Re: XForms: more double buffering strangeness

Steve Lamont (
Thu, 10 Jul 97 08:30:07 PDT

To subscribers of the xforms list from (Steve Lamont) :

> > Is it legal to make non-drawing calls (such as fl_set_slider_value())
> > or fl_redraw_object() calls for objects other than the Free object in
> > the Free object handler?

> Are you doing this in response to an FL_DRAW event? I've had problems when
> a canvas Expose event triggered redrawing of other objects. The solution was
> to postpone the redrawing until after finishing handling the Expose event.
> (But I think this had nothing to do with double buffering.)

Yes, it is in the FL_DRAW handler for a Free object.

I've never had the problem you describe and, in fact, do quite a bit
of object handling in my Canvas Expose handlers and I do force redraws
with fl_redraw_object() or fl_redraw_form() with no difficulty
whatsoever -- at least any that I recall.

I've never tried it in double buffer mode, so I don't know whether
there would be any interaction. Double buffering shouldn't affect
Canvas objects at all -- at least I see no reason for any problem.

What difficulties have you had?

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