dart:async

Future<T>.delayed constructor

Future<T>.delayed(Duration duration, [ FutureOr<T> computation() ])

Creates a future that runs its computation after a delay.

The computation will be executed after the given duration has passed, and the future is completed with the result of the computation.

If computation returns a future, the future returned by this constructor will complete with the value or error of that future.

If the duration is 0 or less, it completes no sooner than in the next event-loop iteration, after all microtasks have run.

If computation is omitted, it will be treated as if computation was () => null, and the future will eventually complete with the null value.

If calling computation throws, the created future will complete with the error.

See also Completer for a way to create and complete a future at a later time that isn't necessarily after a known fixed duration.

Implementation

factory Future.delayed(Duration duration, [FutureOr<T> computation()]) {
  _Future<T> result = new _Future<T>();
  new Timer(duration, () {
    if (computation == null) {
      result._complete(null);
    } else {
      try {
        result._complete(computation());
      } catch (e, s) {
        _completeWithErrorCallback(result, e, s);
      }
    }
  });
  return result;
}