Path: utzoo!attcan!uunet!island!argv
From: argv@island.uu.net (Dan Heller)
Newsgroups: comp.windows.x
Subject: Re: Unwanted Enter/Leave events during XGrabPointer
Message-ID: <495@island.uu.net>
Date: 24 Nov 88 08:33:15 GMT
References: <278@stan.com> <8811171510.AA13680@EXPO.LCS.MIT.EDU>
Reply-To: argv@island.uu.net (Dan Heller)
Organization: Island Graphics, Marin County, California
Lines: 38

In article <8811171510.AA13680@EXPO.LCS.MIT.EDU> rws@EXPO.LCS.MIT.EDU (Bob Scheifler) writes:
>
>    My reading of the event mask passed to XGrabPointer says the Enter/Leave
>    events should be discarded; is there something I am missing here?
>
>Nope, 'tis a bug, plain and simple.  I know where the bug is, and
>basically how to fix it, but it will probably be a little while
>before you see a fix.

But is it a bug?  I depend on this for at least one use.  I have widgets
which need to know whether or not you are inside of the widget's bounding
box.  If you leave it, it needs to dehighlight, XtRemoveTimeOut, etc...
For example, say I have a widget which is an "Open File" command-type
widget.  I am inside the widget, I click on it, and the callback routine
tries to open a file.  At this point, the code is part of the applciation,
_not_ in the user interface.  The application knows nothing of the user
interface layer, but if it fails to open the file, then it needs to 
know what to do next by caling a "generic" routine which asks, "create
the file?"  To do this without relinquishing control back to the top
level, the application calls a routine which creates a dialog box which is
a popup widget that has yes/no widgets and a small MainLoop()-type loop.
It grabs _all_ the events to prevent the user from doing anything else
in the application besides clicking on yes or no.  When the user goes to
click on yes or no, he has left the "Open File" widget which started all
this.  This widget needs to know that the user has left its boundaries
so it can reset itself.

How is this supposed to work if I can't get enter/exit window events?
Obviously, supressing such events is desired, but in cases as I've
described, you need those events.  Perhaps it would be a good idea to
tell the server which window is doing the grabbing and then allow that
window to have enter/exit events... ?

-- 
			--dan

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