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