Path: utzoo!utgpu!news-server.csri.toronto.edu!bonnie.concordia.ca!uunet!imp!diablery.10A.com!devil
From: devil@diablery.10A.com (Gil Tene)
Newsgroups: comp.windows.x
Subject: Xaw AsciiText XtAddCallback ??
Message-ID: <341@imp.UUCP>
Date: 15 May 91 20:31:43 GMT
Sender: devil@imp.UUCP
Organization: Diablery, cloud seven, Hell. (also 10A Inc.)
Lines: 45
Nntp-Posting-Host: imp

Hello X'ers,

I was trying to specify a callback funtions for a Xaw AsciiText,
and found this "strange" behaviour :

When trying to specify the callback using :
    XtAddCallback(text1, XtNcallback, 
			MyTextCBhandler, (XtPointer) &text_data1);

I get a "Warning: Cannot find callback list in XtAddCallbacks" 
at runtime, and the callback doesn't work...

BUT: when I specify an explicit callback list during the creation
of the asciiTextWidget, it works... (took me a while to think of
trying it this way) :

    static XtCallbackRec text_callback_list[] = {
        {MyTextCBhandler, (XtPointer) NULL},
        {(XtCallbackProc) NULL, (caddr_t) NULL}
        };

    .
    .
    .

    XtSetArg(args[0], XtNstring,
             "This is a test...");
    text_callback_list[0].closure = (XtPointer) &text_data1;
    XtSetArg(args[1], XtNcallback, text_callback_list);
 
    text1 = XtCreateManagedWidget("text1", asciiTextWidgetClass, paned,
                                 args, 2);

Any idea why this is? It would seem much easier and much more "elegant"
to use the usual XtAddCallback call...

AdvThanks,

-- Gil.
-- 
--------------------------------------------------------------------
-- Gil Tene			"Some days it just dosn't pay      -
-- devil%imp@uunet.uu.net	   to go to sleep in the morning." -
-- devil@diablery.10A.com 					   -
--------------------------------------------------------------------