1 // Copyright 2014 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
5 #ifndef ScreenOrientationDispatcher_h
6 #define ScreenOrientationDispatcher_h
8 #include "core/frame/PlatformEventDispatcher.h"
9 #include "platform/heap/Handle.h"
13 // ScreenOrientationDispatcher is a singleton that handles whether the current
14 // Blink instance should be listening to the screen orientation platform events.
15 // It is not a common implementation of PlatformEventDispatcher in the sense
16 // that it doesn't actually dispatch events but simply start/stop listening. The
17 // reason being that screen orientation events are always sent to the WebFrame's
18 // but some platforms require to poll to have an accurate reporting. When
19 // ScreenOrientationDispatcher is listening, that means that the platform should
20 // be polling if required.
21 class ScreenOrientationDispatcher final : public GarbageCollectedFinalized<ScreenOrientationDispatcher>, public PlatformEventDispatcher {
22 USING_GARBAGE_COLLECTED_MIXIN(ScreenOrientationDispatcher);
24 static ScreenOrientationDispatcher& instance();
26 virtual void trace(Visitor*) override;
29 ScreenOrientationDispatcher();
31 // Inherited from PlatformEventDispatcher.
32 virtual void startListening() override;
33 virtual void stopListening() override;
38 #endif // ScreenOrientationDispatcher_h