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RE: Agenda + [2.4] CORRECT version of 2.4 proposal

From: Tim Boland <frederick.boland@nist.gov>
Date: Thu, 05 May 2005 11:46:06 -0400
Message-Id: <>
To: "John M Slatin" <john_slatin@austin.utexas.edu>
Cc: w3c-wai-gl@w3.org

By "visual display order" and "CSS positioning" (in excerpted text following),
are you specifically referencing
  implementations of the CSS2.1 visual
  rendering model, in which each element in the document tree generates zero
  or more rectangular boxes in the rendering structure, as well as the visual
rendering model aspects,  the box model (describing
the generation of such boxes, controlled by the "display" property), and 
the visual
flow model, describing how each box receives its final position, based upon
relationships of source elements in the document tree, box dimensions, and
canvas dimensions (and including the "position" and "float 
properties)?     I think that
the "interaction" of values of "display", "position", and "float" 
properties (as well as
applicable values of "top", "right", "bottom", "left", "direction", 
"clear", and
  "z-index" properties) may have accessibility implications pertaining to the
discussion excerpted following..

>my lifetime.  But the replacement-- CSS positioning-- raises the same
>possible problems because it *does* (or can) separate content and
>structure from presentaition (even if the boundary gets blurred
>sometimes).  Mostly that's a good thing for accessibility-- it means
>that the visual display order and the auditory sequence can be different
>and each be "tuned" to the needs of a different segment of the audience.
>But the decoupling can be problematic if the order of the content in the
>delivery unit doesn't work as a linear sequence-- even if the order in
>the source follows the visual order.
Received on Thursday, 5 May 2005 15:46:37 UTC

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