309472 - Start of equations and diagrams not indicated in accessible tree

Status: RESOLVED FIXED

(Core :: Disability Access APIs, defect)

Description

[Aaron Leventhal]

Currently MathML and SVG content is available via ISimpleDOMNode, but there is
no way while reading the MSAA tree to know that content has begun.

We can expose a <math> element as ROLE_EQUATION, and an
                <svg> element as ROLE_DIAGRAM

Comment 1

[Aaron Leventhal]

Test cases:
MathML: http://www.mozilla.org/projects/mathml/demo/texvsmml.xhtml
SVG: http://www.croczilla.com/svg/samples/events1/events1.xml

Comment 2

[Aaron Leventhal]

Attachment: Simple patch to expose ROLE_EQUATION for <math> or ROLE_DIAGRAM for <svg>

The screen reader can look at the DOM children of these IAccessibles by using
ISimpleDOMNode (QI to that from IAccessible)

Comment 3

[parente]

Comment on attachment 196937 [details] [diff] [review]
Simple patch to expose ROLE_EQUATION for <math> or ROLE_DIAGRAM for <svg>

Is the comment block a few lines up in nsAccessibilityService still valid? Says
tags that aren't html, have tab index, or have an XHTML2 role aren't in the
accessible tree. math and svg are exceptions?

Is putting the implementation of GetRole in nsBaseWidgetAccessible.h
recommended?

Comment 4

[Aaron Leventhal]

Comment on attachment 196937 [details] [diff] [review]
Simple patch to expose ROLE_EQUATION for <math> or ROLE_DIAGRAM for <svg>

Good catch on the comment. I don't think it matters if we do inline methods for
really simple stuff. We do that all over the place in Gecko.

Comment 5

[Aaron Leventhal]

Attachment: Changes to nsAccessibilityService: 1) Check namespace of <svg> and <math>, 2) Always use role to create object unless special role=presentation, 3) Remove unnecessary arg from GetRole()

Comment 6

[Aaron Leventhal]

Attachment: Changes to nsAccessibilityService: 1) Check namespace of <svg> and <math>, 2) Always use role to create object unless special role=presentation, 3) Remove unnecessary arg from GetRole()

Comment 7

[parente]

Comment on attachment 197615 [details] [diff] [review]
Changes to nsAccessibilityService: 1) Check namespace of <svg> and <math>, 2) Always use role to create object unless special role=presentation, 3) Remove unnecessary arg from GetRole()

What are objects with roles ending in :presentation?

Comment 8

[Aaron Leventhal]

(In reply to comment #7)
> (From update of attachment 197615 [details] [diff] [review] [edit])
> What are objects with roles ending in :presentation?

That's the DHTML a11y way of removing an object from the accessibility
hierarchy. The author is saying that it is there for presentation only. Thus
<table xhtml2:role="wairole:presentation"> is a table used only for layout, not
for data.

Comment 9

[Asa Dotzler [:asa]]

Comment on attachment 197615 [details] [diff] [review]
Changes to nsAccessibilityService: 1) Check namespace of <svg> and <math>, 2) Always use role to create object unless special role=presentation, 3) Remove unnecessary arg from GetRole()

we're now locked down and in ship mode for 1.8b5. If you'd like to re-request
approval for this change, please set the approval1.8rc1? flag.

Comment 10

[Aaron Leventhal]

Sorry, this was checked into the branch on 9/30 (fixed in 10/1 build).

Comment 11

[Firefox Bug Husbandry Bot]

https://bugzilla.mozilla.org/show_bug.cgi?id=1527381