Justification Keywords for Alignment

The WG resolved to go with another option brought up during the call, and use 'space-between' and 'space-around' for the “Edges flush” and “Equal margins” cases, respectively.

There are three possible behaviors for distributing items evenly along an axis:

Edges flush

 |[item]<-------->[item]<-------->[item]|

Equal spacing

 |<--->[item]<--->[item]<--->[item]<--->|

Equal margins

 |<-->[item]<---->[item]<---->[item]<-->|

Note: In Flexbox, you can get the equal-margins effect with auto margins, but only if you want the minimum spacing to be zero. Which might be sufficient for this level, but would be a candidate for future extension.

Related prior art:

• text-justify: distribute; /* edges flush */
• ruby-align: distribute-letter; /* edges flush */
• ruby-align: distribute-space; /* equal margins */
• background-repeat: space; /* edges flush */

Flexbox currently uses justify to mean “edges flush” and distribute to mean “equal margins”. This has two problems:

• It's unclear from the names which is which.
• The distribute value of text-justify means “edges flush”, which is inconsistent.

We need keywords that clearly and unambiguously specify each of the behaviors (or at least two, really, since only two are wanted).

There are several proposals for distinguishing “edges flush” vs. “equal margins” behavior:

Proposal 0 (current spec)

justify vs. distribute

Proposal A

distribute vs. distribute-space

Proposal B

distribute-flush vs. distribute-space

Proposal C

distribute vs. space

1. http://www.w3.org/TR/css3-ruby/#rubyalign
2. http://www.w3.org/TR/css3-background/#the-background-repeat
3. http://www.w3.org/TR/css3-text/#text-justify