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

I agree. we should provide for alternative modalities besides visual.

Rich Schwerdtfeger
Distinguished Engineer, SWG Accessibility Architect/Strategist


                                                                           
             David Singer                                                  
             <singer@apple.com                                             
             >                                                          To 
             Sent by:                  Ian Hickson <ian@hixie.ch>          
             public-canvas-api                                          cc 
             -request@w3.org           Richard                             
                                       Schwerdtfeger/Austin/IBM@IBMUS,     
                                       "public-canvas-api@w3.org"          
             01/13/2010 08:09          <public-canvas-api@w3.org>,         
             PM                        public-html@w3.org                  
                                                                   Subject 
                                       Re: Proposal: Canvas accessibility  
                                       and a media querries approach for   
                                       alternative content (Action Item 6  
                                       in the HTML Accessibility Task      
                                       Force)                              
                                                                           
                                                                           
                                                                           
                                                                           
                                                                           
                                                                           





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.