Bug 271287 – AX: Mac combo boxes should expose aria-activedescendant as AXSelectedChildren

• Component: Accessibility
• Status: RESOLVED FIXED

[Dominic Mazzoni]

This is necessary, but probably not sufficient, to support https://bugs.webkit.org/show_bug.cgi?id=231724 (AX: VoiceOver doesn't announce aria-activedescendant value for select-only combobox specification). There are other bugs preventing VoiceOver from working but exposing the active descendant is pretty fundamental so I'd like to get that in first.

Part of the bug is that an element can be both a combo box and a text field, so the supported attribute logic needed to be updated to take that into account.

[Radar WebKit Bug Importer]

<rdar://problem/125050867>

[Dominic Mazzoni]

Created attachment 470439 [details]
Patch

[Tyler Wilcock]

Comment on attachment 470439 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=470439&action=review

Thanks Dominic!

> LayoutTests/accessibility/mac/aria-combobox-activedescendant.html:11
> +<div role="list" id="list" aria-label="List1">
> +  <div role="listitem" id="item1" aria-label="item1">item1</div>

Are the id attributes on these elements used? If not, could make the test a bit more concise by removing them?

> LayoutTests/accessibility/mac/aria-combobox-activedescendant.html:25
> +    var output = "On macOS, a combobox should map aria-activedescendant to AXSelectedChildren.\n";
> +
> +    if (window.accessibilityController) {
> +        var combobox = accessibilityController.accessibleElementById("combobox");
> +        output += expect("combobox.selectedChildrenCount", "1");
> +        activeDescendant = combobox.selectedChildAtIndex(0);
> +        output += expect("activeDescendant.role", "'AXRole: AXGroup'");
> +        output += expect("activeDescendant.title", "'AXTitle: item2'");
> +        debug(output);
> +    }

Minor nit, but our layout test style has been moving towards not indenting one level inside script tags (so everything here can be shifted left).

[Dominic Mazzoni]

Created attachment 470516 [details]
Patch

[EWS]

Committed 276627@main (d87f5d670518): <https://commits.webkit.org/276627@main>

All reviewed patches have been landed. Closing bug and clearing flags on attachment 470516 [details].