shaka-packager/base/power_monitor/power_monitor.h

56 lines
1.5 KiB
C++

// Copyright 2013 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 BASE_POWER_MONITOR_POWER_MONITOR_H_
#define BASE_POWER_MONITOR_POWER_MONITOR_H_
#include "base/base_export.h"
#include "base/basictypes.h"
#include "base/memory/ref_counted.h"
#include "base/observer_list_threadsafe.h"
#include "base/power_monitor/power_observer.h"
namespace base {
class PowerMonitorSource;
// A class used to monitor the power state change and notify the observers about
// the change event.
class BASE_EXPORT PowerMonitor {
public:
// Takes ownership of |source|.
explicit PowerMonitor(scoped_ptr<PowerMonitorSource> source);
~PowerMonitor();
// Get the process-wide PowerMonitor (if not present, returns NULL).
static PowerMonitor* Get();
// Add and remove an observer.
// Can be called from any thread.
// Must not be called from within a notification callback.
void AddObserver(PowerObserver* observer);
void RemoveObserver(PowerObserver* observer);
// Is the computer currently on battery power.
bool IsOnBatteryPower();
private:
friend class PowerMonitorSource;
PowerMonitorSource* Source();
void NotifyPowerStateChange(bool battery_in_use);
void NotifySuspend();
void NotifyResume();
scoped_refptr<ObserverListThreadSafe<PowerObserver> > observers_;
scoped_ptr<PowerMonitorSource> source_;
DISALLOW_COPY_AND_ASSIGN(PowerMonitor);
};
} // namespace base
#endif // BASE_POWER_MONITOR_POWER_MONITOR_H_