text: // 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.
  
  #include "base/power_monitor/power_monitor_source.h"
  
  #include "base/power_monitor/power_monitor.h"
  #include "build/build_config.h"
  
  namespace base {
  
  PowerMonitorSource::PowerMonitorSource() = default;
  PowerMonitorSource::~PowerMonitorSource() = default;
  
  bool PowerMonitorSource::IsOnBatteryPower() {
    AutoLock auto_lock(battery_lock_);
    return on_battery_power_;
  }
  
  void PowerMonitorSource::ProcessPowerEvent(PowerEvent event_id) {
    PowerMonitor* monitor = PowerMonitor::Get();
    if (!monitor)
      return;
  
    PowerMonitorSource* source = monitor->Source();
  
    // Suppress duplicate notifications.  Some platforms may
    // send multiple notifications of the same event.
    switch (event_id) {
      case POWER_STATE_EVENT:
        {
          bool new_on_battery_power = source->IsOnBatteryPowerImpl();
          bool changed = false;
  
          {
            AutoLock auto_lock(source->battery_lock_);
            if (source->on_battery_power_ != new_on_battery_power) {
                changed = true;
                source->on_battery_power_ = new_on_battery_power;
            }
          }
  
          if (changed)
            monitor->NotifyPowerStateChange(new_on_battery_power);
        }
        break;
      case RESUME_EVENT:
        if (source->suspended_) {
          source->suspended_ = false;
          monitor->NotifyResume();
        }
        break;
      case SUSPEND_EVENT:
        if (!source->suspended_) {
          source->suspended_ = true;
          monitor->NotifySuspend();
        }
        break;
    }
  }
  
  void PowerMonitorSource::SetInitialOnBatteryPowerState(bool on_battery_power) {
    // Must only be called before a monitor exists, otherwise the caller should
    // have just used a normal ProcessPowerEvent(POWER_STATE_EVENT) call.
    DCHECK(!PowerMonitor::Get());
    on_battery_power_ = on_battery_power;
  }
  
  }  // namespace base
  