Re: gdk_draw_layout seems that it doesn't make damage event for offscreens.

[Alexander Larsson <alexl redhat com>]

On Sun, 2009-12-06 at 13:04 +0000, 박보람 wrote:

> Currently I'm making some customized widgets with GTK+-2.18.
> 
> To test performance about my customized widget, I'm using "gtkperf".
> 
> But a problems running gtkperf. 

> "gdk_draw_layout seems that it doesn't make damage event for
> offscreens"
> 
>
> I wonder whether this problem is the known issue or not.
> 
> Or I just made misunderstanding.

This is actually part of a larger problem. When you draw to an offscreen
window using cairo we don't currently report damage events, because
there is no way to virtualize these drawing operations such that we can
track them.

In practice this is not really a problem since most cairo stuff is
modern, and modern widgets draw everything double buffered, and the
double buffering handling does generate damage events.

It might be possible to make the specific case of gdk_draw_layout() to
cause damage events with some work. What exactly is your usecase here?
Do you draw directly to the window or from an expose handler?

-- 
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
 Alexander Larsson                                            Red Hat, Inc 
       alexl redhat com            alexander larsson gmail com 
He's a one-legged Amish assassin searching for his wife's true killer. She's a 
cold-hearted wisecracking vampire from aristocratic European stock. They fight 
crime!