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From: klee@wsl.dec.com (Ken Lee)
Newsgroups: comp.windows.x
Subject: Re: How do *you* handle multiple displays?
Message-ID: <1991Jun26.131122@wsl.dec.com>
Date: 26 Jun 91 20:11:22 GMT
References: <14246@maslow.ptolemy-ri.arc.nasa.gov>
Sender: news@pa.dec.com (News)
Reply-To: klee@wsl.dec.com
Organization: DEC Western Software Laboratory
Lines: 24

In article <14246@maslow.ptolemy-ri.arc.nasa.gov>, fineman@ptolemy-ri.arc.nasa.gov (Charles Fineman) writes:
|> I'm working on a performance visualization package and I would like to
|> give the user the option of displaying views on multiple screens. The
|> problem comes when trying to wait for events from the different
|> windows. If the windows are handled by different display servers, the
|> event wait loop turns into a spin-loop since there is no way to do a
|> blocking request for events from multiple servers (right???).

If you're using the X Toolkit, just put all the displays in the same
application context and call XtAppMainLoop.  The X Toolkit
automatically handles all the different displays properly.

If you're not using the X Toolkit (why aren't you?), you have to use
operating system dependent techniques for blocking on multiple
connections.  In systems derived from BSD UNIX, the ConnectionNumber()
macro will give you the socket descriptor.  You can pass these to
select(), which will block on all the connections until one is ready
for reading.

-- 
Ken Lee
DEC Western Software Laboratory, Palo Alto, Calif.
Internet: klee@wsl.dec.com
uucp: uunet!decwrl!klee