Path: utzoo!utgpu!watmath!iuvax!mailrus!bcm!moniz!jcarson
From: jcarson@moniz.bcm.tmc.edu (Janet Carson)
Newsgroups: comp.windows.x
Subject: intercepting a call to XtAddCallback
Keywords: XtAddCallback
Message-ID: <1792@gazette.bcm.tmc.edu>
Date: 6 Nov 89 22:43:58 GMT
Sender: usenet@bcm.tmc.edu
Lines: 16

I am writing a widget which is essentially a "wrapper" around
several subwidgets.  By using intialize_hook and set_values_hook, 
I pass the arguments for "my widget" on to the subwidget which
"really" wants them.  However, I have a problem with callbacks.  

If the user passes the callback to my widget during XtCreateWidget, 
I can pass the callback on to the proper subwidget during
initialize_hook.  If the user tries to add the callback later with 
XtAddCallback, my widget doesn't seem to get notified, and my test 
program gets a message "Cannot find callback list."

Is there any way for a widget to intercept a call to XtAddCallback
and re-direct it to another widget?

Janet L. Carson                               internet: jcarson@bcm.tmc.edu 
Baylor College of Medicine              uucp: {rutgers,mailrus}!bcm!jcarson