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MULTIMON.H：源码内容
							#if !defined(_WIN32_WINNT) || (_WIN32_WINNT < 0x0500)
//=============================================================================
//
// MULTIMON
// stub module that fakes multiple monitor apis on pre Memphis Win32 OSes
//
// By using this header your code will work unchanged on Win95,
// you will get back default values from GetSystemMetrics() for new metrics
// and the new APIs will act like only one display is present.
//
// exactly one source must include this with COMPILE_MULTIMON_STUBS defined
//
//=============================================================================
#ifdef __cplusplus
extern "C" {            /* Assume C declarations for C++ */
#endif  /* __cplusplus */
//
// if we are building on Win95/NT4 headers we need to declare this stuff ourselves
//
#ifndef SM_CMONITORS
#define SM_XVIRTUALSCREEN       76
#define SM_YVIRTUALSCREEN       77
#define SM_CXVIRTUALSCREEN      78
#define SM_CYVIRTUALSCREEN      79
#define SM_CMONITORS            80
#define SM_SAMEDISPLAYFORMAT    81
DECLARE_HANDLE(HMONITOR);
#define MONITOR_DEFAULTTONULL       0x00000000
#define MONITOR_DEFAULTTOPRIMARY    0x00000001
#define MONITOR_DEFAULTTONEAREST    0x00000002
#define MONITORINFOF_PRIMARY        0x00000001
typedef struct tagMONITORINFO
{
    DWORD   cbSize;
    RECT    rcMonitor;
    RECT    rcWork;
    DWORD   dwFlags;
} MONITORINFO, *LPMONITORINFO;
#define CCHDEVICENAME 32
#ifdef __cplusplus
typedef struct tagMONITORINFOEX : public tagMONITORINFO
{
    TCHAR       szDevice[CCHDEVICENAME];
} MONITORINFOEX, *LPMONITORINFOEX;
#else
typedef struct
{
    MONITORINFO;
    TCHAR       szDevice[CCHDEVICENAME];
} MONITORINFOEX, *LPMONITORINFOEX;
#endif
typedef BOOL (CALLBACK* MONITORENUMPROC)(HMONITOR, HDC, LPRECT, LPARAM);
#endif  // SM_CMONITORS
#undef GetMonitorInfo
#undef GetSystemMetrics
#undef MonitorFromWindow
#undef MonitorFromRect
#undef MonitorFromPoint
#undef EnumDisplayMonitors
//
// define this to compile the stubs
// otherwise you get the declarations
//
#ifdef COMPILE_MULTIMON_STUBS
//-----------------------------------------------------------------------------
//
// Implement the API stubs.
//
//-----------------------------------------------------------------------------
int      (WINAPI* g_pfnGetSystemMetrics)(int);
HMONITOR (WINAPI* g_pfnMonitorFromWindow)(HWND, BOOL);
HMONITOR (WINAPI* g_pfnMonitorFromRect)(LPCRECT, BOOL);
HMONITOR (WINAPI* g_pfnMonitorFromPoint)(POINT, BOOL);
BOOL     (WINAPI* g_pfnGetMonitorInfo)(HMONITOR, LPMONITORINFO);
BOOL     (WINAPI* g_pfnEnumDisplayMonitors)(HDC, LPCRECT, MONITORENUMPROC, LPARAM);
BOOL InitMultipleMonitorStubs(void)
{
    HMODULE hUser32;
    static BOOL fInitDone;
    if (fInitDone)
    {
        return g_pfnGetMonitorInfo != NULL;
    }
    if ((hUser32 = GetModuleHandle(TEXT("USER32"))) &&
        (*(FARPROC*)&g_pfnGetSystemMetrics    = GetProcAddress(hUser32,"GetSystemMetrics")) &&
        (*(FARPROC*)&g_pfnMonitorFromWindow   = GetProcAddress(hUser32,"MonitorFromWindow")) &&
        (*(FARPROC*)&g_pfnMonitorFromRect     = GetProcAddress(hUser32,"MonitorFromRect")) &&
        (*(FARPROC*)&g_pfnMonitorFromPoint    = GetProcAddress(hUser32,"MonitorFromPoint")) &&
        (*(FARPROC*)&g_pfnEnumDisplayMonitors = GetProcAddress(hUser32,"EnumDisplayMonitors")) &&
#ifdef UNICODE
        (*(FARPROC*)&g_pfnGetMonitorInfo      = GetProcAddress(hUser32,"GetMonitorInfoW")) &&
#else
        (*(FARPROC*)&g_pfnGetMonitorInfo      = GetProcAddress(hUser32,"GetMonitorInfoA")) &&
#endif
        //
        // Old builds of Memphis had different indices for these metrics, and
        // some of the APIs and structs have changed since then, so validate that
        // the returned metrics are not totally stupid.  (for example on an old
        // Memphis build, the new index for SM_CYVIRTUALSCREEN will fetch 0)
        //
        // If this is preventing you from using the shell on secondary monitors
        // under Memphis then upgrade to a new Memphis build that is in sync with
        // the current version of the multi-monitor APIs.
        //
        (GetSystemMetrics(SM_CXVIRTUALSCREEN) >= GetSystemMetrics(SM_CXSCREEN)) &&
        (GetSystemMetrics(SM_CYVIRTUALSCREEN) >= GetSystemMetrics(SM_CYSCREEN)) )
    {
        fInitDone = TRUE;
        return TRUE;
    }
    else
    {
        g_pfnGetSystemMetrics    = NULL;
        g_pfnMonitorFromWindow   = NULL;
        g_pfnMonitorFromRect     = NULL;
        g_pfnMonitorFromPoint    = NULL;
        g_pfnGetMonitorInfo      = NULL;
        g_pfnEnumDisplayMonitors = NULL;
        fInitDone = TRUE;
        return FALSE;
    }
}
//-----------------------------------------------------------------------------
//
// fake implementations of Monitor APIs that work with the primary display
// no special parameter validation is made since these run in client code
//
//-----------------------------------------------------------------------------
int WINAPI
xGetSystemMetrics(int nIndex)
{
    if (InitMultipleMonitorStubs())
        return g_pfnGetSystemMetrics(nIndex);
    switch (nIndex)
    {
    case SM_CMONITORS:
    case SM_SAMEDISPLAYFORMAT:
        return 1;
    case SM_XVIRTUALSCREEN:
    case SM_YVIRTUALSCREEN:
        return 0;
    case SM_CXVIRTUALSCREEN:
        nIndex = SM_CXSCREEN;
        break;
    case SM_CYVIRTUALSCREEN:
        nIndex = SM_CYSCREEN;
        break;
    }
    return GetSystemMetrics(nIndex);
}
#define xPRIMARY_MONITOR ((HMONITOR)0x42)
HMONITOR WINAPI
xMonitorFromRect(LPCRECT lprcScreenCoords, UINT uFlags)
{
    if (InitMultipleMonitorStubs())
        return g_pfnMonitorFromRect(lprcScreenCoords, uFlags);
    if ((uFlags & (MONITOR_DEFAULTTOPRIMARY | MONITOR_DEFAULTTONEAREST)) ||
        ((lprcScreenCoords->right > 0) &&
        (lprcScreenCoords->bottom > 0) &&
        (lprcScreenCoords->left < GetSystemMetrics(SM_CXSCREEN)) &&
        (lprcScreenCoords->top < GetSystemMetrics(SM_CYSCREEN))))
    {
        return xPRIMARY_MONITOR;
    }
    return NULL;
}
HMONITOR WINAPI
xMonitorFromPoint(POINT ptScreenCoords, UINT uFlags)
{
    if (InitMultipleMonitorStubs())
        return g_pfnMonitorFromPoint(ptScreenCoords, uFlags);
    if ((uFlags & (MONITOR_DEFAULTTOPRIMARY | MONITOR_DEFAULTTONEAREST)) ||
        ((ptScreenCoords.x >= 0) &&
        (ptScreenCoords.x < GetSystemMetrics(SM_CXSCREEN)) &&
        (ptScreenCoords.y >= 0) &&
        (ptScreenCoords.y < GetSystemMetrics(SM_CYSCREEN))))
    {
        return xPRIMARY_MONITOR;
    }
    return NULL;
}
HMONITOR WINAPI
xMonitorFromWindow(HWND hWnd, UINT uFlags)
{
    RECT rc;
    if (InitMultipleMonitorStubs())
        return g_pfnMonitorFromWindow(hWnd, uFlags);
    if (uFlags & (MONITOR_DEFAULTTOPRIMARY | MONITOR_DEFAULTTONEAREST))
        return xPRIMARY_MONITOR;
    if (GetWindowRect(hWnd, &rc))
        return xMonitorFromRect(&rc, uFlags);
    return NULL;
}
BOOL WINAPI
xGetMonitorInfo(HMONITOR hMonitor, LPMONITORINFO lpMonitorInfo)
{
    RECT rcWork;
    if (InitMultipleMonitorStubs())
        return g_pfnGetMonitorInfo(hMonitor, lpMonitorInfo);
    if ((hMonitor == xPRIMARY_MONITOR) && lpMonitorInfo &&
        (lpMonitorInfo->cbSize >= sizeof(MONITORINFO)) &&
        SystemParametersInfo(SPI_GETWORKAREA, 0, &rcWork, 0))
    {
        lpMonitorInfo->rcMonitor.left = 0;
        lpMonitorInfo->rcMonitor.top  = 0;
        lpMonitorInfo->rcMonitor.right  = GetSystemMetrics(SM_CXSCREEN);
        lpMonitorInfo->rcMonitor.bottom = GetSystemMetrics(SM_CYSCREEN);
        lpMonitorInfo->rcWork = rcWork;
        lpMonitorInfo->dwFlags = MONITORINFOF_PRIMARY;
        if (lpMonitorInfo->cbSize >= sizeof(MONITORINFOEX))
            lstrcpy(((MONITORINFOEX*)lpMonitorInfo)->szDevice, TEXT("DISPLAY"));
        return TRUE;
    }
    return FALSE;
}
BOOL WINAPI
xEnumDisplayMonitors(HDC hdcOptionalForPainting,
    LPCRECT lprcEnumMonitorsThatIntersect, MONITORENUMPROC lpfnEnumProc,
    LPARAM lData)
{
    RECT rcCallback, rcLimit;
    if (InitMultipleMonitorStubs())
        return g_pfnEnumDisplayMonitors(hdcOptionalForPainting,
            lprcEnumMonitorsThatIntersect, lpfnEnumProc, lData);
    
    if (!lpfnEnumProc)
        return FALSE;
    rcLimit.left   = 0;
    rcLimit.top    = 0;
    rcLimit.right  = GetSystemMetrics(SM_CXSCREEN);
    rcLimit.bottom = GetSystemMetrics(SM_CYSCREEN);
    if (hdcOptionalForPainting)
    {
        RECT rcClip;
        HWND hWnd;
        if ((hWnd = WindowFromDC(hdcOptionalForPainting)) == NULL)
            return FALSE;
        switch (GetClipBox(hdcOptionalForPainting, &rcClip))
        {
        default:
            MapWindowPoints(NULL, hWnd, (LPPOINT)&rcLimit, 2);
            if (IntersectRect(&rcCallback, &rcClip, &rcLimit))
                break;
            //fall thru
        case NULLREGION:
             return TRUE;
        case ERROR:
             return FALSE;
        }
        rcLimit = rcCallback;
    }
    if (!lprcEnumMonitorsThatIntersect ||
        IntersectRect(&rcCallback, lprcEnumMonitorsThatIntersect, &rcLimit))
    {
        lpfnEnumProc(xPRIMARY_MONITOR, hdcOptionalForPainting, &rcCallback,
            lData);
    }
    return TRUE;
}
#undef xPRIMARY_MONITOR
#undef COMPILE_MULTIMON_STUBS
#else	// COMPILE_MULTIMON_STUBS
extern int	WINAPI xGetSystemMetrics(int);
extern HMONITOR WINAPI xMonitorFromWindow(HWND, UINT);
extern HMONITOR WINAPI xMonitorFromRect(LPCRECT, UINT);
extern HMONITOR WINAPI xMonitorFromPoint(POINT, UINT);
extern BOOL	WINAPI xGetMonitorInfo(HMONITOR, LPMONITORINFO);
extern BOOL	WINAPI xEnumDisplayMonitors(HDC, LPCRECT, MONITORENUMPROC, LPARAM);
#endif	// COMPILE_MULTIMON_STUBS
//
// build defines that replace the regular APIs with our versions
//
#define GetSystemMetrics    xGetSystemMetrics
#define MonitorFromWindow   xMonitorFromWindow
#define MonitorFromRect     xMonitorFromRect
#define MonitorFromPoint    xMonitorFromPoint
#define GetMonitorInfo      xGetMonitorInfo
#define EnumDisplayMonitors xEnumDisplayMonitors
#ifdef __cplusplus
}
#endif	/* __cplusplus */
#endif  /* !defined(_WIN32_WINNT) || (_WIN32_WINNT < 0x0500) */

						