[css-values] Logical equivalents for vw/vh units

[upsuper]

People may need to use viewport units in a writing-mode-aware way, so probably we should add logical equivalents for vw and vh. They could be called vis and vbs or something like that.

[bradkemper]

I understand i for inline, and b for block, but what does s stand for?

I assume the dimension would remain constant based on the writing mode of the root element only, and not vary relative to the element they are used in?

[upsuper]

is and bs means inline-size and block-size which are the logical equivalents for width and height in CSS Logical Properties spec.

[tabatkins]

Yeah, I'm fine with this.

[fantasai]

I'd drop the s, seems unnecessary.

[fantasai]

Btw, here's the www-style thread on this: https://lists.w3.org/Archives/Public/www-style/2015Sep/0253.html

[tabatkins]

We resolved in the telcon to add vi and vb.

[tabatkins]

Hm, unexpected complication: I'm defining them to take their direction from the root element, but what do we do when you evaluate them in a context without an element? Like, in MQ we define rem without reference to a root element. Do we have a usable notion of writing mode at the document level, without referencing elements or CSS?

[frivoal]

How about simply going with the initial value of the writing-mode property, which means in an MQ context, vi=vw and vb=vh?

[tabatkins]

I suppose we should be using the same concept as (overflow-block), but that doesn't appear to actually be well-defined.

[frivoal]

I agree it should be the same for both, and I think that going with the initial value of the writing mode property (i.e. vertical is block, horizontal is inline) is the sane thing to do.

[tabatkins]

Sounds good to me.

[fantasai]

Tab, this goes into L4. Which hasn't forked yet because we've got outstanding issues on L3 and can't republish CR. I've commented it out for now.

[The-Peppester]

I am soooo pumped for this. Ben waiting 20 some odd years to have something like vi and vb. Also, you rlly need to additionally add ci and cb which will stand for content inline (width) and content box (height) so you can dynamically scale your content to the size of its contents. To be honest, im just plain tired of all this crazy hacky, exhausting css whcih makes developers lives alot harder. If web browsers added in just theese 4 units, then CSS would be a billion times easier. Btw. I dont care about how hacky or inefficient the polyfill is for them, I just want em now! By the way, to avoid recursion, which theese units would make pretty easy, just make it so that the max recursion levels is like 1, or decideable by CSS like unit-recursion-levels: 1 or something.