atk <-> MSAA once more

[Allin Cottrell <cottrell wfu edu>]

I'm following up on an issue I raised a few weeks back.  I got busy 
with other things, but would still like to take a crack at bridging 
between gtk/atk and MSAA to provide a measure of accessibility for 
gtk apps on win32.

So far I have made a Windows DLL of libgail (though I'm not quite 
sure what that buys me) and have done some reading on MSAA.  I'd be 
grateful if anyone could check my (still vague) understanding of 
what has to be done.

> From the MS docs, I gather than if Jaws (say) is to read the menus 
from a gtk appplication, it proceeds by asking OLEACC to quiz the 
app.  OLEACC sends a WM_GETOBJECT message to the "server" (e.g. the 
gtk app).  The server either returns zero (in which case OLEACC 
attempts to construct a proxy), or it returns an "Iaccessible 
object".  I'm supposing that if the gtk app returns zero, OLEACC is 
not going to make much headway trying to construct a proxy, since 
the app is not composed of standard Windows controls.  Therefore 
(?), the app will have to build and return an Iaccessible object.

I can sort of see from the MS docs how one might go about 
constructing an Iaccessible object.  What I'm very hazy on is how 
one would hook this up with atk/gail.  Or how one would receive and 
recognize OLEACC's WM_GETOBJECT message in the first place.

Would this involve (something like) creating an intermediary process 
which would listen for WM_GETOBJECT, and with which one's gtk app 
would be "registered" in some way.  Is this roughly what gail does 
on gnome (or is it at-spi that does that)?

Sorry for all the questions.  It may be that I'm simply out of my 
depth here, but I'm still keen to try if I can get a better handle 
on what's required.

Allin Cottrell
Department of Economics
Wake Forest University, NC