Newsgroups: comp.windows.x
Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!think.com!mintaka!bloom-beacon!dont-send-mail-to-path-lines
From: converse@expo.lcs.mit.EDU (Donna Converse)
Subject: Re: HELP !!!
Message-ID: <9104161509.AA06215@excess.lcs.mit.edu>
Sender: daemon@athena.mit.edu (Mr Background)
Organization: X Consortium, MIT Laboratory for Computer Science
References: <1991Apr15.215153.23046@metro.ucc.su.OZ.AU>
Date: 16 Apr 91 15:09:35 GMT
Lines: 34


> What I want to do is to have a menu bar and when
> the user chooses an option the main interface (not menu bar)
> should change correspondingly. For example the user chooses
> letter format so the main area should display the fields for this
> options and when the user chooses fax format this should be
> displayed.


If you want widgets to disappear but still take up the same space 
within the parent widget, use XtSetMappedWhenManaged to set 
mapped_when_managed to False, and use XtMapWidget and XtUnmapWidget
to control which widgets can be seen.

If you want other widgets to shift positions within the parent as
their siblings disappear, use XtManageChild(ren) and XtUnmanageChild(ren).
This can lead to the parent making changes in its own geometry, as well
as recomputation of the layout of children, depending on values of various 
constraint resources, and that could be distracting to the user, or expensive 
to compute.  Some composite widgets allow you to effectively "batch" these 
requests, by temporarily turning off the recomputation of the layout until 
all the changes in resources and managed children have been made.  

There is a discussion of these issues in Asente & Swick, in the 
Programmer's Guide section 4.3.


Donna Converse