DDE.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.
\******************************************************************************/
/***************************************************************************
* *
* MODULE : dde.c *
* *
* PURPOSE : Contains routines for handling of DDE interaction with *
* DDEML. *
* *
***************************************************************************/
#include "client.h"
#include <string.h>
#include <memory.h>
#include "infoctrl.h"
#include "huge.h"
TCHAR szT[100];
/****************************************************************************
* *
* FUNCTION : CreateXactionWindow() *
* *
* PURPOSE : Creates a transaction window for the given transaction *
* under the given conversation window. *
* *
* RETURNS : TRUE - If successful. *
* FALSE - otherwise. *
* *
****************************************************************************/
HWND CreateXactionWindow(
HWND hwndMDI,
XACT *pxact)
{
PTSTR pszFmt, pszItem;
PTSTR pData;
HWND hwnd;
pszItem = GetHSZName(pxact->hszItem);
pszFmt = GetFormatName(pxact->wFmt);
pData = GetTextData(pxact->hDdeData);
/*
* type/opts ITEM ret GWL_USER=pxact
*
*
*
*
* DATA
*
*
*
*
* state/error FORMAT Result
*/
hwnd = CreateInfoCtrl((LPTSTR)pData,
(INT)SendMessage(hwndMDI, UM_GETNEXTCHILDX, 0, 0L),
(INT)SendMessage(hwndMDI, UM_GETNEXTCHILDY, 0, 0L),
200, 100, hwndMDI, hInst,
Type2String(pxact->wType, pxact->fsOptions), pszItem, NULL,
TEXT("Starting"), (LPTSTR)pszFmt, NULL,
ICSTY_SHOWFOCUS, 0, (DWORD)(LPTSTR)pxact);
MyFree(pszItem);
MyFree(pszFmt);
MyFree(pData);
return(hwnd);
}
/****************************************************************************
* *
* FUNCTION : ProcessTransaction() *
* *
* PURPOSE : Processes synchronous transactions entirely and starts *
* async transactions. Transaction attempts result in a *
* transaction window being created which displays the state *
* or results of the transaction. (the callback function *
* updates these windows as it gets calls) Transaction *
* windows stay around until abandoned by the user or until *
* the conversation is disconnected. Advise Data and Advise *
* Stop transactions are special. We don't create a new *
* window if the associated advise start transaction window *
* can be found. *
* *
* RETURNS : TRUE - If successful. *
* FALSE - otherwise. *
* *
****************************************************************************/
BOOL ProcessTransaction(
XACT *pxact)
{
CONVINFO ci;
HWND hwndInfoCtrl = 0;
/* create transaction window to show we tried (except in ADVSTOP case) */
pxact = (XACT *)memcpy(MyAlloc(sizeof(XACT)), (PTSTR)pxact, sizeof(XACT));
ci.cb = sizeof(CONVINFO);
DdeQueryConvInfo(pxact->hConv, QID_SYNC, &ci); // ci.hUser==hConv
if (pxact->wType == XTYP_ADVSTOP) {
hwndInfoCtrl = FindAdviseChild((HWND)ci.hUser, pxact->hszItem,
pxact->wFmt);
if (hwndInfoCtrl) {
SendMessage(hwndInfoCtrl, ICM_SETSTRING, ICSID_UL,
(DWORD)(LPTSTR)Type2String(pxact->wType, pxact->fsOptions));
DdeFreeStringHandle(idInst, pxact->hszItem);
}
}
/*
* If we still need to create a transaction window, do so here.
*/
if (!hwndInfoCtrl) {
hwndInfoCtrl = CreateXactionWindow((HWND)ci.hUser, pxact);
if (!hwndInfoCtrl) {
MyFree(pxact);
return 0;
}
SetFocus(hwndInfoCtrl);
}
/*
* Disable callbacks for this conversation now if the XOPT_DISABLEFIRST
* option is set. This tests disabling asynchronous transactions
* before they are completed.
*/
if (pxact->fsOptions & XOPT_DISABLEFIRST)
DdeEnableCallback(idInst, pxact->hConv, EC_DISABLE);
/*
* Adjust the timeout for asynchronous transactions.
*/
if (pxact->fsOptions & XOPT_ASYNC)
pxact->ulTimeout = TIMEOUT_ASYNC;
/*
* start transaction with DDEML here
*/
pxact->ret = (DWORD) DdeClientTransaction((LPBYTE)pxact->hDdeData, 0xFFFFFFFF,
pxact->hConv, pxact->hszItem, pxact->wFmt,
pxact->wType,
pxact->ulTimeout, (LPDWORD)&pxact->Result);
/*
* show return value in transaction window
*/
wsprintf(szT, TEXT("ret=%lx"), pxact->ret);
SendMessage(hwndInfoCtrl, ICM_SETSTRING, ICSID_UR, (DWORD)(LPTSTR)szT);
/*
* show result or ID value in transaction window
*/
wsprintf(szT, pxact->fsOptions & XOPT_ASYNC ? TEXT("ID=%ld") :
TEXT("result=0x%lx"), pxact->Result);
SendMessage(hwndInfoCtrl, ICM_SETSTRING, ICSID_LR, (DWORD)(LPTSTR)szT);
if ((pxact->fsOptions & XOPT_ASYNC) && pxact->ret) {
/*
* asynchronous successful start - link transaction to window.
*/
DdeSetUserHandle(pxact->hConv, pxact->Result, (DWORD)hwndInfoCtrl);
/*
* Abandon started async transaction after initiated if
* XOPT_ABANDONAFTERSTART is chosen. This tests the mid-transaction
* abandoning code.
*/
if (pxact->fsOptions & XOPT_ABANDONAFTERSTART)
DdeAbandonTransaction(idInst, pxact->hConv, pxact->Result);
/*
* show actual status
*/
ci.cb = sizeof(CONVINFO);
DdeQueryConvInfo(pxact->hConv, pxact->Result, &ci);
SendMessage(hwndInfoCtrl, ICM_SETSTRING, ICSID_LL,
(DWORD)(LPTSTR)State2String(ci.wConvst));
} else {
/*
* Synchronous transactions are completed already so pass on to
* CompleteTransaction right away.
*/
CompleteTransaction(hwndInfoCtrl, pxact);
}
return TRUE;
}
/****************************************************************************
* *
* FUNCTION : CompleteTransaction() *
* *
* PURPOSE : This handles completed synchronous and asynchronous *
* transactions as well as failed attempted transactions. *
* *
* RETURNS : TRUE - If successful. *
* FALSE - otherwise. *
* *
****************************************************************************/
VOID CompleteTransaction(
HWND hwndInfoCtrl,
XACT *pxact)
{
PTSTR psz;
if (pxact->ret) {
/*
* Successful transaction case
*/
SendMessage(hwndInfoCtrl, ICM_SETSTRING, ICSID_LL,
(DWORD)(LPTSTR)TEXT("Completed"));
if (pxact->wType == XTYP_REQUEST) {
/*
* Show resulting data
*/
psz = GetTextData((HDDEDATA)pxact->ret);
if (!DdeCmpStringHandles(pxact->hszItem, hszHuge) &&
!CheckHugeData((HDDEDATA)pxact->ret)) {
SendMessage(hwndInfoCtrl, ICM_SETSTRING, ICSID_CENTER,
(DWORD)(LPTSTR)TEXT("Invalid Huge Data"));
} else {
SendMessage(hwndInfoCtrl, ICM_SETSTRING, ICSID_CENTER,
(DWORD)(LPTSTR)psz);
}
MyFree(psz);
/*
* free returned data since it is displayed.
*/
DdeFreeDataHandle((HDDEDATA)pxact->ret);
pxact->ret = 0L;
SendMessage(hwndInfoCtrl, ICM_SETSTRING, ICSID_UR, 0);
}
} else {
/*
* failed - show error result.
*/
SendMessage(hwndInfoCtrl, ICM_SETSTRING, ICSID_LL,
(DWORD)(LPTSTR)Error2String(DdeGetLastError(idInst)));
}
pxact->fsOptions |= XOPT_COMPLETED;
}
/****************************************************************************
* *
* FUNCTION : DdeCallback() *
* *
* PURPOSE : This handles all callbacks from the DDEML. This handles *
* updating of the associated conversation and any special *
* testing cases such as blocking callbacks etc. *
* *
* For the most part, clients only handle advise data and *
* asynchronous transaction completion here. *
* *
* RETURNS : Results vary depending on transaction type. *
* *
****************************************************************************/
HDDEDATA CALLBACK DdeCallback(
UINT wType,
UINT wFmt,
HCONV hConv,
HSZ hsz1,
HSZ hsz2,
HDDEDATA hData,
DWORD lData1,
DWORD lData2)
{
HWND hwnd;
CONVINFO ci;
XACT *pxact;
if (hConv) {
/*
* update conversation status if it changed.
*/
MYCONVINFO *pmci;
ci.cb = sizeof(CONVINFO);
if (!DdeQueryConvInfo(hConv, QID_SYNC, &ci) || (!IsWindow((HWND)ci.hUser))) {
/*
* This conversation does not yet have a corresponding MDI window
* or is disconnected.
*/
return 0;
}
if (pmci = (MYCONVINFO *)GetWindowLong((HWND)ci.hUser, 0)) {
if (pmci->ci.wStatus != ci.wStatus ||
pmci->ci.wConvst != ci.wConvst ||
pmci->ci.wLastError != ci.wLastError) {
/*
* Things have changed, updated the conversation window.
*/
InvalidateRect((HWND)ci.hUser, NULL, TRUE);
}
if (ci.wConvst & ST_INLIST) {
/*
* update the associated list window (if any) as well.
*/
if (hwnd = FindListWindow(ci.hConvList))
InvalidateRect(hwnd, NULL, TRUE);
}
}
}
/*
* handle special block on next callback option here. This demonstrates
* the CBR_BLOCK feature.
*/
if (fBlockNextCB && !(wType & XTYPF_NOBLOCK)) {
fBlockNextCB = FALSE;
return(CBR_BLOCK);
}
/*
* handle special termination here. This demonstrates that at any time
* a client can drop a conversation.
*/
if (fTermNextCB && hConv && wType != XTYP_DISCONNECT) {
fTermNextCB = FALSE;
MyDisconnect(hConv);
return(0);
}
/*
* Now we begin sort out what to do.
*/
switch (wType) {
case XTYP_REGISTER:
case XTYP_UNREGISTER:
/*
* This is where the client would insert code to keep track of
* what servers are available. This could cause the initiation
* of some conversations.
*/
break;
case XTYP_DISCONNECT:
if (fAutoReconnect) {
/*
* attempt a reconnection
*/
if (hConv = DdeReconnect(hConv)) {
AddConv(ci.hszServiceReq, ci.hszTopic, hConv, FALSE);
return 0;
}
}
/*
* update conv window to show its new state.
*/
SendMessage((HWND)ci.hUser, UM_DISCONNECTED, 0, 0);
return 0;
break;
case XTYP_ADVDATA:
/*
* data from an active advise loop (from a server)
*/
Delay(wDelay);
hwnd = FindAdviseChild((HWND)ci.hUser, hsz2, wFmt);
if (!IsWindow(hwnd)) {
PTSTR pszItem, pszFmt;
/*
* AdviseStart window is gone, make a new one.
*/
pxact = (XACT *)MyAlloc(sizeof(XACT));
pxact->wType = wType;
pxact->hConv = hConv;
pxact->wFmt = wFmt;
pxact->hszItem = hsz2;
DdeKeepStringHandle(idInst, hsz2);
pszItem = GetHSZName(hsz2);
pszFmt = GetFormatName(wFmt);
hwnd = CreateInfoCtrl(NULL,
(INT)SendMessage((HWND)ci.hUser, UM_GETNEXTCHILDX, 0, 0L),
(INT)SendMessage((HWND)ci.hUser, UM_GETNEXTCHILDY, 0, 0L),
200, 100,
(HWND)ci.hUser, hInst,
Type2String(wType, 0), (LPTSTR)pszItem, NULL,
NULL, (LPTSTR)pszFmt, NULL,
ICSTY_SHOWFOCUS, 0, (DWORD)(LPTSTR)pxact);
MyFree(pszFmt);
MyFree(pszItem);
if (!IsWindow(hwnd))
return(DDE_FNOTPROCESSED);
}
if (!hData) {
/*
* XTYPF_NODATA case - request the info. (we do this synchronously
* for simplicity)
*/
hData = DdeClientTransaction(NULL, 0L, hConv, hsz2, wFmt,
XTYP_REQUEST, DefTimeout, NULL);
}
if (hData) {
PTSTR pData;
/*
* Show incomming data on corresponding transaction window.
*/
pData = GetTextData(hData);
SendMessage(hwnd, ICM_SETSTRING, ICSID_CENTER, (DWORD)(LPTSTR)pData);
MyFree(pData);
DdeFreeDataHandle(hData);
}
SendMessage(hwnd, ICM_SETSTRING, ICSID_LL, (DWORD)(LPTSTR)TEXT("Advised"));
return((HDDEDATA)DDE_FACK);
break;
case XTYP_XACT_COMPLETE:
/*
* An asynchronous transaction has completed. Show the results.
*
* ...unless the XOPT_BLOCKRESULT is chosen.
*/
ci.cb = sizeof(CONVINFO);
if (DdeQueryConvInfo(hConv, lData1, &ci) &&
IsWindow((HWND)ci.hUser) &&
(pxact = (XACT *)GetWindowLong((HWND)ci.hUser, GWL_USER))) {
if (pxact->fsOptions & XOPT_BLOCKRESULT) {
pxact->fsOptions &= ~XOPT_BLOCKRESULT;
return(CBR_BLOCK);
}
pxact->Result = lData2;
pxact->ret = (DWORD)hData;
CompleteTransaction((HWND)ci.hUser, pxact);
}
break;
}
}
/****************************************************************************
* *
* FUNCTION : FindAdviseChild() *
* *
* PURPOSE : Search through the child windows of hwndMDI for an info *
* ctrl that has the same Item and format and is an *
* ADVSTART ADVSTOP or ADVDATA transaction window. *
* *
* We use these to show the associated advise data. *
* *
* RETURNS : The transaction window handle or 0 on failure. *
* *
****************************************************************************/
HWND FindAdviseChild(
HWND hwndMDI,
HSZ hszItem,
DWORD wFmt)
{
HWND hwnd, hwndStart;
XACT *pxact;
if (!IsWindow(hwndMDI))
return 0;
hwnd = hwndStart = GetWindow(hwndMDI, GW_CHILD);
while (hwnd && IsChild(hwndMDI, hwnd)) {
pxact = (XACT *)GetWindowLong(hwnd, GWL_USER);
if (pxact &&
(pxact)->wFmt == wFmt &&
(pxact)->hszItem == hszItem &&
(
((pxact->wType & XTYP_ADVSTART) == XTYP_ADVSTART) ||
(pxact->wType == XTYP_ADVSTOP) ||
(pxact->wType == XTYP_ADVDATA)
)
) {
return(hwnd);
}
hwnd = GetWindow(hwnd, GW_HWNDNEXT);
if (hwnd == hwndStart)
return 0;
}
return 0;
}
/****************************************************************************
* *
* FUNCTION : FindListWindow() *
* *
* PURPOSE : Locates the list window associated with this conversation *
* list. *
* *
* RETURNS : The window handle of the list window or 0 on failure. *
* *
****************************************************************************/
HWND FindListWindow(
HCONVLIST hConvList)
{
HWND hwnd;
MYCONVINFO *pmci;
hwnd = GetWindow(hwndMDIClient, GW_CHILD);
while (hwnd) {
if (GetWindowLong(hwnd, GWL_WNDPROC) == (LONG)MDIChildWndProc) {
pmci = (MYCONVINFO *)GetWindowLong(hwnd, 0);
if (pmci != NULL && pmci->fList &&
pmci->hConv == (HCONV)hConvList)
return(hwnd);
}
hwnd = GetWindow(hwnd, GW_HWNDNEXT);
}
return 0;
}
/****************************************************************************
* *
* FUNCTION : GetTextData() *
* *
* PURPOSE : Allocates and returns a pointer to the data contained in *
* hData. This assumes that hData points to text data and *
* will properly handle huge text data by leaving out the *
* middle of the string and placing the size of the string *
* into this string portion. *
* *
* RETURNS : A pointer to the allocated string. *
* *
****************************************************************************/
PTSTR GetTextData(
HDDEDATA hData)
{
PTSTR psz;
DWORD cb;
#define MAXCCH 1024
if (hData == 0) {
return(NULL);
}
cb = DdeGetData(hData, NULL, 0, 0);
if (!hData || !cb)
return NULL;
if (cb > MAXCCH) { // possibly HUGE object!
psz = MyAlloc(MAXCCH * sizeof(TCHAR));
DdeGetData(hData, (PBYTE)psz, MAXCCH - 46 * sizeof(TCHAR), 0L);
wsprintf(&psz[MAXCCH - 46], TEXT("<---Size=%ld"), cb);
} else {
psz = MyAlloc((DWORD)cb);
DdeGetData(hData, (LPBYTE)psz, cb, 0L);
}
return psz;
#undef MAXCCH
}
/****************************************************************************
* *
* FUNCTION : MyGetClipboardFormatName() *
* *
* PURPOSE : Properly retrieves the string associated with a clipboard *
* format. If the format does not have a string associated *
* with it, the string #dddd is returned. *
* *
* RETURNS : The number of characters copied into lpstr or 0 on error. *
* *
****************************************************************************/
INT MyGetClipboardFormatName(
DWORD fmt,
LPTSTR lpstr,
INT cbMax)
{
if (fmt < 0xc000) {
// predefined or integer format - just get the atom string
// wierdly enough, GetClipboardFormatName() doesn't support this.
return(GlobalGetAtomName((ATOM)fmt, lpstr, cbMax));
} else {
return(GetClipboardFormatName(fmt, lpstr, cbMax));
}
}
/****************************************************************************
* *
* FUNCTION : GetFormatName() *
* *
* PURPOSE : allocates and returns a pointer to a string representing *
* a format. Use MyFree() to free this string. *
* *
* RETURNS : The number of characters copied into lpstr or 0 on error. *
* *
****************************************************************************/
PTSTR GetFormatName(
DWORD wFmt)
{
PTSTR psz;
DWORD cb;
if (wFmt == CF_UNICODETEXT) {
psz = MyAlloc(40);
_tcscpy(psz, TEXT("CF_UNICODETEXT"));
return psz;
}
if (wFmt == CF_TEXT) {
psz = MyAlloc(40);
_tcscpy(psz, TEXT("CF_TEXT"));
return psz;
}
psz = MyAlloc(255);
*psz = TEXT('\0');
cb = GetClipboardFormatName(wFmt, psz, 255) + 1;
return((PTSTR)LocalReAlloc((HANDLE)psz, cb, LMEM_MOVEABLE));
}
/****************************************************************************
* *
* FUNCTION : MyDisconnect() *
* *
* PURPOSE : Disconnects the given conversation after updating the *
* associated conversation window. *
* *
* RETURNS : TRUE on success, FALSE on failuer. *
* *
****************************************************************************/
BOOL MyDisconnect(
HCONV hConv)
{
CONVINFO ci;
HWND hwnd;
// before we disconnect, invalidate the associated list window - if
// applicable.
ci.cb = sizeof(CONVINFO);
if (DdeQueryConvInfo(hConv, QID_SYNC, &ci) && ci.hConvList &&
(hwnd = FindListWindow(ci.hConvList)))
InvalidateRect(hwnd, NULL, TRUE);
return(DdeDisconnect(hConv));
}