Bug 122320 – AX: WebKit needs heuristics to differentiate lists used for layout from semantic data lists, similar to the heuristics for layout tables versus data tables.

• Status: RESOLVED
• Resolution: FIXED
• Component: Accessibility

[James Craig]

AX: WebKit needs heuristics to differentiate lists used for layout from semantic data lists, similar to the heuristics for layout tables versus data tables, and weeding out spacer images. Extra lists cause VoiceOver to speak stuff like "list, one item" and sometime group things erroneously or speak labels twice.

Some potential criteria:
1. If it uses ARIA roles, keep it as a semantic list.
2. If it displays generated list markers (like bullets or numbers), keep it as a semantic list. 
3. If it contains well-formed nested lists, assume they are all semantic lists.
4. If the list only contains a single item, presume it's a layout list.
7. If it ~acts like a large scale container (e.g. contains a large amount of distinct content elements), assume it's a layout list. (This will be the tricky one.)

More…

[Radar WebKit Bug Importer]

<rdar://problem/15150097>

[chris fleizach]

Created attachment 224138 [details]
patch

[WebKit Commit Bot]

Attachment 224138 [details] did not pass style-queue:


ERROR: Source/WebCore/accessibility/AccessibilityList.cpp:149:  An else should appear on the same line as the preceding }  [whitespace/newline] [4]
Total errors found: 1 in 6 files


If any of these errors are false positives, please file a bug against check-webkit-style.

[chris fleizach]

Created attachment 224140 [details]
patch

[Build Bot]

Comment on attachment 224140 [details]
patch 

Attachment 224140 [details] did not pass mac-wk2-ews (mac-wk2):
Output: http://webkit-queues.appspot.com/results/6052477241655296

New failing tests:
accessibility/aria-roles.html

[Build Bot]

Created attachment 224146 [details]
Archive of layout-test-results from webkit-ews-13 for mac-mountainlion-wk2

The attached test failures were seen while running run-webkit-tests on the mac-wk2-ews.
Bot: webkit-ews-13  Port: mac-mountainlion-wk2  Platform: Mac OS X 10.8.5

[Build Bot]

Comment on attachment 224140 [details]
patch 

Attachment 224140 [details] did not pass mac-ews (mac):
Output: http://webkit-queues.appspot.com/results/5354837650702336

New failing tests:
accessibility/aria-roles.html

[Build Bot]

Created attachment 224179 [details]
Archive of layout-test-results from webkit-ews-01 for mac-mountainlion

The attached test failures were seen while running run-webkit-tests on the mac-ews.
Bot: webkit-ews-01  Port: mac-mountainlion  Platform: Mac OS X 10.8.5

[Mario Sanchez Prada]

Comment on attachment 224140 [details]
patch 

View in context: https://bugs.webkit.org/attachment.cgi?id=224140&action=review

The change looks good to me. My only comments/suggestions is to remove the PLATFORM(MAC) guard and make the tests cross platform, since I believe this is a change other ports can benefit of as well.

As for the failing tests in the Mac EWS, it seems to me that the problem is that the test aria-roles.html needs to be changed because the following snippet does not match the heuristic to determine that something is a list:

  <!--List-->
  <div class="newRole">
    <p>The following should be a list:</p>
    <p><span tabindex="0" role="list" id="ariaList">X</span></p>
    <p>Actual list:</p>
    <ul id="realList">
        <li>Broccoli</li>
        <li>Beets</li>
    </ul>
    <span id="resultList"></span>
    <script>
        validateRole(document.getElementById('ariaList'),
            document.getElementById('realList'),
            document.getElementById('resultList'));
    </script>
  </div>

The problem is that <span tabindex="0" role="list" id="ariaList">X</span> is no longer going to be identified as a list so I'd say either this whole snippet of code should be removed (it's tested anyway by list-detection.html, and in a better way) or adapted.

But other than that I think the patch is fine. Setting r+ anyway, but please consider these comments before landing

> Source/WebCore/accessibility/AccessibilityList.cpp:120
> +#if PLATFORM(MAC)

I think this change could be done as a cross-platform one

> LayoutTests/ChangeLog:9
> +        * platform/mac/accessibility/list-detection-expected.txt: Added.
> +        * platform/mac/accessibility/list-detection.html: Added.

This tests could be moved up to LayoutTests/accessibility if the change is made cross platform

[Build Bot]

Comment on attachment 224140 [details]
patch 

Attachment 224140 [details] did not pass mac-ews (mac):
Output: http://webkit-queues.appspot.com/results/4667337135357952

New failing tests:
accessibility/aria-roles.html

[Build Bot]

Created attachment 224184 [details]
Archive of layout-test-results from webkit-ews-06 for mac-mountainlion

The attached test failures were seen while running run-webkit-tests on the mac-ews.
Bot: webkit-ews-06  Port: mac-mountainlion  Platform: Mac OS X 10.8.5

[chris fleizach]

(In reply to comment #9)
> (From update of attachment 224140 [details])
> View in context: https://bugs.webkit.org/attachment.cgi?id=224140&action=review

Thanks. Will take care of these suggestions.

[chris fleizach]

Created attachment 224220 [details]
patch for EWS

[chris fleizach]

http://trac.webkit.org/changeset/164107

[James Craig]

The original test case is here:
https://bug-134187-attachments.webkit.org/attachment.cgi?id=233587

Posting here in case I follow a git blame here again.