RE: [css3-text] scoping line break controls, characters that disappear at the end of lines

This is a follow-up on the thread that were idle for a while. We discussed on this in the last F2F, and I said that I'll propose something for this issue soon[1], so here it is.

My recommendation is to handle U+3000 IDEOGRAPHIC SPACE the same as an ideographic character with its "break before" prohibited. This behavior is the same as Firefox behavior as far as I observed.

IE's behavior is similar to Word's, and as good as Firefox's for Japanese typography. But it requires a little more logic over UAX#14[2], and it is not suitable for Chinese honorific spaces[3].

UAX#14 defines U+3000 as ID (Ideographic.) Safari, Chrome, and Opera behave this way today. This algorithm has benefits for some scenarios such as editing, but after several discussions in Japan, many considered that it's not very good for reflowable documents such as HTML, and it is also not suitable for Chinese honorific spaces.

JLREQ authors consider both IE and Firefox good for reflowable Japanese typography. Each produces better result in some scenarios than the other, but both are good and acceptable for all scenarios.

With all these combined, my conclusion is as I proposed above.

Note that this is implementable using UAX#14 just by changing the value for U+3000, so I have proposed to change UAX#14 at Unicode ML[4] in the hope that UAX#14 and CSS Text Level 3 are in sync in this regard. This issue wasn't discussed at Unicode recently, so the mail has more detailed summary if you're interested in.

[1] http://lists.w3.org/Archives/Public/www-style/2012May/0541.html CSS-ISSUE-220
[2] http://unicode.org/reports/tr14/

[3] http://lists.w3.org/Archives/Public/www-style/2012Apr/0013.html

[4] http://www.unicode.org/mail-arch/unicode-ml/y2012-m06/0142.html


Regards,
Koji

Received on Monday, 11 June 2012 10:43:44 UTC