| // Copyright (c) 2009 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 APP_SYSTEM_MONITOR_H_ |
| #define APP_SYSTEM_MONITOR_H_ |
| |
| #include "build/build_config.h" |
| |
| // Windows HiRes timers drain the battery faster so we need to know the battery |
| // status. This isn't true for other platforms. |
| #if defined(OS_WIN) |
| #define ENABLE_BATTERY_MONITORING 1 |
| #else |
| #undef ENABLE_BATTERY_MONITORING |
| #endif // !OS_WIN |
| |
| #include "base/observer_list_threadsafe.h" |
| #if defined(ENABLE_BATTERY_MONITORING) |
| #include "base/timer.h" |
| #endif // defined(ENABLE_BATTERY_MONITORING) |
| |
| // Class for monitoring various system-related subsystems |
| // such as power management, network status, etc. |
| // TODO(mbelshe): Add support beyond just power management. |
| class SystemMonitor { |
| public: |
| // Create SystemMonitor. Only one SystemMonitor instance per application |
| // is allowed. |
| SystemMonitor(); |
| ~SystemMonitor(); |
| |
| // Get the application-wide SystemMonitor (if not present, returns NULL). |
| static SystemMonitor* Get(); |
| |
| // |
| // Power-related APIs |
| // |
| |
| // Is the computer currently on battery power. |
| // Can be called on any thread. |
| bool BatteryPower() const { |
| // Using a lock here is not necessary for just a bool. |
| return battery_in_use_; |
| } |
| |
| // Normalized list of power events. |
| enum PowerEvent { |
| POWER_STATE_EVENT, // The Power status of the system has changed. |
| SUSPEND_EVENT, // The system is being suspended. |
| RESUME_EVENT // The system is being resumed. |
| }; |
| |
| // Callbacks will be called on the thread which creates the SystemMonitor. |
| // During the callback, Add/RemoveObserver will block until the callbacks |
| // are finished. Observers should implement quick callback functions; if |
| // lengthy operations are needed, the observer should take care to invoke |
| // the operation on an appropriate thread. |
| class PowerObserver { |
| public: |
| // Notification of a change in power status of the computer, such |
| // as from switching between battery and A/C power. |
| virtual void OnPowerStateChange(bool on_battery_power) {} |
| |
| // Notification that the system is suspending. |
| virtual void OnSuspend() {} |
| |
| // Notification that the system is resuming. |
| virtual void OnResume() {} |
| }; |
| |
| // Add a new observer. |
| // Can be called from any thread. |
| // Must not be called from within a notification callback. |
| void AddObserver(PowerObserver* obs); |
| |
| // Remove an existing observer. |
| // Can be called from any thread. |
| // Must not be called from within a notification callback. |
| void RemoveObserver(PowerObserver* obs); |
| |
| #if defined(OS_WIN) |
| // Windows-specific handling of a WM_POWERBROADCAST message. |
| // Embedders of this API should hook their top-level window |
| // message loop and forward WM_POWERBROADCAST through this call. |
| void ProcessWmPowerBroadcastMessage(int event_id); |
| #endif |
| |
| // Cross-platform handling of a power event. |
| void ProcessPowerMessage(PowerEvent event_id); |
| |
| private: |
| // Platform-specific method to check whether the system is currently |
| // running on battery power. Returns true if running on batteries, |
| // false otherwise. |
| bool IsBatteryPower(); |
| |
| // Checks the battery status and notifies observers if the battery |
| // status has changed. |
| void BatteryCheck(); |
| |
| // Functions to trigger notifications. |
| void NotifyPowerStateChange(); |
| void NotifySuspend(); |
| void NotifyResume(); |
| |
| scoped_refptr<ObserverListThreadSafe<PowerObserver> > observer_list_; |
| bool battery_in_use_; |
| bool suspended_; |
| |
| #if defined(ENABLE_BATTERY_MONITORING) |
| base::OneShotTimer<SystemMonitor> delayed_battery_check_; |
| #endif |
| |
| DISALLOW_COPY_AND_ASSIGN(SystemMonitor); |
| }; |
| |
| #endif // APP_SYSTEM_MONITOR_H_ |