RE: SVG accessibility - how capture the reading order of text

At 03:32 AM 2001-09-07 , DPawson@rnib.org.uk wrote:
>
>> Do you have a clear model for the way an SVG user agent 
>> should interact with
>> assistive technology with respect to Title and Description? If I were
>> linearizing an SVG document, should the linearized version 
>> include all titles
>> and/or descriptions? Should it stop descending the hierarchy 
>> as soon as it
>> encounters a description? Are descriptions attached to nodes 
>> of a complex
>> graphic each intended to be a stand-alone replacement for the 
>> attached node?
>> Should they assume the context of encompassing descriptions?
>
>Charles and I played with this some time ago, with a particularly nasty
>piece of text in SVG.
>
>I tried using relative positions, to sort out the ordering of text
>elementw within the page, i.e. using the xy positions to determine
>the order of presentation. It didn't work particularly well for that
>example. I was using xslt to obtain text elements, titles etc.
>
>Charles, you did something different IIRC, which produced an improvement?
>

AG::

[I have changed the subject line as I believe this is a somewhat different
question from what Charles was asking.]

** summary

If I recall correctly, what I took away from that exercise was that it is
preferrable to put the text in the XML in a reasonable reading order, and to
textref it into the layout from there.

While it is mathematically possible to re-assemble the reading order by
threading created in the markup, it is an inferior solution in that authoring
processes are unlikely to get it right.  The experience we have had with
TABINDEX in HTML is relevant and cautionary.  [Not a rule-out, but genuinely a
warning.]

** discussion

A linear discourse is not obvious from a graphical design.  Unless the author
thinks about how to couch their message as a narrative, you don't get a
narrative flow by assembling the pieces that appear in a graphical exposition
of an idea.  Fluent narrative has glue in it that the layout does without, for
one thing.

The XML format forces you to linearize the content somehow.  Best practice is
that text appear in this flow already in the right order, such that if you
filter the content for the text, the order of what passes the filter is the
correct reading order, without needing any rearrangement.

>Regards DaveP
>
>- 
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Received on Friday, 7 September 2001 10:10:36 UTC