[css-align][css-flexbox][css-grid] Can baseline content-aligned items and baseline self-aligned items align together?

[fantasai]

There's a note in CSS Grid (11.5 step 1) saying that these are handled as separate categories, but nothing in css-align says so. And also the Grid Container Baselines section (10.6 in Grid) also seems to imply that there is only one set of baselines. So we need to be clear about which is true.

Secondly, if they are in fact two different sets of baseline-aligned things, then which set is used when propagating the baseline up the box tree? E.g. a grid container with 50% items baseline content-aligned and baseline self-aligned, which is itself baseline (content- or self-) aligned in a parent grid or flexbox.

Proposal: Align the note and clarify css-align to match 10.6 in Grid: there is only one baseline that is shared across items in an alignment context, and both types of baseline alignment use it.

[fantasai]

@dholbert @MatsPalmgren @javifernandez Thoughts?

[dholbert]

Proposal: Align the note and clarify css-align to match 10.6 in Grid: there is only one baseline that is shared across items in an alignment context, and both types of baseline alignment use it.

Just to clarify, by "only one baseline" I think you really mean "only one first baseline & only one last baseline", right? (and "only" = there isn't a separate set for self-alignment vs. content-alignment)

This sounds reasonable to me, anyway.

[fantasai]

@dholbert Right.

This sounds reasonable to me, anyway.

Cool. :)

[javifernandez]

Proposal: Align the note and clarify css-align to match 10.6 in Grid: there is only one baseline that is shared across items in an alignment context, and both types of baseline alignment use it.

I think the proposal makes sense.

[css-meeting-bot]

The CSS Working Group just discussed Can baseline content-aligned items and baseline self-aligned items align together?, and agreed to the following:

• RESOLVED: Content alignment and self alignment share a baseline

The full IRC log of that discussion

<dael> Topic: Can baseline content-aligned items and baseline self-aligned items align together?
<dael> github: https://github.com//issues/3200
<dael> fantasai: We noticed spec was inconsistant on if there is 1 or 2 first and last baselines. Depends on if elements use content or self baseline alignment
<dael> fantasai: We think intent was 1 baseline and that simplifies amount of info impl keeps. Want to make sure there aren't problems we didn't think of
<dael> fantasai: dholbert and javier think it's right way to go
<fantasai> Proposal: Align the note and clarify css-align to match 10.6 in Grid: there is only one baseline that is shared across items in an alignment context, and both types of baseline alignment use it.
<dael> astearns: Thanks for dholbert and javier for putting their approval in issue
<dael> astearns: Other opinions?
<dael> fantasai: Content alignment and self alignment share a baseline
<dael> astearns: Objections to Content alignment and self alignment share a baseline?
<dael> RESOLVED: Content alignment and self alignment share a baseline

[fantasai]

OK, fixed the bad note in css-grid-1, and added a clarifying note in css-align-3. @tabatkins can you verify the edits and make sure they're in the best place? :)