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From: asente@adobe.com (Paul Asente)
Newsgroups: comp.windows.x
Subject: Re: Timer Interrupt
Keywords: Timer, Event handler
Message-ID: <10287@adobe.UUCP>
Date: 24 Jan 91 19:32:03 GMT
References: <1100@unisql.UUCP<
Sender: news@adobe.COM
Organization: Adobe Systems Inc.
Lines: 34

In article <1100@unisql.UUCP> yu@unisql.UUCP (Yeong-Ho Yu) writes:
< I am trying to make a main event handler which will run for at least
<the given time, and returns the control back to the program.
<That is, it should be a temparary XtAppMainLoop.
<
< I made up the following function:
<
<void TempEventH(XtAppContext app, unsigned int time)
<{
<  XEvent event;
<
<  XtAppAddTimeOut(app, time, NULL, NULL);  /* put up a timer event */
<  while(!(XtAppPending(app) & XtIMTimer)){ /* until it arrives */
<    XtAppNextEvent(app, &event);           /* do the event  processing */
<    XtDispatchEvent(&event);
<  }
<}  
<
<Of course, it does not work.  But, I don't know why.
<Any suggestions?  Many thanks in advance.

From section 7.4 of the Xt spec, discussing XtAppNextEvent:

If the X event queue is empty, XtAppNextEvent flushes the X output buffers of
each Display in the application context and waits for an X event **while
looking at the other input sources and timeout values and calling any
callback procedures triggered by them.** [emphasis added]

In other words, your timer is getting triggered in XtAppNextEvent.  You need
to use use XtAppProcessEvent to get the degree of control over event
dispatching that you want here.

	-paul asente
		asente@adobe.com	...decwrl!adobe!asente