onRising static method

LxWorker<bool> onRising(
  1. LxReactive<bool> source,
  2. void callback(), {
  3. dynamic onProcessingError(
    1. Object error,
    2. StackTrace stackTrace
    )?,
})

Triggers callback only when source transitions from false to true.

Implementation

static LxWorker<bool> onRising(
  LxReactive<bool> source,
  void Function() callback, {
  Function(Object error, StackTrace stackTrace)? onProcessingError,
}) {
  var previous = source.value;
  return LxWorker<bool>(
    source,
    (value) {
      final didRise = !previous && value;
      previous = value;
      if (didRise) callback();
    },
    onProcessingError: onProcessingError,
  );
}