[orca-list] "impressive" tool for presentations and seeking programming pointers

[<prayner unimelb edu au>]

We've been discussing on and off tools for doing presentations which
can be made accessible. A friend pointed out the Impressive tool
<http://impressive.sourceforge.net/> which seems to have much of the
infrastructure we need. In particular transitions into pages as well
as keystrokes can be associated with python functions which makes lots
of things possible. It even sounds possible to solve one of my
longstanding problems with presentations, making sure the slides on
the screen are synchronized with my notes. I can imagine a case where
transitioning into a page also displays my talk notes for that page on
my braille display.

A nice dream but there are a few hurdles in the way. First and
simplest is the pdftk library which seems to depend on some software
with problematic licensing. That seems soluble with the mcpdf package.
More challenging is the integration of the pygame machinery used by
impressive for drawing and event handling and something accessible.
Here I see two routes.
1) write something simple, direct and low-level (probably using
liblouis python bindings) that talks directly to the braille display.
2) Use pygtk and make sure the application is orca-friendly. 

(1) sounds like a crude hack ... I like those :-) but is pretty likely
to work in the end.
(2) sounds like a lot more learning but probably a more useful product
provided it will work. It's also a great excuse for me to learn pygtk
and a bit about accessibility.

I've a week's vacation at the moment so would like to tackle this
asap. Novice question 1, if I use standard pygtk widgets are they
exposed automatically to atspi and hence orca? I'm guessing yes and
can test but confirmation/guidance would be welcome.
Novice question 2, if we use orca for this we're effectively going to
be using two displays, the braille display for the main event loop and
displaying text and the screen/projector for displaying the
presentation. I don't expect a problem with this once I learn how to
make gnome do it but I'd welcome advice if anyone else sees a problem.
Any other advice on the project (e.g. you're mad :-) also welcome.
cheers
Peter



-- 
Peter Rayner
Leader, Clean Air and Urban Landscapes NESP hub <http://www.nespurban.edu.au>
room 343 
School of Earth Sciences, University of Melbourne, 3010, Vic, Australia
tel: work: +61 (0)3 8344 9708; fax: +61 (0)3 8344 7761 
mobile +61 402 752 379, skype: petermorag 
mail-to: prayner unimelb edu au
google scholar profile <http://scholar.google.com.au/citations?user=H3up71wAAAAJ&hl=en>