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

[CSS21] WAI Issue 5: Master meta-media type 'render' needed [DRAFT]

From: Gregory J. Rosmaita <oedipus@hicom.net>
Date: Tue, 11 Dec 2007 03:07:04 +0000
To: wai-xtech@w3.org, wai-liaison@w3.org
Message-Id: <20071211030552.M62674@hicom.net>

[Reviewer's Note 1: this post refers to the Candidate Recommendation
draft of CSS 2.1,
http://www.w3.org/TR/2007/CR-CSS21-20070719
comments upon which are due by 20 December 2007]

[Reviewer's Note 2: this may have been rendered moot by WCAG2 Repair 
Technique C7, which uses the "overflow" property to hide text 
which appears in the document source from visual renderers which 
support CSS -- HOWEVER, my musings on the braille media type, i 
believe, need to be addressed, probably/perhaps as a discrete issue;
i will attempt to restate those particular comments into a single
issue draft post]

One solution to the ambiguity of the CSS2.1 spec and the modality-
specific slash modality-oriented markup may lie in the adoptation 
of a master meta-media type, named render: 

render: expose; 
render: hide; 

which would clearly and unambiguously signal to ALL renderers, 
regardless of modality, that what is styled with render is 
supposed to be either exposed to all media or hidden from 
all media.  "expose" would, obviously cause all renderers to expose 
the content so defined; hide would, likewise cause all renderers 
to keep the content so defined hidden;

visibility: hidden;
and
volume: silent;

would then be synonyms -- the first applicable to visual media canvases, 
the second to the aural media canvas.  A question this brings to mind is 
whether there is a need for a collapse property for the tactile media 
type braille, so that a refreshable display wouldn't have to render what 
could be large chunks of blank space, and an embosser wouldn't have to 
waste valuable tactile real estate, but could -- as could the braille 
media type -- simply explicitly describe the blank space in the visual 
and aural canvas, for example: quote 7 blank lines unquote or quote empty 
block skipped unquote.

display:inline; 
display:block; 
display:none; 

would then be visual media selectors; with display:none available to 
the author to paint to the aural canvas without "disturbing" the visual 
canvas. multiple use cases for exposing aurally what is not rendered 
visually, have already been advanced; for example, the use of 
display:none 
to convey orientational and contextualizing information in the aural 
canvas that doesn't "intrude" on the visual canvas.  This should be 
extended to the braille media type (orientation and contextualization 
for users of refreshable braille displays), whereas the embossed media 
type, would obey the display:none rules, as embossing is to the print 
media type as aural is to the braille media type.

This is a much more logical and semantically meaningful disambiguation of 
terms.



----------------------------------------------------------------
CONSERVATIVE, n.  A statesman who is enamored of existing evils,
as distinguished from the Liberal, who wishes to replace them 
with others.         -- Ambrose Bierce, _The Devil's Dictionary_
----------------------------------------------------------------
             Gregory J. Rosmaita, oedipus@hicom.net
  Camera Obscura: http://www.hicom.net/~oedipus/index.html
----------------------------------------------------------------
Received on Tuesday, 11 December 2007 03:07:40 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Friday, 27 April 2012 13:15:44 GMT