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Re: [CSS21][css3-text] letter-spacing, word-spacing and justification

From: fantasai <fantasai.lists@inkedblade.net>
Date: Thu, 11 Jul 2013 16:39:01 -0700
Message-ID: <51DF4215.3080509@inkedblade.net>
To: Stephen Zilles <szilles@adobe.com>
CC: "www-style@w3.org" <www-style@w3.org>
On 07/03/2013 08:57 AM, Stephen Zilles wrote:
> Elika,
> Your comments below help, but I do not believe the address my main concern;
> namely, that using spaces between letter for justification (Use Case 1) is
> very different than using letter spacing for readability (Use Case 2) and
> the mixing them together in the specification will lead to confusion on the
> part of authors.

I suspect authors are unlikely to be reading too much into the details
of the justification rules, if they look at this spec at all. :) But ok.

> Furthermore, it is not at all clear to me, despite the examples given
> this last week (your interchanges with Liam), that "letter" is the right
> term to use for spacing between glyphs (or glyph clusters) in East Asian
> and Northern Indic based typographies. The examples show Use Case 1
> spacing. It is not clear that Use Case 2 spacing (for readability) makes
> sense in these non Western scripts (except when sequences of Arabic
> numerals are shown)

Indeed. I can't actually change the name of the property, but it is
actually defined in terms of spacing between grapheme clusters, which
is what we want (afaik).

> If the issue is that both types of spacing need the same definitions,
> then lets factor out the definitions and reference the definitions
> from both the "letter-space" and "text-justify" sections.  Then
> letter-space can talk about setting an amount of space between letters
> and text justify can talk about adding space between letters and words
> in a relevant way.

Well, let me see if I can tweak the wording more. What I really want
is to just reference 'letter-spacing' and 'word-spacing' from the
justification section and say "add more space, just like that".
Because that's exactly what's going on.

>> Is this the only use case for "letter-spacing" in East Asian Text?
>> Is it also used, as in the second use case for Western text, to put a
>> desired amount of space between East Asian glyphs without necessarily
>> justifying a line?
>
> Yes, I believe this is also the case.
> SZ: Do you have examples?

http://www.w3.org/TR/jlreq/#principles_of_arrangement_of_kanji_and_kana_characters
I've seen it used for titles reasonably often. For example, my copy
of 文字の組方 has positive letter-spacing applied to the heading of page 1,

                            本 書 の 読 み 方

> SZ: Compat is a worry because "fixed" is, I believe, ill specified.
> Going back to the point that I am trying to make above, it is note
> Use Case 2 letter space that you want to control; it is Use Case 1
> justification space between letters that you want to control. It
> was noted that Japanese wants to allow negative spacing, but English
> typography does not want to allow this. Perhaps we need to introduce
> the Min and Max values now and have them be associated with
> "text-justify" rather than "letter-space".

I don't think we want them associated with 'text-justify'; that's
telling you what kinds of justification opportunities are available.
What you want to do here is associate limits and weights with those
opportunities... which is somewhat of an advanced topic we should
save for level 4/5!

Note that 'word-spacing' still has min/max limits. I really would
like to keep 'word-spacing' and 'letter-spacing' behaving the same
way. Which is one of the reasons to make 'letter-spacing: <length>'
not disable inter-character justification!

~fantasai
Received on Thursday, 11 July 2013 23:39:29 UTC

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