OnProgress

A Stream of callbacks

Having a callback from Flutter Sound during a playback or a recording is convenient and very simple. This guide is only because too many Flutter Sound users get problems with this very simple feature.

The Player API

Declare a subscription and listen to it

StreamSubscription? _mPlayerSubscription;
...
  await _mPlayer.openPlayer();
  _mPlayerSubscription = _mPlayer.onProgress!.listen((e) {
    setState(() {
      pos = e.position.inMilliseconds;
    });
  });

Call setSubscripionDuration. This step is very important. By default, the duration is Duration.zero which means that the feature is desactivated. Many, many Flutter Sound users forget to call this verb.
```
  await _mPlayer.setSubscriptionDuration(
    Duration(milliseconds: 100), // 100 ms
  );
```

When finished you can cancel your subscription

  if (_mPlayerSubscription != null) {
    _mPlayerSubscription!.cancel();
    _mPlayerSubscription = null;
  }

Example

A runnable example is here.

The Recorder API

Declare a subscription and listen to it

StreamSubscription? _recorderSubscription;
...
  await await _mRecorder.openRecorder();;
  _recorderSubscription = _mRecorder.onProgress!.listen((e) {
    setState(() {
      pos = e.duration.inMilliseconds;
      if (e.decibels != null) {
        dbLevel = e.decibels as double;
      }
    });
  });

Call setSubscripionDuration. This step is very important. By default, the duration is Duration.zero which means that the feature is desactivated. Many, many Flutter Sound users forget to call this verb.
```
  setState(() {});
  await _mRecorder.setSubscriptionDuration(
    Duration(milliseconds: 100), // 100 ms
  );
```

When finished you can cancel your subscription

  if (_recorderSubscription != null) {
    _recorderSubscription!.cancel();
    _recorderSubscription = null;
  }

Example

A runnable example is here.

Trouble shooting

I don’t receive any event in my stream subscription

Warning: If you don’t receive any callback in your stream, this is certainly because you forgot to call setSubscripionDuration.

On Android, the Player position restarts sometimes to 0

There is a bug inside Android. I am not sure that we can do anything for that.