Re: [g-a-devel]Representing Accessible Text in gnome-help

[Peter Korn <Peter Korn Sun COM>]

Hi Padraig,

> > > 1) Run the commannd
> > > gnome-help ghelp:///opt/gnome-2.4/share/gnome/help/user-guide/C/wgosnautilus.xml
> > > to display nautilus help amd chhose section 1.1 Introduction to
> > > Nautilus File Manager.
> >
> > First off, I'm getting lots of Glib-GObject-WARNINGS at 
> > (gnomehelp:2055) - something about an invalid cast from
> > 'HtlmlLinkAccessible' to 'AtkObject'
> >
> 
> Are you running an AT as well, i.e. gok, gnopernicus or at-poke? I am
> not seeing these warning messages. It sounds like bug #120659.

I'm running at-poke, as that is how I am viewing the accessibility
heirarchy you are creating.  It does sound like the same bug, although the
author of 120659 doesn't specify in the bug enough information about the
error message to be 100% certain...

> > Second, I see no use of relations.  Since you are making a large 
> > heirarchy of objects for this document, using the flows-from and 
> > flows-to relations to ensure a screen reader can read the whole 
> > document seems like it could be important.  Especially when it comes 
> > to rendering more complex documents with tables and the like.
> 
> There is currently no use of relations. I think I need to get the
> objects right before worrying about the relations. Are you content
> with the choice of accessible objects used to present the text in
> this example? I haev attached a dump of the layout structure which
> is available to me to construct the accessible objects. If so, do
> you recommend that each object with role text should have flows-from
> and flows-to relations?

I agree, get the objects right first.

I'm concerned about using flows-from and flows-to relations everywhere. 
That introduces a whole lot of objects.  I'm not aware of us ever having
defined where they are needed and where they aren't.  The classic case
(and why they were invented) is StarOffice/OpenOffice.org, where the body
of the text flow across the header and footer objects.  

A very good question is whether we can have a cannonical ordering of
objects, such that flows-from/flows-to is only needed when the ordering is
non-cannonical...

> > Third, I wonder about the use of the atk-table widget for the top 
> > content region object that contains "Previous" and "Next".  Tables are 
> > used a lot for layout in HTML, and also sometimes for actualy tabular 
> > data.  It isn't clear to me that we have a foolproof algorythm to 
> > determine which use, but it would certainly be nice if possible.  At 
> > the very least, a screen reader shouldn't be telling a user that 
> > "Previous" is cell #1 and "Next' is cell #2.  That just doesn't make
> > conceptual sense.
> >
> 
> Setting the role to TABLE only if the layout object, which is a
> HtmlBoxTable, has more than one row seems to solves this case. Is that
> a reasonable algorithm?

It is a worrisome algorithm.  One could imagine a single row table with
meaning as a table.  I would more likely collaspe a single column table
into a list object, than collapse a single row table.

It may be that we need a more sophisticated approach, and that it should
live in the AT (which potentially has more knowledge in some respects).  I
defintely suggest that you don't put such code in at this time.

> > > 2) Run the command
> > > gnome-help
> > > to display a man page. On Solaris I choose Manual
> > > Pages|Applications|X11|dsdm(1x)
> >
> > Can you provide the specific command line you used to invoke the man 
> > page in question?
> >
> 
> I run the command gnome-help without any arguments and I get a window
> containing a link called "Manual Pages". Clicking on that link gives
> me a window containg a link called "Applications" etc.. Perhaps we
> should postpone this discussion until we have finished discussing
> nautilus help.

Hmmm... I played a bunch more with gnome-help and at-poke, and found some
interesting things.

Looking at a directory listing of help files (specifically the one at
"Manual pages/Applications"), I see in at-poke only two objects in the
content region of the gnome-help application: the title object "Manual
pages/Applications", and then a 23,452 character text object containing
all of the rest.  

I think that ATs will have to deal with both situations - very
heirarchical in a document with tons of small accessible-text objects, and
very flat.

I did notice what appears to be a bug though: I'm unable to get gnome-help
to expose the correct objects for one of the man pages in the list of
applications (e.g. the man page for 'ar').  at-poke insists that I'm still
looking at the directory listing for "Manual pages/Applications").


Peter Korn
Sun Accessibility team