content/browser/device_orientation/data_fetcher_impl_win.h

   1 // Copyright (c) 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_BROWSER_DEVICE_ORIENTATION_DATA_FETCHER_IMPL_WIN_H_
   6 #define CONTENT_BROWSER_DEVICE_ORIENTATION_DATA_FETCHER_IMPL_WIN_H_
   7
   8 #include <SensorsApi.h>
   9
  10 #include "base/compiler_specific.h"
  11 #include "base/memory/scoped_ptr.h"
  12 #include "base/synchronization/lock.h"
  13 #include "base/win/scoped_comptr.h"
  14 #include "content/browser/device_orientation/data_fetcher.h"
  15 #include "content/browser/device_orientation/device_data.h"
  16
  17 namespace content {
  18
  19 class Orientation;
  20
  21 // Windows implementation of DeviceOrientation API.
  22 // The SensorEventSink is installed to Windows sensor thread to listen for
  23 // sensor's data. Upon each notification, DataFetcherImplWin buffers the data.
  24 // Then Chrome sensor polling thread pulls the buffered data via GetDeviceData.
  25 // The Inclinometer 3D sensor (SENSOR_TYPE_INCLINOMETER_3D) is used to get the
  26 // orientation data.
  27
  28 class DataFetcherImplWin : public DataFetcher {
  29  public:
  30   virtual ~DataFetcherImplWin();
  31
  32   // Factory function. It returns NULL on error.
  33   // The created object listens for events for the whole lifetime.
  34   static DataFetcher* Create();
  35
  36   // Implement DataFetcher.
  37   virtual const DeviceData* GetDeviceData(DeviceData::Type type) OVERRIDE;
  38
  39  private:
  40   class SensorEventSink;
  41   friend SensorEventSink;
  42
  43   DataFetcherImplWin();
  44   bool Initialize();
  45   void OnOrientationData(Orientation* orientation);
  46   const Orientation* GetOrientation();
  47
  48   base::win::ScopedComPtr<ISensor> sensor_;
  49
  50   // Value returned by GetDeviceData.
  51   scoped_refptr<Orientation> current_orientation_;
  52
  53   // The 1-element buffer follows DataFetcherImplAndroid implementation.
  54   // It is written by OnOrientationData and read by GetDeviceData.
  55   base::Lock next_orientation_lock_;
  56   scoped_refptr<Orientation> next_orientation_;
  57
  58   DISALLOW_COPY_AND_ASSIGN(DataFetcherImplWin);
  59 };
  60
  61 }  // namespace content
  62
  63 #endif  // CONTENT_BROWSER_DEVICE_ORIENTATION_DATA_FETCHER_IMPL_WIN_H_