[csswg-drafts] [css-text-3] line breaks and ideographic space

frivoal has just created a new issue for https://github.com/w3c/csswg-drafts:

== [css-text-3] line breaks and ideographic space ==
(reference: https://bugzilla.mozilla.org/show_bug.cgi?id=1450228)

Browsers differ in how they handle line breaks for  IDEOGRAPHIC SPACE (U+3000):
* Firefox allows break before and after
* Chrome and Safari forbid a break before, and allow a break after
* Edge forbids a break before and allow a break after, but also allows hanging overflow

[try it here](https://software.hixie.ch/utilities/js/live-dom-viewer/?%3C!DOCTYPE%20html%3E%0A%3Cstyle%3E%0Ap%20%7B%0A%20%20%20%20width%3A%2010em%3B%0A%7D%0A%3C%2Fstyle%3E%0A%3Cp%3E%E3%81%82%E3%81%84%E3%81%86%E3%81%88%E3%81%8A%E3%81%A0%E3%82%8D%E3%81%86%E3%81%8B%EF%BC%9F%E3%80%80%E3%81%9D%E3%82%8C%E3%81%AF%E4%BD%95%E3%81%AE%E3%81%9F%E3%82%81%E3%81%AB%EF%BC%81%E3%80%80%E7%A7%81%E3%81%AF%E3%80%81%E3%81%8B%E3%81%8D%E3%81%8F%E3%81%91%E3%81%93%E3%81%A0%E3%80%82%3C%2Fp%3E)


Quoting @MurakamiShinyu

> This is important because IDEOGRAPHIC SPACE is normally used after "！" or "？" in the middle of a paragraph to keep 1em space after such punctuation marks as explained in JLREQ [3.1.6 Positioning of Dividing Punctuation Marks (Question Mark and Exclamation Mark) and Hyphens](https://www.w3.org/TR/jlreq/#positioning_of_dividing_punctuation_marks)

That logic would favor Edge's behavior.

UAX-14 says that IDEOGRAPHIC SPACE (U+3000) has class BA (for break after), which would support the behavior of Chrome/Safari/Edge over Firefox's, but:
* I cannot I cannot find any reference in css-text-3 to UAX-14's BA class
* The line-break property does not mention IDEOGRAPHIC SPACE (U+3000)

Should we reference the BA class somehow?
Should we directly list DEOGRAPHIC SPACE (U+3000) in some level of line-break?
Should we say something about allowing/requiring it to hang?

Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/2500 using your GitHub account

Received on Wednesday, 4 April 2018 05:37:42 UTC