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Re: CSS issue: Need control of what is perceived by which technologies

From: James Craig <jcraig@apple.com>
Date: Mon, 26 Nov 2012 12:08:03 -0800
Cc: Antony Kennedy <antony@silversquid.com>, www-style list <www-style@w3.org>
Message-id: <C7D1BD2A-85BB-4840-B2A3-CF5078CE9F3F@apple.com>
To: "Tab Atkins Jr." <jackalmage@gmail.com>
On Nov 26, 2012, at 10:01 AM, Tab Atkins Jr. <jackalmage@gmail.com> wrote:

> On Mon, Nov 19, 2012 at 2:58 AM, Antony Kennedy <antony@silversquid.com> wrote:
>> Is this something that can be sensibly achieved with media queries?  @media
>> not speech and  @media speech seem like they should work great here.
>> However, the screen reader attaches to the output of the browser (what the
>> browser sends via Operating System APIs) and not the browser itself, so when
>> the browser is parsing the CSS it never understands to expose or not expose
>> these pieces. aria attributes work correctly here though, so there must be a
>> solution!
> 
> If this were true, then "speech" media would be completely useless.  I
> believe browsers can tell when a page is being read by AT, and can
> provide customized information for it.  (I could be wrong, though...)


AT is a broad term and browsers cannot detect all forms, though providing customized information on a per-AT case is usually unnecessary. 

I don't think a new "perceivable" property is necessary here, because I believe the @media type query fits well here:

	element::before { content: ":"; }
	@media speech or reader { element::before { content: ""; } }

In this case, the UA should just not expose the text contents of the pseudo-element to the accessibility API, or mark it in the API as decorative or otherwise hidden.

I think what Antony is requesting is that the CSS spec should state something explicit to that effect.

James
Received on Monday, 26 November 2012 20:08:31 GMT

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