[BUG] YouTubePlayerController emits two states PlayerState.ended

When the video ends the controller should emit PlayerState.ended value. Unfortunately, it emits it twice, not once. This is very problematic while performing actions with help of listeners.

I want to load nextTrack() on data change in the DB. When the data changes, the other listener invokes _controller.load('newVideoId') method.

late final YoutubePlayerController _controller;

  @override
  void initState() {
    super.initState();
    _controller = YoutubePlayerController(
      initialVideoId: 'initialVideoId',
    );
    _controller.addListener(() {
      if (_controller.value.playerState == PlayerState.ended) {
        nextTrack();
      }
    });
  }

  @override
  Widget build(BuildContext context) {
    return BlocListener<Cubit, State>(
      listener: (context, state) {
        final videoId = state.videoId;
        if (videoId != null) {
          _controller.load(videoId);
        }
      },
      child: ...

The nextTrack() method should be invoked once but it is not.

I handled this with throttler but it is not a very nice solution I think. Those two PlayerState.ended values are emitted in a very short period of time so this solution works.

class ThrottleFirst {
  final int milliseconds;
  Timer? _timer;

  ThrottleFirst({this.milliseconds = 1000});

  void run(VoidCallback action) {
    if (_timer != null) return;
    action();
    _timer = Timer(Duration(milliseconds: milliseconds), () {
      _timer = null;
    });
  }
}

ThrottleFirst throttler = ThrottleFirst();
 throttler.run(() => nextTrack());

Flutter doctor:

[✓] Flutter (Channel stable, 2.2.3, on macOS 11.2.3 20D91 darwin-x64, locale en-PL) • Flutter version 2.2.3 at /Users/konradbejger/Development/flutter • Framework revision f4abaa0735 (4 weeks ago), 2021-07-01 12:46:11 -0700 • Engine revision 241c87ad80 • Dart version 2.13.4

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sarbagyastha / youtube_player_flutter

[BUG] YouTubePlayerController emits two states PlayerState.ended #523