Re: UI reading for gnome/gtk apps

[Peter Korn <peter korn sun com>]

Hi Geoff,

> I would be interested in working on contributing to the effort to having
> decent user interface reading and audio feed back for the GNOME desktop.
> I've done a little bit of rough work to this end quite a while ago, AFAIK
> before the GNOME accessibility project was started.  

The approach of the GNOME Accessibility effort is to do the following five
general things:

 1. define a comprehensive accessibility API for the GTK+ widgets that
    GTK+ (and thereby GNOME) are built with -> this is ATK - the 
    Accessibility ToolKit

 2. implement full support for this API in the GTK+ widgets -> this is
    GAIL - the GNOME Accessibility Implementation Library

 3. implement full keyboard (mouseless) accessibility to all GTK+ widgets

 4. define a comprehensive accessibility API for the desktop, which
    would look remarkably like ATK in #1 above, but also include 
    inter-window functions, etc. -> this is the AT SPI - the Assistive
    Technology Service Provider Interface

 5. implement a bridge between #1 and #4 above, so that an AT product
    uses the AT SPI, they get all the information they need from all
    GTK+ applications

#1 is done and part of GNOME 2.0/GTK+.  #2 is fairly far along and looking
pretty good, though if you want to help here, that'd be great..  #3 still
needs a lot of help, and that work has generally be distributed amoung all of
the widget owners (perhaps you might help there?).  #4 and #5 are in their
early stages, but coming along.


If you want to develop user-interface reading and audio feedback, you could
do it at the GTK+ level (using ATK as your interface), or you might wait a
bit, and write to the AT SPI.  The main reason to wait is that non-GTK+
applications will be part of a GNOME desktop - applications such as those
written in Java, for which we will be writing a bridge (and equivalent to #5
above, but from Java to the AT SPI).  And even if you don't care about non
GTK+ applications, being able to enumerate the set of GTK+ windows and
applications via an accessibility API, for full desktop access, is something
you will need the AT SPI to do.


Regards,

Peter Korn
Sun Accessibility team