How to adjust the audio volume using the audio_service package? I don’t see any methods in the AudioHandler class that can do this.
For example, how can I adjust the volume with simple buttons on the Flutter UI, and/or change the volume gradually over say 5 seconds to fade in or out?
These operations are easy with just_audio by using the setVolume function, but I’m not sure how to integrate it with audio_service.
Here is my code for completeness.
class MyAudioHandler extends BaseAudioHandler {
final _player = AudioPlayer();
MyAudioHandler() {
_player.playbackEventStream.map(updatePlaybackState).pipe(playbackState);
}
@override
Future<void> play() async {
await _player.play();
return super.play();
}
@override
Future<void> playMediaItem(MediaItem item) async {
mediaItem.add(item);
_player.setAudioSource(AudioSource.asset(item.id));
await _player.play();
return super.playMediaItem(item);
}
@override
Future<void> stop() async {
await _player.stop();
}
PlaybackState updatePlaybackState(PlaybackEvent event) {
return PlaybackState(
processingState: const {
ProcessingState.idle: AudioProcessingState.idle,
ProcessingState.loading: AudioProcessingState.loading,
ProcessingState.buffering: AudioProcessingState.buffering,
ProcessingState.ready: AudioProcessingState.ready,
ProcessingState.completed: AudioProcessingState.completed,
}[_player.processingState]!,
playing: _player.playing,
updatePosition: _player.position,
repeatMode: AudioServiceRepeatMode.all
);
}
}
return Scaffold(
body: StreamBuilder<PlaybackState>(
stream: _audioHandler.playbackState,
builder: (context, snapshot) {
bool isPlaying = snapshot.data?.playing ?? false;
return Column(
mainAxisAlignment: MainAxisAlignment.center,
crossAxisAlignment: CrossAxisAlignment.stretch,
children: [
if (isPlaying)
ElevatedButton(
onPressed: () {
_audioHandler.stop();
},
child: Text('Stop'),
)
else ...[
ElevatedButton(
onPressed: () async {
const item = MediaItem(
title: 'Sea',
id: 'assets/audio/seaside.mp3',
);
_audioHandler.playMediaItem(item);
},
child: Text('Play Seaside'),
),
],
Row(
mainAxisAlignment: MainAxisAlignment.center,
children: [
//// HOW TO ADJUST VOLUME FROM BUTTONS???
IconButton(onPressed: () {}, icon: Icon(Icons.add)),
IconButton(onPressed: () {}, icon: Icon(Icons.remove)),
],
),
],
);
}),
);
