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Re: bidi discussion list was: Bidi Markup vs Unicode control characters

From: Tex Texin <tex@xencraft.com>
Date: Wed, 10 Aug 2005 00:10:04 -0700
Message-ID: <42F9A84C.D96AC984@xencraft.com>
To: Ognyan Kulev <ogi@fmi.uni-sofia.bg>
CC: Stephen Deach <sdeach@adobe.com>, Addison Phillips <addison.phillips@quest.com>, www-international@w3.org, Richard Ishida <ishida@w3.org>, Bert Bos <bert@w3.org>

Ogi,
I think the short answer is no. "Direction" has a number of components
to it.
Instead of thinking of an instance of a single text string, consider a
series of text runs, with direction changes.

When the language changes, does the direction level increase, is it
reduced, or is it a start of a new top-level direction setting? How does
each run relate to the surrounding runs? (In terms of the bidi
algorithm.)

Also, what is the layout direction, regardless of the language of each
text run?
For example, as you know in HTML, tables have a direction. Regardless of
the language of each cell's contents, the placement of the cell (or
column actually) is determined by the direction of the table.

Direction for a language can also be ambiguous. Chinese can be written
lr-tb, rl-tb, tb-rl...
(where l,r,t,b are left, right, top, bottom). The front page of some
Chinese newspapers can use all 3 of those directions/layouts.

So xml:lang might be suggestive, but it is not explicit or informative
enough to base bidi layout upon it alone.

That's also why CSS doesn't just have "direction", but also
"unicode-bidi" (normal, embed, bidi-override)

tex

Ognyan Kulev wrote:
> 
> Stephen Deach wrote:
> >   It may be a mistake for section 508 to require the ability to
> > completely turn off attached style sheets, since this will render many
> > non-(X)HTML documents unusable (whether the style-sheets are CSS or
> > XSLT). It should be possible for the browser/reader to override aspects
> > of the styling such as background, text-color, and size for readability
> > purposes (in CSS, by appending a user-specified style sheet to the
> > existing cascade). If it is required to be able to turn-off/ignore the
> > attached/referenced style sheets (and I am forwarding this internally to
> > check with our accessibility and section 508 compliance expert), then it
> > may be necessary to add an xml:dir attribute so that directionality and
> > language can both be encoded via markup when xml content is not xhtml.
> 
> Isn't direction implied in xml:lang which is part of the core XML spec?
> 
> Regards,
> ogi

-- 
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Tex Texin   cell: +1 781 789 1898   mailto:Tex@XenCraft.com
Xen Master                          http://www.i18nGuy.com
                         
XenCraft		            http://www.XenCraft.com
Making e-Business Work Around the World
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Received on Wednesday, 10 August 2005 07:10:17 GMT

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