RFR: 8311895: CSS Transitions [v2]

[Michael Strauß]

On Mon, 31 Jul 2023 13:33:41 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/javafx/css/TransitionEvent.java line 88:
> 
>> 86:      * @param eventType the event type
>> 87:      * @param property the {@code StyleableProperty} that is targeted by the transition
>> 88:      * @param elapsedTime the time that has elapsed since the transition has entered its active period
> 
> Can property be `null`?  Any restrictions on `elapsedTime`?

Added a `@throws` tag.
Interestingly, `Event` doesn't specify or assert that its `eventType` parameter is non-null. Maybe we should investigate this further.

> modules/javafx.graphics/src/main/java/javafx/css/TransitionEvent.java line 111:
> 
>> 109:      * not including the time spent in the delay phase.
>> 110:      *
>> 111:      * @return the elapsed time
> 
> Any guarantees here?  Can it be `null`, negative, zero, infinite?

Added that the elapsed time is zero if the transition has not entered its active period. I usually don't document that a return value is always non-null, since I believe this to be the default assumption unless otherwise noted. Additionally, the constructor of `TransitionEvent` now documents that it will not accept `null`.

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PR Review Comment: https://git.openjdk.org/jfx/pull/870#discussion_r1279708076
PR Review Comment: https://git.openjdk.org/jfx/pull/870#discussion_r1279706369