screensaver.c

ReactOS是一些高手根据Windows XP的内核编写出的类XP。内核实现机理和API函数调用几乎相同。甚至可以兼容XP的程序。喜欢研究系统内核的人可以看一看。

/* 
 * COPYRIGHT:       See COPYING in the top level directory
 * PROJECT:         ReactOS Display Control Panel
 * FILE:            dll/cpl/desk/screensaver.c
 * PURPOSE:         Screen saver property page
 * 
 * PROGRAMMERS:     Trevor McCort ([e-mail])
 *                  Ged Murphy ([e-mail])
 */

#include "desk.h"

#define MAX_SCREENSAVERS 100

typedef struct
{
    BOOL  bIsScreenSaver; /* Is this background a wallpaper */
    TCHAR szFilename[MAX_PATH];
    TCHAR szDisplayName[256];
} ScreenSaverItem;


typedef struct _GLOBAL_DATA
{
    ScreenSaverItem ScreenSaverItems[MAX_SCREENSAVERS];
    PROCESS_INFORMATION PrevWindowPi;
    int Selection;
} GLOBAL_DATA, *PGLOBAL_DATA;


static LPTSTR
GetCurrentScreenSaverValue(LPTSTR lpValue)
{
    HKEY hKey;
    LPTSTR lpBuf = NULL;
    DWORD BufSize, Type = REG_SZ;
    LONG Ret;

    Ret = RegOpenKeyEx(HKEY_CURRENT_USER,
                       _T("Control Panel\\Desktop"),
                       0,
                       KEY_READ,
                       &hKey);
    if (Ret != ERROR_SUCCESS)
        return NULL;

    Ret = RegQueryValueEx(hKey,
                          lpValue,
                          0,
                          &Type,
                          NULL,
                          &BufSize);
    if (Ret == ERROR_SUCCESS)
    {
        lpBuf = HeapAlloc(GetProcessHeap(),
                          0,
                          BufSize);
        if (lpBuf)
        {
            Ret = RegQueryValueEx(hKey, 
                                  lpValue,
                                  0,
                                  &Type,
                                  (LPBYTE)lpBuf,
                                  &BufSize);
            if (Ret != ERROR_SUCCESS)
                lpBuf = NULL;
        }
    }

    RegCloseKey(hKey);
    
    return lpBuf;
}


static VOID
SelectionChanged(HWND hwndDlg, PGLOBAL_DATA pGlobalData)
{
    HWND hwndCombo;
    BOOL bEnable;
    INT i;

    hwndCombo = GetDlgItem(hwndDlg, IDC_SCREENS_LIST);

    i = (INT)SendMessage(hwndCombo, CB_GETCURSEL, 0, 0);
    i = (INT)SendMessage(hwndCombo, CB_GETITEMDATA, i, 0);

    pGlobalData->Selection = i;

    bEnable = (i != 0);

    EnableWindow(GetDlgItem(hwndDlg, IDC_SCREENS_SETTINGS), bEnable);
    EnableWindow(GetDlgItem(hwndDlg, IDC_SCREENS_TESTSC), bEnable);
    EnableWindow(GetDlgItem(hwndDlg, IDC_SCREENS_USEPASSCHK), bEnable);
    EnableWindow(GetDlgItem(hwndDlg, IDC_SCREENS_TIMEDELAY), bEnable);
    EnableWindow(GetDlgItem(hwndDlg, IDC_SCREENS_TIME), bEnable);
    EnableWindow(GetDlgItem(hwndDlg, IDC_WAITTEXT), bEnable);
    EnableWindow(GetDlgItem(hwndDlg, IDC_MINTEXT), bEnable);
}


static VOID
SetScreenSaverPreviewBox(HWND hwndDlg, PGLOBAL_DATA pGlobalData)
{
    HWND hPreview = GetDlgItem(hwndDlg, IDC_SCREENS_PREVIEW);
    STARTUPINFO si;
    TCHAR szCmdline[2048];

    /* kill off the previous preview process*/
    if (pGlobalData->PrevWindowPi.hProcess)
    {
        TerminateProcess(pGlobalData->PrevWindowPi.hProcess, 0);
        CloseHandle(pGlobalData->PrevWindowPi.hProcess);
        CloseHandle(pGlobalData->PrevWindowPi.hThread);
        pGlobalData->PrevWindowPi.hThread = pGlobalData->PrevWindowPi.hProcess = NULL;
    }

    if (pGlobalData->Selection > 0)
    {
        _stprintf(szCmdline, 
                  _T("%s /p %u"),
                  pGlobalData->ScreenSaverItems[pGlobalData->Selection].szFilename,
                  hPreview);

        ZeroMemory(&si, sizeof(si));
        si.cb = sizeof(si);
        ZeroMemory(&pGlobalData->PrevWindowPi, sizeof(pGlobalData->PrevWindowPi));

        if (!CreateProcess(NULL, 
                           szCmdline, 
                           NULL, 
                           NULL, 
                           FALSE, 
                           0, 
                           NULL, 
                           NULL, 
                           &si, 
                           &pGlobalData->PrevWindowPi))
        {
            pGlobalData->PrevWindowPi.hThread = pGlobalData->PrevWindowPi.hProcess = NULL;
        }
    }
}

static BOOL
WaitForSettingsDialog(HWND hwndDlg,
                      HANDLE hProcess)
{
    while (TRUE)
    {
        DWORD Ret;
        MSG msg;

        while (PeekMessage(&msg,
                           NULL,
                           0,
                           0,
                           PM_REMOVE))
        { 
            if (msg.message == WM_QUIT)
                return FALSE;

            if (IsDialogMessage(hwndDlg, &msg))
            {
                TranslateMessage(&msg);
                DispatchMessage(&msg);
            }
        }

        Ret = MsgWaitForMultipleObjects(1,
                                        &hProcess,
                                        FALSE,
                                        INFINITE,
                                        QS_ALLINPUT);
        if (Ret == (WAIT_OBJECT_0))
        {
            return TRUE;
        } 
    }
}


static VOID
ScreensaverConfig(HWND hwndDlg, PGLOBAL_DATA pGlobalData)
{
    /*
       /c:<hwnd>  Run configuration, hwnd is handle of calling window
    */

    TCHAR szCmdline[2048];
    STARTUPINFO si;
    PROCESS_INFORMATION pi;

    if (pGlobalData->Selection < 1)
        return;

    _stprintf(szCmdline, 
              _T("%s /c:%u"),
              pGlobalData->ScreenSaverItems[pGlobalData->Selection].szFilename,
              hwndDlg);

    ZeroMemory(&si, sizeof(si));
    si.cb = sizeof(si);
    ZeroMemory(&pi, sizeof(pi));
    if(CreateProcess(NULL,
                     szCmdline,
                     NULL,
                     NULL,
                     FALSE,
                     0,
                     NULL,
                     NULL,
                     &si,
                     &pi))
    {
        /* kill off the previous preview process */
        if (pGlobalData->PrevWindowPi.hProcess)
        {
            TerminateProcess(pGlobalData->PrevWindowPi.hProcess, 0);
            CloseHandle(pGlobalData->PrevWindowPi.hProcess);
            CloseHandle(pGlobalData->PrevWindowPi.hThread);
            pGlobalData->PrevWindowPi.hThread = pGlobalData->PrevWindowPi.hProcess = NULL;
        }

        if (WaitForSettingsDialog(hwndDlg, pi.hProcess))
            SetScreenSaverPreviewBox(hwndDlg, pGlobalData);
    }
}


static VOID
ScreensaverPreview(HWND hwndDlg, PGLOBAL_DATA pGlobalData)
{
    /*
       /s         Run normal
    */

    WCHAR szCmdline[2048];
    STARTUPINFO si;
    PROCESS_INFORMATION pi;

    if (pGlobalData->Selection < 1)
        return;

    /* kill off the previous preview process*/
    if (pGlobalData->PrevWindowPi.hProcess)
    {
        TerminateProcess(pGlobalData->PrevWindowPi.hProcess, 0);
        CloseHandle(pGlobalData->PrevWindowPi.hProcess);
        CloseHandle(pGlobalData->PrevWindowPi.hThread);
        pGlobalData->PrevWindowPi.hThread = pGlobalData->PrevWindowPi.hProcess = NULL;
    }

    _stprintf(szCmdline, 
              _T("%s /s"),
              pGlobalData->ScreenSaverItems[pGlobalData->Selection].szFilename);

    ZeroMemory(&si, sizeof(si));
    si.cb = sizeof(si);
    ZeroMemory(&pi, sizeof(pi));
    if(CreateProcess(NULL,
                     szCmdline,
                     NULL,
                     NULL,
                     FALSE,
                     0,
                     NULL,
                     NULL,
                     &si,
                     &pi))
    {
        WaitForSingleObject(pi.hProcess, INFINITE);
        CloseHandle(pi.hProcess);
        CloseHandle(pi.hThread);
    }
}


static VOID
CheckRegScreenSaverIsSecure(HWND hwndDlg)
{
    HKEY hKey;
    TCHAR szBuffer[2];
    DWORD bufferSize = sizeof(szBuffer);
    DWORD varType = REG_SZ;
    LONG result;

    if (RegOpenKeyEx(HKEY_CURRENT_USER,
                     _T("Control Panel\\Desktop"),
                     0,
                     KEY_ALL_ACCESS,
                     &hKey) == ERROR_SUCCESS)
    {
        result = RegQueryValueEx(hKey,
                                _T("ScreenSaverIsSecure"),
                                0,
                                &varType,
                                (LPBYTE)szBuffer,
                                &bufferSize);
        RegCloseKey(hKey);

        if (result == ERROR_SUCCESS)
        {
            if (_ttoi(szBuffer) == 1)
            {
                SendDlgItemMessage(hwndDlg,
                                   IDC_SCREENS_USEPASSCHK,
                                   BM_SETCHECK,
                                   (WPARAM)BST_CHECKED,
                                   0);
                return;
            }
        }

        SendDlgItemMessage(hwndDlg,
                           IDC_SCREENS_USEPASSCHK,
                           BM_SETCHECK,
                           (WPARAM)BST_UNCHECKED,
                           0);
    }
}


static VOID
AddScreenSavers(HWND hwndDlg, PGLOBAL_DATA pGlobalData)
{
    HWND hwndScreenSavers = GetDlgItem(hwndDlg, IDC_SCREENS_LIST);
    WIN32_FIND_DATA fd;
    HANDLE hFind;
    TCHAR szSearchPath[MAX_PATH];
    INT i;
    int ScreenSaverCount = 0;
    ScreenSaverItem *ScreenSaverItem = NULL;
    HANDLE hModule = NULL;

    /* Add the "None" item */
    ScreenSaverItem = &pGlobalData->ScreenSaverItems[ScreenSaverCount];

    ScreenSaverItem->bIsScreenSaver = FALSE;

    LoadString(hApplet,
               IDS_NONE,
               ScreenSaverItem->szDisplayName,
               sizeof(ScreenSaverItem->szDisplayName) / sizeof(TCHAR));

    i = SendMessage(hwndScreenSavers,
                    CB_ADDSTRING,
                    0,
                    (LPARAM)ScreenSaverItem->szDisplayName);

    SendMessage(hwndScreenSavers,
                CB_SETITEMDATA,
                i,
                (LPARAM)ScreenSaverCount);

    ScreenSaverCount++;

    /* Add all the screensavers in the C:\ReactOS\System32 directory. */

    GetSystemDirectory(szSearchPath, MAX_PATH);
    _tcscat(szSearchPath, TEXT("\\*.scr"));

    hFind = FindFirstFile(szSearchPath, &fd);
    while (ScreenSaverCount < MAX_SCREENSAVERS-1 &&
           hFind != INVALID_HANDLE_VALUE)
    {
        /* Don't add any hidden screensavers */
        if ((fd.dwFileAttributes & FILE_ATTRIBUTE_HIDDEN) == 0)