PROGHELP.C

/******************************************************************************\ 
*       This is a part of the Microsoft Source Code Samples.  
*       Copyright 1993 - 1998 Microsoft Corporation. 
*       All rights reserved.  
*       This source code is only intended as a supplement to  
*       Microsoft Development Tools and/or WinHelp documentation. 
*       See these sources for detailed information regarding the  
*       Microsoft samples programs. 
\******************************************************************************/ 
 
/*****************************************************************************\ 
* PROGHELP.C 
* 
* Main module to implement a simple DDEML service DLL that makes interaction 
* with progman simple. 
\*****************************************************************************/ 
 
#include <windows.h> 
#include <ddeml.h> 
#include <string.h> 
 
typedef struct { 
    HCONV hConv; 
    DWORD idInst; 
} THREADINFO; 
 
DWORD TlsIndex; 
 
/* 
 * This is the default DDEML callback function for ProgHelp 
 */ 
HDDEDATA CALLBACK ProgHelpDdeCallback( 
UINT wType, 
UINT wFmt, 
HCONV hConv, 
HSZ hsz1, 
HSZ hsz2, 
HDDEDATA hData, 
DWORD dwData1, 
DWORD dwData2) 
{ 
    return(0); 
} 
 
 
/* 
 * This is the DLL init routine called by the system at attach/detatch time. 
 * 
 * We allocate a Tls for each thread that calls this DLL so that their state 
 * can be tracked independently. 
 */ 
BOOLEAN APIENTRY DllMain( 
IN PVOID hmod, 
ULONG Reason, 
IN PCONTEXT pctx OPTIONAL) 
{ 
    THREADINFO *pti; 
    UNREFERENCED_PARAMETER(hmod); 
    UNREFERENCED_PARAMETER(pctx); 
 
    switch (Reason) { 
    case DLL_PROCESS_ATTACH: 
        TlsIndex = TlsAlloc(); 
 
    case DLL_THREAD_ATTACH: 
        pti = (THREADINFO *)LocalAlloc(LPTR, sizeof(THREADINFO)); 
        if (!pti) { 
            return(FALSE); 
        } 
        TlsSetValue(TlsIndex, pti); 
        break; 
 
    case DLL_THREAD_DETACH: 
    case DLL_PROCESS_DETACH: 
        pti = TlsGetValue(TlsIndex); 
        LocalFree(pti); 
        if (Reason == DLL_PROCESS_DETACH) { 
            TlsFree(TlsIndex); 
        } 
        break; 
    } 
    return TRUE; 
} 
 
/* 
 * An application must call this API first to establish a conversation 
 * with progman.  DDEML initialization is done automatically if needed. 
 */ 
BOOL ConnectToProgmanA() 
{ 
    THREADINFO *pti; 
    HSZ hszProgman; 
 
    pti = TlsGetValue(TlsIndex); 
 
    if (!pti->idInst) { 
        if (DdeInitializeA(&(pti->idInst), ProgHelpDdeCallback, 
                APPCMD_CLIENTONLY | CBF_SKIP_ALLNOTIFICATIONS, 
                0L) != DMLERR_NO_ERROR) { 
            return(FALSE); 
        } 
    } 
 
    if (pti->hConv == 0) { 
        hszProgman = DdeCreateStringHandleA(pti->idInst, "Progman", 0); 
        pti->hConv = DdeConnect(pti->idInst, hszProgman, hszProgman, NULL); 
    } 
    return(pti->hConv != 0); 
} 
 
 
 
BOOL ConnectToProgmanW() 
{ 
    THREADINFO *pti; 
    HSZ hszProgman; 
 
    pti = TlsGetValue(TlsIndex); 
 
    if (!pti->idInst) { 
        if (DdeInitializeW(&(pti->idInst), ProgHelpDdeCallback, 
                APPCMD_CLIENTONLY | CBF_SKIP_ALLNOTIFICATIONS, 
                0L) != DMLERR_NO_ERROR) { 
            return(FALSE); 
        } 
    } 
 
    if (pti->hConv == 0) { 
        hszProgman = DdeCreateStringHandleA(pti->idInst, "Progman", 0); 
        pti->hConv = DdeConnect(pti->idInst, hszProgman, hszProgman, NULL); 
    } 
    return(pti->hConv != 0); 
} 
 
 
 
/* 
 * This API should be called when operations with progman are complete. 
 * We shutdown DDEML here as well so we don't have to deal with it 
 * at DLL detatch time. 
 */ 
BOOL DisconnectFromProgman() 
{ 
    THREADINFO *pti; 
 
    pti = TlsGetValue(TlsIndex); 
 
    if (!pti->idInst) { 
        return(TRUE); 
    } 
 
    if (pti->hConv) { 
        DdeDisconnect(pti->hConv); 
        pti->hConv = 0; 
    } 
 
    DdeUninitialize(pti->idInst); 
    pti->idInst = 0; 
    return(TRUE); 
} 
 
 
/* 
 * This API sends an ASCII execute string to progman.  It immediately returns 
 * and the results of the execute are not known.  Calling applications should 
 * be aware that these transactions are done asynchronously.  This allows 
 * this API to work under modal-loop conditions.  DisconnectFromProgman() 
 * will not succeed until all transactions are complete. 
 */ 
BOOL ProgmanExecuteStringA( 
LPSTR pszExec) 
{ 
    THREADINFO *pti; 
    DWORD dwResult; 
 
    pti = TlsGetValue(TlsIndex); 
 
    if (!pti->idInst || !pti->hConv) { 
        return(FALSE); 
    } 
    if (!DdeClientTransaction((PBYTE)pszExec, strlen(pszExec) + 1, 
            pti->hConv, 0, 0, XTYP_EXECUTE, TIMEOUT_ASYNC, &dwResult)) { 
        return(FALSE); 
    } 
    return(TRUE); 
} 
 
 
 
BOOL ProgmanExecuteStringW( 
LPWSTR pszExec) 
{ 
    THREADINFO *pti; 
    DWORD dwResult; 
 
    pti = TlsGetValue(TlsIndex); 
 
    if (!pti->idInst || !pti->hConv) { 
        return(FALSE); 
    } 
    if (!DdeClientTransaction((PBYTE)pszExec, 
            (wcslen(pszExec) + 1)  * sizeof(WCHAR), 
            pti->hConv, 0, 0, XTYP_EXECUTE, TIMEOUT_ASYNC, &dwResult)) { 
        return(FALSE); 
    } 
    return(TRUE); 
}