Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!umich!samsung!usc!snorkelwacker!bloom-beacon!EXPO.LCS.MIT.EDU!kit
From: kit@EXPO.LCS.MIT.EDU (Chris D. Peterson)
Newsgroups: comp.windows.x
Subject: Re: Synchronous vs Asynchrounous
Message-ID: <9002021641.AA24460@expo.lcs.mit.edu>
Date: 2 Feb 90 16:41:32 GMT
References: <1990Feb1.213625.12870@ux1.cso.uiuc.edu>
Sender: root@athena.mit.edu (Wizard A. Root)
Organization: The Internet
Lines: 40


[ David Hammerslag (hammer@uicsrd.csrd.uiuc.edu) writes: ]

> I faced a similar problem.  Here is what I did.  (Caveat:  it ain't pretty,
> but is seems to work). If anybody is willing to share a more reasonable 
> solution, I would like to see it.

> XfWorking()
> {
>     register XEvent event;
>     XtAppContext app = _XtDefaultAppContext();
>     Widget bboard;
>     Window win;
> 
>     bboard = XtParent(standby);
>     XtManageChild(bboard);  /* this pops up the shell */
> 
>     win = XtWindow(bboard);
>     do /* be XtMainLoop until the bboard gets an expose event */
>     {
> 	XtAppNextEvent(app, &event);
> 	XtDispatchEvent(&event);
>     } while ((event.xany.window != win) ||
> 	     (event.type != Expose));
> 
>     XFlush(XtDisplay(standby));
> }

This is one of the best solutions I have seen to this problem.  In face using
XtAppAddTimeout() you can even set a global variable to have this loop time out
after a few seconds, so that your application doesn't hang if the window
happens to be covered and doesn't receive an expose event.  


						Chris D. Peterson     
						MIT X Consortium 

Net:	 kit@expo.lcs.mit.edu
Phone:   (617) 253 - 9608	
Address: MIT - Room NE43-213