StreamSubscription listen()

in lib/src/subscription_stream.dart [43:60]

• 17 lines of code
• 3 McCabe index (conditional complexity)

  StreamSubscription<T> listen(void Function(T)? onData,
      {Function? onError, void Function()? onDone, bool? cancelOnError}) {
    var subscription = _source;
    if (subscription == null) {
      throw StateError('Stream has already been listened to.');
    }
    cancelOnError = (true == cancelOnError);
    _source = null;

    var result = cancelOnError
        ? _CancelOnErrorSubscriptionWrapper<T>(subscription)
        : subscription;
    result.onData(onData);
    result.onError(onError);
    result.onDone(onDone);
    subscription.resume();
    return result;
  }