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RE: [SVGMobile12] Lack of BIDI 'direction'

From: Phillips, Addison <addison@amazon.com>
Date: Fri, 10 Oct 2008 14:41:08 -0700
To: Chris Lilley <chris@w3.org>, fantasai <fantasai.lists@inkedblade.net>
CC: "www-style@w3.org" <www-style@w3.org>, "public-i18n-core@w3.org" <public-i18n-core@w3.org>, "www-svg@w3.org" <www-svg@w3.org>
Message-ID: <4D25F22093241741BC1D0EEBC2DBB1DA014EED335F@EX-SEA5-D.ant.amazon.com>
Hello Chris,

Thanks for this note. A few comments.

> 
> That is correct. Thank you for pointing out this omission. SVG 1.1
> has
> a direction property, as does SVG Basic 1.1. SVG Tiny 1.1 did not
> have
> it, because the text element could not have a tspan child element
> in
> Tiny 1.1 and thus adittional levels of embedding were not possible.

Additional levels of embedding were, in fact, possible, since most embedding levels come from character properties. The lack of 'tspan' meant that no additional overriding markup was possible.

> 
> > This is a problem because the Unicode bidirectional algorithm
> needs a
> > base direction for each "paragraph" that it operates on. For
> plain text
> > it guesses based on the first character in the text, but this is
> not
> > always accurate.
> 
> Yes, if the initial character is directionally weak, or neutral, it
> will not give the expected results and must be overidden.

The first character might even be strongly opposed to the base direction of the overall paragraph. A paragraph might start, for example, with a word in Arabic script, even though the sentence is in English. That does not mean the whole paragraph should have a base direction of RTL for layout purposes.

> 
> The SVG WG has discussed your recommendation and agrees with it. In
> response you your last call feedback, SVG Tiny 1.2 will re-instate
> both the 'direction' and the 'unicode-bidi' properties from SVG 1.1.

Thanks. I18N Core supports Fantasai's comment. I suspect the WG will concur with the resolution at our next teleconference (Wednesday)

Addison


Addison Phillips
Globalization Architect -- Lab126
Chair -- W3C Internationalization Core WG

Internationalization is not a feature.
It is an architecture.



Received on Friday, 10 October 2008 21:41:58 GMT

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