base/power_monitor/power_monitor_device_source_win.cc

   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 #include "base/power_monitor/power_monitor.h"
   6 #include "base/power_monitor/power_monitor_device_source.h"
   7 #include "base/power_monitor/power_monitor_source.h"
   8 #include "base/win/wrapped_window_proc.h"
   9
  10 namespace base {
  11
  12 void ProcessPowerEventHelper(PowerMonitorSource::PowerEvent event) {
  13   PowerMonitorSource::ProcessPowerEvent(event);
  14 }
  15
  16 namespace {
  17
  18 const wchar_t kWindowClassName[] = L"Base_PowerMessageWindow";
  19
  20 void ProcessWmPowerBroadcastMessage(WPARAM event_id) {
  21   PowerMonitorSource::PowerEvent power_event;
  22   switch (event_id) {
  23     case PBT_APMPOWERSTATUSCHANGE:  // The power status changed.
  24       power_event = PowerMonitorSource::POWER_STATE_EVENT;
  25       break;
  26     case PBT_APMRESUMEAUTOMATIC:  // Resume from suspend.
  27       //case PBT_APMRESUMESUSPEND:  // User-initiated resume from suspend.
  28       // We don't notify for this latter event
  29       // because if it occurs it is always sent as a
  30       // second event after PBT_APMRESUMEAUTOMATIC.
  31       power_event = PowerMonitorSource::RESUME_EVENT;
  32       break;
  33     case PBT_APMSUSPEND:  // System has been suspended.
  34       power_event = PowerMonitorSource::SUSPEND_EVENT;
  35       break;
  36     default:
  37       return;
  38
  39       // Other Power Events:
  40       // PBT_APMBATTERYLOW - removed in Vista.
  41       // PBT_APMOEMEVENT - removed in Vista.
  42       // PBT_APMQUERYSUSPEND - removed in Vista.
  43       // PBT_APMQUERYSUSPENDFAILED - removed in Vista.
  44       // PBT_APMRESUMECRITICAL - removed in Vista.
  45       // PBT_POWERSETTINGCHANGE - user changed the power settings.
  46   }
  47
  48   ProcessPowerEventHelper(power_event);
  49 }
  50
  51 }  // namespace
  52
  53 // Function to query the system to see if it is currently running on
  54 // battery power.  Returns true if running on battery.
  55 bool PowerMonitorDeviceSource::IsOnBatteryPowerImpl() {
  56   SYSTEM_POWER_STATUS status;
  57   if (!GetSystemPowerStatus(&status)) {
  58     DPLOG(ERROR) << "GetSystemPowerStatus failed";
  59     return false;
  60   }
  61   return (status.ACLineStatus == 0);
  62 }
  63
  64 PowerMonitorDeviceSource::PowerMessageWindow::PowerMessageWindow()
  65     : instance_(NULL), message_hwnd_(NULL) {
  66   if (!MessageLoopForUI::IsCurrent()) {
  67     // Creating this window in (e.g.) a renderer inhibits shutdown on Windows.
  68     // See http://crbug.com/230122. TODO(vandebo): http://crbug.com/236031
  69     DLOG(ERROR)
  70         << "Cannot create windows on non-UI thread, power monitor disabled!";
  71     return;
  72   }
  73   WNDCLASSEX window_class;
  74   base::win::InitializeWindowClass(
  75       kWindowClassName,
  76       &base::win::WrappedWindowProc<
  77           PowerMonitorDeviceSource::PowerMessageWindow::WndProcThunk>,
  78       0, 0, 0, NULL, NULL, NULL, NULL, NULL,
  79       &window_class);
  80   instance_ = window_class.hInstance;
  81   ATOM clazz = RegisterClassEx(&window_class);
  82   DCHECK(clazz);
  83
  84   message_hwnd_ = CreateWindowEx(WS_EX_NOACTIVATE, kWindowClassName,
  85       NULL, WS_POPUP, 0, 0, 0, 0, NULL, NULL, instance_, NULL);
  86 }
  87
  88 PowerMonitorDeviceSource::PowerMessageWindow::~PowerMessageWindow() {
  89   if (message_hwnd_) {
  90     DestroyWindow(message_hwnd_);
  91     UnregisterClass(kWindowClassName, instance_);
  92   }
  93 }
  94
  95 // static
  96 LRESULT CALLBACK PowerMonitorDeviceSource::PowerMessageWindow::WndProcThunk(
  97     HWND hwnd,
  98     UINT message,
  99     WPARAM wparam,
 100     LPARAM lparam) {
 101   switch (message) {
 102     case WM_POWERBROADCAST:
 103       ProcessWmPowerBroadcastMessage(wparam);
 104       return TRUE;
 105     default:
 106       return ::DefWindowProc(hwnd, message, wparam, lparam);
 107   }
 108 }
 109
 110 }  // namespace base