Re: A few outstanding issues with ATK API

[Bill Haneman <Bill Haneman Sun COM>]

Owen said, of setting attributes on AtkEditableText:

[snip]
>
>OK, that makes it clearer - I was wondering if this interface
>was meant to be for the user to set attributes on the text, or
>whether it was for use for things like highlighting the current
>word/phrase.
>
>I think there is are fundemental problems with trying to abstract
>this away from the application user interface:
>
> - Not all applications using a widget that supports styled text
>   may support setting the styles. (Imagine a programming editor
>   or plain text editor)
>
> - Not all applications supporting styles will support all possible
>   styles.
> 
> - Updating the styles may involve updating internal application
>   data structures as well as updating the visual text. For instance,
>   a HTML editor will need to update its editor tree.
>
>Regards,
>                                        Owen

It's not easy to abstract this out of the UI, Owen is right about that.  
But I think an attempt to do some will add a lot of value for some 
users, even if we cannot implement the interface fully for all "text 
entry" widgets.

This might be OK if we keep the convention of returning booleans from 
our set() methods (we haven't been entirely consistent to date, but we 
are fixing this at the moment).  That way we can expose useful features 
even if we expect that they will not always be implementable.

Admittedly it's a drag for a user to find an advertised interface that 
refuses admittance, but it's arguably better than bricking up the 
windows where they do occur :-)

We could perhaps break AtkText into a more detailed hierarchy, with 
AtkText, AtkStyledText, AtkEditableText, AtkStylableText, etc... but I'd 
do this only if consensus says that having "set" return FALSE sometimes 
is onerous.  Even in that scenario one can't count on all styles being 
available, as Owen points out.  I would prefer not to add a 
get_available_styles() method, etc., the interfaces would really start 
to bloat.

-Bill

------
Bill Haneman x19279
Gnome Accessibility / Batik SVG Toolkit
Sun Microsystems Ireland