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From: morreale@bierstadt.scd.ucar.edu (Peter Morreale)
Newsgroups: comp.windows.x
Subject: asychronous callbacks with X11?
Keywords: Xt/ Xaw application
Message-ID: <9206@ncar.ucar.edu>
Date: 17 Nov 90 17:38:56 GMT
Sender: news@ncar.ucar.edu
Reply-To: morreale@bierstadt.scd.ucar.edu (Peter Morreale)
Distribution: usa
Organization: Scientific Computing Division/NCAR, Boulder, CO
Lines: 32

(WARNING:  New X programmer, the following may fall into the 
	   "extremely dumb question" catagory.....  :-)

I have an Xt application in which I would like to have a 
particular callback execute asychronously.  

This particular callback fills in several text widgets with data parsed
from a rather large file.  I would like the user to be able to click on
a button, have the callback start working, and allow the user to
immediately start filling in a separate text widget.

(BTW: I haven't written the callback yet, and I have the "synchronous"
      resource set for debugging purposes....)

If this *is* a truely dumb question (and I have a feeling that is may
be, but what the heck, it's saturday and the C.U. Buffs are about to
cream Kansas State...), then  I have another question.....

Providing that the default is asychronous, How do I prevent the user
from invoking a different callback until the "fill" callback has
completed it's task?  (this other callback writes to a file and disaster
could result if the user started writing the data before the widgets
were completely filled in.)  Is there an X function I can use, or do I
have to develop my own scheme?

Thanks,
-PWM
--
------------------------------------------------------------------
Peter W. Morreale                  email:  morreale@ncar.ucar.edu
Nat'l Center for Atmos Research    voice:  (303) 497-1293
Scientific Computing Division