Re: [css-ui-3] box-sizing: padding-box

> On 22 Jun 2015, at 22:33, Florian Rivoal <florian@rivoal.net> wrote:
> 
>> Also, margins have 'auto', which complicates things.  Border/padding
>> are always lengths/percentages, much simpler.
> 
> That's probably more thorny.

Actually, thinking of it, this is probably simple to resolve. auto margins resolve to 0 when box-sizing:margin-box. Done.

This is not just an easy way out, this would actually be consistent with the way things are already done.

When you're using box-sizing with some other box than content-box, and setting a value for the width, you're effectively asking for the content-width to resolve itself to let the rest fit.

Here is what CSS2.1 sentence has to say about the other situation where margins and content-width are all unknowns to be solved in the same equation:
"If 'width' is set to 'auto', any other 'auto' values become '0' and 'width' follows from the resulting equality."

That requires a tiny bit of spec work, but it is far from a hard problem. But again, as long as there's not motivation from browser vendors to actually implement this, it doesn't matter much how Hixie or I think this is easy to spec.

 - Florian

Received on Monday, 22 June 2015 20:53:24 UTC