Re: [g-a-devel] Re: AT-SPI, focus leaving and window IDs

[Bill Haneman <Bill Haneman Sun COM>]

Dave Mielke wrote:
> [quoted lines by Bill Haneman on 2005/03/04 at 13:07 +0000]
>
>
> > we expect ALL applications which care about 
> > accessibility to participate and cooperate in the at-spi environment.
>
>
> I think it'd be unreasonable to require a text mode only BrlAPI application to
> have a dependency on the graphical environment. I also think it'd be
> unreasonable for the basic infrastructure to preclude the possibility of a text
> mode only accessible application.

AT-SPI was designed to encompass graphical and non-graphical 
applications.  There is nothing in the AT-SPI interfaces which 
presupposes a graphical interface.  For instance, a non-graphical 
application will expose a hierarchy of AT-SPI objects, but those objects 
will not expose the 'AccessibleComponent' API (which is concerned with 
onscreen real-estate and graphical extents, etc.).

> Right now, BrlAPI allows a text mode application to claim the braille display.
> It knows which application should be in control of the display, or (the
> default) that BRLTTY should be in control of the display, based on the tty
> which is currently active. It'd be nice if this same capability were available
> for a text mode application running within a terminal window. 

This seems like a good model to me, but I am not sure how or whether 
virtual graphical terminals are mapped to 'pseudo-terminals' on 
Linux/Unix or not.  If they are, then I suppose BRLTTY or a similar 
text-mode application which wishes to use brlapi could use such a 
mechanism to grab a "virtual" tty.

If there's no nice way to do it at the TTY level in a virtual/graphical 
terminal, we may need to invent some API for it.

> The default
> within a terminal window would be that Gnopernicus is in control of the
> display. If, however, a text mode BrlAPI application is running within a
> particular terminal window then BrlAPI needs to be able to know/detect this so
> that it can give control to that application while its terminal window has the
> focus.

I think that it should be possible to inform a text-mode application, 
running in a graphical terminal, when it gains or loses focus, 
programmatically.  Certainly this could happen via at-spi, though I 
think there is some Xlib notification that happens to terminal emulators 
which ought to get passed on to the text mode applications running 
inside them.  To get hard answers to this we need to chat to some 
virtual terminal (i.e. xterm/gnome-terminal) developers.

- Bill