Path: utzoo!attcan!uunet!lll-winken!ames!pasteur!ucbvax!bloom-beacon!decwin.DEC.COM!fisher
From: fisher@decwin.DEC.COM (VMS DECwindows Engineering, 381-1466)
Newsgroups: comp.windows.x
Subject: RE: GrabServer/UngrabServer nesting?!?
Message-ID: <8904141314.AA08815@decwrl.dec.com>
Date: 14 Apr 89 13:14:29 GMT
Sender: daemon@bloom-beacon.MIT.EDU
Organization: The Internet
Lines: 17

I was about to tell you that grabs don't nest, and that the client should
look at the "Already Grabbed" status that comes back and not do the
ungrab if they come back.  Alas, a quick check proves that this status
is only returned for grabbing keys and mice.  Bummer.

The protocol says nothing about nesting grabs; therefore they don't nest.
Therefore, the sample server is doing it right.  You can argue that this
is a bug in the protocol, but I don't think you can argue that it is a bug
in the server.

Of course, one can always implement the nesting functionality at the client
level quite easily by keeping a ref count and only sending the grab to the
server when the count is 0 and only sending the ungrab when the count is
one.  (You don't have to worry about other clients horning in when the count
is non-zero, obviously).

Burns