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