content/renderer/device_sensors/device_orientation_event_pump.h

   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 CONTENT_RENDERER_DEVICE_SENSORS_DEVICE_ORIENTATION_EVENT_PUMP_H_
   6 #define CONTENT_RENDERER_DEVICE_SENSORS_DEVICE_ORIENTATION_EVENT_PUMP_H_
   7
   8 #include "base/memory/scoped_ptr.h"
   9 #include "content/renderer/device_sensors/device_sensor_event_pump.h"
  10 #include "content/renderer/shared_memory_seqlock_reader.h"
  11 #include "third_party/WebKit/public/platform/modules/device_orientation/WebDeviceOrientationData.h"
  12
  13 namespace blink {
  14 class WebDeviceOrientationListener;
  15 }
  16
  17 namespace content {
  18
  19 typedef SharedMemorySeqLockReader<blink::WebDeviceOrientationData>
  20     DeviceOrientationSharedMemoryReader;
  21
  22 class CONTENT_EXPORT DeviceOrientationEventPump
  23     : public DeviceSensorEventPump<blink::WebDeviceOrientationListener> {
  24  public:
  25   // Angle threshold beyond which two orientation events are considered
  26   // sufficiently different.
  27   static const double kOrientationThreshold;
  28
  29   explicit DeviceOrientationEventPump(RenderThread* thread);
  30   ~DeviceOrientationEventPump() override;
  31
  32   // PlatformEventObserver.
  33   bool OnControlMessageReceived(const IPC::Message& message) override;
  34   void SendFakeDataForTesting(void* data) override;
  35
  36  protected:
  37   void FireEvent() override;
  38   bool InitializeReader(base::SharedMemoryHandle handle) override;
  39
  40   // PlatformEventObserver.
  41   void SendStartMessage() override;
  42   void SendStopMessage() override;
  43
  44   bool ShouldFireEvent(const blink::WebDeviceOrientationData& data) const;
  45
  46   blink::WebDeviceOrientationData data_;
  47   scoped_ptr<DeviceOrientationSharedMemoryReader> reader_;
  48
  49   DISALLOW_COPY_AND_ASSIGN(DeviceOrientationEventPump);
  50 };
  51
  52 }  // namespace content
  53
  54 #endif  // CONTENT_RENDERER_DEVICE_SENSORS_DEVICE_ORIENTATION_EVENT_PUMP_H_