| // Copyright (c) 2011, 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. |
| |
| /// @assertion Stream<T> asBroadcastStream ( |
| /// {void onListen(StreamSubscription<T> subscription), |
| /// void onCancel(StreamSubscription<T> subscription)}) |
| /// Returns a multi-subscription stream that produces the same events as this. |
| /// |
| /// The returned stream will subscribe to this stream when its first subscriber |
| /// is added, and will stay subscribed until this stream ends, or a callback |
| /// cancels the subscription. |
| /// |
| /// @description Checks that the returned stream will unsubscribe from |
| /// this stream when onCancel callback cancels the subscription. |
| /// |
| /// @author a.semenov@unipro.ru |
| |
| import "dart:async"; |
| import "../../../Utils/expect.dart"; |
| |
| main() { |
| bool hasListener = false; |
| bool listenerCancelled = false; |
| StreamController controller = new StreamController( |
| onListen:() { hasListener = true;}, |
| onCancel:() { listenerCancelled = true;} |
| ); |
| Stream b = controller.stream.asBroadcastStream( |
| onCancel:(StreamSubscription subscription){ |
| subscription.cancel(); |
| } |
| ); |
| Expect.isFalse(hasListener); |
| Expect.isFalse(listenerCancelled); |
| asyncStart(); |
| var ss; |
| ss = b.listen( |
| (_) { |
| Future f = ss.cancel(); |
| if (f == null) { |
| f = new Future.value(0); |
| } |
| f.then( |
| (_) { |
| Expect.isTrue(listenerCancelled); |
| controller.close(); |
| asyncEnd(); |
| } |
| ); |
| } |
| ); |
| |
| Expect.isTrue(hasListener); |
| Expect.isFalse(listenerCancelled); |
| controller.add("a"); |
| controller.add("b"); |
| new Future(() => controller.close()); |
| } |