Re: ATK ,GTK...

[<mongoose magic shiman com>]

  So let me get this straight. ATK is just the definition of an
interface and GAIL implements this interface. So does GAIL take gtk data
and convert it to be accessed through the ATK interface? That is, does the
Assistive Technology (Screen reader, etc...) access a GUI's data through
the ATK interface without any knowledge of the GUI itself?

If so then ATK could become an interface standard for AT
devices/applications to access and get information on a GUI.

Is SPI going to be the solution to access data from a GUI that does not
have an ATK interface? Looking at the diagram it looks like it will rely
on intercepting events sent to and from the GUI.

On Fri, 8 Jun 2001, Bill Haneman wrote:

> 
> >  I'm browsing around these accessibility docs and I'm a little 
> confused.
> >Are there two projects going on with gnome for accessiblity? An 
> addition
> >to GTK to make applications using GTK accessible, and another project 
> (ATK
> >I think it's called?) to make applications that don't use GTK 
> accessible?
> >Am I correct? Thanks
> 
> Not quite ;-)
> 
> ATK is a set of interface definitions and wrappers defining 
> accessibility.  ATK is not GTK-specific, but ATK does define the 
> accessibility interfaces which GTK uses.
> 
> In turn, the actual implementation of those interfaces on behalf of the 
> GTK+ widgets is in a project called GAIL, which is dynamically loadable 
> by a GTK+ application.
> 
> Thus:
> 
> GTK+ depends on the accessibility interfaces in ATK (thus ATK "defines" 
> accessibility for GTK+).
> 
> ATK itself has no dependencies on GTK+, thus other toolkits could still 
> use ATK as their accessibility interface definition and accessibility 
> API.
> 
> The actual widget-specific code that implements those interfaces lives 
> in another module which is dynamically loadable (GAIL).  If GAIL is not 
> loaded, GTK+ widgets will have a default accessibility implementation 
> that basically returns "null" information though it nominally conforms 
> to the ATK API.  
> 
> ATK depends on glib, so any toolkits wishing to implement ATK as their 
> accessibility interfaces will need to link to glib.
> 
> Status:  ATK is basically complete/frozen, GAIL is under active 
> development, somewhere around 35% complete.
> 
> There is another set of interfaces, still being finalized, called the 
> accessibility Service Provider Interface (SPI).  These interfaces are 
> used by out-of-process clients to obtain accessibility information about 
> running applications.  (ATK can't be used for this since ATK is an 
> in-process interface, and can only be used directly within the 
> application's own process space).  This SPI can be implemented by any 
> toolkit.  In the case of GTK+, the internal ATK interfaces are exported 
> to the SPI via the "Accessibility Bridge".
> 
> Two diagrams of interest:
> 
> http://developer.gnome.org/projects/gap/presentations/GUADEC/gnomeaccess
> architecture.html
> 
> http://developer.gnome.org/projects/gap/tech-docs/SPIBlockDiagram.png
> 
> Regards,
> 
> -Bill
> 
> > Garrett Banuk
> >
> >
> >_______________________________________________
> >gnome-accessibility-list mailing list
> >gnome-accessibility-list gnome org
> >http://mail.gnome.org/mailman/listinfo/gnome-accessibility-list
> 
> ------
> Bill Haneman x19279
> Gnome Accessibility / Batik SVG Toolkit
> Sun Microsystems Ireland 
> 
> 
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