Re: Request for advice on <canvas> accessibility

Hi Ian,
its great that you are reaching out to the W3C accessibility
community. I for one feel honoured.

I would suggest 3 things:

1. For a problem that has stumped you we need as much technical
expertise as is possible, so have included the HTML WG in this email.
2. we use an example that embodies the problem:
contains 2 examples of UI controls rendered using canvas.

3. rephrase the question:  what  would need to be added to the canvas
API so that the UI controls in the example could have
programmtic focus (like an area on an image map)
name, role and state information provided.


2009/6/26 Ian Hickson <>:
> Hi,
> It has been suggested that the <canvas> feature in HTML5 should have an
> accessibililty solution more thorough that its current solution, which is
> based on the <object> fallback model.
> To this end, I would like to look to the W3C WAI groups for guidance on
> this issue.
> To help me understand how <canvas> could be made more accessible, I would
> like to work from a concrete example:
> This page uses <canvas> to generate a graph. Could I ask for advice on
> what the best possible way to make this page universally accessible would
> be? I would like to maintain the same visual presentation, but would like
> to make this page accessible to users of ATs.
> Could the WAI groups provide sample pages showing how, in an ideal world,
> with whatever APIs or accessibility hooks need to be made available, the
> page could be made accessible, while still maintaining its current dynamic
> generation and visual presentation?
> My goal here is to determine what the best APIs and other technical
> solutions would be to provide good accessibility as automatically as
> possible for people using <canvas>. I hope the combined accessibility
> expertise of the WAI groups will be able to design a solution for this
> that we can use in HTML5.
> I am at a loss personally as to how to do this. Any help would be greatly
> appreciated on this issue.
> Cheers,
> --
> Ian Hickson

with regards

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

Received on Saturday, 27 June 2009 06:23:08 UTC