348037 - getIndexInParent return value incorrect for embeds

Status: RESOLVED FIXED

(Core :: Disability Access APIs, defect)

Description

[parente]

Consider the page http://www.mozilla.org/access/unix/new-atk.html. Let acc be the accessible for the page's html container which has 21 children. The following at-spi calls return odd results:

(Pdb) acc.getChildAtIndex(0).getIndexInParent()
0
(Pdb) acc.getChildAtIndex(1).getIndexInParent()
1
(Pdb) acc.getChildAtIndex(2).getIndexInParent()
2
(Pdb) acc.getChildAtIndex(3).getIndexInParent()
3
(Pdb) acc.getChildAtIndex(4).getIndexInParent()
5
(Pdb) acc.getChildAtIndex(5).getIndexInParent()
8
(Pdb) acc.getChildAtIndex(6).getIndexInParent()
17
...

The getIndexInParent return value does not match the index of the child as it is known to the parent. At first, I thought it might have been counting chunks of text between embeds in the child count. But that doesn't fully explain the large gaps between children 5 and 6. Maybe it's also counting descendants? If so, it is undesirable. Since there is no concept of prev/next in at-spi like there in other a11y APIs, ATs have to rely on accurate getIndexInParent values to determine next/previous within a level of the accessible hierarchy.

Comment 1

[Aaron Leventhal]

Attachment: Don't count text or whitespace objects

At the very least it *is* counting text/whitespace objects and it should not be. So we need this fix either way. Let's get this in and see if it fixes the problem.

Comment 2

[Ginn Chen]

Why do we patch nsAccessibleWrap.cpp but not nsAccessible.cpp?

Comment 3

[Aaron Leventhal]

(In reply to comment #2)
> Why do we patch nsAccessibleWrap.cpp but not nsAccessible.cpp?

Because in both nsIAccessible and IAccessible we do have the ROLE_TEXT_LEAF children exposed. It's only in ATK where we hide those and only expose that text via nsIAccessibleText in the parent.

Comment 4

[Ginn Chen]

Comment on attachment 233034 [details] [diff] [review]
Don't count text or whitespace objects

sorry for the late,

please add a comment to explain the difference between getIndexInParentCB and nsAccessible::GetIndexInParent