content/renderer/device_orientation/device_orientation_event_pump.h

   1 // Copyright 2013 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 CONTENT_RENDERER_DEVICE_ORIENTATION_EVENT_PUMP_H_
   6 #define CONTENT_RENDERER_DEVICE_ORIENTATION_EVENT_PUMP_H_
   7
   8 #include "base/memory/scoped_ptr.h"
   9 #include "content/renderer/device_orientation/device_sensor_event_pump.h"
  10 #include "content/renderer/shared_memory_seqlock_reader.h"
  11 #include "third_party/WebKit/public/platform/WebDeviceOrientationData.h"
  12
  13 namespace WebKit {
  14 class WebDeviceOrientationListener;
  15 }
  16
  17 namespace content {
  18
  19 typedef SharedMemorySeqLockReader<WebKit::WebDeviceOrientationData>
  20     DeviceOrientationSharedMemoryReader;
  21
  22 class CONTENT_EXPORT DeviceOrientationEventPump : public DeviceSensorEventPump {
  23  public:
  24   // Angle threshold beyond which two orientation events are considered
  25   // sufficiently different.
  26   static const double kOrientationThreshold;
  27
  28   DeviceOrientationEventPump();
  29   explicit DeviceOrientationEventPump(int pump_delay_millis);
  30   virtual ~DeviceOrientationEventPump();
  31
  32   // Sets the listener to receive updates for device orientation data at
  33   // regular intervals. Returns true if the registration was successful.
  34   bool SetListener(WebKit::WebDeviceOrientationListener* listener);
  35
  36   // RenderProcessObserver implementation.
  37   virtual bool OnControlMessageReceived(const IPC::Message& message) OVERRIDE;
  38
  39  protected:
  40   virtual void FireEvent() OVERRIDE;
  41   virtual bool InitializeReader(base::SharedMemoryHandle handle) OVERRIDE;
  42   virtual bool SendStartMessage() OVERRIDE;
  43   virtual bool SendStopMessage() OVERRIDE;
  44
  45   bool ShouldFireEvent(const WebKit::WebDeviceOrientationData& data) const;
  46
  47   WebKit::WebDeviceOrientationListener* listener_;
  48   WebKit::WebDeviceOrientationData data_;
  49   scoped_ptr<DeviceOrientationSharedMemoryReader> reader_;
  50 };
  51
  52 }  // namespace content
  53
  54 #endif  // CONTENT_RENDERER_DEVICE_ORIENTATION_EVENT_PUMP_H_