[css-backgrounds-4] Order of keywords in border-*-radius shorthands

[SebastianZ]

Currently, the order of the border-*-radius shorthand values is defined as top to bottom and left to right for the physical properties and start to end for the logical properties.

Though @Loirooriol questioned this and proposed to rather follow the clockwise order used for the border-radius shorthand.

So border-radius: 1px 2px 3px 4px would be equivalent to

border-top-radius: 1px 2px;
border-bottom-radius: 3px 4px;

instead of

border-top-radius: 1px 2px;
border-bottom-radius: 4px 3px;

The question is, do authors rather expect opposite sides to always follow one direction or have a clockwise order?

This question similarily applies to the logical shorthands. Should they always be start to end or should they map differently?

I tend to say one direction, though it also goes against border-radius.

Sebastian

[tabatkins]

I really don't think they should follow the clockwise ordering. The clockwise ordering makes sense in the context of four values; if you're only specifying two values it's nonsense, because it gives opposite orders for opposite sides. top and bottom should definitely set the values left->right (or start->end), etc.

[Loirooriol]

start->end totally makes sense for logical shorthands. But do we have a precedent for assuming that physical left->right and top->bottom is the natural progression?

[tabatkins]

Yes, any property with single-axis values uses that progression unless there's a good reason not to. See 'background-position', for instance - each axis's length is measured from the top/left, with larger values proceeding downward/rightward.

(Note that some seeming exceptions, like the 'right' property, are not based on an axis, but rather on a side, and thus are measuring along an outside <-> inside dimension.)

[Loirooriol]

Mm, OK, in background-position it's not for the purpose of shorthand expansion, but I guess it's close enough.

[SebastianZ]

As it seems we agree on this now, let's make this official.

Proposed resolution: Close this issue without changing the spec. I.e. the order for the border-*-radius shorthands is always left to right and top to bottom for physical values and start to end for logical values.

Sebastian

[astearns]

If there is no spec change, then we do not need a resolution. Particularly since you opened the issue @SebastianZ feel free to close no change and add a 'commenter satisfied' label.

[SebastianZ]

Thanks for the hint, @astearns!