Re: [css-transforms] Adding specialized properties for simple transforms

On Thursday 2014-07-17 09:47 -0700, Tab Atkins Jr. wrote:
> I propose we add the following three properties to the Transforms spec:
> 
> * translate: <length>{1,3}
>     - specifies a translation in the X, Y, and Z axises, respectively.
> Missing values default to 0.
> * rotate: <angle> <number>{3}? <'transform-origin'>?
>     - specifies a rotation along a given axis from a given origin. An
> omitted axis defaults to 0,0,1; an omitted origin defaults to
> 'transform-origin's initial value.
> * scale: <number>{1,3} <'transform-origin'>?
>     - specifies a scale in the X, Y, and Z axises, respectively, from
> a given origin. Missing values default to 1; an omitted origin default
> to 'transform-origin's initial value.

I'm mostly ok with this.  One concern is about the syntax of the
<'transform-origin'>? bits at the end of the 'scale' and 'rotate'
properties; I wonder how readable they are as written.  I think an
author seeing a declaration looking like:

  scale: 0.5 0.3 50px 25px;

might find such a declaration confusing.  I wonder if the
transform-origin would be better separated somehow, e.g., with a
function:

  scale: 0.5 0.3 origin(50px 25px);

(I also wonder whether there's any risk of future syntax collisions
between the two.  There's certainly a risk of having to take a bit
of work to figure out which value something belongs to, e.g., with
calc().)

-David

-- 
𝄞   L. David Baron                         http://dbaron.org/   𝄂
𝄢   Mozilla                          https://www.mozilla.org/   𝄂
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