Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!bloom-beacon!SUN.COM!dshr
From: dshr@SUN.COM (David Rosenthal)
Newsgroups: comp.windows.x
Subject: Re: Reparenting WM's
Message-ID: <8902071725.AA02778@devnull.sun.com>
Date: 7 Feb 89 14:11:14 GMT
Sender: daemon@bloom-beacon.MIT.EDU
Organization: The Internet
Lines: 38

> I am porting an application that currently uses serial graphics terminals
> for graphics.  Occasionally, the program needs to display a large quantity
> of text, and switches the terminal to text mode (and hides the graphics).
> 
> In porting this application, the power that be decided that the mechanism
> we would use would be to raise the xterm from which the application was
> invoked and display the text.  (We use the WINDOWID environment variable to
> determine the correct xterm.)

There is another point to be considered here.  No interface that depends
on application control over the stack order of top-level windows can
be guaranteed to work with all window managers.  The ICCCM specifies the
way in which a client can REQUEST a change in stack order.  But stack
order,  like window size and placement,  is under window manager control.
There is no guarantee that the window manager will honor the request for
a change in stack order.  Indeed,  there are window managers (tiled ones,
for example) for which the request has no meaning.  Once the window
managers catch up with the ICCCM,  one would expect that most of them
would attempt to satisfy the request,  but there would be no guarantee.

In other words,  if you build the application the way you suggest,  you
will have to ensure that it is run with a specific window manager,  and
probably with a specific window manager configuration file (such as .uwmrc),
in order to ensure that the window manager policy you depend on will be
in effect.

Once again,  it is important to observe that X provides no guarantee of
portability or inter-operability.  The use of X makes it easier to provide
both,  but you cannot simply assume that something that works on your
workstation with your window manager will automatically work on all
workstations and with all window managers.  That is the reason for the
conventions (restrictions) set out in the ICCCM,  and for the techniques
set out in our Usenix paper on the choice of Visuals.  There are many
other areas yet to be covered in which portability problems may arise -
one obvious example is the question of running out of resources on X
terminals.

	David.