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Re: Proposal: Canvas accessibility and a media querries approach for alternative content (Action Item 6 in the HTML Accessibility Task Force)

From: David Singer <singer@apple.com>
Date: Wed, 13 Jan 2010 18:09:42 -0800
Cc: Richard Schwerdtfeger <schwer@us.ibm.com>, "public-canvas-api@w3.org" <public-canvas-api@w3.org>, public-html@w3.org
Message-Id: <6A12711A-8E78-43F6-9DE7-76F35752C2B7@apple.com>
To: Ian Hickson <ian@hixie.ch>

On Jan 13, 2010, at 18:03 , Ian Hickson wrote:

> On Wed, 13 Jan 2010, David Singer wrote:
>> On Jan 12, 2010, at 14:52 , Ian Hickson wrote:
>>> 
>>> I don't understand why we would want, or need, to make the accessible 
>>> canvas DOM any different than the regular fallback DOM.
>> 
>> I may be misunderstanding the question, and if so, I apologize.
>> 
>> If I have some kind of scientific visualization with controls that I do 
>> in canvas, and there really isn't a way to do that without canvas (i.e. 
>> no real way to draw it), my fallback for browsers not capable of canvas 
>> may be "we regret the loss of picture", whereas my shadow for the 
>> accessible user using canvas may well be a set of controls -- 
>> check-boxes ('Gravity morphing?') sliders ('Phi incursion angle!'), 
>> buttons ('fire photon torpedo!') and so on.
>> 
>> If I am right, I would tend to ask the opposite: how can we be sure that 
>> the fallback for non-canvas-capable browsers will essentially always be 
>> the same as the shadow for canvas-capable browsers needing accessible 
>> access?
> 
> In this scenario, how is the data made accessible to blind users?


Why is the accessibility need assumed to be visual?  We have motor-impaired people who cannot operate a mouse, but who can interact with buttons/sliders etc. using, for example, voice controls.

David Singer
Multimedia and Software Standards, Apple Inc.
Received on Thursday, 14 January 2010 02:10:16 GMT

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