RE: draw signals

["Dugas, Alan" <alan dugas analog com>]

Carlos,

Thanks for your response.  I would love to forget about "draw" :-)  However, I
don't see how I can.  Everytime I uncover a portion of a window with a pixmap in
it, I get an "expose_event" (which I use to refresh the screen) and a "draw"
signal which repaints my pixmap and then refreshes the screen a second time.
The repainting of my pixmap seems unnecessary IMHO and is forcing me to allocate
memory and attach data to every pixmap I use.  I would like to eliminate this
redundancy so that I don't need to use up the extra memory and waste time doing
the same thing twice.  Any ideas on how to solve this problem would be greatly
appreciated!



				-- Stupid Genius
P.S.
I guess I just don't understand why a "draw" signal is emitted when an
"expose_event" appears to be all that is needed.

> ----------
> From: 	Carlos Pereira[SMTP:carlos@pehoe.civil.ist.utl.pt]
> Sent: 	Friday, December 22, 2000 12:09 PM
> To: 	gtk-app-devel-list@gnome.org
> Subject: 	Re: draw signals
> 
> >Opps, let me correct myself.  I'm finding that a "draw" AND an "expose_event"
> >are being emitted.  Is there any way to filter this so that only the
> >"expose_event" is acted upon.  My pixmaps are being refreshed by the
> >"expose_event" and then redrawn by the "draw" signal unnecessarily.  By doing
> so
> >it is forcing my to allocate memory for the redraw, when I don't really need
> to.
> >The pixmap hasn't changed, so I only need to refresh it.  In and all help
> would
> >be greatly appreciated.  Thanks in advance!
> 
> 
> I might be wrong, so don't take my words for granted,
> but I really believe you will be much better if you
> just forget about "draw" signals at all. You don't
> need "draw" for nothing. Just forget that it exists.
> Do yourself a favor and erase "draw" from your app, completely,
> your app will be simpler and will behave better.
> 
> "expose_event" "configure_event" and "motion_notify_event"
> are the signals you usually need when handling complex
> drawing areas (or opengl_areas for that matter).
> 
> Carlos
> 
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