Implement createMappedAudioSourceSource API in MethodChannelAudioPlayer

just_audio/lib/just_audio.dart

@@ -1329,6 +1329,11 @@ class AudioPlayer {
       final platform = active
           ? await (_nativePlatform = _pluginPlatform.init(InitRequest(
               id: _id,
+              getAudioSourceMessage: (id) {
+                assert(_audioSources.containsKey(id),
+                    'Audio source with ID $id does not exist!');
+                return _audioSources[id]!._toMessage();
+              },
               audioLoadConfiguration: _audioLoadConfiguration?._toMessage(),
               androidAudioEffects: (_isAndroid() || _isUnitTest())
                   ? _audioPipeline.androidAudioEffects

just_audio_platform_interface/lib/just_audio_platform_interface.dart

@@ -63,8 +63,12 @@ abstract class JustAudioPlatform extends PlatformInterface {
 /// [AudioPlayerPlatform] methods.
 abstract class AudioPlayerPlatform {
   final String id;
+  final AudioSourceMessageGetter getAudioSourceMessage;
 
-  AudioPlayerPlatform(this.id);
+  AudioPlayerPlatform(
+    this.id, {
+    this.getAudioSourceMessage = _unimplementedGetAudioServiceMessage,
+  });
 
   /// A broadcast stream of playback events.
   Stream<PlaybackEventMessage> get playbackEventMessageStream {
@@ -222,8 +226,14 @@ abstract class AudioPlayerPlatform {
     throw UnimplementedError(
         "androidEqualizerBandSetGain() has not been implemented.");
   }
+
+  static Never _unimplementedGetAudioServiceMessage(String id) =>
+      throw UnimplementedError(
+          'getAudioServiceMessage() has not been implemented.');
 }
 
+typedef AudioSourceMessageGetter = AudioSourceMessage Function(String id);
+
 /// A data update communicated from the platform implementation to the Flutter
 /// plugin. Each field should trigger a state update in the frontend plugin if
 /// and only if it is not null. Normally, the platform implementation will not
@@ -385,13 +395,15 @@ class IcyHeadersMessage {
 /// player instance.
 class InitRequest {
   final String id;
+  AudioSourceMessageGetter getAudioSourceMessage;
   final AudioLoadConfigurationMessage? audioLoadConfiguration;
   final List<AudioEffectMessage> androidAudioEffects;
   final List<AudioEffectMessage> darwinAudioEffects;
   final bool? androidOffloadSchedulingEnabled;
 
   InitRequest({
     required this.id,
+    required this.getAudioSourceMessage,
     this.audioLoadConfiguration,
     this.androidAudioEffects = const [],
     this.darwinAudioEffects = const [],

just_audio_platform_interface/lib/method_channel_just_audio.dart

@@ -11,7 +11,10 @@ class MethodChannelJustAudio extends JustAudioPlatform {
   @override
   Future<AudioPlayerPlatform> init(InitRequest request) async {
     await _mainChannel.invokeMethod<void>('init', request.toMap());
-    return MethodChannelAudioPlayer(request.id);
+    return MethodChannelAudioPlayer(
+      request.id,
+      getAudioSourceMessage: request.getAudioSourceMessage,
+    );
   }
 
   @override
@@ -35,9 +38,16 @@ class MethodChannelJustAudio extends JustAudioPlatform {
 class MethodChannelAudioPlayer extends AudioPlayerPlatform {
   final MethodChannel _channel;
 
-  MethodChannelAudioPlayer(String id)
-      : _channel = MethodChannel('com.ryanheise.just_audio.methods.$id'),
-        super(id);
+  MethodChannelAudioPlayer(
+    String id, {
+    required AudioSourceMessageGetter getAudioSourceMessage,
+  })  : _channel = MethodChannel('com.ryanheise.just_audio.methods.$id'),
+        super(
+          id,
+          getAudioSourceMessage: getAudioSourceMessage,
+        ) {
+    _channel.setMethodCallHandler(_methodCallHandler);
+  }
 
   @override
   Stream<PlaybackEventMessage> get playbackEventMessageStream =>
@@ -223,4 +233,16 @@ class MethodChannelAudioPlayer extends AudioPlayerPlatform {
         (await _channel.invokeMethod<Map<dynamic, dynamic>>(
             'androidEqualizerBandSetGain', request.toMap()))!);
   }
+
+  Future<Object?> _methodCallHandler(MethodCall call) async {
+    switch (call.method) {
+      case 'createMappedAudioSourceSource':
+        final id = (call.arguments as Map)['id'] as String;
+        final message = getAudioSourceMessage(id) as MappingAudioSourceMessage;
+        final innerMessage = await message.createAudioSourceMessage();
+        return innerMessage.toMap();
+      default:
+        throw UnimplementedError('Unimplemented method: ${call.method}');
+    }
+  }
 }

just_audio_web/lib/just_audio_web.dart

@@ -23,7 +23,10 @@ class JustAudioPlugin extends JustAudioPlatform {
           code: "error",
           message: "Platform player ${request.id} already exists");
     }
-    final player = Html5AudioPlayer(id: request.id);
+    final player = Html5AudioPlayer(
+      id: request.id,
+      getAudioServiceMessage: request.getAudioSourceMessage,
+    );
     players[request.id] = player;
     return player;
   }
@@ -57,7 +60,13 @@ abstract class JustAudioPlayer extends AudioPlayerPlatform {
   double _speed = 1.0;
 
   /// Creates a platform player with the given [id].
-  JustAudioPlayer({required String id}) : super(id);
+  JustAudioPlayer({
+    required String id,
+    required AudioSourceMessageGetter getAudioServiceMessage,
+  }) : super(
+          id,
+          getAudioSourceMessage: getAudioServiceMessage,
+        );
 
   @mustCallSuper
   Future<void> release() async {
@@ -108,7 +117,13 @@ class Html5AudioPlayer extends JustAudioPlayer {
   final Map<String, AudioSourcePlayer> _audioSourcePlayers = {};
 
   /// Creates an [Html5AudioPlayer] with the given [id].
-  Html5AudioPlayer({required String id}) : super(id: id) {
+  Html5AudioPlayer(
+      {required String id,
+      required AudioSourceMessageGetter getAudioServiceMessage})
+      : super(
+          id: id,
+          getAudioServiceMessage: getAudioServiceMessage,
+        ) {
     _audioElement.addEventListener('durationchange', (event) {
       _durationCompleter?.complete();
       broadcastPlaybackEvent();