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Re: implementing Canvas to assure accessibility


From: Steve Faulkner
Date: Mar 11, 2014 3:25AM

hi Jennifer current state of canvas accessibility:

all modern browsers support navigable canvas sub DOM refer to

the other parts of the puzzle are:
focus rings: ability to draw focus rings on a canvas that correspond to
interactive elements in the canvas sub DOM: implemented in Firefox nightly.
hit regions: ability to bind a region of the canvas to an element in the
sub DOM and pass events to the element in the sub DOM: implemented in
Firefox nightly.
Example of hit regions and drawFocusIfNeeded



HTML 5.1 <http://www.w3.org/html/wg/drafts/html/master/>;

On 10 March 2014 03:34, Jennifer Sutton < <EMAIL REMOVED> > wrote:

> Greetings, WAI-IG:
> I posted a message similar to this one to the WebAIM list on February 27,
> but I didn't receive any answers to the thread:
> http://webaim.org/discussion/mail_thread?thread=6335
> So, I'm slightly modifying my message and posting here, in hopes of
> gathering input.
> I'm wondering if involved parties could offer the list an update on Canvas
> accessibility. One of Steve's recent tweets, pasted below my name, suggests
> that there's progress .
> What I'd welcome is an update on the application of/implications for the
> use of Canvas, with respect to accessibility, in the real world, right now.
> I'm working with a client who's implementing it, and I need to provide
> guidance to assure both that the Canvas implementation can be made as
> accessible as possible (not just to screen reader users, of course). And I
> want to provide guidance about fallback techniques.
> Questions that are crossing my mind include:
> -- If Canvas is implemented to create an image, but the raw data is still
> available, will that raw data suffice, in terms of accessibility? I would
> think some kind of textual description would be valuable to all, including
> anyone using an older browser that might not support Canvas.
> -- Are there any Canvas-generating libraries that are particularly
> focusing on assuring accessibility?
> -- What is the best source of accessible examples?
> Thanks.
> Best,
> Jennifer
> @stevefaulkner tweeted:
> HTML5 <canvas> hit Region and focus ring details and example
> http://t.co/WxhkuSN4TD
> Wednesday, February 26, 2014 at 9:14:40 AM
> http://twitter.com/stevefaulkner/status/438723805067096066