SystemMonitor refactoring: move power state monitor into a separate class called PowerMonitor

base/system_monitor/system_monitor_win.cc

-// Copyright (c) 2011 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.
-
-#include "base/system_monitor/system_monitor.h"
-
-#include "base/win/wrapped_window_proc.h"
-
-namespace base {
-
-namespace {
-
-const wchar_t kWindowClassName[] = L"Base_PowerMessageWindow";
-
-}  // namespace
-
-// Function to query the system to see if it is currently running on
-// battery power.  Returns true if running on battery.
-bool SystemMonitor::IsBatteryPower() {
-  SYSTEM_POWER_STATUS status;
-  if (!GetSystemPowerStatus(&status)) {
-    DLOG_GETLASTERROR(ERROR) << "GetSystemPowerStatus failed";
-    return false;
-  }
-  return (status.ACLineStatus == 0);
-}
-
-SystemMonitor::PowerMessageWindow::PowerMessageWindow()
-    : instance_(NULL), message_hwnd_(NULL) {
-  WNDCLASSEX window_class;
-  base::win::InitializeWindowClass(
-      kWindowClassName,
-      &base::win::WrappedWindowProc<
-          SystemMonitor::PowerMessageWindow::WndProcThunk>,
-      0, 0, 0, NULL, NULL, NULL, NULL, NULL,
-      &window_class);
-  instance_ = window_class.hInstance;
-  ATOM clazz = RegisterClassEx(&window_class);
-  DCHECK(clazz);
-
-  message_hwnd_ = CreateWindowEx(WS_EX_NOACTIVATE, kWindowClassName,
-      NULL, WS_POPUP, 0, 0, 0, 0, NULL, NULL, instance_, NULL);
-  SetWindowLongPtr(message_hwnd_, GWLP_USERDATA,
-                   reinterpret_cast<LONG_PTR>(this));
-}
-
-SystemMonitor::PowerMessageWindow::~PowerMessageWindow() {
-  if (message_hwnd_) {
-    DestroyWindow(message_hwnd_);
-    UnregisterClass(kWindowClassName, instance_);
-  }
-}
-
-void SystemMonitor::PowerMessageWindow::ProcessWmPowerBroadcastMessage(
-    int event_id) {
-  SystemMonitor::PowerEvent power_event;
-  switch (event_id) {
-    case PBT_APMPOWERSTATUSCHANGE:  // The power status changed.
-      power_event = SystemMonitor::POWER_STATE_EVENT;
-      break;
-    case PBT_APMRESUMEAUTOMATIC:  // Resume from suspend.
-    //case PBT_APMRESUMESUSPEND:  // User-initiated resume from suspend.
-                                  // We don't notify for this latter event
-                                  // because if it occurs it is always sent as a
-                                  // second event after PBT_APMRESUMEAUTOMATIC.
-      power_event = SystemMonitor::RESUME_EVENT;
-      break;
-    case PBT_APMSUSPEND:  // System has been suspended.
-      power_event = SystemMonitor::SUSPEND_EVENT;
-      break;
-    default:
-      return;
-
-    // Other Power Events:
-    // PBT_APMBATTERYLOW - removed in Vista.
-    // PBT_APMOEMEVENT - removed in Vista.
-    // PBT_APMQUERYSUSPEND - removed in Vista.
-    // PBT_APMQUERYSUSPENDFAILED - removed in Vista.
-    // PBT_APMRESUMECRITICAL - removed in Vista.
-    // PBT_POWERSETTINGCHANGE - user changed the power settings.
-  }
-
-  SystemMonitor::Get()->ProcessPowerMessage(power_event);
-}
-
-LRESULT CALLBACK SystemMonitor::PowerMessageWindow::WndProc(
-    HWND hwnd, UINT message, WPARAM wparam, LPARAM lparam) {
-  switch (message) {
-    case WM_POWERBROADCAST: {
-      DWORD power_event = static_cast<DWORD>(message);
-      ProcessWmPowerBroadcastMessage(power_event);
-      return TRUE;
-    }
-    default:
-      break;
-  }
-  return ::DefWindowProc(hwnd, message, wparam, lparam);
-}
-
-// static
-LRESULT CALLBACK SystemMonitor::PowerMessageWindow::WndProcThunk(
-    HWND hwnd, UINT message, WPARAM wparam, LPARAM lparam) {
-  SystemMonitor::PowerMessageWindow* message_hwnd =
-      reinterpret_cast<SystemMonitor::PowerMessageWindow*>(
-          GetWindowLongPtr(hwnd, GWLP_USERDATA));
-  if (message_hwnd)
-    return message_hwnd->WndProc(hwnd, message, wparam, lparam);
-  return ::DefWindowProc(hwnd, message, wparam, lparam);
-}
-
-}  // namespace base