[g-a-devel] Exposing document selection

[Aaron Leventhal <aaron moonset net>]

Here is the current plan for exposing selection in documents -- please 
let me know if there is a better way:

1. Any object which has any part in the document selection will have 
STATE_SELECTED, which will allow the collection interface to be used to 
get all the currently selected nodes.
2. We will use the AccessibleText interface to expose selection via 
getNSelections and getSelection for each container in the document which 
has text. The document itself is currently also one such container, 
which supports AccessibleText.
3. Any accessible node which has any descendant even partially selected 
will be considered selected.

Therefore, if the AT wants to know the entire selection, it can start 
from the document and drill down. Since any child object in a selection 
range that reports itself as selected may be only partially selected, 
the AT will need to recursively QI that child to nsIAccessibleText to 
get further information about what is selected within it.

For performance reasons it would be useful to have a way to say, this 
accessible node is completely selected, there is no need to drill down 
to look if it's partial or not. However, I don't know of a way to do 
that currently.

- Aaron