935992 - Firefox does not support accessibility hit testing of canvas fallback content

Status: RESOLVED FIXED

(Core :: Graphics: Canvas2D, defect, P2)

Description

[Rich Schwerdtfeger]

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.9; rv:28.0) Gecko/20100101 Firefox/28.0 (Beta/Release)
Build ID: 20131105214748

Steps to reproduce:

I used the Firefox 28.0a nigthly. Then enable the new canvas 2D API for drawing focus rings:

Turned on canvas.focusring.enabled in about:config

Load this file in the browser. Tab to the first checkbox and then the second checkbox. If you use Inspect32 and run the mouse pointer over the first checkbox it only says canvas. 

There is a bug with the location on the second checkbox.


http://www.w3.org/2013/08/canvas-editor.html

In this example there are two fallback content sliders representing the hour and minute hand. These also cannot be found using the pointer and inspect32.

http://www.w3.org/2013/09/accessible_canvas_clock.html


Actual results:

If you use Inspect32 and run the mouse pointer over the first checkbox it only reports canvas as the accessible object.


Expected results:

It should have reported the accessible for the first checkbox, including its location information in inspect32. 

It appears that the hit test is stopping at canvas and not proceeding to the fallback content.

Comment 1

[alexander :surkov (:asurkov)]

It seems nsLayoutUtils::GetFrameForPoint we rely on doesn't see a shadow content of the canvas. Robert, do you have ideas how to workaround it?

Comment 2

[Robert O'Callahan (:roc) (email my personal email if necessary)]

Call nsLayoutUtils::GetFramesForArea and walk through the resulting list, ignoring canvas frames?

Comment 3

[Rik Cabanier]

The spec needs to be updated for this to work. Only keyboard navigation is specced today, not mouse.

Comment 4

[Sebastian Zartner [:sebo]]

As Rik was not active on Bugzilla since last year, I remove him as assignee.

Sebastian

Comment 5

[Jonathan Watt [:jwatt]]

Mass bug change to replace various 'parity' whiteboard flags with the new canonical keywords. (See bug 1443764 comment 13.)

Comment 6

[Gregory Pappas [:gregp]]

All dependencies are fixed, closing.