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      1 // Copyright 2013 The Chromium Authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style license that can be
      3 // found in the LICENSE file.
      4 
      5 #ifndef BASE_POWER_MONITOR_POWER_MONITOR_DEVICE_SOURCE_H_
      6 #define BASE_POWER_MONITOR_POWER_MONITOR_DEVICE_SOURCE_H_
      7 
      8 #include "base/base_export.h"
      9 #include "base/macros.h"
     10 #include "base/memory/ref_counted.h"
     11 #include "base/observer_list_threadsafe.h"
     12 #include "base/power_monitor/power_monitor_source.h"
     13 #include "base/power_monitor/power_observer.h"
     14 #include "build/build_config.h"
     15 
     16 #if defined(OS_WIN)
     17 #include <windows.h>
     18 
     19 // Windows HiRes timers drain the battery faster so we need to know the battery
     20 // status.  This isn't true for other platforms.
     21 #define ENABLE_BATTERY_MONITORING 1
     22 #else
     23 #undef ENABLE_BATTERY_MONITORING
     24 #endif  // !OS_WIN
     25 
     26 #if defined(ENABLE_BATTERY_MONITORING)
     27 #include "base/timer/timer.h"
     28 #endif  // defined(ENABLE_BATTERY_MONITORING)
     29 
     30 #if defined(OS_IOS)
     31 #include <objc/runtime.h>
     32 #endif  // OS_IOS
     33 
     34 namespace base {
     35 
     36 // A class used to monitor the power state change and notify the observers about
     37 // the change event.
     38 class BASE_EXPORT PowerMonitorDeviceSource : public PowerMonitorSource {
     39  public:
     40   PowerMonitorDeviceSource();
     41   ~PowerMonitorDeviceSource() override;
     42 
     43 #if defined(OS_MACOSX)
     44   // Allocate system resources needed by the PowerMonitor class.
     45   //
     46   // This function must be called before instantiating an instance of the class
     47   // and before the Sandbox is initialized.
     48 #if !defined(OS_IOS)
     49   static void AllocateSystemIOPorts();
     50 #else
     51   static void AllocateSystemIOPorts() {}
     52 #endif  // OS_IOS
     53 #endif  // OS_MACOSX
     54 
     55 #if defined(OS_CHROMEOS)
     56   // On Chrome OS, Chrome receives power-related events from powerd, the system
     57   // power daemon, via D-Bus signals received on the UI thread. base can't
     58   // directly depend on that code, so this class instead exposes static methods
     59   // so that events can be passed in.
     60   static void SetPowerSource(bool on_battery);
     61   static void HandleSystemSuspending();
     62   static void HandleSystemResumed();
     63 #endif
     64 
     65  private:
     66 #if defined(OS_WIN)
     67   // Represents a message-only window for power message handling on Windows.
     68   // Only allow PowerMonitor to create it.
     69   class PowerMessageWindow {
     70    public:
     71     PowerMessageWindow();
     72     ~PowerMessageWindow();
     73 
     74    private:
     75     static LRESULT CALLBACK WndProcThunk(HWND hwnd,
     76                                          UINT message,
     77                                          WPARAM wparam,
     78                                          LPARAM lparam);
     79     // Instance of the module containing the window procedure.
     80     HMODULE instance_;
     81     // A hidden message-only window.
     82     HWND message_hwnd_;
     83   };
     84 #endif  // OS_WIN
     85 
     86 #if defined(OS_MACOSX)
     87   void PlatformInit();
     88   void PlatformDestroy();
     89 #endif
     90 
     91   // Platform-specific method to check whether the system is currently
     92   // running on battery power.  Returns true if running on batteries,
     93   // false otherwise.
     94   bool IsOnBatteryPowerImpl() override;
     95 
     96   // Checks the battery status and notifies observers if the battery
     97   // status has changed.
     98   void BatteryCheck();
     99 
    100 #if defined(OS_IOS)
    101   // Holds pointers to system event notification observers.
    102   std::vector<id> notification_observers_;
    103 #endif
    104 
    105 #if defined(ENABLE_BATTERY_MONITORING)
    106   base::OneShotTimer delayed_battery_check_;
    107 #endif
    108 
    109 #if defined(OS_WIN)
    110   PowerMessageWindow power_message_window_;
    111 #endif
    112 
    113   DISALLOW_COPY_AND_ASSIGN(PowerMonitorDeviceSource);
    114 };
    115 
    116 }  // namespace base
    117 
    118 #endif  // BASE_POWER_MONITOR_POWER_MONITOR_DEVICE_SOURCE_H_
    119