Re: Adventures in calling Atspi from JavaScript

[Joseph Scheuhammer <clown alum mit edu>]

Mike wrote:
> Hi Joseph,
>
> > 1. Registering 'object:text-caret-moved' always results in an error.
> >
> > The actual error is garbled, containing non-printable characters. 
> > Here is what I get:
> >
> > > Window manager warning: Log level 16: Atspi: Adding match: 
> > Interface name
> > > 'org.a11y.atspi.Event.object' is invalid.
>
> This is strange; I'm not seeing anything obvious when looking at the 
> code, and I can't reproduce it. Does valgrind show any invalid reads 
> or writes? 

I discovered that the event string I was passing contained an invisible 
character.  Deleting that invisible character fixed registering the 
'object:text-caret-moved' event.  It now works as expected.

> Atspi_event_listener_register_from_callback and 
> deregister_from_callback are convenience functions intended to avoid 
> needing to create an AtspiEventListener. The scope annotations on 
> those functions are incorrect. Changing the scope to "notify" and 
> adding a GDestroyNotify callback might work, although that would mean 
> an API break. Anyway, gjs is creating a wrapper around the callback 
> when it is called, so libatspi sees a different pointer for the 
> deregister call than it saw for the register call, so it does not make 
> a match.
> Doing something like the following works for me, though:
> function cb(e)
> {
>   print(e)
> }
>
> l = Atspi.EventListener.new(cb)
> registered = l.register('object:text-caret-moved')
> l.deregister('object:text-caret-moved') 

Previously I replied that doing the above fixes the register/deregister 
issues I was having.  Thank you very much for the pointers, Mike!

There still remains the issue of of the freezing when focussing on GNOME 
Shell widgets, and a new issue in terms of too many caret tracking 
events.  I document these a bit more on the focus tracker bugzilla.  
More importantly, there is now a patch attached to that bugzilla which 
shows the focus tracking code, warts and all:
https://bugzilla.gnome.org/show_bug.cgi?id=647074#c5

P.S. Aleiva, I couldn't add 'aleiva emergya es' to the CC list of the 
bugzilla.  It did accept 'aleiva emergya com'.  I hope that's right.

--
;;;;joseph.


'A: After all, it isn't rocket science.'
'K: Right. It's merely computer science.'
             - J. D. Klaun -