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Re: Using @aria-describedby for long described image links [Was: Using an image map for long described image links [Was: Revert Request]]

From: Maciej Stachowiak <mjs@apple.com>
Date: Mon, 06 Feb 2012 17:57:03 -0800
Cc: Benjamin Hawkes-Lewis <bhawkeslewis@googlemail.com>, John Foliot <john@foliot.ca>, Matthew Turvey <mcturvey@gmail.com>, Leif Halvard Silli <xn--mlform-iua@xn--mlform-iua.no>, Silvia Pfeiffer <silviapfeiffer1@gmail.com>, Laura Carlson <laura.lee.carlson@gmail.com>, Sam Ruby <rubys@intertwingly.net>, Paul Cotton <Paul.Cotton@microsoft.com>, HTML WG <public-html@w3.org>
Message-id: <ECC9BB47-D833-4779-B42C-89A46CA25A46@apple.com>
To: Steve Faulkner <faulkner.steve@gmail.com>

On Feb 2, 2012, at 3:14 AM, Steve Faulkner wrote:

> Hi ben, 
> 
> >But that's the very least of the problems here, since the same company
> >who maintain VoiceOver also maintain the accessibility API and the
> >main browser on VoiceOver's platform, so they are free to make changes
> >to the rest of the stack to support VoiceOver.
> 
> Indeed
> just didn't want arguments to be based on false assumptions.
> While it is true they are "free to make changes to the rest of the stack to support VoiceOver." assuming they will, without clear indications from them is not useful.

You're both more or less correct about how things work.

All direct querying of the DOM (and also of rendering information) is done by WebKit, which then communicates the info to VoiceOver using the NSAccessibility API. However, we are able to change any or all of those layers as necessary to get a better overall experience, and we try to do better with each release.

I don't think Apple has a strong stance either way on using @aria-describedby to point to @hidden elements, but I believe we could reasonably expose full semantics of hidden content pointed to by aria-describedby, this is more or less the same as the work we'd have to do to expose <canvas> children as an accessible tree.

I also expect that we make descriptions optional rather than in the default speech flow, at least when a label or other short textual equivalent (such as alt text) is also present.

Regards,
Maciej

> 
> regards
> steve
> 
> 
> On 2 February 2012 11:05, Benjamin Hawkes-Lewis <bhawkeslewis@googlemail.com> wrote:
> On Thu, Feb 2, 2012 at 10:39 AM, Steve Faulkner
> <faulkner.steve@gmail.com> wrote:
> >> Apple Accessibility API), AT could query the DOM to find the referenced
> >> description elements and map them
> >> back to the accessibility tree.
> >
> > my understanding is that VoicOver does not query the DOM directly at all, by
> > design.
> 
> Indeed.
> 
> But that's the very least of the problems here, since the same company
> who maintain VoiceOver also maintain the accessibility API and the
> main browser on VoiceOver's platform, so they are free to make changes
> to the rest of the stack to support VoiceOver.
> 
> --
> Benjamin Hawkes-Lewis
> 
> 
> 
> -- 
> with regards
> 
> Steve Faulkner
> Technical Director - TPG
> 
> www.paciellogroup.com | www.HTML5accessibility.com | www.twitter.com/stevefaulkner
> HTML5: Techniques for providing useful text alternatives - dev.w3.org/html5/alt-techniques/
> Web Accessibility Toolbar - www.paciellogroup.com/resources/wat-ie-about.html 
> 
Received on Tuesday, 7 February 2012 02:00:46 GMT

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