Re: [g-a-devel]Accessibility for cdplayer applet

["Padraig O'Briain" <Padraig Obriain sun com>]

For anything that is defined as a "property" a "notify" signal is emitted when 
the value of the property changes. Accessible name and accessible description 
are defined as properties. This means that a "notify" signal is emitted when the 
value changes even if the object does not have focus.

See atk_object_class_init() in atk/atkobject.c for the properties which are 
defined for AtkObject.

Of course, one can ignore the notification and check the value when focus 
notification is received but we cannot avoid emitting the notification. 

The concern about performance was that we would be emitting a notification, 
possibly every second, when the time elapsed is updated. As the GUI needs to be 
updated the extra cost of doing the notification is probably not something to 
worry about.

Padraig
 
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> To: "Padraig O'Briain" <Padraig Obriain sun com>, marc mulcahy sun com
> CC: gnome-accessibility-devel gnome org
> Subject: Re: [g-a-devel]Accessibility for cdplayer applet
> 
> 
> I was thinking if i set the name and description it would suffice. As,
> when the widget gets focus the AT would query and i would keep the
> values for the time/track info updated. That way it At would get the
> latest value.
> 
> But i am virtually ignorant about how an AT works and hence wonder why
> we need to emit name-changed/description-changed.
> 
> Thanks,
> Deepa.
> 
> 
> 
> 
> > > My opinion is that name and description would be adequate for these two
> > > fields.  then just emit name-changed and description-changed when they
> > > change so the AT can know about the changes.  Value doesn't work well for
> > > time values, I.E. values which are based on hours:minutes:seconds format,
> > > so I don't think it would work well.
> > >
> > > Just my opinion...
> > >
> > 
> > Good enough for me ...
> > 
> > Padraig
> > 
> > > Marc
> > >
> > > At 03:58 PM 2/28/2002 +0000, Padraig O'Briain wrote:
> > >
> > >
> > > > > HI,
> > > > >
> > > > > > > All the buttons and track info are packed inside a box. Buttons
> > already
> > > > > > > have tooltips.
> > > > > > >
> > > > > > > Accessible name and description has to be set for gtk-buttons. The
> > > > track
> > > > > >
> > > > > > Are the tooltips referred to above adequate for the description?
> > > > >
> > > > > E.g. : for a stop button the tooltip is "Stop". I thought i could set
> > > > > this as the accessible name and set description as "Click this button 
to
> > > > > stop" Is that o.k. ?
> > > >
> > > >What you are saying is that the tooltip is inadequate. Your other option
> > > >would
> > > >be to change the tooltip. I have no opinion on the best approach.
> > > >
> > > > >
> > > > > In case this lengthy description is not required then i could do away
> > > > > with what the tooltip gives me.
> > > > >
> > > > > > > information and time elapsed is displayed using
> > > > > > > gkt_image_new_from_pixbuf. Now i could set up the accessible name 
and
> > > > > > > description for these 2 images. But the gtk-image here does not
> > > > react to
> > > > > > > state change. So ferret does not report this widget. But 
considering
> > an
> > > > > > > AT would get to the atk object by traversing the tree of 
accessible
> > > > > > > objects, i could do away with this implementation.
> > > > > > >
> > > > > >
> > > > > > How will a blind user get the track information and time elapsed?
> > > > >
> > > > > The time elapsed is drawn using a gtk_image_new_from_pixbuf. If i do a
> > > > > get accessible for the image and set the AtkObject name to : time [
> > > > > which i plan to get from
> > > > > cdrom_deveice_status_t.relative_address.minute/second ]. Then would 
that
> > > > > be o.k ?
> > > > >
> > > > > The description could be more descriptive, like "time elapsed is :
> > > > > <time>"
> > > > >
> > > > > And i do the same mentioned for track information.
> > > > >
> > > > > What is your opinion
> > > > >
> > > >
> > > >I believe that there have been discussions questioning the 
appropriateness of
> > > >using name and description for values which change but I was not paying
> > > >attention. Perhaps Marc has a view on this.
> > > >
> > > >Could you implement AtkValue for information such as time elapsed and
> > > >description would identify the units.
> > > >
> > > >I am not sure whether a similar approach would work for track 
information.
> > > >
> > > >Padraig