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Re: Helping Canvas Tag Be Accessible

From: Anne van Kesteren <annevk@opera.com>
Date: Thu, 30 Jul 2009 15:10:49 +0200
To: "Richard Schwerdtfeger" <schwer@us.ibm.com>, "Steven Faulkner" <faulkner.steve@gmail.com>
Cc: "HTML WG" <public-html@w3.org>, "W3C WAI-XTECH" <wai-xtech@w3.org>
Message-ID: <op.uxvtkbsy64w2qv@annevk-t60>
On Thu, 30 Jul 2009 14:50:45 +0200, Richard Schwerdtfeger <schwer@us.ibm.com> wrote:
> In order to make canvas accessible we will need:
>    An object model to which authors can apply an accessibility API.

Doesn't this defeat the whole idea of <canvas>? If you want an object model you could use SVG.

>    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.

I'm not quite I follow this point.

>    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.

This is already possible. Just include content between the two tags of the element.

> [...] For those who do not know this WCAG 1 required that you be
> accessible with Script and CSS turned off in the browser.

<canvas> is still compatible with that model as fallback must be shown if JavaScript is disabled. Having said that, since JavaScript is part of the semantics of a page that seems like an odd restriction to make, though probably in line with best practices of its time.

Anne van Kesteren
Received on Thursday, 30 July 2009 13:11:36 UTC

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