1893238 - [css-text] text-wrap-style:balance should be allowed to affect the block height

Status: NEW

(Core :: Layout: Text and Fonts, defect)

Description

[Mozilla Apprentice]

A resolution was made for csswg-drafts/#10186.

[css-text] Should text-wrap-style:balance be allowed to affect the block height?

• RESOLVED: Number of lines can change if it's 6+ lines being balanced, and note that this is about line breaks not content height shifts

Discussion.

Comment 1

[Daniel Holbert [:dholbert]]

jfkthame, do you want to take this (and/or organize it amongst text-wrap-balance:followup work)?

To recap, there were two relevant decisions here:

• There's not supposed to be a restriction on the block-height changing (though I think we do have such a restriction right now).
• There is supposed to be a restriction on the number-of-lines changing (since authors probably don't want balancing to inadvertently turn 2 lines of text into 3 lines of text), but we decided in this meeting to allow the number of lines to change by a bit if there are roughly 6 or more lines (exact spec text TBD)

Comment 2

[Jonathan Kew [:jfkthame]]

(In reply to Daniel Holbert [:dholbert] from comment #1)

jfkthame, do you want to take this (and/or organize it amongst text-wrap-balance:followup work)?

To recap, there were two relevant decisions here:

• There's not supposed to be a restriction on the block-height changing (though I think we do have such a restriction right now).

Right -- this means we may want to revisit the fix that was landed in bug 1888449 (which implemented that constraint), and resolve the original bug there slightly differently. (Though AIUI the spec probably won't require such a change -- what we're doing would still be conformant -- but results may sometimes be improved by taking advantage of the additional flexibility it allows.)

• There is supposed to be a restriction on the number-of-lines changing (since authors probably don't want balancing to inadvertently turn 2 lines of text into 3 lines of text), but we decided in this meeting to allow the number of lines to change by a bit if there are roughly 6 or more lines (exact spec text TBD)

With the way our implementation currently works, there's no incentive for us to actually do that, even when it's allowed. In a future world where we have a full text-wrap-style:pretty implementation, and perhaps base balance on that underlying mechanism, it may be more relevant.

So for now, in this bug, I think we should look into the first issue here: relaxing our unchanged-block-size constraint, which sometimes can prevent us using "more balanced" line breaks that would otherwise be available.