blob: 5fa7b01756a5559b6c804658c4e1f8e897399403 [file] [log] [blame]
// Copyright (c) 2015, the Dart project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.
import 'dart:async';
import '../typed/stream_subscription.dart';
/// Simple delegating wrapper around a [StreamSubscription].
/// Subclasses can override individual methods.
class DelegatingStreamSubscription<T> implements StreamSubscription<T> {
final StreamSubscription _source;
/// Create delegating subscription forwarding calls to [sourceSubscription].
DelegatingStreamSubscription(StreamSubscription<T> sourceSubscription)
: _source = sourceSubscription;
/// Creates a wrapper which throws if [subscription]'s events aren't instances
/// of `T`.
/// This soundly converts a [StreamSubscription] to a `StreamSubscription<T>`,
/// regardless of its original generic type, by asserting that its events are
/// instances of `T` whenever they're provided. If they're not, the
/// subscription throws a [CastError].
static StreamSubscription/*<T>*/ typed/*<T>*/(
StreamSubscription subscription) =>
subscription is StreamSubscription/*<T>*/
? subscription
: new TypeSafeStreamSubscription/*<T>*/(subscription);
void onData(void handleData(T data)) {
void onError(Function handleError) {
void onDone(void handleDone()) {
void pause([Future resumeFuture]) {
void resume() {
Future cancel() => _source.cancel();
Future/*<E>*/ asFuture/*<E>*/([/*=E*/ futureValue]) =>
bool get isPaused => _source.isPaused;