Device Orientation API on Chrome OS

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/synchronization/lock.h"
+#include "chromeos/accelerometer/accelerometer_reader.h"
+#include "content/common/content_export.h"
+#include "content/common/device_sensors/device_orientation_hardware_buffer.h"
+
+template <typename T>
+struct DefaultSingletonTraits;

[timvolodine, 2015/01/21 13:16:57]

is this needed?

[jonross, 2015/01/21 16:02:11]

Nope, missed removing it.

+
+namespace content {
+
+class SensorManagerChromeOSTest;

[timvolodine, 2015/01/21 13:16:57]

is this needed?

[jonross, 2015/01/21 16:02:11]

Done.

+
+// Observes Chrome OS accelerometer sensors, and provides updated device
+// orientation information.
+class CONTENT_EXPORT SensorManagerChromeOS

[timvolodine, 2015/01/21 13:16:57]

you could probably put this class entirely inside an anonymous namespace in
data_fetcher_shared_memory_chromeos.cc since it does not look like it needs to
be exposed anywhere else.. however I am fine if you prefer to keep it in a
separate file.

[jonross, 2015/01/21 16:02:11]

I had considered that. However keeping it separate makes testing easier. So I
plan to keep separate.

+    : public chromeos::AccelerometerReader::Observer {
+ public:
+  SensorManagerChromeOS();
+  ~SensorManagerChromeOS() override;
+
+  // Returns true if there are buffers being updated with accelerometer data.
+  bool IsFetching();
+
+  // Begins monitoring of orientation events, the shared memory of |buffer| will
+  // be updated upon subsequent events.
+  bool StartFetchingDeviceOrientationData(
+      DeviceOrientationHardwareBuffer* buffer);
+
+  // Stops monitoring orientation events. Returns true if there is an active
+  // |orientation_buffer_| and fetching stops. Otherwise returns false.
+  bool StopFetchingDeviceOrientationData();
+
+  // chromeos::AccelerometerReader::Observer:
+  void OnAccelerometerUpdated(const ui::AccelerometerUpdate& update) override;
+
+ private:
+  // Shared memory to to update.
+  DeviceOrientationHardwareBuffer* orientation_buffer_;
+
+  // Synchronize orientation_buffer_ across threads.
+  base::Lock orientation_buffer_lock_;
+
+  DISALLOW_COPY_AND_ASSIGN(SensorManagerChromeOS);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_DEVICE_SENSORS_SENSOR_MANAGER_CHROMEOS_H_