Re: Tree sample code

Here are my comments on Microsoft's tree sample:

1. It uses aria-level, aria-setsize and aria-posinset when it doesn't need 
to.
The idea is that authors only need to do that if the tree is not DOM 
complete -- iow it's loaded dynamically. When the entire tree structure is 
there the user agent is supposed to calculate that info from the 
structure.

2. It uses <li><a/></li> constructs.
This seems to be to allow for graceful degredation for non-ARIA clients. 
However, it means that the tree has list, list item and tree item objects 
mixed together, and no longer looks like a tree widget to current 
generation ATs. Neither current ATs nor Firefox 3 will process the 
structure and automatically provide info like the level, posinset and 
setsize.
In general, the current implementors guide algorithm will not work with 
this tree. So either the tree needs to change, or the impl guide algorithm 
or both.

What do you suggest?

- Aaron




From:
Cynthia Shelly <cyns@exchange.microsoft.com>
To:
"wai-xtech@w3.org" <wai-xtech@w3.org>
Cc:
George Young <gcyoung@microsoft.com>
Date:
07/07/2008 11:21 PM
Subject:
Tree sample code



As promised, here is a zip of the tree sample I demo’d at the face to 
face. 
 
Tree.htm uses only nested unordered lists of links (with onclick handlers) 
to achieve tree behavior.  JAWS in virtual cursor mode with medium 
verbosity does a good job of reading the list levels.  Tab+enter opens and 
closes the tree levels.
 
Ariatree.htm is the same tree, with aria markup added to the links.  With 
virtual cursor turned off, list level information is exposed to MSAA. This 
was tested with IE8 beta 1 and JAWS 9.  There are a few bugs in what is 
exposed to MSAA by IE in this early build, which will be fixed.
 
I’ve copied George Young, who wrote the original tree, to which I added 
ARIA for the CSUN demo.  George is the best person to work with on 
combining this tree with any other samples that have more extensive 
keyboard handling features.[attachment "trees.zip" deleted by Aaron M 
Leventhal/Cambridge/IBM]