Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!ucbvax!hplabs!hp-pcd!hpcvlx!ben
From: ben@hpcvlx.cv.hp.com (Benjamin Ellsworth)
Newsgroups: comp.windows.x
Subject: Re: Need help in interactive selection of a motif widget/gadget
Message-ID: <100920123@hpcvlx.cv.hp.com>
Date: 27 Oct 89 00:40:36 GMT
References: <4219@hplabsz.HPL.HP.COM>
Organization: Hewlett-Packard Co., Corvallis, OR, USA
Lines: 43


(I don't understand why you cross posted to comp.windows.x.  Anyways...)

> ...Am I doing something wrong?

In a word, yes.

The easy answer is to set owner events true on the grab, and then the
data in the event are exactly what you want.

Looking at your code, I don't understand how it would ever work for the
general case.  Specifically:

>   while (XTranslateCoordinates(display,
> 			       parent_win, child_win,
> 			       parent_win_x, parent_win_y,
> 			       &parent_win_x, &parent_win_y,
> 			       &win)
> 	 && win) {
>     parent_win = child_win;
>     child_win = win;
>     child_win_x = parent_win_x;
>     child_win_y = parent_win_y;
>   }

When win is set to NULL by XTranslateCoordinates, the entry condition
for the while loop becomes false and the loop terminates.
Unfortunately it terminates before updating child_win_x and
child_win_y.  The rest is, as they say, history.  

As far as I can tell, this code will *only* work when the parent and 
child window have coincident origins (such as a rowcolumn in a 
scrolledwindow before any user scrolling).


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