Path: utzoo!utgpu!watmath!att!tut.cis.ohio-state.edu!cs.utexas.edu!csd4.csd.uwm.edu!mailrus!ncar!boulder!stan!toml
From: toml@Solbourne.COM (Tom LaStrange)
Newsgroups: comp.windows.x
Subject: Re: Window Managers.
Message-ID: <1946@imelda.Solbourne.COM>
Date: 15 Aug 89 17:39:51 GMT
References: <252@bii.UUCP>
Organization: Solbourne Computer Inc., Longmont, Co.
Lines: 23

> Is there any way for a client to poll if a window manager
> is present. I think this would be an important feature
> when installing colormaps and trying to be ICCCM compliant
> at the same time. Please post the result because there 
> might be other people that would want to know the answer.

Sure, you can do the same thing that most window managers will do 
to determine if another window manager is running.  Set up an error
handler and XSelectInput on the root window with SubstructureRedirectMask.
If you go through your error handler, chances are good that a window manager
is running.  The only problem is that if you start your application 
when no window manager is running, how do you detect when a window manager
is started sometime later?

You can look in contrib/windowmgrs/twm/twm.c for an example of the
above code.

--
Tom LaStrange

Solbourne Computer Inc.    ARPA: toml@Solbourne.COM
1900 Pike Rd.              UUCP: ...!{boulder,nbires,sun}!stan!toml
Longmont, CO  80501