Re: [css-text] I18N-ISSUE-331: No kashida style or relationship to styles 'distribute' and 'inter-word'

> I suspect we should say as little as possible for now in the spec about text elongation in Arabic script for justification of running text in paragraphs, since I believe that in the end the requirements will be somewhat complex, and we are a long way from understanding them yet.

I agree.

> I guess we can say that inter-word turns off elongation, since that is the purpose of that value.  I'm not sure we can say much yet, until we understand things better, of the relationship between distribute and elongation, since elongation seems to involve far too many, poorly understood, complications.

Are you suggesting we should add “inter-word turns off elongation”, or it’s implied enough that the current text is fine?

> The current text says "Justification adjusts spacing between each pair of adjacent visually-perceived characters", which may be sufficient to deal with elongations, since joined cursive letters don't have any spaces between them. I suppose it introduces a question about stretching of gaps inside a word where letters don't join to the left, though.


This is about “distribute”, right? According to the spec, yes, non-joining letters will stretch gaps between characters. I’m not sure if it makes sense for cursive scripts, nor if there were any needs for “distribute” value in cursive scripts. Any suggestions here?

/koji


On May 28, 2014, at 0:56, Richard Ishida <ishida@w3.org> wrote:

> I suspect we should say as little as possible for now in the spec about text elongation in Arabic script for justification of running text in paragraphs, since I believe that in the end the requirements will be somewhat complex, and we are a long way from understanding them yet.
> 
> For example, it appears that some font types (eg. Ruqah style fonts) should not be used with elongation at all - all the justification is therefore done by manipulating space.  Also, it's looking to me as if justification in, say, a naskh type font is likely to involve adjusting spacing a lot of the time, but may occasionally involve that plus some elongation when the spaces get too wide (eg. when a url is embedded in a narrow column). In other cases, however, a greater amount of elongation may be favoured in a naskh type font.  Nastaliq font types, on the other hand, seem to rely more on elongation (and ligation and other shortening techniques) than naskh (since spaces are seen in a somewhat different light for nastaliq script). Also, btw, the rules for elongation are somewhat different in nastaliq than for naskh.
> 
> Like detection of conjunct behaviour in indic scripts, the determination of the correct behaviour seems to be font dependent, and it's not clear to me how to handle that.  Note that all this therefore also raises questions about how to do the right thing when a user changes the font by design or a font is substituted due to availability of fonts on a particular device).  It suggests that maybe we need special controls for elongation that say something like: apply elongation if the font is X or Y only.
> 
> (By the way, in passing, note that in Tasmeem it is possible to independently set parameters for the size of spaces inside a word (ie. where a letter doesn't join to the left) as well as outside a word.)
> 
> I guess we can say that inter-word turns off elongation, since that is the purpose of that value.  I'm not sure we can say much yet, until we understand things better, of the relationship between distribute and elongation, since elongation seems to involve far too many, poorly understood, complications.
> 
> The current text says "Justification adjusts spacing between each pair of adjacent visually-perceived characters", which may be sufficient to deal with elongations, since joined cursive letters don't have any spaces between them. I suppose it introduces a question about stretching of gaps inside a word where letters don't join to the left, though.
> 
> 
> 
> PS: For a discussion of nastaliq justification in Urdu see http://www.cle.org.pk/Publication/papers/2004/rule-based-expert-system.pdf
> 
> 
>> Resent-Date: Fri, 09 May 2014 00:30:14 +0000
>> Resent-From: www-style@w3.org
>> Date: Thu, 08 May 2014 17:29:44 -0700
>> From: fantasai <fantasai.lists@inkedblade.net>
>> To: www-style@w3.org
>> 
>> On 01/24/2014 10:30 AM, Phillips, Addison wrote:
>>> State:
>>>     OPEN WG Comment
>>> Product:
>>>     CSS3-text
>>> Raised by:
>>>     Addison Phillips
>>> Opened on:
>>>     2014-01-23
>>> Description:
>>>     Section 7.3: Surprisingly there is no keyword specifically
>>> associated
>>>     with kashida (other than "auto"). Shouldn't there be?
>> 
>> There is no special keyword for it, just as there is no special keyword
>> for standard Japanese justification.
>> 
>>>     Or is it a special case of "distribute"?
>> 
>> No. It is most definitely not a special case of "distribute".
>> 
>>>     Some WG members [1] thought that "inter-word" implies turning
>>> kashida off.
>> 
>> This is true. It turns it off, because it only allows expansion
>> at spaces.
>> 
>> ~fantasai
>> 
>> 
>> 
>> 
> 

Received on Thursday, 26 June 2014 05:35:48 UTC