Move power event handling logic from ui/ to base/ on Windows

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 {
 
-void SystemMonitor::ProcessWmPowerBroadcastMessage(int event_id) {
-  PowerEvent power_event;
+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 = POWER_STATE_EVENT;
+      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 = RESUME_EVENT;
+      power_event = SystemMonitor::RESUME_EVENT;
       break;
     case PBT_APMSUSPEND:  // System has been suspended.
-      power_event = SUSPEND_EVENT;
+      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.
   }
-  ProcessPowerMessage(power_event);
+
+  SystemMonitor::Get()->ProcessPowerMessage(power_event);
 }
 
-// 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;
+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 (status.ACLineStatus == 0);
+  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