[comp.windows.x] Asynch events?

jg@max.crl.dec.com (Jim Gettys) (07/20/89)

No, Xlib does not itself provide a read with timeout feature, though it will
provide you with enough information to do this in an OS dependent fashion.

The Xt intrinsics, however, I believe provide this functionality, and in an
OS independent fashion.  I suspect other toolkits do as well.

You should be using a toolkit in any case.  Xlib is not the right level
of abstraction for building entire serious applications, unless you are a
masochist, or a toolkit implementer.
				- Jim Gettys

chan@hpfcmgw.HP.COM (Chan Benson) (07/22/89)

> You should be using a toolkit in any case.  Xlib is not the right level
> of abstraction for building entire serious applications, unless you are a
> masochist, or a toolkit implementer.

Or want to do any of a number of things that are difficult or impossible
with Xtk; or want to make a lean and mean application.

			-- Chan Benson
			HP Fort Collins

rcb@ccpv1.ncsu.edu (Randy Buckland) (08/15/89)

Is there any way with Xlib to read events with a timeout? The only way
I can think of would be to flush the internal queue and then 
do a select on the file number that Xlib is using to talk to the server.
However this is not very portable. What I would like would be a version 
of XNextEvent with a timeout parameter that can take sub-second values.


Randy Buckland
rcb@ncsuvx.ncsu.edu

rws@EXPO.LCS.MIT.EDU (Bob Scheifler) (08/28/89)

    The only way
    I can think of would be to flush the internal queue and then 
    do a select on the file number that Xlib is using to talk to the server.

Right.

    However this is not very portable.

Also Right.

    What I would like would be a version 
    of XNextEvent with a timeout parameter that can take sub-second values.

But many others will argue that this isn't sufficient, since they need to
wait on other things besides X events, or they need to wait on multiple
displays, or ...  It isn't obvious to me what a reasonable and portable
interface would be.