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Re: Helping Canvas Tag Be Accessible

From: Richard Schwerdtfeger <schwer@us.ibm.com>
Date: Thu, 30 Jul 2009 07:50:45 -0500
To: Steven Faulkner <faulkner.steve@gmail.com>
Cc: HTMLWG WG <public-html@w3.org>, public-html-request@w3.org, W3C WAI-XTECH <wai-xtech@w3.org>
Message-ID: <OF14D0DF3D.711137B3-ON86257603.00439C3F-86257603.00469011@us.ibm.com>

I have been following a number of threads and I think you can agree that,
although the HTML working group has stated that canvas should only be used
for drawings, authors will do what they want. It is just a fact of life.

In order to make canvas accessible we will need:

   An object model to which authors can apply an accessibility API.
   A collection of callback interfaces that can be applied to objects to
   support an accessibility API mapping on each browser and platform and
   potentially a vehicle to fire events to ATs.
   A provision for equivalent alternative references that allow a canvas
   author to specify an alternative resource for drawing that cannot be
   made accessible through traditional API.

I would agree with Raman that the equivalent of MSAA is a start. We will
need more than that to bring it in line with what is in ARIA. To be clear
the implementation of ARIA support in the browser has caused browser
manufacturers to improve their accessibility API support.  It is true that
both Flash and Silverlight provide vehicles for authors to bind
accessibility API support to drawings.

It is important that we get on this. With new legislation coming out:

   U.S. 508 Refresh (our projection 2011)
   WCAG 2 adoption world wide for web accessibility (happening now)
   EU Mandate 376 (our projection 2011)

If we don't address gaps in HTML 5, I am concerned that it will be
blackballed by governments similar to what happened with CSS and
JavaScript. ARIA's success and the release of WCAG 2 are moving governments
toward removing those restrictions as we speak. Both the recommendations
for the 508 refresh and WCAG 2 remove the restrictions on CSS and
JavaScript. For those who do not know this WCAG 1 required that you be
accessible with Script and CSS turned off in the browser.


Rich Schwerdtfeger
Distinguished Engineer, SWG Accessibility Architect/Strategist

             Steven Faulkner                                               
             mail.com>                                                  To 
             Sent by:                  HTMLWG WG <public-html@w3.org>, W3C 
             public-html-reque         WAI-XTECH <wai-xtech@w3.org>        
             st@w3.org                                                  cc 
             07/24/2009 04:24          Helping Canvas Tag Be Accessible    

Helping Canvas Tag Be Accessible - discussion thread on open web advocacy
mailing list

with regards

Steve Faulkner
Technical Director - TPG Europe
Director - Web Accessibility Tools Consortium

www.paciellogroup.com | www.wat-c.org
Web Accessibility Toolbar -

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Received on Thursday, 30 July 2009 12:52:52 UTC

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