W3C home > Mailing lists > Public > public-html-a11y@w3.org > February 2010

Survey ready on canvas proposal

From: Richard Schwerdtfeger <schwer@us.ibm.com>
Date: Mon, 22 Feb 2010 18:13:18 -0600
To: public-html-a11y@w3.org, mjs@apple.com
Message-ID: <OFD0207342.3A5DD471-ON862576D3.00007065-862576D3.00013813@us.ibm.com>

On Feb 22, 2010, at 2:23 PM, Michael Cooper wrote:

>> There is a one-question survey ready on the proposal from the canvas
>> sub-team:
>> http://www.w3.org/2002/09/wbs/44061/20100225_canvas/
>> Please take a moment to provide your view. While the survey will be
>> open until Thursday, if you can, try to provide your input by the
>> end of Wednesday in order to allow input to be incorporated prior to
>> Thursday discussions.
>I'd like to ask for a clarification on something that is not fully
>clear to me from the proposed spec changes. If adom is not set, are
>user agents forbidden to expose the children of <canvas> to assistive
>technologies? Or is it meant as a hint that they don't need to, and
>the contents may not meet the stated requirements?
>Specifically, this is the sentence that is not totally clear to me:

>  "The default value for adom is false to indicate that the canvas
>subtree is only used as fallback content and may not be used as an
>accessible DOM subtree representation of what is drawn on canvas."


What we are saying is that when adom is set it indicates the subtree is
mapped to the accessibility API as the representation of the <canvas>
rendering. If it is set to all it is NOT the accessible representation of
the <canvas> rendering and should not be exposed to the AT. However, if the
fallback content is rendered instead of <canvas> (canvas is hidden) then by
all means it should be mapped. It is for this reason we did not make a MUST
not. Are you suggesting that to address this point we should make it a MUST

>Is the "may not" in that sentence meant to be a UA requirement, and is
>it meant to be mandatory or optional? Does "used as an accessible DOM
>subtree representation of what is drawn on canvas" apply to any form
>of exposing the content to AT?

I think I answered this above. If not please let me know. ... Should we be
more prescriptive in the text?



Received on Monday, 22 February 2010 22:36:20 GMT

Rich Schwerdtfeger
Distinguished Engineer, SWG Accessibility Architect/Strategist
Received on Tuesday, 23 February 2010 00:14:29 UTC

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