Bug 95248 – AX: Canvas should have a distinct role

• Component: Accessibility
• Status: RESOLVED FIXED

[Dominic Mazzoni]

On many platforms, the role of "image" or "graphic" is not allowed to have children, so we should use a special role for canvas inside WebCore and let each platform decide on the appropriate role to use, taking into account if the canvas has fallback content.

[Dominic Mazzoni]

Created attachment 161067 [details]
Patch

[WebKit Review Bot]

Please wait for approval from [e-mail], [e-mail], [e-mail], [e-mail] or [e-mail] before submitting, as this patch contains changes to the Chromium public API. See also https://trac.webkit.org/wiki/ChromiumWebKitAPI.

[Adam Barth]

Comment on attachment 161067 [details]
Patch

WebKit API change LGTM.

[Dominic Mazzoni]

Created attachment 161076 [details]
Patch

Update tests. Moved accessibility/canvas.html to platform/mac since it tests for a Mac-specific role.

[chris fleizach]

Comment on attachment 161076 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=161076&action=review

> Source/WebCore/accessibility/AccessibilityRenderObject.cpp:1994
> +            return false;

i don't think we want to ignore the canvas element when it has fallback content. I think we just want to make it a "group" role. we should still be able to gather info from it like an aria-label for example

[Dominic Mazzoni]

Comment on attachment 161076 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=161076&action=review

>> Source/WebCore/accessibility/AccessibilityRenderObject.cpp:1994
>> +            return false;
> 
> i don't think we want to ignore the canvas element when it has fallback content. I think we just want to make it a "group" role. we should still be able to gather info from it like an aria-label for example

This is in accessibilityIsIgnored, so false means "don't ignore". If it has fallback content, we'll always include it and we'll make it a group role,

If it does not have any fallback content, we'll ignore it if its size is 1x1, or if it has no title, description, or help.

[chris fleizach]

Comment on attachment 161076 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=161076&action=review

just one question inline. otherwise looks good

> Source/WebCore/accessibility/AccessibilityNodeObject.cpp:318
> +    Element* element = toElement(node);

it doesn't appear that you need to case to Element in this case

[Dominic Mazzoni]

Created attachment 161151 [details]
Patch for landing

[WebKit Review Bot]

Comment on attachment 161151 [details]
Patch for landing

Clearing flags on attachment: 161151

Committed r126972: <http://trac.webkit.org/changeset/126972>

[WebKit Review Bot]

All reviewed patches have been landed.  Closing bug.

[WebKit Review Bot]

Re-opened since this is blocked by 95349

[Julien Chaffraix]

Link to the test failures:

http://test-results.appspot.com/dashboards/flakiness_dashboard.html#tests=accessibility%2Fcanvas-description-and-role.html

http://build.webkit.org/results/Apple%20Lion%20Debug%20WK1%20%28Tests%29/r127000%20%282336%29/results.html

The failure is the same in both cases:

-PASS axContainer.childrenCount is 2
+FAIL axContainer.childrenCount should be 2. Was 4.

[Dominic Mazzoni]

Created attachment 161273 [details]
Patch for landing

[WebKit Review Bot]

Comment on attachment 161273 [details]
Patch for landing

Clearing flags on attachment: 161273

Committed r127084: <http://trac.webkit.org/changeset/127084>

[WebKit Review Bot]

All reviewed patches have been landed.  Closing bug.

[Joanmarie Diggs]

Dominic, since we have a test without results for Gtk, I was looking at the test. Was there a reason you mapped the new CanvasRole to ATK_ROLE_IMAGE in the Gtk platform instead of ATK_ROLE_CANVAS?

[Dominic Mazzoni]

(In reply to comment #16)
> Dominic, since we have a test without results for Gtk, I was looking at the test. Was there a reason you mapped the new CanvasRole to ATK_ROLE_IMAGE in the Gtk platform instead of ATK_ROLE_CANVAS?

See comment on https://bugs.webkit.org/show_bug.cgi?id=95644