RFR: 8311895: CSS Transitions [v2]

[Michael Strauß]

On Mon, 31 Jul 2023 12:56:10 GMT, John Hendrikx <jhendrikx at openjdk.org> wrote:

>> Michael Strauß has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Make TransitionEvent final
>
> modules/javafx.graphics/src/main/java/com/sun/scenario/animation/StepInterpolator.java line 73:
> 
>> 71:         }
>> 72: 
>> 73:         if (t >= 0 && step < 0) {
> 
> `t >= 0` always holds, perhaps the original `t` was meant here?  The `t` parameter is re-assigned, which may be confusing.

This algorithm is implemented as [specified](https://www.w3.org/TR/css-easing-1/#step-easing-algo), which accounts for the possibility that the interpolator is used for a back-filling animation (`t < 0`). While this is not possible in JavaFX (but may be possible in the future), I think it makes sense to keep the algorithm as is, because it ensures that its results are always correct, even though negative values for `t` are currently out of spec.

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PR Review Comment: https://git.openjdk.org/jfx/pull/870#discussion_r1279695148