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Re: [css3-values] accessibility review

From: Kang-Hao (Kenny) Lu <kennyluck@csail.mit.edu>
Date: Thu, 05 Apr 2012 09:55:55 +0800
Message-ID: <4F7CFBAB.2000709@csail.mit.edu>
To: "Tab Atkins Jr." <jackalmage@gmail.com>, Cynthia Shelly <cyns@microsoft.com>
CC: "www-style@w3.org" <www-style@w3.org>, "wai-xtech@w3.org" <wai-xtech@w3.org>
(12/03/31 2:13), Tab Atkins Jr. wrote:
> On Fri, Mar 30, 2012 at 10:54 AM, Cynthia Shelly <cyns@microsoft.com> wrote:
>> 5.1.2
>> Are ‘ vw’ ‘vh’ ‘vmin’ supported in any existing browsers?
>> Is there a way to specify a minimum absolute size for these?  It seems like
>> this could easily get too small to read.
>> It does, however, seem useful for scalable/zooming UI
> 
> The v* units are currently supported in IE, and a patch applying them
> to WebKit is nearly finished.  I'm not sure of their status in other
> browsers.
> 
> There is no way to set an absolute minimum size for them.  The v*
> units are effectively identical to using percentages; their advantage
> is that you don't need the entire ancestor chain to be "100%" in the
> relevant property.

Would something like 'min-width'[1] and 'min-height' in @viewport
fulfilll this need?

>> 6.3 frequency
>> Please add a note that frequencies near 7hz can cause seizures, and link to
>> WCAG.  More detail in WCAG
>> http://www.w3.org/WAI/WCAG20/quickref/20071211/Overview.php#seizure
> 
> This only applies to the frequency of things that are flashing or
> changing color/brightness/etc., right?  There is no such use of
> frequencies in CSS right now.  The frequency units are currently used
> only in the Speech spec, where such a warning would be nonsensical.

Or in some sense interchangeable, a duration of 0.142857s can cause
seisure. However, I think this sort of note would be more useful if it's
part of CSS3 Animations.

A side comment, it seems reasonable to have the 'animation' shorthand
accept <frequncy> to simultaneously set 'animation-iteration-count' to
'infinite' and 'animation-duration' to the reciprocal, but I am not a
Web Developer and I am not sure if this is useful.

>> 8.3 attribute reference
>> It would be great to have an example of using this to style elements with
>> ARIA attributes on them.  Would you be willing to work with PF and WCAG on a
>> set of techniques around this, in addition to a simple example in the spec.
> 
> As far as I know, there's no aria attribute where you'd ever want to
> use its value as a CSS value.  You want to apply properties *based on*
> the values, but that's done with Selectors.
> 
> Do you have an example to the contrary?

It seems interesting combination if attr() supports 'element' as a
<type>. Something in the line of

  [aria-describedby] {
     nav-left: attr(aria-describedby element);
  }

but again, I am not close to knowing ARIA much to actually raise such a
proposal. What do you think?

[1]
http://dev.w3.org/csswg/css-device-adapt/#the-lsquomin-widthrsquo-and-lsquomax-wid


Cheers,
Kenny
Received on Thursday, 5 April 2012 01:56:25 GMT

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