[css-flexbox] max-content contribution not defined for flex items

The spec currently defines the max-content contribution of a flex
item as its hypothetical base size. However, I don't think this
works correctly for flexible items with a definite flex base size.
In particular, notice
   # For each flex item, subtract its flex base size from its
   # max-content contribution size,
This calculation will end up at zero for items with "flex: 1",
when the intention was for it to tend up at the max-content size.

Proposed definition:

  | The max-content main-size contribution of a flex item is:
  |   * if the item is growable, max(max-content, flex base size)
  |   * otherwise, its flex base size
  | clamped by its min and max main size properties.

Together with the definition of the max-content size of flex containers [1],
I think this will give the expected results (no unnecessary wrapping
of shrinkwrapped flexboxes, no unnecessary or unrequested extra space).

However, we'd also want to change the expansion of 'flex: <integer>'
from 'flex: <integer> 1 0%' to 'flex: <integer> 1 0'. (The 0% hack
doesn't give very good results when there are multiple items anyway.)

Thoughts? Corrections? Alterations?

[Still trying to think through min-content contributions.]

Received on Tuesday, 28 July 2015 20:22:18 UTC