[css-flexbox] Investigate applying align-content to single-line flex containers · Issue #3052 · w3c/csswg-drafts (original) (raw)

Right now, single-line (flex-wrap:nowrap) flex containers don't pay attention to align-content at all; they always stretch to fill the container.

This has some odd implications; although you can align individual items to each other within the line, you can't start/end/center the line as a whole in a non-wrapping flexbox--for no reason that's apparent to authors, because this is totally possible in wrappable flexbox with one line.

This also makes baseline alignment impossible across flex or grid items when one of them is a single-line row flex container, because you can't add magic margin to the flex line to align the contents appropriately.

Filing this issue to see if Web-compat will allow making non-initial values of 'align-content' take effect on single-line flex containers. This would be a change in behavior for:

• single-line row flex containers with a non-initial 'align-content' and non-'auto' cross size (auto cross size will shrink-wrap the container to the flex line anyway, so alignment is a no-op in that case)
• and single-line column flex containers with a non-initial 'align-content' and whose items have fixed cross sizes (an auto-sized item will fill the flexbox and stretch the flex line to fill it, so again alignment is a no-op in that case)