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Re: Please vote on the canvas accessibility proposal

From: Silvia Pfeiffer <silviapfeiffer1@gmail.com>
Date: Fri, 26 Feb 2010 12:02:40 +1100
Message-ID: <2c0e02831002251702v4c01d447pe0f93a35f641d6e3@mail.gmail.com>
To: Richard Schwerdtfeger <schwer@us.ibm.com>
Cc: Steven Faulkner <faulkner.steve@gmail.com>, Ian Hickson <ian@hixie.ch>, public-canvas-api@w3.org, "public-html-a11y@w3.org" <public-html-a11y@w3.org>, public-html-a11y-request@w3.org
On Fri, Feb 26, 2010 at 2:19 AM, Richard Schwerdtfeger
<schwer@us.ibm.com> wrote:
> Silvia, For the 12th time now. adom is not a statement of accessibility. It
> simply says to use the subtree as the accessibility mapping as intended by
> the author. It is NOT  A COMPLIANCE STATEMENT. It is a way for the author to
> associate their subtree of canvas as their accessibility implementation of
> canvas.

Sorry, but if people that have held discussions with your for weeks
still do not understand your meaning about @adom, how is a Web
developer supposed to?

Also, if I have understood the previous discussion correctly, then
everything that is inside the <canvas> is already by definition both
accessibility and fallback markup. There is no distinction being made
between the two. Any subtree inside the <canvas> is already associated
as an accessibility implementation of canvas.

Anyway - maybe it makes sense to provide some explicit examples of the
use of @adom and how it will make a difference to the interpretation.
I think concrete markup will expose the use case more than any
argument will.

> I need you and Ian to point me to the text in the proposal that makes the
> claim you are both making.

I am not making any claims. I am asking questions and making logical
deductions from the answers I am getting.

>> accessibility. What if the Web developer thinks they have made the
>> subtree accessible, but have in fact forgotten to add aria attributes
> What if they forget to do this in the areamap example? What if they forget
> to do this elswhere in the document?

There is no markup elsewhere in HTML claiming there is accessibility
information available for an element. The claim that accessibility
information is available should not be made by the Web developer, but
by a user or a tool that checks for accessibility markup.

> Ian's example was a non-interactive picture on the web page. This about the
> most trivial accessibility issue to address. Are you trying to tell everyone
> that <canvas> is going to be used to create non-interactive pictures most of
> the time? If that is the case I would suggest dumping it from HTML 5.

No, I also stated that Ian's picture was simple and that there are
probably others where there is tighter integration between the
accessibility data inside the <canvas> and the <canvas> itself. Please
read my replies fully.

>> I think a tool that needs to evaluate whether something is accessible
>> cannot rely on an attribute but has to do the hard work of actually
>> walking through the DOM tree and identifying whether there is actual
>> effort done in providing accessibility markup.
> Exactly, and it needs to know what part of the web page to test. That is all
> adom is doing for the test tool.

But ... the part that it needs to test is inside the <canvas> element.
There is no need to express where it is. I really don't follow.

Honestly, do provide some example markups that show the difference
that the element makes. Thus far it's all theoretical and one cannot
have factual discussions about theories, only theological ones.

Best Regards,
Received on Friday, 26 February 2010 01:03:38 UTC

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