- From: Tab Atkins Jr. <jackalmage@gmail.com>
- Date: Tue, 8 Mar 2016 15:17:07 -0800
- To: Brian Birtles <bbirtles@mozilla.com>
- Cc: www-style list <www-style@w3.org>, "L. David Baron" <dbaron@dbaron.org>, Rachel Nabors <rachelnabors@gmail.com>, "public-fx@w3.org" <public-fx@w3.org>
On Mon, Mar 7, 2016 at 9:00 PM, Brian Birtles <bbirtles@mozilla.com> wrote: > On 2012/12/21 3:46, Tab Atkins Jr. wrote: >> On Wed, Dec 19, 2012 at 6:40 PM, L. David Baron <dbaron@dbaron.org> wrote: >>> >>> On Wednesday 2012-12-19 10:29 -0800, Tab Atkins Jr. wrote: >>>> >>>> I propose another steps value: step-mid. It splits the animation curve >>>> into n segments, makes the first n-1 do step-end behavior, and leaves >>>> the last to just run normally. The above example could instead be >>>> written as "steps(4, step-mid)" and have this behavior: >>> >>> >>> I like the idea, but I find the name confusing; it sounded like >>> something that would give the first and last steps half the duration >>> of the other steps. (I also find the description quoted above >>> confusing, but the rest of the email made it clear.) >> >> >> I have absolutely no attachment to the name. It was the first thing >> that came to mind. >> >> I assume that Rachel's suggestion comes from her association of >> steps(n, end) with meaning "eat the end of the animation" (and >> likewise for "start"), so "none" is reasonable in that sense. I'm not >> sure it makes sense if your understanding comes from the spec's >> explanation, though, where "end" means "transitions all at once at the >> end of the step". >> >> Another possibility is just a new function. I'm not sure what I'd >> want to name it, though. > > > I spoke with Rachel and a few others about this recently and we were > wondering about the name step-equal? Unfortunately, that doesn't translate > into a function very well ('step-equal(2)'? Alternatively, what about > 'step-stagger' and 'stagger(5)', or just the function?). > > I'd like to settle on this soon because Chrome is shipping Element.animate() > with support for 'step-middle' as defined by Web Animations.[1] We went to > implement this in Firefox[2] but I'm concerned that there aren't use cases > for step-middle as currently specced and instead what we want is what Tab > originally proposed in this thread. > > Assuming usage is low in Chrome, I'd like to drop step-middle from Web > Animations and replace it with this revised timing function. Yeah, WA's "middle" value doesn't do a very useful thing - it does at least *show* the starting and ending values, but only for a half-interval each. I'm not sure where this came from - was it just a misreading of the original request, maybe? On Tue, Mar 8, 2016 at 2:24 PM, Rachel Nabors <rachelnabors@gmail.com> wrote: > I was thinking of "steps(5, equal)" when discussing this syntax, as an > expansion of the steps() formula. I think it looks sensible, if that's > possible? I'm not a huge fan of that name - step() *always* splits it into equal pieces, so it's not clear why this one in particular is more "equal" than the others. I'm feeling like a new function entirely might be a good thing - the stagger() name works for me. Another possibility is discrete(). (Benefit - the behavior of "non-animatable" values, which we usually informally call "discrete animation", is precisely discrete(2) or "discrete" if we added a keyword for the minimal form.) Mainly I'd like to pretend step() doesn't exist at all - the step-start and step-end keywords are useful, but going to >1 steps with those behaviors is just somewhat confusing imo. Maybe we can add a note to step() saying that its behavior is confusing, and authors probably want to use discrete()? ~TJ
Received on Tuesday, 8 March 2016 23:17:57 UTC