Re: [g-a-devel] AtkInterfaces for gnome-about

["Padraig O'Briain" <Padraig Obriain Sun COM>]

> X-Accept-Language: en
> MIME-Version: 1.0
> To: "Padraig O'Briain" <Padraig Obriain Sun COM>, marc mulcahy Sun COM, 
gnome-accessibility-devel gnome org
> Subject: Re: [g-a-devel] AtkInterfaces for gnome-about
> 
> 
> > > (1) Should I override the parent's AtkObject interface ? In
> > the case of
> > > GtkDrawingArea, it's GailWidget.
> > >
> >
> > It is GailWidget because we have not yet found anything
> > interesting about
> > GtkDrawingArea to justify implementing a GailDrawingArea in
> > the gail library.
> >
> 
> Am outlining my implementation approach; would help if you could
> validate the same.
> 
> Because the widget doesn't gain focus, I plan to set the atk object in
> the following manner:
> 
> 1) In main function, check if gail is loaded

I am not convinced that this check is necessary. How you you propose to do this 
check?

> 2) If loaded, invoke gtk_widget_get_accessible, passing widget id of the
> GtkDrawingArea
> 3) This would return me the parent (GailWidget) object - pobj
> 4) Set pobj's atk_object_set_name to "List of contributors' names"

Do you mean to call atk_object_set_name (pobj, " ...");
That seems OK.

> 5) Also set pobj's atk_object_get_n_children to ZERO so the AT knows
> there's no other info to traverse down for this object.
> 

The problem here is there is no function to set the number of children to 0.
However, the GtkDrawingArea does not have any children so if you do anything 
the AT will not expect any children.


> > > (2) If not, I will have to create a new Atk object for this widget and 
expose the information through it.
> 
> > One could implement, say, a GailDrawingArea in gnome-about whose name is the 
list of contributors' names. In gnome-about, you would have
> > to override the get_accessible method in the GtkWidgetClass structure for 
GtkDrawingArea to ensure that the correct type of object is reated > when 
gtk_widget_get_accessible() is called for the GtkDrawingArea
> 
> Does this mean that you would concatenate all the contributors' names
> and pass it to atk_object_set_name ?
> 

I was not expressing any opinion here. I was reflecting what I understood you 
proposed to do. As I said before I do not regard reporting the list of 
contributors names as a high prioity for accessibility , except in so far as it 
helps us discuss problems which have applicability elsewhere.


> In which case, I could as well do the above (concatenation of strings)
> for the first approach too, right ? But this would mean that, somehow,
> the AT is informed as to what delimits each names ??
> 
> Could I do the same for the gnome logo that appears in the canvas area .
> i.e. set the name and description, using atk_object_set_name /
> description. In which case a screen reader or a magnifier would not be
> able to get the position or co-ordinates of the image.
> 

Yes. You could use atk_object_set_name and atk_object_set_description.

I would hope that the implementation of GailCanvasItem would give the position 
correctly.

If not, please log a bug against it and we can look at it.

Padraig

> 
> Thanks,
> Deepa.