Read and expose accelerometer values from cros-ec-accel trigger.

ash/accelerometer/accelerometer_controller.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 ASH_ACCELEROMETER_ACCELEROMETER_CONTROLLER_H_
+#define ASH_ACCELEROMETER_ACCELEROMETER_CONTROLLER_H_
+
+#include "ash/ash_export.h"
+#include "base/memory/ref_counted.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/observer_list.h"
+
+#if defined(OS_CHROMEOS)
+#include "chromeos/accelerometer/accelerometer_reader.h"
+#endif
+
+namespace base {
+class TaskRunner;
+}
+
+namespace gfx {
+class Vector3dF;
+}
+
+namespace ash {
+
+class AccelerometerObserver;
+
+// This class owns the communication interface for talking to the accelerometer
+// on supporting devices. Observers will be delivered OnAccelerometerRead
+// notifications if an accelerometer was detected.
+class ASH_EXPORT AccelerometerController
+#if defined(OS_CHROMEOS)
+    : public chromeos::AccelerometerReader::Delegate {
+#else
+    {
+#endif
+ public:
+  AccelerometerController();
+  virtual ~AccelerometerController();
+
+  // Initialize the accelerometer reader.
+  void Initialize(scoped_refptr<base::TaskRunner> blocking_task_runner);
+
+  // Add/remove observer.
+  void AddObserver(AccelerometerObserver* observer);
+  void RemoveObserver(AccelerometerObserver* observer);
+
+  // chromeos::AccelerometerReader::Delegate:
+  virtual void HandleAccelerometerReading(const gfx::Vector3dF& base,
+                                          const gfx::Vector3dF& lid) OVERRIDE;
+ private:
+#if defined(OS_CHROMEOS)
+  // The AccelerometerReader which directly triggers and reads from the
+  // accelerometer device.
+  scoped_ptr<chromeos::AccelerometerReader> reader_;
+#endif
+
+  ObserverList<AccelerometerObserver, true> observers_;

[Daniel Erat, 2014/04/02 20:22:57]

cool, i'd never seen the 'check_empty' template parameter before!

+
+  DISALLOW_COPY_AND_ASSIGN(AccelerometerController);
+};
+
+}  // namespace ash
+
+#endif  // ASH_ACCELEROMETER_ACCELEROMETER_CONTROLLER_H_