RE: [css3-animations] `alternate-reverse` vs `alternate reverse`

[Lea Verou:]
> 
> On 5/5/12 19:16, Sylvain Galineau wrote:
> > So the set of possible values would be:
> > normal
> > alternate
> > reverse
> > alternate reverse
> > reverse alternate
> Yes.
> > Is that right? I can see how I no longer need to remember whether
> > alternate comes first or last but if it looks like a toggle then I'd
> > also expect alternate normal to do something and it wouldn't. So while
> > there is a bit of extra user-friendliness it seems specific to this
> > one keyword. Or did I get the intent and grammar wrong?
> My proposed grammar left combinations of `normal` and the other keywords
> out, but I don't have a strong opinion on it. I think we need more input
> about whether such combinations facilitate learning or confuse authors.
> Functionality-wise, they are completely redundant, so consistency and
> learnability are the only possible benefits.
> 
> To be clear, we're talking about these 4 combinations:
> alternate normal
> normal alternate
> reverse normal
> normal reverse
> 
mmm...missing alternate reverse?

> Consistency-wise, I think existing CSS properties usually allow `normal`
> to be combined with other keywords, as long as disambiguation is possible.
> For example, the following declaration is perfectly valid (albeit
> needlessly verbose), even in CSS1:
> 
I'm not sure we want or need this consistency here; I think normal was just
a poor choice as the opposite to alternate. Maybe 'continuous' would have
been better?

I think a case could be made that the property should have been a combination
of two keywords: one describing the timeline direction, the other the repetition
direction. They'd have two values each and 4 combinations. But web sites already
use alternate so I'd rather not make a cosmetic change. Unless, maybe, we have
solid reasons to believe the 2x2 matrix could turn into a 3x3 one, in which case
the current flat model is painful.

Overall, the change seems a nice to have. I can't yet convince myself it's a must-have.
Interested in what others think though.

Received on Saturday, 5 May 2012 19:33:25 UTC