Re: [g-a-devel]active-descendant-changed signal and at-spi

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

I have started trying to add support for active-descendant-changed in the bridge 
and I have hit a problem.

The any_data field in Accessibility_Event is a CORBA_any and the function 
spi_init_any_object() returns a CORBA_any for a CORBA_object. I have an 
AtkObject. I can create an SpiAccessible from it but how do I get a 
CORBA_object?

Padraig

> > The only interesting thing in the active-descendant-changed signal is the 
object 
> > which is the new active descendant.
> > 
> > Do I need to call BONOBO_OBJECT_REF (spi_accessible_new()) on it and stick 
it 
> > into the any_data field?
> 
> If you did, you of course would need to unref it again after the event
> emission since at the moment listeners are not guaranteed to do the
> unref (and it would be more traffic over the wire anyway).  
> 
> You will note that at the moment the code to do this lives in
> spi_atk_signal_emit_event (and, in turn, in spi_init_any_object () which
> it calls); there's some commented-out stuff for the child-changed
> signal, and presumably we'd need to add code to handle the
> active-descendant-changed signal as well.  As Michael has pointed out
> recently, the existing code is not the correct way of doing this (see
> below), which is the main reason the implementation is commented out
> until somebody has time to do this thoughtfully and properly.
> 
> For the cases where the Any contains an object reference I think we
> should not take ownership of the reference or increment it; this has the
> disadvantage that the listener must make sure the object is still alive
> before using the reference, but the advantage of preventing leaks and
> extra CORBA traffic if the listening client doesn't choose to use the
> reference.
> 
> In the meantime if you just add the signal listener, we can handle the
> any_data initialization in the emission handler (above), just as we
> intend to for child-changed events once we get spi_init_any_object()
> fixed.
> 
> -Bill
> 
> > Padraig
> > 
> > > Subject: Re: [g-a-devel]active-descendant-changed signal and at-spi
> > > To: "Padraig O'Briain" <Padraig Obriain Sun COM>
> > > Cc: accessibility mailing list <gnome-accessibility-devel gnome org>
> > > Mime-Version: 1.0
> > > Content-Transfer-Encoding: 7bit
> > > 
> > > Hi Padraig,
> > > 
> > > On Wed, 2002-11-27 at 11:48, Padraig O'Briain wrote:
> > > > I am trying to figure out what needs to change in at-spi to support 
> > > > active-descendant-changed signal.
> > > > 
> > > > It looks like a signal handler for it needs to be added to the bridge.
> > > 
> > > 	Quite.
> > > 
> > > > What should happen when the signal is emitted?
> > > 
> > > 	You get to make up some string name for it; ram whatever detail you
> > > think is useful into the event structure; and do an emitv of some sort
> > > in the handler.
> > > 
> > > 	HTH,
> > > 
> > > 		Michael.
> > > 
> > > -- 
> > >  mmeeks gnu org  <><, Pseudo Engineer, itinerant idiot
> > > 
> > 
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> 
> 
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