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Re: Example canvas element use - accessibility concerns

From: Steven Faulkner <faulkner.steve@gmail.com>
Date: Mon, 8 Jun 2009 18:21:23 +0100
Message-ID: <55687cf80906081021naa34c09wa24f8cbaf6bc3b35@mail.gmail.com>
To: HTML WG <public-html@w3.org>
Cc: W3C WAI-XTECH <wai-xtech@w3.org>, Janina Sajka <janina@rednote.net>
Thinking about canvas accessibility
http://www.paciellogroup.com/blog/?p=362

2009/2/18 Steven Faulkner <faulkner.steve@gmail.com>:
> The recently released code editor Bespin
> (https://bespin.mozilla.com/index.html) is a great example of the utility of
> the canvas element, its also a worrying example of the barriers to
> accessibility its use will produce. It includes editable text, folder lists
> and interactive elements that are all essentially a graphic. there does not
> appear to be a way to extract any usable information to support Assistive
> technology to interpret or provide interaction.
>
> The current advice on its use and provision of fallback content seems
> somewhat weak given the example of its use in Bespin:
>
> "Authors should not use the canvas element in a document when a more
> suitable element is available. For example, it is inappropriate to use a
> canvas element to render a page heading: if the desired presentation of the
> heading is graphically intense, it should be marked up using appropriate
> elements (typically h1) and then styled using CSS and supporting
> technologies such as XBL.
>
> When authors use the canvas element, they should also provide content that,
> when presented to the user, conveys essentially the same function or purpose
> as the bitmap canvas. This content may be placed as content of the canvas
> element. The contents of the canvas element, if any, are the element's
> fallback content." [1]
>
> Are there plans to provide mechanisms to add accessibility hooks for content
> produced using canvas? As providing a secondary accessible version of an
> application such as bespin seems like a non starter, and is a prime example
> of the sort of "bolt on" accessibility that HTML5 was trying to move away
> from.
>
> [1] http://www.w3.org/TR/html5/the-canvas-element.html#the-canvas-element
>
> --
> with regards
>
> Steve Faulkner
> Technical Director - TPG Europe
> Director - Web Accessibility Tools Consortium
>
> www.paciellogroup.com | www.wat-c.org
> Web Accessibility Toolbar -
> http://www.paciellogroup.com/resources/wat-ie-about.html
>



-- 
with regards

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

www.paciellogroup.com | www.wat-c.org
Web Accessibility Toolbar -
http://www.paciellogroup.com/resources/wat-ie-about.html
Received on Monday, 8 June 2009 17:22:02 GMT

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