Re: How should at-spi be turned on?

[Bill Haneman <bill haneman sun com>]

Hi Greg:

Unfortunately there are two mechanisms for enabling at-spi support, and
to get "total coverage" you must use both.  That's because "pure gtk+"
applications can't take advantage of the gconf and gnome_program_init
mechanisms that are the preferred means of enabling assistive technology
support.

At the moment gtk-demo is one of the only gtk+-only applications that's
commonly encountered in the GNOME-2 distribution.

One reason that this hasn't been documented in the 2.2 user guide is
because, until recently, there haven't been any clients of this service
that are of interest to users.  The recent GOK and gnopernicus releases
are changing that, and one of the additions we think is important for
gnome 2.4 is a UI (checkbox or similar) for turning on the gconf key. 
The gconf key in question is "desktop/gnome/interface/accessibility" and
it's a boolean with values "true" or "false".  There's a convenience
script floating around that sets it, which I believe has been posted to
this list before.  Of course for the end-users who need it most,
something like a script or wizard makes more sense than a preferences
dialog (since with assistive technology support turned off, such users
wouldn't be able to use the GUI), but certainly we should provide a GUI
for consistency with the rest of GNOME, for testers, etc.

The reason that the GTK_MODULES environment variable (which is used for
gtk+-only applications, set to "gail:atk-bridge") doesn't work for
everything is this: some kinds of applications need different loadable
modules for their accessibility support, for instance applications that
use bonobo or libgnomeui need libgail-gnome as well as gail, and some
GNOME applications may choose to provide their own additional
accessibility modules rather than put the ATK support directly into
their widget code base.  (There are some other possible cases which I
won't go into here).

So at the moment the proposal is to use the gconf key, provide a GUI,
and document both the GUI and the script in the accessibility and user
guides.  We would also document the need for GTK_MODULES for "gtk+ only"
applications, but it does raise the issue of how to make that
distinction in a way that's appropriate to end-users... perhaps we can
build some sort of intelligence into at-spi, at-poke, or the
accessibility GUI so that gtk+-2-based applications that aren't
registering with accessibility can be detected, and the user prompted
appropriately.  

I don't know of a clean way to set/unset the user's environment for all
shells via the GUI we mention; all that comes to mind offhand are dirty
hacks like hacking the .login file, which I doubt we really want to do
silently :-)

Ideas?

regards,

Bill

On Wed, 2003-04-30 at 11:27, Gregory Merchan wrote:
> Hi.
> 
> I was playing with at-poke and since it didn't find any of my running gtk
> apps, I took a look at the source.
> 
> I see that before running gtk-demo it sets the GTK_MODULES environment
> variable. How is at-spi supposed to work for already running applications?
> 
> Do I need to set GTK_MODULES when logging in?
> 
> I see there has been discussion of this on g-a-d and g-a-l, but I didn't
> find a conclusion. Also, I don't see any mention of this in the user, admin,
> or accessibility guides at http://www.gnome.org/start/2.2/ .
> 
> Cheers,
> Greg
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