485273 - Items in threaded message list should be exposed with an accessible role of tree item

Status: VERIFIED WORKSFORME

(Thunderbird :: Folder and Message Lists, defect)

Description

[James Teh [:Jamie]]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2a1pre) Gecko/20090324 Minefield/3.6a1pre
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.1b4pre) Gecko/20090325 Shredder/3.0b3pre

Currently, when the message list is set to be threaded, the message list itself receives an accessible role of tree (ROLE_SYSTEM_OUTLINE for MSAA), but its items (children) receive an accessible role of list item (ROLE_SYSTEM_LISTITEM for MSAA). They should instead receive a role of tree item (ROLE_SYSTEM_OUTLINEITEM for MSAA).

Reproducible: Always

Steps to Reproduce:
1. Move focus to the message list.
2. Select View -> Sort by -> Threaded. Observe the accessible roles of the message list itself and of its children.
Actual Results:  
The accessible role of the message list is tree. However, the accessible role of the message items is list item.

Expected Results:  
The accessible role of the message list should be tree (which is true). However, the accessible role of the message items should be tree item, not list item.

Exposing this role correctly will allow NVDA to speak the level first if it has changed from the last reported item (which only happens for tree items).

Comment 1

[Marco Zehe (:MarcoZ)]

Whether a tree table item is exposed as an outline item or a list item is being determined by the fact whether the item has a primary column or not. See this comment in the MSAA wrapper:
http://mxr.mozilla.org/mozilla1.9.1/source/accessible/src/msaa/nsXULTreeAccessibleWrap.cpp#83

What we could do, as to not break all implementations across all Mozilla-based platforms, is this:

In Thunderbird and SeaMonkey, when filling the xul:treechildren container with actual data, determine whether the view is threaded.
If yes: Give each item an ARIA role of "treeitem" by setting the @role attribute.
If no, simply don't do anything and remove the role attribute if it exists.

The underlying problem is that Windows simply doesn't know of expandable multi-column tree items yet, it only knows of multi-column list items AKA list views.

Comment 2

[alexander :surkov (:asurkov)]

I would rather suggest to check role of parent accessible (nsXULTreeAccessible) or have the same logic like nsXULTreeAccessible (check if there primary column). Actually problem is I guess key column is changed when user chooses sort threaded and we do not invalidate tree children so that it means tree item accessible points to non key column. But if this is bug not very urgent then we should wait for ongoing tree reorganization where we will start to expose cells.

Comment 3

[James Teh [:Jamie]]

This is fixed for me in: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.2.5pre) Gecko/20100510 Lanikai/3.1pre
I assume this would have been part of the new tree table code.

Comment 4

[Marco Zehe (:MarcoZ)]

Jamie, you are correct.