Path: utzoo!utgpu!watserv1!watmath!att!tut.cis.ohio-state.edu!zaphod.mps.ohio-state.edu!usc!snorkelwacker!bloom-beacon!EXPO.LCS.MIT.EDU!rws
From: rws@EXPO.LCS.MIT.EDU (Bob Scheifler)
Newsgroups: comp.windows.x
Subject: Re: XReparentWindow vs. ALL window managers
Message-ID: <9004122050.AA15913@expire.lcs.mit.edu>
Date: 12 Apr 90 20:50:41 GMT
References: <1990Apr10.203116.25044@Solbourne.COM>
Sender: daemon@athena.mit.edu (Mr Background)
Organization: The Internet
Lines: 14


    Here's the real solution.  I think it's something that every
    reparenting window manager is going to have to do.  When you get the
    UnmapNotify event, do an XQueryTree on whatever window (typically your
    frame) you think should be the parent.  If you don't find the window in
    the list of children, the window has been reparented someplace else and
    you shouldn't do an explicit reparent back to the root.

There's a race condition unless the WM does a GrabServer for this.
An alternative is that the client is required to notice that the
window was reparented by the WM, and when it wants to know the
window has been withdrawn, it must wait for the unmap notify and
a subsequent reparent notify back to the root, before itself
attempting to reparent.