W3C home > Mailing lists > Public > wai-xtech@w3.org > May 2007

Re: Developers' Poll: support for overflow: hidden;

From: Gregory J. Rosmaita <unagi69@concentric.net>
Date: Tue, 22 May 2007 13:26:40 -0400 (EDT)
To: Gez Lemon <gez.lemon@gmail.com>, <unagi69@concentric.net>
Cc: "Gregory J. Rosmaita" <oedipus@hicom.net>, <wai-xtech@w3.org>, <wai-liaison@w3.org>
Message-Id: <20070522172640.CC0F97A5@captain.cnc.net>

aloha, gez!

thanks for your quick, and as usual, concise and on-the-point 

what bothers me is that amazon thinks it is communicating to screen 
readers, as is evident from the snippet of document source i cited 
in my post, which happens to be an instance of using the style 
attribute to define the same CSS values you defined, and which 
WCAG2 uses as an example of hiding text...  what i'm trying to 
figure out is: what is amazon's purpose -- clearly from the 
hidden text, it is to provide a more accessible version for 
screen readers and mobile devices alike...  but the only time this 
notice is spoken is when a non-CSS capable browser exposes the 
content without it's inline styling, as would be expected when using 
a text-based browser such as lynx...

so, are they trying to hide the text from the visual canvas and 
paint it to the aural canvas? (or, as in the case of lynx, 
having it rendered on a non-CSS capable UA?)  this seems clearly 
to be their intent, judging by the inline styling and the text 
contained therein...

what i want to know is: is this an effective way of presenting 
such information to the aural canvas?  i couldn't find any 
display:none rules that would apply to the DIV styling cited 
in my original post about the use of overflow:hidden on amazon...

are they making a good-faith effort that fails because assistive 
technologies will not render anything marked as :hidden or are 
they misimplementing the technique, assuming that screen readers 
will speak the text marked as overflow:hidden?  (i'm talking from
a strictly technical point of view, as i abhore the cyberghettoization 
of content -- especially the words quote similar content unquote)

what i am ultimately attempting to determine is, what is the proper 
way to use CSS to paint to the aural canvas while leaving the visual 
canvas unmodified?  given the state of the CSS 2.1 draft and its 
ambiguities, i sincerely think this needs to be sorted out, one way 
or the other, which is why i proposed a quote render unquote meta 
media property, which unambiguously signals to all canvases that what 
is marked hidden is to be hidden from all possible canvases, and 
what is marked exposed is exposed to all possible canvases...  this 
would allow display:none to be a visual property, affecting only the 
visual canvas, leaving the text so styled available to the aural and 
or tactile canvases, while visibility:hidden (a modality-dependent 
property) would be to the visual canvas what volume:silent is to the 
aural canvas (leave a silent gap corresponding to the hidden block, 
just as visibility:hidden; hides content, but leaves an empty, canvas-
consuming block.

likewise, speak:none; is the aural equivalent of display:none, in 
that it does not interupt the aural flow to indicate invisible 
text, as does volume:silent

so i'm trying to figure out a way of assisting amazon in conveying 
content to the aural, tactile and the CSS-incapable canvas without 
intruding or leaving a footprint on the visual canvas...  i 
understand that the collapse property allows the content so styled 
to be invisible, hence hidden, from the visual canvas, but does a 
property named visibility really apply to the aural and tactile 
canvases, especially when the analogy -- or rather, synonymetry -- 
between visibility:hidden and volume:silent is so explicitly 


Note the difference between an element whose 'volume' property has 
a value of 'silent' and an element whose 'speak' property has the value 'none'. The former takes up the same time as if it had been 
spoken, including any pause before and after the element, but no 
sound is generated. The latter requires no time and is not 
rendered (though its descendants may be).


The 'visibility' property specifies whether the boxes generated 
by an element are rendered. Invisible boxes still affect layout 
(set the 'display' property to 'none' to suppress box generation 

"He who lives on Hope, dies farting."
  -- Benjamin Franklin, Poor Richard's Almanack
Gregory J. Rosmaita, unagi69@concentric.net
Camera Obscura: http://www.hicom.net/~oedipus/
Received on Tuesday, 22 May 2007 17:26:50 UTC

This archive was generated by hypermail 2.3.1 : Tuesday, 6 January 2015 21:51:32 UTC