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. 4 5 #ifndef ScreenOrientationDispatcher_h 6 #define ScreenOrientationDispatcher_h 7 8 #include "core/frame/PlatformEventDispatcher.h" 9 10 namespace blink { 11 12 class FrameView; 13 class ScreenOrientation; 14 15 // ScreenOrientationDispatcher is a singleton that handles whether the current 16 // Blink instance should be listening to the screen orientation platform events. 17 // It is not a common implementation of PlatformEventDispatcher in the sense 18 // that it doesn't actually dispatch events but simply start/stop listening. The 19 // reason being that screen orientation events are always sent to the WebFrame's 20 // but some platforms require to poll to have an accurate reporting. When 21 // ScreenOrientationDispatcher is listening, that means that the platform should 22 // be polling if required. 23 class ScreenOrientationDispatcher FINAL : 24 public PlatformEventDispatcher { 25 public: 26 static ScreenOrientationDispatcher& instance(); 27 28 private: 29 ScreenOrientationDispatcher(); 30 virtual ~ScreenOrientationDispatcher(); 31 32 // Inherited from PlatformEventDispatcher. 33 virtual void startListening() OVERRIDE; 34 virtual void stopListening() OVERRIDE; 35 }; 36 37 } // namespace blink 38 39 #endif // ScreenOrientationDispatcher_h 40
