AX: The isolated tree needs to fix-up table cell parent relationships

• Component: Accessibility
• Status: RESOLVED FIXED

[Tyler Wilcock]

Tables are not very navigable by AX clients in isolated tree mode. This is because our current representation of table elements doesn't perfectly follow the normal parent-child relationship of other elements, i.e. some non-row elements can return cells from children(), but the cells must regard their row as the "real" parent. When creating the isolated tree, we need to work around this.

We've had to work around this in the live tree in AccessibilityObject::insertChild, too:

https://github.com/WebKit/WebKit/blob/main/Source/WebCore/accessibility/AccessibilityObject.cpp#L626#L628

[Radar WebKit Bug Importer]

<rdar://problem/88506756>

[Tyler Wilcock]

Created attachment 450936 [details]
Patch

[chris fleizach]

Comment on attachment 450936 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=450936&action=review

> Source/WebCore/accessibility/isolatedtree/AXIsolatedTree.cpp:212
> +

extra newline

> Source/WebCore/accessibility/isolatedtree/AXIsolatedTree.h:389
> +    AXID computeParentForObject(AXCoreObject&, AXID assumedParentID);

feel like compute might not be a necessary verb here

is 

parentIDForObject() 

sufficient?

[Tyler Wilcock]

> > Source/WebCore/accessibility/isolatedtree/AXIsolatedTree.h:389
> > +    AXID computeParentForObject(AXCoreObject&, AXID assumedParentID);
> 
> feel like compute might not be a necessary verb here
> 
> is 
> 
> parentIDForObject() 
> 
> sufficient?
Yeah, that sounds good to me. Will change in the next revision of the patch.

[Tyler Wilcock]

Created attachment 450986 [details]
Patch

[Tyler Wilcock]

Created attachment 450987 [details]
Patch

[Tyler Wilcock]

Created attachment 451025 [details]
Patch

[Andres Gonzalez]

Can we fix the table hierarchy in the live tree instead? 

Does this fix some of the existing table tests that are failing in ITM?

Thanks.

[Tyler Wilcock]

(In reply to Andres Gonzalez from comment #8)
> Can we fix the table hierarchy in the live tree instead?
The problem is that AccessibilityTableColumn and AccessibilityTableHeaderContainer return children that they shouldn't (e.g table cells). The AccessibilityTableRows also (rightly) return cells as their children.

Unfortunately, it seems that AppKit expects that AccessibilityTableColumn and AccessibilityTableHeaderContainer return these children, so I think this workaround is required.

> Does this fix some of the existing table tests that are failing in ITM?
No, seems like those tests are failing for other reasons, and we don't have a test that exercises search traversal of a table (until this patch).

[EWS]

Committed r289238 (246922@main): <https://commits.webkit.org/246922@main>

All reviewed patches have been landed. Closing bug and clearing flags on attachment 451025 [details].