base/power_monitor/power_monitor_device_source.h

   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/basictypes.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
  15 #if defined(OS_WIN)
  16 #include <windows.h>
  17
  18 // Windows HiRes timers drain the battery faster so we need to know the battery
  19 // status.  This isn't true for other platforms.
  20 #define ENABLE_BATTERY_MONITORING 1
  21 #else
  22 #undef ENABLE_BATTERY_MONITORING
  23 #endif  // !OS_WIN
  24
  25 #if defined(ENABLE_BATTERY_MONITORING)
  26 #include "base/timer/timer.h"
  27 #endif  // defined(ENABLE_BATTERY_MONITORING)
  28
  29 #if defined(OS_IOS)
  30 #include <objc/runtime.h>
  31 #endif  // OS_IOS
  32
  33 namespace base {
  34
  35 // A class used to monitor the power state change and notify the observers about
  36 // the change event.
  37 class BASE_EXPORT PowerMonitorDeviceSource : public PowerMonitorSource {
  38  public:
  39   PowerMonitorDeviceSource();
  40   virtual ~PowerMonitorDeviceSource();
  41
  42 #if defined(OS_MACOSX)
  43   // Allocate system resources needed by the PowerMonitor class.
  44   //
  45   // This function must be called before instantiating an instance of the class
  46   // and before the Sandbox is initialized.
  47 #if !defined(OS_IOS)
  48   static void AllocateSystemIOPorts();
  49 #else
  50   static void AllocateSystemIOPorts() {}
  51 #endif  // OS_IOS
  52 #endif  // OS_MACOSX
  53
  54  private:
  55 #if defined(OS_WIN)
  56   // Represents a message-only window for power message handling on Windows.
  57   // Only allow PowerMonitor to create it.
  58   class PowerMessageWindow {
  59    public:
  60     PowerMessageWindow();
  61     ~PowerMessageWindow();
  62
  63    private:
  64     static LRESULT CALLBACK WndProcThunk(HWND hwnd,
  65                                          UINT message,
  66                                          WPARAM wparam,
  67                                          LPARAM lparam);
  68     // Instance of the module containing the window procedure.
  69     HMODULE instance_;
  70     // A hidden message-only window.
  71     HWND message_hwnd_;
  72   };
  73 #endif  // OS_WIN
  74
  75 #if defined(OS_MACOSX)
  76   void PlatformInit();
  77   void PlatformDestroy();
  78 #endif
  79
  80   // Platform-specific method to check whether the system is currently
  81   // running on battery power.  Returns true if running on batteries,
  82   // false otherwise.
  83   virtual bool IsOnBatteryPowerImpl() OVERRIDE;
  84
  85   // Checks the battery status and notifies observers if the battery
  86   // status has changed.
  87   void BatteryCheck();
  88
  89 #if defined(OS_IOS)
  90   // Holds pointers to system event notification observers.
  91   std::vector<id> notification_observers_;
  92 #endif
  93
  94 #if defined(ENABLE_BATTERY_MONITORING)
  95   base::OneShotTimer<PowerMonitorDeviceSource> delayed_battery_check_;
  96 #endif
  97
  98 #if defined(OS_WIN)
  99   PowerMessageWindow power_message_window_;
 100 #endif
 101
 102   DISALLOW_COPY_AND_ASSIGN(PowerMonitorDeviceSource);
 103 };
 104
 105 }  // namespace base
 106
 107 #endif  // BASE_POWER_MONITOR_POWER_MONITOR_DEVICE_SOURCE_H_