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Re: [html5alt] some thoughts on LEGEND (with example)

From: Gregory J. Rosmaita <oedipus@hicom.net>
Date: Fri, 6 Mar 2009 15:03:30 +0000
To: html5alt@lists.wisc.edu
Cc: www-archive@w3.org
Message-Id: <20090306150148.M79008@hicom.net>
due to health problems, i was not online yesterday, and although i haven't
yet caught up on this thread, i did want to clarify my thoughts in 
response to Gregg's reply to my initial post...

aloha, gregg!

perhaps i should have slept on it after all <grin>

yes, each of the images in the 3 stages of a butterfly's life REQUIRE
alt text and/or labelledby to provide them with unique and appropriate
terse descriptions, just as each form control in a FIELDSET has its 
own LABEL defined for it, with the value of the LEGEND element providing
a CAPTION-like function for the FIELDSET, so too does LEGEND provide 
a means of declaratively marking explicit bindings of groups of related
objects, as in:

<FIGURE aria-labelledby="l1">
<LEGEND id="l1">The Three Stages of a Butterfly's Life Cycle</LEGEND>
<IMG alt="Stage 1: The larval stage." src="butterfly1.svg" 
     longdesc="butterfly1.html">
<IMG alt="Stage 2: The pupal stage." src="butterfly2.svg" 
     longdesc="butterfly2.html">
<IMG alt="Stage 3: The adult stage." src="butterfly3.svg" 
     longdesc="butterfly3.html">
</FIGURE>

the LEGEND applies to all three images as a collection of related 
objects, available, for example, in a screen reader situation, 
either through a verbosity setting or via an extended query, 
such as MagicKey+TAB reads the alt text of the individual graphic
which has focus, MagicKey+TAB pressed twice rapidly (or with a 
moderator key) provides the user with the LEGEND which describes,
tersely, the group to which the individual image belongs, so that
the user can be made aware of:

a) each individual image's terse alternative text; 

b) the grouping to which the image belongs (if it is one of a series
   presented in a FIGURE) or any other modality-specific content 
   contained in HTML5's media-specific elements, including AUDIO, 
   VIDEO, OBJECT and CANVAS;

actually, if focus is on the graphic, i would require 3 levels of query:

1. what is the textual alternative for the graphical object with focus?

2. does the graphical object with focus belong in a grouping?  if so,
   what is the "title" stroke name of the group?

3. please provide me with a detailed description of the graphical object 
   with focus (read me the contents of the LONGDESC page referenced for
   the graphical image, if i am using synthesized speech, as if it is 
   an embedded object, render it (if so a user sets her user agent) 
   side-by-side, in a side-bar, or whatever other exposition strategy
   is offered by the user agent (and not just those provided by the user 
   agent plus a plug-in plus a specific assistive technology product)

does this make my line of thought any easier to follow, or have the 
crows of my cranium eaten the trail of thoughtcrumbs i attempted to 
leave behind me?

most evolutionary paths end in dead ends, and HTML5 is chartered to 
evolve a language based on HTML 4.01, so it would not surprise me if
what i took for an insight was merely an internal refraction...

gregory.
-----------------------------------------------------------------
Sometimes I think my writing sounds like I walked out of the room
and left the typewriter running.                   -- Gene Fowler 
-----------------------------------------------------------------
Gregory J. Rosmaita: oedipus@hicom.net OR gregory@ubats.org
     Camera Obscura: http://www.hicom.net/~oedipus/
            Oedipus' Online Complex: http://my.opera.com/oedipus/
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Received on Friday, 6 March 2009 15:04:19 UTC

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