From:	Matthew Mastracci <mmastrac AT acs DOT ucalgary DOT ca>
Newsgroups:	comp.os.msdos.djgpp
Subject:	Re: Compiler bug in Allegro? Shawn, DJ?
Date:	Thu, 10 Apr 1997 21:34:08 -0600
Organization:	The University of Calgary
Lines:	41
Message-ID:	<Pine.A41.3.96.970410212828.138294A-100000@acs2.acs.ucalgary.ca>
References:	<5ik06u$42q AT yayrap DOT cc DOT muroran-it DOT ac DOT jp>
NNTP-Posting-Host:	mmastrac AT acs2 DOT acs DOT ucalgary DOT ca
Mime-Version:	1.0
In-Reply-To:	<5ik06u$42q@yayrap.cc.muroran-it.ac.jp>
To:	djgpp AT delorie DOT com
DJ-Gateway:	from newsgroup comp.os.msdos.djgpp

On Fri, 11 Apr 1997, Patrick G. Kutch wrote:

>    for (c=0; d[c].proc; c++)
>       if ((mouse_x >= d[c].x) && (mouse_y >= d[c].y) &&
>     (mouse_x < d[c].x + d[c].w) && (mouse_y < d[c].y + d[c].h) &&
>     (!(d[c].flags & (D_HIDDEN | D_DISABLED))))
>     {
>         mouse_object = c;
>         break;
>     }
> 
>    return mouse_object;

> However, this causes all kind of problems.  After doing this, the
> routine doesn't seem to work properly.  The focus will be lost while
> definitley moving over a button.

I'm guessing that Allegro uses the last-in-first-to-get-focus stack.  When
you short-circuit the for-loop, some of the later objects lose their
ability to get the focus.  If you want to optimize this loop, set a
pointer to the current last object in the list (maintain it too! :) and
step backwards like so:

for (c = last_element;; c--) 
  if (blah)
  {
    mouse_object = c;
    break;
  }

return mouse_object;

This will act in the same way as the current Allegro proc.  I'm not 100%
sure that Allegro does it this way, but give it a try.  :)

/\/\att /\/\astracci                  mmastrac AT acs DOT ucalgary DOT ca

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