attach method

Stream<MeteringData> attach(Stream<List<int>> dataResponse)

Attach this RxMeteringData to the Frame's dataResponse characteristic stream.

Implementation

Stream<MeteringData> attach(Stream<List<int>> dataResponse) {
  // TODO check for illegal state - attach() already called on this RxMeteringData etc?
  // might be possible though after a clean close(), do I want to prevent it?

  // the subscription to the underlying data stream
  StreamSubscription<List<int>>? dataResponseSubs;

  // Our stream controller that transforms/accumulates the raw tap events into multi-taps
  _controller = StreamController();

  _controller!.onListen = () {
    dataResponseSubs = dataResponse
      .where((data) => data[0] == meteringFlag)
      .listen((data) {
        // parse the metering data from the raw data
        _log.finer('metering data detected');
        _controller!.add(MeteringData(
          spotR: data[1],
          spotG: data[2],
          spotB: data[3],
          matrixR: data[4],
          matrixG: data[5],
          matrixB: data[6],
        ));
    }, onDone: _controller!.close, onError: _controller!.addError);
    _log.fine('MeteringDataResponse stream subscribed');
  };

  _controller!.onCancel = () {
    _log.fine('MeteringDataResponse stream unsubscribed');
    dataResponseSubs?.cancel();
    _controller!.close();
  };

  return _controller!.stream;
}