On 2015/06/23 8:57, Shane Stephens wrote:
An alternative proposal:
CSS animations use sequence number as priority, and are created in tree-
and list- order. CSS Animations are still prioritized absolutely above
script animations (there are two lists). Changing an animation-name
property triggers an update of all listed sequence numbers. So:
elem.style.animation = 'a 2s, b 3s, c 4s'; // a: 0, b: 1, c: 2
let b = elem.getAnimations[1];
let c = elem.getAnimations[2];
elem.style.animation = 'a 2s, d 5s'; //a: 3, d: 4
c.play(); // c promoted to script animation, keeps sequence number
b.play(); // b promoted to script animation, keeps sequence number
elem.getAnimations(); // what is the order here? b,c,a,d
Script animations have preserved text order in terms of their
*definition* (which is important, see below).
I'm trying to work through this (and hopefully implement it) but I think
I'm not certain I understand it.
Working through an example:
elem.style.animation = 'a 2s'; // a: 0;
var a = elem.getAnimations()[0];
var b = elem.animate(...); // b: 1;
// Currently if a and b target the same property, b will win
// (Actually, see below, this is probably wrong.)
// Now if I do:
elem.style.animation = 'a 2s, c 3s';
// From what I understand of your proposal that would give:
// a: 2, c: 3
// i.e. now a beats b simply because we added an animation?
Clearly I've misunderstood something.
I guess either you're suggesting:
a) Updating animation properties triggers a global sequence number
rewrite (I hope this isn't the case), or
b) Script-animations and CSS animations share the same source of
sequence numbers but when we come to prioritize animations we
don't use them for prioritizing CSS animations (or at least we
*first* sort by script vs CSS, then by document order, then
finally by animation-name order which happens to match sequence
number order).
I'm pretty sure you're suggesting (b) but I want to be sure.
I think I was confused because at one point you suggested that the
prioritization we do for CSS animations and transitions could be
expressed using sequence numbers.
Best regards,
Brian
