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From: labc-1ic@e260-1c.berkeley.edu (Willy S. Liao)
Newsgroups: comp.sys.mac.programmer
Subject: What am I doing wrong?--modal dialog use crashes
Message-ID: <1991May7.234354.26431@agate.berkeley.edu>
Date: 7 May 91 23:43:54 GMT
Sender: root@agate.berkeley.edu (Charlie Root)
Organization: University of California, Berkeley
Lines: 48

OK dokee, I have a problem that's driving me nuts.  I'm sure I'm doing
something wrong, but I don't know what it is...I'm using THINK C 4.04 with
System 7.0f4 and the Think Class Library.  The following function is invoked
by my document initialization method (it gets an integer for the size of the
game board).  Whenever this function gets run with NO other windows on the
screen, it works fine.  However, if there is another window open in the
application layer (i.e. another instance of a document is in memory), this
function chokes with a syserr 28 (stack has moved into heap) error on the
call to ModalDialog().  Can anyone suggest anything?  Boosting the memory
partition up to larger sizes doesn't help (although the crash sometimes
turns into an error 25, out of memory).

My function:

static short
GetBoardsize(void)
{
	Str255 req, answer;
	DialogPtr dptr;
	short temp;
	long size;
	Rect rect;
	Handle ihandle;
	DialogRecord dRec;
	
	GetIndString(req, GAME_MSGS, GET_SIZE_STR);
	ParamText(req, "\p","\p","\p");
	dptr = GetNewDialog(GENERAL_REQ_DIALOG, &dRec, NULL);
	GetDItem(dptr, GENERAL_ETEXT_NUM, &temp, &ihandle, &rect);
	do {
		NumToString((long) DEFAULT_BSIZE, answer);
		SetIText(ihandle, answer);
		SelIText(dptr, GENERAL_ETEXT_NUM, 0, (short) answer[0]);
		ShowWindow(dptr);
		ModalDialog(NULL, &temp);
		GetDItem(dptr, GENERAL_ETEXT_NUM, &temp, &ihandle, &rect);
		GetIText(ihandle, answer);
		StringToNum(answer, &size);
	} while (size < MIN_BOARDSIZE || size > MAX_BOARDSIZE);
	CloseDialog(dptr);
	DisposHandle(dRec.items);
	return (short) size;
}

All of the all-caps identifiers are #define's.

Willy Liao
labc-1ic@web.berkeley.edu