ui/base/idle/idle_win.cc

   1 // Copyright (c) 2011 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 "ui/base/idle/idle.h"
   6
   7 #include <limits.h>
   8 #include <windows.h>
   9
  10 #include "ui/base/win/lock_state.h"
  11
  12 namespace ui {
  13 namespace {
  14
  15 DWORD CalculateIdleTimeInternal() {
  16   LASTINPUTINFO last_input_info = {0};
  17   last_input_info.cbSize = sizeof(LASTINPUTINFO);
  18   DWORD current_idle_time = 0;
  19   if (::GetLastInputInfo(&last_input_info)) {
  20     DWORD now = ::GetTickCount();
  21     if (now < last_input_info.dwTime) {
  22       // GetTickCount() wraps around every 49.7 days -- assume it wrapped just
  23       // once.
  24       const DWORD kMaxDWORD = static_cast<DWORD>(-1);
  25       DWORD time_before_wrap = kMaxDWORD - last_input_info.dwTime;
  26       DWORD time_after_wrap = now;
  27       // The sum is always smaller than kMaxDWORD.
  28       current_idle_time = time_before_wrap + time_after_wrap;
  29     } else {
  30       current_idle_time = now - last_input_info.dwTime;
  31     }
  32
  33     // Convert from ms to seconds.
  34     current_idle_time /= 1000;
  35   }
  36
  37   return current_idle_time;
  38 }
  39
  40 bool IsScreensaverRunning() {
  41   DWORD result = 0;
  42   if (::SystemParametersInfo(SPI_GETSCREENSAVERRUNNING, 0, &result, 0))
  43     return result != FALSE;
  44   return false;
  45 }
  46
  47 }  // namespace
  48
  49 void CalculateIdleTime(IdleTimeCallback notify) {
  50   notify.Run(static_cast<int>(CalculateIdleTimeInternal()));
  51 }
  52
  53 bool CheckIdleStateIsLocked() {
  54   return ui::IsWorkstationLocked() || IsScreensaverRunning();
  55 }
  56
  57 }  // namespace ui