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From: kenk@sunHd.tellabs.com (Ken Konecki)
Newsgroups: comp.sys.mac.programmer
Subject: Dialog problems in DA
Message-ID: <4927@tellab5.tellabs.com>
Date: 2 Jan 91 18:13:23 GMT
Sender: news@Tellabs.COM
Organization: Tellabs, Inc. Lisle, IL
Lines: 139
Originator: kenk@sunHd

I'm having trouble getting dialogs to work inside of a desk accessory. I
keep the item list as an owned resource and do a GetResource() call to get
a handle to it. When I create the dialog, I use NewDialog() and pass the
handle of the item list obtained from GetResource() as the item list
parameter. I do the dialogging and then call CloseDialog() at the end of
the routine. Everything works as I expect it to but only on the first time
I bring up the dialog. The second time I try, I get an address error and
get dropped into Macsbug. Stepping through the routine with Macsbug, I've
found that the call to NewDialog() returns a valid dialog record, but the
control list is NIL. As you would expect, the first time through the
routine, the control list of the dialog window is not NIL. This is of
course why it the routine bombs the second time but not the first. The big
question is: Why is the control list NIL the second time I call
NewDialog()?

I have enclosed the offending routine at the end of this post. The desk
accessory I'm writing is a simple calendar display. The dialog is used to
set the month and year that is being displayed. I'm using Think C 4.0 on a
Mac SE.

Thanks in advance for any help.

Cheers,
    -Ken K


#define ITEMS_ID	1

#define	JAN_BTN	3
#define	YEAR_ITEM JAN_BTN + 12

#define OFF	0
#define ON 1

static 
rsrcID(id)
int     id;
{
    return (0xc000 + (~dce->dCtlRefNum << 5) + id);
}

static Handle dlogItems;

int
checkItems()
{
    return ((dlogItems = GetResource('DITL', rsrcID(ITEMS_ID))) != NULL);
}


void
setMonth(month, year)
unsigned *month,
       *year;
{
    int     itemHit;
    register DialogPtr monthDlog;
    Str255  text;
    int     oldMonth;
    Rect    box;
    int     itemType;
    Handle  item,
            yearItem;
    long    newYear;
    int     dlogDone = FALSE;

    Debugger();

    dlogItems = GetResource('DITL', rsrcID(ITEMS_ID));
    SetRect(&box, 110, 68, 400, 200);
    monthDlog = NewDialog(NULL, &box, "\pSet Month", FALSE,
			  1, PUT_IN_FRONT, FALSE, 0L, dlogItems);

    /*
     * Unhilite the old button and hilite the new
     */
    oldMonth = *month;
    GetDItem(monthDlog, oldMonth + JAN_BTN - 1, &itemType, &item, &box);
    SetCtlValue((ControlHandle) item, ON);

    /*
     * Set the current year as the default year
     */
    NumToString((long) (*year), text);
    GetDItem(monthDlog, YEAR_ITEM, &itemType, &yearItem, &box);
    SetIText(yearItem, text);
    SelIText(monthDlog, YEAR_ITEM, 0, 32767);

    ShowWindow(monthDlog);
    /* DrawControls(monthDlog); */

    /*
     * Do the dialogging
     */
    while (!dlogDone)
    {
	ModalDialog(NULL, &itemHit);
	if (itemHit == 1)
	{
	    /*
	     * Ok button
	     */
	    *month = oldMonth;
	    GetIText(yearItem, text);
	    StringToNum(text, &newYear);
	    *year = (int) newYear;

	    /*
	     * Do some error checking
	     */
	    dlogDone = TRUE;
	}
	else if (itemHit == 2)
	{
	    /*
	     * Cancel Button
	     */
	    dlogDone = TRUE;
	}
	else if ((itemHit >= JAN_BTN) && (itemHit < YEAR_ITEM))
	{
	    /*
	     * One of the radio buttons was hit
	     */
	    GetDItem(monthDlog, oldMonth + JAN_BTN - 1,
		     &itemType, &item, &box);
	    SetCtlValue((ControlHandle) item, OFF);
	    oldMonth = itemHit - JAN_BTN + 1;
	    GetDItem(monthDlog, itemHit, &itemType, &item, &box);
	    SetCtlValue((ControlHandle) item, ON);
	}
    }
    updateCalendar();
    CloseDialog(monthDlog);
}
-- 
Ken Konecki
"Eat well, stay fit, and die anyway"
e-mail:kenk@tellabs.com    -or-    ...!uunet!tellab5!kenk