content/browser/device_sensors/sensor_manager_chromeos.h

   1 // Copyright 2015 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_SENSORS_SENSOR_MANAGER_CHROMEOS_H_
   6 #define CONTENT_BROWSER_DEVICE_SENSORS_SENSOR_MANAGER_CHROMEOS_H_
   7
   8 #include "base/macros.h"
   9 #include "base/synchronization/lock.h"
  10 #include "chromeos/accelerometer/accelerometer_reader.h"
  11 #include "chromeos/accelerometer/accelerometer_types.h"
  12 #include "content/common/content_export.h"
  13 #include "content/common/device_sensors/device_orientation_hardware_buffer.h"
  14
  15 namespace content {
  16
  17 // Observes Chrome OS accelerometer sensors, and provides updated device
  18 // orientation information.
  19 class CONTENT_EXPORT SensorManagerChromeOS
  20     : public chromeos::AccelerometerReader::Observer {
  21  public:
  22   SensorManagerChromeOS();
  23   ~SensorManagerChromeOS() override;
  24
  25   // Begins monitoring of orientation events, the shared memory of |buffer| will
  26   // be updated upon subsequent events.
  27   bool StartFetchingDeviceOrientationData(
  28       DeviceOrientationHardwareBuffer* buffer);
  29
  30   // Stops monitoring orientation events. Returns true if there is an active
  31   // |orientation_buffer_| and fetching stops. Otherwise returns false.
  32   bool StopFetchingDeviceOrientationData();
  33
  34   // chromeos::AccelerometerReader::Observer:
  35   void OnAccelerometerUpdated(
  36       const chromeos::AccelerometerUpdate& update) override;
  37
  38  protected:
  39   // Begins/ends the observation of accelerometer events.
  40   virtual void StartObservingAccelerometer();
  41   virtual void StopObservingAccelerometer();
  42
  43  private:
  44   // Shared memory to update.
  45   DeviceOrientationHardwareBuffer* orientation_buffer_;
  46
  47   // Synchronize orientation_buffer_ across threads.
  48   base::Lock orientation_buffer_lock_;
  49
  50   DISALLOW_COPY_AND_ASSIGN(SensorManagerChromeOS);
  51 };
  52
  53 }  // namespace content
  54
  55 #endif  // CONTENT_BROWSER_DEVICE_SENSORS_SENSOR_MANAGER_CHROMEOS_H_