On Fri, Jun 22, 2012 at 06:25:22PM EST, Sebastien Bacher wrote:
> So I've read the bug upstream and I'm not sure how they are
> addressing the performances concerns, is the bottom line there "gtk3
> has no performance issues, a11y will not be turned on for gtk2 but
> only for gtk3"? If that's the case, what does it mean for gtk2
> applications? Do we get part of the desktop accessible and some
> other parts not? Do firefox and libreoffice use enough gtk to rely
> on the a11y to be turned on in gtk2 to be accessible in an usable
> way?

With regards to performance, upstream knows that there are still issues. If one 
is running an assistive technology like Orca, and opens a directory with a 
large number of folders and files in it using nautilus, there is currently a 
performance hit when the directory is opened, because nautilus/gtk/atk has to 
iterate through all of those entries, and create atk objects to associate with 
the GTK widgets in the icon view. How that will be solved long term I don't 
know, but the client tracking by atk and at-spi has been implemented to work 
around issues like the above.

The only change to the GTK2 module is to be linked against the new 
libatk-bridge library, which will do all the heavy lifting. The module still 
has the same symbols that it has always had. The only slight difference is that 
the GTK2 atk module will get loaded every time, assuming the GTK_MODULES 
environment variable is set or gnome-settings-daemon tells GTK the list of 
modules it should load. I think the libatk-bridge library has the smarts to go 
no further if it can't find the at-spi bus but even then, the same assistive 
technology client tracking comes into play as above, so no events will be 
emitted if there is nothing listening for events.

> Out of those questions I'm fine with follow upstream's lead there,
> we should just make sure it lands early so we have time to test and
> have a plan B to disable it again by default if that turns out
> creating too much issues.

It will land this week, and I should have the new libatk-bridge library 
packaged and ready to go in the archive by the time you and Jeremy get to 
updating GTK and gnome-shell, at least in source form. It will have to go 
through binary new due to new binary packages being added. Plan B will 
essentially involve reverting patches in GTK, GNOME shell, and at-spi2-atk to 
return to the previous behavior. I am pretty sure the gsettings key will stay 
around at least for now, and may or may not go away in future cycles depending 
on how well this a11y always on test works out this cycle.

Luke

-- 
ubuntu-desktop mailing list
[email protected]
https://lists.ubuntu.com/mailman/listinfo/ubuntu-desktop

Reply via email to