More info on ATK interfaces

Hello,

I am doing some research on implementing and understanding ATK 
interfaces, but I am still unclear on a few parts.

I found this page: 
https://www.freedesktop.org/wiki/Accessibility/Walkthrough/

It states: "The Orca screen reader can explicitly request for 
information for a given widget of a given application, for instance 
getText".

How does Orca decide to query for this information? Which widgets get 
queried? Is there a way to specify which widgets get queried (example: I 
have a child widget, but I want Orca to query its parent)?

Thanks,

-- 
Eric Williams
Associate Software Engineer - Eclipse Team
Red Hat