platform) {
-      _playbackEventSubject.add,
+      platform.playbackEventMessageStream.listen((message) {
-      onError: _playbackEventSubject.addError,
+        try {
-    );
+          final playbackEvent = PlaybackEvent(
+            processingState:
+                ProcessingState.values[message.processingState.index],
+            updateTime: message.updateTime,
+            updatePosition: message.updatePosition,
+            bufferedPosition: message.bufferedPosition,
+            duration: message.duration,
+            icyMetadata: message.icyMetadata == null
+                ? null
+                : IcyMetadata._fromMessage(message.icyMetadata),
+            currentIndex: message.currentIndex,
+            androidAudioSessionId: message.androidAudioSessionId,
+          );
+          _durationFuture = Future.value(playbackEvent.duration);
+          if (playbackEvent.duration != _playbackEvent.duration) {
+            _durationSubject.add(playbackEvent.duration);
+          }
+          _playbackEventSubject.add(_playbackEvent = playbackEvent);
+        } catch (e, stacktrace) {
+          print("Error parsing event: $e");
+          print("$stacktrace");
+          rethrow;
+        }
+      }, onError: _playbackEventSubject.addError);
+    });
     _sequenceSubject.add(null);
     // Respond to changes to AndroidAudioAttributes configuration.
     AudioSession.instance.then((audioSession) {
@@ -491,8 +479,9 @@ class AudioPlayer {
         }
       }
       await source._setup(this);
-      _durationFuture = _invokeMethod('load', [source.toJson()]).then(
+      _durationFuture = (await _platform)
-          (ms) => (ms == null || ms < 0) ? null : Duration(milliseconds: ms));
+          .load(LoadRequest(audioSourceMessage: source._toMessage()))
+          .then((response) => response.duration);
       final duration = await _durationFuture;
       _durationSubject.add(duration);
       return duration;
@@ -549,7 +538,7 @@ class AudioPlayer {
     final audioSession = await AudioSession.instance;
     if (await audioSession.setActive(true)) {
       _playingSubject.add(true);
-      await _invokeMethod('play');
+      await (await _platform).play(PlayRequest());
     }
   }
 
@@ -567,7 +556,7 @@ class AudioPlayer {
     _playingSubject.add(false);
     // TODO: perhaps modify platform side to ensure new state is broadcast
     // before this method returns.
-    await _invokeMethod('pause');
+    await (await _platform).pause(PauseRequest());
   }
 
   /// Convenience method to pause and seek to zero.
@@ -579,7 +568,7 @@ class AudioPlayer {
   /// Sets the volume of this player, where 1.0 is normal volume.
   Future<void> setVolume(final double volume) async {
     _volumeSubject.add(volume);
-    await _invokeMethod('setVolume', [volume]);
+    await (await _platform).setVolume(SetVolumeRequest(volume: volume));
   }
 
   /// Sets the playback speed of this player, where 1.0 is normal speed.
@@ -590,7 +579,7 @@ class AudioPlayer {
     );
     _playbackEventSubject.add(_playbackEvent);
     _speedSubject.add(speed);
-    await _invokeMethod('setSpeed', [speed]);
+    await (await _platform).setSpeed(SetSpeedRequest(speed: speed));
   }
 
   /// Sets the [LoopMode]. The gapless looping support is as follows:
@@ -601,13 +590,16 @@ class AudioPlayer {
   /// * Web: not supported
   Future<void> setLoopMode(LoopMode mode) async {
     _loopModeSubject.add(mode);
-    await _invokeMethod('setLoopMode', [mode.index]);
+    await (await _platform).setLoopMode(
+        SetLoopModeRequest(loopMode: LoopModeMessage.values[mode.index]));
   }
 
   /// Sets whether shuffle mode is enabled.
   Future<void> setShuffleModeEnabled(bool enabled) async {
     _shuffleModeEnabledSubject.add(enabled);
-    await _invokeMethod('setShuffleModeEnabled', [enabled]);
+    await (await _platform).setShuffleMode(SetShuffleModeRequest(
+        shuffleMode:
+            enabled ? ShuffleModeMessage.all : ShuffleModeMessage.none));
   }
 
   /// Sets automaticallyWaitsToMinimizeStalling for AVPlayer in iOS 10.0 or later, defaults to true.
@@ -616,8 +608,9 @@ class AudioPlayer {
       final bool automaticallyWaitsToMinimizeStalling) async {
     _automaticallyWaitsToMinimizeStalling =
         automaticallyWaitsToMinimizeStalling;
-    await _invokeMethod('setAutomaticallyWaitsToMinimizeStalling',
+    await (await _platform).setAutomaticallyWaitsToMinimizeStalling(
-        [automaticallyWaitsToMinimizeStalling]);
+        SetAutomaticallyWaitsToMinimizeStallingRequest(
+            enabled: automaticallyWaitsToMinimizeStalling));
   }
 
   /// Seeks to a particular [position]. If a composition of multiple
@@ -635,7 +628,8 @@ class AudioPlayer {
           updateTime: DateTime.now(),
         );
         _playbackEventSubject.add(_playbackEvent);
-        await _invokeMethod('seek', [position?.inMilliseconds, index]);
+        await (await _platform)
+            .seek(SeekRequest(position: position, index: index));
     }
   }
 
@@ -658,20 +652,22 @@ class AudioPlayer {
   Future<void> setAndroidAudioAttributes(
       AndroidAudioAttributes audioAttributes) async {
     if (audioAttributes == null) return;
-    await _invokeMethod(
+    await (await _platform).setAndroidAudioAttributes(
-        'setAndroidAudioAttributes', [audioAttributes.toJson()]);
+        SetAndroidAudioAttributesRequest(
+            contentType: audioAttributes.contentType.index,
+            flags: audioAttributes.flags.value,
+            usage: audioAttributes.usage.value));
   }
 
   /// Release all resources associated with this player. You must invoke this
   /// after you are done with the player.
   Future<void> dispose() async {
-    await _invokeMethod('dispose');
+    await (await _platform).dispose(DisposeRequest());
     _audioSource = null;
     _audioSources.values.forEach((s) => s._dispose());
     _audioSources.clear();
     _proxy?.stop();
     await _durationSubject.close();
-    await _eventChannelStreamSubscription.cancel();
     await _loopModeSubject.close();
     await _shuffleModeEnabledSubject.close();
     await _playingSubject.close();
@@ -679,9 +675,6 @@ class AudioPlayer {
     await _speedSubject.close();
     await _sequenceSubject.close();
   }
-
-  Future<dynamic> _invokeMethod(String method, [dynamic args]) async =>
-      (await _channel).invokeMethod(method, args);
 }
 
 /// Captures the details of any error accessing, loading or playing an audio
@@ -829,6 +822,11 @@ class IcyInfo {
   final String title;
   final String url;
 
+  static IcyInfo _fromMessage(IcyInfoMessage message) => IcyInfo(
+        title: message.title,
+        url: message.url,
+      );
+
   IcyInfo({@required this.title, @required this.url});
 
   IcyInfo.fromJson(Map json) : this(title: json['title'], url: json['url']);
@@ -852,6 +850,15 @@ class IcyHeaders {
   final String url;
   final bool isPublic;
 
+  static IcyHeaders _fromMessage(IcyHeadersMessage message) => IcyHeaders(
+        bitrate: message.bitrate,
+        genre: message.genre,
+        name: message.name,
+        metadataInterval: message.metadataInterval,
+        url: message.url,
+        isPublic: message.isPublic,
+      );
+
   IcyHeaders({
     @required this.bitrate,
     @required this.genre,
@@ -887,6 +894,13 @@ class IcyMetadata {
   final IcyInfo info;
   final IcyHeaders headers;
 
+  static IcyMetadata _fromMessage(IcyMetadataMessage message) => IcyMetadata(
+        info: message.info == null ? null : IcyInfo._fromMessage(message.info),
+        headers: message.headers == null
+            ? null
+            : IcyHeaders._fromMessage(message.headers),
+      );
+
   IcyMetadata({@required this.info, @required this.headers});
 
   IcyMetadata.fromJson(Map json)
@@ -1109,6 +1123,8 @@ abstract class AudioSource {
     _player = null;
   }
 
+  AudioSourceMessage _toMessage();
+
   bool get _requiresHeaders;
 
   List<IndexedAudioSource> get sequence;
@@ -1205,6 +1221,10 @@ abstract class UriAudioSource extends IndexedAudioSource {
 class ProgressiveAudioSource extends UriAudioSource {
   ProgressiveAudioSource(Uri uri, {Map headers, dynamic tag})
       : super(uri, headers: headers, tag: tag, type: 'progressive');
+
+  @override
+  AudioSourceMessage _toMessage() => ProgressiveAudioSourceMessage(
+      id: _id, uri: uri.toString(), headers: headers);
 }
 
 /// An [AudioSource] representing a DASH stream. The following URI schemes are
@@ -1221,6 +1241,10 @@ class ProgressiveAudioSource extends UriAudioSource {
 class DashAudioSource extends UriAudioSource {
   DashAudioSource(Uri uri, {Map headers, dynamic tag})
       : super(uri, headers: headers, tag: tag, type: 'dash');
+
+  @override
+  AudioSourceMessage _toMessage() =>
+      DashAudioSourceMessage(id: _id, uri: uri.toString(), headers: headers);
 }
 
 /// An [AudioSource] representing an HLS stream. The following URI schemes are
@@ -1236,6 +1260,10 @@ class DashAudioSource extends UriAudioSource {
 class HlsAudioSource extends UriAudioSource {
   HlsAudioSource(Uri uri, {Map headers, dynamic tag})
       : super(uri, headers: headers, tag: tag, type: 'hls');
+
+  @override
+  AudioSourceMessage _toMessage() =>
+      HlsAudioSourceMessage(id: _id, uri: uri.toString(), headers: headers);
 }
 
 /// An [AudioSource] representing a concatenation of multiple audio sources to
@@ -1267,8 +1295,11 @@ class ConcatenatingAudioSource extends AudioSource {
     children.add(audioSource);
     _player._broadcastSequence();
     if (_player != null) {
-      await _player
+      await (await _player._platform).concatenatingInsertAll(
-          ._invokeMethod('concatenating.add', [_id, audioSource.toJson()]);
+          ConcatenatingInsertAllRequest(
+              id: _id,
+              index: children.length,
+              children: [audioSource._toMessage()]));
     }
   }
 
@@ -1277,8 +1308,9 @@ class ConcatenatingAudioSource extends AudioSource {
     children.insert(index, audioSource);
     _player._broadcastSequence();
     if (_player != null) {
-      await _player._invokeMethod(
+      await (await _player._platform).concatenatingInsertAll(
-          'concatenating.insert', [_id, index, audioSource.toJson()]);
+          ConcatenatingInsertAllRequest(
+              id: _id, index: index, children: [audioSource._toMessage()]));
     }
   }
 
@@ -1287,8 +1319,11 @@ class ConcatenatingAudioSource extends AudioSource {
     this.children.addAll(children);
     _player._broadcastSequence();
     if (_player != null) {
-      await _player._invokeMethod('concatenating.addAll',
+      await (await _player._platform).concatenatingInsertAll(
-          [_id, children.map((s) => s.toJson()).toList()]);
+          ConcatenatingInsertAllRequest(
+              id: _id,
+              index: this.children.length,
+              children: children.map((child) => child._toMessage()).toList()));
     }
   }
 
@@ -1297,8 +1332,11 @@ class ConcatenatingAudioSource extends AudioSource {
     this.children.insertAll(index, children);
     _player._broadcastSequence();
     if (_player != null) {
-      await _player._invokeMethod('concatenating.insertAll',
+      await (await _player._platform).concatenatingInsertAll(
-          [_id, index, children.map((s) => s.toJson()).toList()]);
+          ConcatenatingInsertAllRequest(
+              id: _id,
+              index: index,
+              children: children.map((child) => child._toMessage()).toList()));
     }
   }
 
@@ -1308,7 +1346,9 @@ class ConcatenatingAudioSource extends AudioSource {
     children.removeAt(index);
     _player._broadcastSequence();
     if (_player != null) {
-      await _player._invokeMethod('concatenating.removeAt', [_id, index]);
+      await (await _player._platform).concatenatingRemoveRange(
+          ConcatenatingRemoveRangeRequest(
+              id: _id, startIndex: index, endIndex: index + 1));
     }
   }
 
@@ -1318,8 +1358,9 @@ class ConcatenatingAudioSource extends AudioSource {
     children.removeRange(start, end);
     _player._broadcastSequence();
     if (_player != null) {
-      await _player
+      await (await _player._platform).concatenatingRemoveRange(
-          ._invokeMethod('concatenating.removeRange', [_id, start, end]);
+          ConcatenatingRemoveRangeRequest(
+              id: _id, startIndex: start, endIndex: end));
     }
   }
 
@@ -1328,8 +1369,9 @@ class ConcatenatingAudioSource extends AudioSource {
     children.insert(newIndex, children.removeAt(currentIndex));
     _player._broadcastSequence();
     if (_player != null) {
-      await _player
+      await (await _player._platform).concatenatingMove(
-          ._invokeMethod('concatenating.move', [_id, currentIndex, newIndex]);
+          ConcatenatingMoveRequest(
+              id: _id, currentIndex: currentIndex, newIndex: newIndex));
     }
   }
 
@@ -1338,7 +1380,9 @@ class ConcatenatingAudioSource extends AudioSource {
     children.clear();
     _player._broadcastSequence();
     if (_player != null) {
-      await _player._invokeMethod('concatenating.clear', [_id]);
+      await (await _player._platform).concatenatingRemoveRange(
+          ConcatenatingRemoveRangeRequest(
+              id: _id, startIndex: 0, endIndex: children.length));
     }
   }
 
@@ -1362,6 +1406,12 @@ class ConcatenatingAudioSource extends AudioSource {
         'audioSources': children.map((source) => source.toJson()).toList(),
         'useLazyPreparation': useLazyPreparation,
       };
+
+  @override
+  AudioSourceMessage _toMessage() => ConcatenatingAudioSourceMessage(
+      id: _id,
+      children: children.map((child) => child._toMessage()).toList(),
+      useLazyPreparation: useLazyPreparation);
 }
 
 /// An [AudioSource] that clips the audio of a [UriAudioSource] between a
@@ -1398,6 +1448,10 @@ class ClippingAudioSource extends IndexedAudioSource {
         'start': start?.inMilliseconds,
         'end': end?.inMilliseconds,
       };
+
+  @override
+  AudioSourceMessage _toMessage() => ClippingAudioSourceMessage(
+      id: _id, child: child._toMessage(), start: start, end: end);
 }
 
 // An [AudioSource] that loops a nested [AudioSource] a finite number of times.
@@ -1436,6 +1490,10 @@ class LoopingAudioSource extends AudioSource {
         'audioSource': child.toJson(),
         'count': count,
       };
+
+  @override
+  AudioSourceMessage _toMessage() => LoopingAudioSourceMessage(
+      id: _id, child: child._toMessage(), count: count);
 }
 
 enum LoopMode { off, one, all }

just_audio/pubspec.lock

@@ -100,6 +100,13 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "0.16.1"
+  just_audio_platform_interface:
+    dependency: "direct main"
+    description:
+      path: "../just_audio_platform_interface"
+      relative: true
+    source: path
+    version: "0.0.1"
   matcher:
     dependency: transitive
     description:

just_audio/pubspec.yaml

@@ -8,6 +8,8 @@ environment:
   flutter: ">=1.12.13+hotfix.5"
 
 dependencies:
+  just_audio_platform_interface:
+    path: ../just_audio_platform_interface
   audio_session: ^0.0.7
   rxdart: ^0.24.1
   path: ^1.6.4