barrier/lib/platform/CMSWindowsScreenSaver.cpp

369 lines
9.5 KiB
C++

/*
* synergy -- mouse and keyboard sharing utility
* Copyright (C) 2002 Chris Schoeneman
*
* This package is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* found in the file COPYING that should have accompanied this file.
*
* This package is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include "CMSWindowsScreenSaver.h"
#include "CThread.h"
#include "CLog.h"
#include "TMethodJob.h"
#include "CArch.h"
#include <malloc.h>
#include <tchar.h>
#if !defined(SPI_GETSCREENSAVERRUNNING)
#define SPI_GETSCREENSAVERRUNNING 114
#endif
//
// CMSWindowsScreenSaver
//
CMSWindowsScreenSaver::CMSWindowsScreenSaver() :
m_process(NULL),
m_threadID(0),
m_watch(NULL)
{
// detect OS
m_is95Family = false;
m_is95 = false;
m_isNT = false;
OSVERSIONINFO info;
info.dwOSVersionInfoSize = sizeof(info);
if (GetVersionEx(&info)) {
m_is95Family = (info.dwPlatformId == VER_PLATFORM_WIN32_WINDOWS);
if (info.dwPlatformId == VER_PLATFORM_WIN32_NT &&
info.dwMajorVersion <= 4) {
m_isNT = true;
}
else if (info.dwPlatformId == VER_PLATFORM_WIN32_WINDOWS &&
info.dwMajorVersion == 4 &&
info.dwMinorVersion == 0) {
m_is95 = true;
}
}
// check if screen saver is enabled
SystemParametersInfo(SPI_GETSCREENSAVEACTIVE, 0, &m_wasEnabled, 0);
}
CMSWindowsScreenSaver::~CMSWindowsScreenSaver()
{
unwatchProcess();
}
bool
CMSWindowsScreenSaver::checkStarted(UINT msg, WPARAM wParam, LPARAM lParam)
{
// screen saver may have started. look for it and get
// the process. if we can't find it then assume it
// didn't really start. we wait a moment before
// looking to give the screen saver a chance to start.
// this shouldn't be a problem since we only get here
// if the screen saver wants to kick in, meaning that
// the system is idle or the user deliberately started
// the screen saver.
Sleep(250);
// set parameters common to all screen saver handling
m_threadID = GetCurrentThreadId();
m_msg = msg;
m_wParam = wParam;
m_lParam = lParam;
// we handle the screen saver differently for the windows
// 95 and nt families.
if (m_is95Family) {
// on windows 95 we wait for the screen saver process
// to terminate. get the process.
DWORD processID = findScreenSaver();
HANDLE process = OpenProcess(SYNCHRONIZE, FALSE, processID);
if (process == NULL) {
// didn't start
LOG((CLOG_DEBUG "can't open screen saver process"));
return false;
}
// watch for the process to exit
watchProcess(process);
}
else {
// on the windows nt family we wait for the desktop to
// change until it's neither the Screen-Saver desktop
// nor a desktop we can't open (the login desktop).
watchDesktop();
}
return true;
}
void
CMSWindowsScreenSaver::enable()
{
SystemParametersInfo(SPI_SETSCREENSAVEACTIVE, m_wasEnabled, 0, 0);
}
void
CMSWindowsScreenSaver::disable()
{
SystemParametersInfo(SPI_GETSCREENSAVEACTIVE, 0, &m_wasEnabled, 0);
SystemParametersInfo(SPI_SETSCREENSAVEACTIVE, FALSE, 0, 0);
}
void
CMSWindowsScreenSaver::activate()
{
// don't activate if already active
if (!isActive()) {
HWND hwnd = GetForegroundWindow();
if (hwnd != NULL) {
PostMessage(hwnd, WM_SYSCOMMAND, SC_SCREENSAVE, 0);
}
else {
// no foreground window. pretend we got the event instead.
DefWindowProc(NULL, WM_SYSCOMMAND, SC_SCREENSAVE, 0);
}
}
}
void
CMSWindowsScreenSaver::deactivate()
{
bool killed = false;
if (!m_is95Family) {
// NT runs screen saver in another desktop
HDESK desktop = OpenDesktop("Screen-saver", 0, FALSE,
DESKTOP_READOBJECTS | DESKTOP_WRITEOBJECTS);
if (desktop != NULL) {
EnumDesktopWindows(desktop,
&CMSWindowsScreenSaver::killScreenSaverFunc,
reinterpret_cast<LPARAM>(&killed));
CloseDesktop(desktop);
}
}
// if above failed or wasn't tried, try the windows 95 way
if (!killed) {
// find screen saver window and close it
HWND hwnd = FindWindow("WindowsScreenSaverClass", NULL);
if (hwnd == NULL) {
// win2k may use a different class
hwnd = FindWindow("Default Screen Saver", NULL);
}
if (hwnd != NULL) {
PostMessage(hwnd, WM_CLOSE, 0, 0);
}
}
// force timer to restart
SystemParametersInfo(SPI_GETSCREENSAVEACTIVE, 0, &m_wasEnabled, 0);
SystemParametersInfo(SPI_SETSCREENSAVEACTIVE,
!m_wasEnabled, 0, SPIF_SENDWININICHANGE);
SystemParametersInfo(SPI_SETSCREENSAVEACTIVE,
m_wasEnabled, 0, SPIF_SENDWININICHANGE);
}
bool
CMSWindowsScreenSaver::isActive() const
{
if (m_is95) {
return (FindWindow("WindowsScreenSaverClass", NULL) != NULL);
}
else if (m_isNT) {
// screen saver runs on a separate desktop
HDESK desktop = OpenDesktop("Screen-saver", 0, FALSE, MAXIMUM_ALLOWED);
if (desktop == NULL && GetLastError() != ERROR_ACCESS_DENIED) {
// desktop doesn't exist so screen saver is not running
return false;
}
// desktop exists. this should indicate that the screen saver
// is running but an OS bug can cause a valid handle to be
// returned even if the screen saver isn't running (Q230117).
// we'll try to enumerate the windows on the desktop and, if
// there are any, we assume the screen saver is running. (note
// that if we don't have permission to enumerate then we'll
// assume that the screen saver is not running.) that'd be
// easy enough except there's another OS bug (Q198590) that can
// cause EnumDesktopWindows() to enumerate the windows of
// another desktop if the requested desktop has no windows. to
// work around that we have to verify that the enumerated
// windows are, in fact, on the expected desktop.
CFindScreenSaverInfo info;
info.m_desktop = desktop;
info.m_window = NULL;
EnumDesktopWindows(desktop,
&CMSWindowsScreenSaver::findScreenSaverFunc,
reinterpret_cast<LPARAM>(&info));
// done with desktop
CloseDesktop(desktop);
// screen saver is running if a window was found
return (info.m_window != NULL);
}
else {
BOOL running;
SystemParametersInfo(SPI_GETSCREENSAVERRUNNING, 0, &running, 0);
return (running != FALSE);
}
}
BOOL CALLBACK
CMSWindowsScreenSaver::findScreenSaverFunc(HWND hwnd, LPARAM arg)
{
CFindScreenSaverInfo* info = reinterpret_cast<CFindScreenSaverInfo*>(arg);
if (info->m_desktop != NULL) {
DWORD threadID = GetWindowThreadProcessId(hwnd, NULL);
HDESK desktop = GetThreadDesktop(threadID);
if (desktop != NULL && desktop != info->m_desktop) {
// stop enumerating -- wrong desktop
return FALSE;
}
}
// found a window
info->m_window = hwnd;
// don't need to enumerate further
return FALSE;
}
BOOL CALLBACK
CMSWindowsScreenSaver::killScreenSaverFunc(HWND hwnd, LPARAM arg)
{
if (IsWindowVisible(hwnd)) {
PostMessage(hwnd, WM_CLOSE, 0, 0);
*reinterpret_cast<bool*>(arg) = true;
}
return TRUE;
}
DWORD
CMSWindowsScreenSaver::findScreenSaver()
{
// try windows 95 way
HWND hwnd = FindWindow("WindowsScreenSaverClass", NULL);
// get process ID of process that owns the window, if found
if (hwnd != NULL) {
DWORD processID;
GetWindowThreadProcessId(hwnd, &processID);
return processID;
}
// not found
return 0;
}
void
CMSWindowsScreenSaver::watchDesktop()
{
// stop watching previous process/desktop
unwatchProcess();
// watch desktop in another thread
LOG((CLOG_DEBUG "watching screen saver desktop"));
m_watch = new CThread(new TMethodJob<CMSWindowsScreenSaver>(this,
&CMSWindowsScreenSaver::watchDesktopThread));
}
void
CMSWindowsScreenSaver::watchProcess(HANDLE process)
{
// stop watching previous process/desktop
unwatchProcess();
// watch new process in another thread
if (process != NULL) {
LOG((CLOG_DEBUG "watching screen saver process"));
m_process = process;
m_watch = new CThread(new TMethodJob<CMSWindowsScreenSaver>(this,
&CMSWindowsScreenSaver::watchProcessThread));
}
}
void
CMSWindowsScreenSaver::unwatchProcess()
{
if (m_watch != NULL) {
LOG((CLOG_DEBUG "stopped watching screen saver process/desktop"));
m_watch->cancel();
m_watch->wait();
delete m_watch;
m_watch = NULL;
}
if (m_process != NULL) {
CloseHandle(m_process);
m_process = NULL;
}
}
void
CMSWindowsScreenSaver::watchDesktopThread(void*)
{
DWORD reserved = 0;
TCHAR* name = NULL;
for (;;) {
// wait a bit
ARCH->sleep(0.2);
// get current desktop
HDESK desk = OpenInputDesktop(0, FALSE, GENERIC_READ);
if (desk == NULL) {
// can't open desktop so keep waiting
continue;
}
// get current desktop name length
DWORD size;
GetUserObjectInformation(desk, UOI_NAME, NULL, 0, &size);
// allocate more space for the name, if necessary
if (size > reserved) {
reserved = size;
name = (TCHAR*)alloca(reserved + sizeof(TCHAR));
}
// get current desktop name
GetUserObjectInformation(desk, UOI_NAME, name, size, &size);
// compare name to screen saver desktop name
if (_tcsicmp(name, TEXT("Screen-saver")) == 0) {
// still the screen saver desktop so keep waiting
continue;
}
// send screen saver deactivation message
PostThreadMessage(m_threadID, m_msg, m_wParam, m_lParam);
return;
}
}
void
CMSWindowsScreenSaver::watchProcessThread(void*)
{
for (;;) {
CThread::testCancel();
if (WaitForSingleObject(m_process, 50) == WAIT_OBJECT_0) {
// process terminated
LOG((CLOG_DEBUG "screen saver died"));
// send screen saver deactivation message
PostThreadMessage(m_threadID, m_msg, m_wParam, m_lParam);
return;
}
}
}