DeviceOrientation API on ChromeOS

content/browser/device_sensors/sensor_manager_chromeos.h

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CONTENT_BROWSER_DEVICE_SENSORS_SENSOR_MANAGER_CHROMEOS_H_
+#define CONTENT_BROWSER_DEVICE_SENSORS_SENSOR_MANAGER_CHROMEOS_H_
+
+#include "base/macros.h"
+#include "base/memory/ref_counted.h"
+#include "base/synchronization/lock.h"
+#include "content/common/content_export.h"
+#include "content/common/device_sensors/device_orientation_hardware_buffer.h"
+
+template <typename T>
+struct DefaultSingletonTraits;
+
+namespace content {
+
+class SensorManagerChromeOSTest;
+
+// Notifies Chrome OS sensors to start and stop observing accelerometer sensors.
+// Provides a callback, which interprets accelerometer data for
+// Device Orientation events.
+class CONTENT_EXPORT SensorManagerChromeOS
+    : public base::RefCountedThreadSafe<SensorManagerChromeOS> {
+ public:
+  // Retrieves the singleton instance.
+  static SensorManagerChromeOS* GetInstance();
+
+  // Begins monitoring of orientation events, the shared memory of |buffer| will
+  // be updated upon subsequent events.
+  bool StartFetchingDeviceOrientationData(
+      DeviceOrientationHardwareBuffer* buffer);
+
+  // Stops monitoring orientation events.
+  void StopFetchingDeviceOrientationData();
+
+ protected:
+  virtual ~SensorManagerChromeOS();
+
+ private:
+  friend class base::RefCountedThreadSafe<SensorManagerChromeOS>;
+  friend class SensorManagerChromeOSTest;
+  friend struct DefaultSingletonTraits<SensorManagerChromeOS>;
+
+  // Shared memory to to update.
+  DeviceOrientationHardwareBuffer* orientation_buffer_;
+
+  // Synchronize orientation_buffer_ across threads.
+  base::Lock orientation_buffer_lock_;
+
+  // Thread safe tracking of callback for Chrome OS sensors.
+  scoped_refptr<SensorManagerChromeOS> callback_ref_;
+
+  SensorManagerChromeOS();
+
+  // Callback that receives accelerometer events. These events are interpreted
+  // into orientation events.
+  void OnAccelerationIncludingGravity(double x, double y, double z);
+
+  DISALLOW_COPY_AND_ASSIGN(SensorManagerChromeOS);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_DEVICE_SENSORS_SENSOR_MANAGER_CHROMEOS_H_