Re: Plans for drawing in GDK-1.4.

[Damon Chaplin <damon karuna freeserve co uk>]

Owen Taylor wrote:
> 
> I've been recently planning some changes
> to the draw/update model in GDK for 1.4.
> 
> I've put a description of some of my plans at:
> 
>  http://www.gtk.org/~otaylor/gdk-1.4.html


I noticed in gtklayout.h that you didn't think the freeze & thaw functions
worked. I just wanted to point out that I have found them useful, when using
a GnomeCanvas.

I needed to scroll the canvas, but have the entire canvas redrawn since
parts of it needed updating. Without the freeze/thaw calls this would flicker,
as the bits were copied around and then the canvas was later redrawn in an
idle handler.

So I hope something like this stays in 1.4, if it is still useful.


Another minor point is that I'm not sure the default widget draw function
(gtk_widget_real_draw) should send an expose event. If you use a widget
like a drawing area, and connect to both "draw" and "expose_event", then
when a "draw" signal is emitted both handlers get called. I'm not sure
it's good for consistency. It took me a while to figure out why I was
drawing everything twice all the time. (Though since this 'feature' is used
in the scribble-simple example, it may be used in a lot of code.)

Damon