104 lines
1.5 KiB
C++
104 lines
1.5 KiB
C++
/*++
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Copyright (c) 2000 Microsoft Corporation
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Module Name:
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LazyReleaseDC.cpp
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Abstract:
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Delay releasing a DC by one call. A DC is not released until the next call to ReleaseDC
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Notes:
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This is a general purpose shim.
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History:
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10/10/1999 linstev Created
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--*/
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#include "precomp.h"
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IMPLEMENT_SHIM_BEGIN(LazyReleaseDC)
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#include "ShimHookMacro.h"
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APIHOOK_ENUM_BEGIN
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APIHOOK_ENUM_ENTRY(ReleaseDC)
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APIHOOK_ENUM_END
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HWND g_hWndPrev;
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HDC g_hDcPrev;
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CRITICAL_SECTION g_MakeThreadSafe;
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/*++
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Save this hWnd and hdc for releasing later. If there is already a DC to be
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released, release it now.
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--*/
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int
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APIHOOK(ReleaseDC)(
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HWND hWnd,
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HDC hdc
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)
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{
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UINT uRet = 1; // All's well
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EnterCriticalSection(&g_MakeThreadSafe);
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// If there is a previous DC, release it now
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if (g_hDcPrev) {
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uRet = ORIGINAL_API(ReleaseDC)(g_hWndPrev, g_hDcPrev);
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}
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g_hWndPrev = hWnd;
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g_hDcPrev = hdc;
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LeaveCriticalSection(&g_MakeThreadSafe);
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return uRet;
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}
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/*++
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Register hooked functions
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--*/
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BOOL
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NOTIFY_FUNCTION(
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DWORD fdwReason
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)
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{
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if (fdwReason == DLL_PROCESS_ATTACH) {
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g_hWndPrev = 0;
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g_hDcPrev = 0;
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InitializeCriticalSection(&g_MakeThreadSafe);
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}
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// Ignore Detach code
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/*
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else if (fdwReason == DLL_PROCESS_DETACH) {
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DeleteCriticalSection(&g_MakeThreadSafe);
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}
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*/
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return TRUE;
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}
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HOOK_BEGIN
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CALL_NOTIFY_FUNCTION
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APIHOOK_ENTRY(USER32.DLL, ReleaseDC)
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HOOK_END
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IMPLEMENT_SHIM_END
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