Re: AtkImage

[Bill Haneman <bill haneman ireland sun com>]

Padraig said:
> 
> I agree that the set/get_image_description  and get_image_height/width methods 
> seem to duplicate methods on AtkObject. My weak excuse is that is what the Java 
> interface provides. Perhaps, Peter can comment on this and the usefulness of the 
> interface.
> 
Bill here:

One possible use for this apparent duplication is in the case of
AtkObjects which implement AtkImage but not AtkComponent.  For
instance, a rendered HTML page may be in an AtkObject which is a
container with an ordered list of children for successive bits of
content, including text, hyperlinked text, and images.  The children
won't necessarily implement AtkComponent (since at the moment
AtkComponent is reserved for accessibles that have associated
widgets).

In such a case, a screen magnifier will need geometry info.

A possible fallback for AtkImages that can't access this information
would be to either return special values (-1 is a frequent GTK
convention) or, my preference, to return the bounds of their
AtkComponent parent (though the latter might be more compute
intensive).

-Bill

--------------
Bill Haneman
Gnome Accessibility / Batik SVG Toolkit
Sun Microsystems Ireland