[orca-list] About accessible features of ROLE_UNKNOWN in evince

[leena chourey <leenagour gmail com>]

Hello Orca Developers,

As explored and discussed with community people, It is clear that a particular part  of evince application window does not have the accessibility features. 
Currently Evince uses poppler lib to render content of pdf doc on an unknown widget. Will it be feasible if we try to render the content of pdf doc on an accessible widget in place of unknown widget? This will require changes in evince application itself.

I wanted to make sure that will this be enough to make that unknown part accessible by assistive technology  (ORCA)

Thanks & regards
Leena C

On Thu, Apr 1, 2010 at 11:11 PM, Joanmarie Diggs <joanmarie diggs gmail com> wrote:

Hi Leena.

On Thu, 2010-04-01 at 15:16 +0530, leena chourey wrote:
> Can anybody tell about What accessibility features atspi ROLE_UNKNOWN
> has?

I'm afraid you cannot make a one-to-one correspondence between an Atk
role of an object and the accessibility features (e.g. whether or not it
implements the accessible text interface).

In other words, this documentation you quote:

> As said in the doc: Accessibility Namespace Reference. :
> "ROLE_UNKNOWN
> The object contains some Accessible
> information, but its role is not
> known."

should be taken quite literally, at face value: It means you don't know
the role. Period.

> But I am not able to find those features Or how can we add feature to
> any GNOME widget.

If you want to see if a given object, of any Atk role -- including
ATK_ROLE_UNKNOWN -- implements a particular accessible interface, you
should query that interface. For instance, given accessible object acc
and using Python, acc.queryText() will return the accessible text
interface should it exist for that object.

Note that it is possible for some parts of a given interface to be
implemented (hypothetically atk_text_get_text might be implemented, but
atk_text_add_selection might not be).

As for how to add features to (i.e. implement the above interfaces in) a

widget, that is something that we don't do on the Orca side of things.
The creator of the widget must do the implementation. Then Orca can

access what has been implemented.

HTH.
--joanie

-- 
Leena C