Re: Backing Store (was Re: Desktop Kernel Stuff)

[Ettore Perazzoli <ettore ximian com>]

On Fri, 2003-07-11 at 18:07, Owen Taylor wrote:
> On Fri, 2003-07-11 at 17:25, Ettore Perazzoli wrote:
> > On a slighty unrelated note, I was actually wondering about this. 
> > Shouldn't GTK set BackingStore to WhenMapped in all windows these days? 
> > Besides the swapping that Alan is mentioning, it would also prevent the
> > ugliness that happens when applications are not redrawing themselves
> > because they are busy doing something.
[...]
> The main reason is that for technical reasons, backing store as
> implemented in X is conceptually broken. One major problem is that 
> for a guffawed scrolled window (like a GtkTextView with an embedded
> widget), X will happily backing store the entire contents of the
> window, not just the visible part.

Hmm OK I was not aware of that.

> Also, I think it's wrong for GTK+ to tell the X server that it is 
> especially interesting to backing store. GTK+ is no more interesting
> to backing store than any other app, and if backing store make
> sense for GTK+, the server should be doing it for all apps.

Makes sense.

So, what needs to happen before we have buffered windows on X?  I wonder
if anyone has considered the problem in recent times.

-- Ettore