Index: tools/dom/src/Microtask.dart |
diff --git a/tools/dom/src/Microtask.dart b/tools/dom/src/Microtask.dart |
deleted file mode 100644 |
index 327ddf1df51cb71317d8bf4f0d77a6d861d961f9..0000000000000000000000000000000000000000 |
--- a/tools/dom/src/Microtask.dart |
+++ /dev/null |
@@ -1,156 +0,0 @@ |
-// Copyright (c) 2012, 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. |
- |
-part of html; |
- |
-typedef void _MicrotaskCallback(); |
- |
-/** |
- * This class attempts to invoke a callback as soon as the current event stack |
- * unwinds, but before the browser repaints. |
- */ |
-abstract class _MicrotaskScheduler { |
- bool _nextMicrotaskFrameScheduled = false; |
- final _MicrotaskCallback _callback; |
- |
- _MicrotaskScheduler(this._callback); |
- |
- /** |
- * Creates the best possible microtask scheduler for the current platform. |
- */ |
- factory _MicrotaskScheduler.best(_MicrotaskCallback callback) { |
- if (Window._supportsSetImmediate) { |
- return new _SetImmediateScheduler(callback); |
- } else if (MutationObserver.supported) { |
- return new _MutationObserverScheduler(callback); |
- } |
- return new _PostMessageScheduler(callback); |
- } |
- |
- /** |
- * Schedules a microtask callback if one has not been scheduled already. |
- */ |
- void maybeSchedule() { |
- if (this._nextMicrotaskFrameScheduled) { |
- return; |
- } |
- this._nextMicrotaskFrameScheduled = true; |
- this._schedule(); |
- } |
- |
- /** |
- * Does the actual scheduling of the callback. |
- */ |
- void _schedule(); |
- |
- /** |
- * Handles the microtask callback and forwards it if necessary. |
- */ |
- void _onCallback() { |
- // Ignore spurious messages. |
- if (!_nextMicrotaskFrameScheduled) { |
- return; |
- } |
- _nextMicrotaskFrameScheduled = false; |
- this._callback(); |
- } |
-} |
- |
-/** |
- * Scheduler which uses window.postMessage to schedule events. |
- */ |
-class _PostMessageScheduler extends _MicrotaskScheduler { |
- final _MICROTASK_MESSAGE = "DART-MICROTASK"; |
- |
- _PostMessageScheduler(_MicrotaskCallback callback): super(callback) { |
- // Messages from other windows do not cause a security risk as |
- // all we care about is that _handleMessage is called |
- // after the current event loop is unwound and calling the function is |
- // a noop when zero requests are pending. |
- window.onMessage.listen(this._handleMessage); |
- } |
- |
- void _schedule() { |
- window.postMessage(_MICROTASK_MESSAGE, "*"); |
- } |
- |
- void _handleMessage(e) { |
- this._onCallback(); |
- } |
-} |
- |
-/** |
- * Scheduler which uses a MutationObserver to schedule events. |
- */ |
-class _MutationObserverScheduler extends _MicrotaskScheduler { |
- MutationObserver _observer; |
- Element _dummy; |
- |
- _MutationObserverScheduler(_MicrotaskCallback callback): super(callback) { |
- // Mutation events get fired as soon as the current event stack is unwound |
- // so we just make a dummy event and listen for that. |
- _observer = new MutationObserver(this._handleMutation); |
- _dummy = new DivElement(); |
- _observer.observe(_dummy, attributes: true); |
- } |
- |
- void _schedule() { |
- // Toggle it to trigger the mutation event. |
- _dummy.hidden = !_dummy.hidden; |
- } |
- |
- _handleMutation(List<MutationRecord> mutations, MutationObserver observer) { |
- this._onCallback(); |
- } |
-} |
- |
-/** |
- * Scheduler which uses window.setImmediate to schedule events. |
- */ |
-class _SetImmediateScheduler extends _MicrotaskScheduler { |
- _SetImmediateScheduler(_MicrotaskCallback callback): super(callback); |
- |
- void _schedule() { |
- window._setImmediate(_handleImmediate); |
- } |
- |
- void _handleImmediate() { |
- this._onCallback(); |
- } |
-} |
- |
-List<TimeoutHandler> _pendingMicrotasks; |
-_MicrotaskScheduler _microtaskScheduler = null; |
- |
-void _maybeScheduleMicrotaskFrame() { |
- if (_microtaskScheduler == null) { |
- _microtaskScheduler = |
- new _MicrotaskScheduler.best(_completeMicrotasks); |
- } |
- _microtaskScheduler.maybeSchedule(); |
-} |
- |
-/** |
- * Registers a [callback] which is called after the current execution stack |
- * unwinds. |
- */ |
-void _addMicrotaskCallback(TimeoutHandler callback) { |
- if (_pendingMicrotasks == null) { |
- _pendingMicrotasks = <TimeoutHandler>[]; |
- _maybeScheduleMicrotaskFrame(); |
- } |
- _pendingMicrotasks.add(callback); |
-} |
- |
- |
-/** |
- * Complete all pending microtasks. |
- */ |
-void _completeMicrotasks() { |
- var callbacks = _pendingMicrotasks; |
- _pendingMicrotasks = null; |
- for (var callback in callbacks) { |
- callback(); |
- } |
-} |