RFR: 8236753: Animations do not play backwards after being stopped

[Scott Palmer]

> On Jan 14, 2020, at 11:50 AM, Ambarish Rapte <arapte at openjdk.java.net> wrote:
> 
> On Fri, 10 Jan 2020 00:39:53 GMT, Kevin Rushforth <kcr at openjdk.org> wrote:
> 
>>> I'll review this next week. This seems a fine candidate for openjfx14, so it (along with a couple other pending reviews that can be for 14) will be a good test of targeting a PR to the stabilization branch.
>>> 
>>> I also request @arapte to review.
>> 
>> I should add that it will depend on whether there are any regressions. One thing we do need to be careful of is introducing regressions during rampdown.
> 
> The fix looks good to me.
> After this change the steps needed for playing an `Animation` backwards will change.
> Earlier this was documented with `Animation.play()` API as below.
> -------------
> To play an `Animation` backwards from the end:
> animation.setRate(negative rate);
> animation.jumpTo(overall duration of animation);
> animation.play();
> -------------
> 
> After this PR call to `jumpTo()` won't be needed here.
> So this PR may need a document change for `Animation.play()`.
> Also to note that the behavior of above mentioned three calls remains same with the changes in this change.

If the jumpTo isn’t required, then this isn’t this a change in behaviour?  I’m wonder in particular if this has an effect on cycleCount.

If cycleCount is set to 2 does the animation play the same number of times with or without the jumpTo both before and after this change?

Scott