[webkit-dev] Proposal: Add support for focus rings in Canvas 2d

[Rik Cabanier]

On Thu, Oct 10, 2013 at 5:49 PM, Chris Fleizach <cfleizach at apple.com> wrote:

>
> On Oct 10, 2013, at 1:35 PM, Rik Cabanier <cabanier at gmail.com> wrote:
>
>
>
>
> On Thu, Oct 10, 2013 at 1:14 PM, Ryosuke Niwa <rniwa at webkit.org> wrote:
>
>> On Wed, Oct 9, 2013 at 9:08 PM, Rik Cabanier <cabanier at gmail.com> wrote:
>>
>>> I'd like to add for focus rings. They are currently specified in the w3c
>>> and whatwg canvas specs:
>>>
>>> http://www.whatwg.org/specs/web-apps/current-work/multipage/the-canvas-element.html#dom-context-2d-drawsystemfocusring
>>> http://www.w3.org/TR/2dcontext/#dom-context-2d-drawsystemfocusring
>>>
>>
>> Could you point us to the list of use cases or the whatwg/w3c thread
>> where the discussion took place?
>>
>
> Rich should be able to point you to where those are posted since he was
> the main contributor. (You can also do a search for "canvas focus rings" to
> find many email threads on whatwg)
>
>
>>
>> Support (behind runtime flags) has landed in:
>>> - Firefox: https://bugzilla.mozilla.org/show_bug.cgi?id=540456
>>> - chrome: https://code.google.com/p/chromium/issues/detail?id=261998
>>>
>>> Focus rings associate elements that are in a canvas tag with areas of
>>> the canvas.
>>> If the user tabs into the hidden element or the accessibility software
>>> selects them, these methods will draw or let the author draw the focus
>>> rings.
>>>
>>
>> How does this API address this use case?  It seems like each Web app
>> needs to explicitly opt-in and manually draw focus ring?
>>
>
> That is correct. This is code that the canvas developer needs to implement.
>
>
>>  I'm not sure if that's a good accessibility API given that many authors
>> don't even use most basic accessibility feature such as ARIA roles.
>>
>
> There's not much we can do about this. However, for authors that DO want
> to provide this, there's is currently no way to provide accessibility for
> canvas.
>
>
>>
>> e.g. why can't UA automatically draw focus ring on top of the canvas?
>>
>
> The problem is that the UA doesn't know what part of the canvas area
> corresponds with the hidden element. This API is designed to make that
> association
>
>
> It seems this API will draw an area that corresponds to a hidden element.
> Is there a way to provide actual information about the element? (label,
> role, etc)
>

The UA knows what element is focused so it can provide the accessibility
software (such as voiceover) with that information.


>
>
>
>
>>
>> Also, the spec seems to indicate that the physical (rendered) position of
>> an element can change dynamically without UA being notified.
>> How are ATs supposed to inform users of the ordering of those focusable
>> elements?
>>
>
> I'm unsure I follow. Can you elaborate?
>
>
>>
>>  I created a patch (https://bugs.webkit.org/show_bug.cgi?id=122177) but
>>> it needs more tests.
>>> Also, should I implement it behind a runtime flags?
>>>
>>
>> I definitely would like to see a build flag around it.
>>
>
> OK. I will do so.
> _______________________________________________
> webkit-dev mailing list
> webkit-dev at lists.webkit.org
> https://lists.webkit.org/mailman/listinfo/webkit-dev
>
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.webkit.org/pipermail/webkit-dev/attachments/20131010/aaaf4eaf/attachment.html>