feat: TimerActionComponent to schedule actions per entity.

[michqql]

Addresses issue #1439.

Summary

Component that wraps a Timer object and updates timer actions dependent on the entities time per frame value. This component can be used to schedule actions with either a delay or interval, with overloaded functions matching the underlying Timer class.

A PongVsComputerApp sample is included to see example usage of the TimerActionComponent.

Features

Includes the same overloaded methods as Timer:

• runAtInterval(Runnable action, Duration interval)
• runAtInterval(Runnable action, Duration interval, int limit)
• runAtIntervalWhile(Runnable action, Duration interval, ReadOnlyBooleanProperty whileCondition)
• runOnceAfter(Runnable action, Duration delay)
• clear()

Testing

TimerActionComponentTest includes 12 tests to verify the actions are executed. However these tests try not to duplicate TimerActionTest.

Example Usage

(From the sample)

TimerActionComponent timerComponent = new TimerActionComponent();

/* Move the Y position of the computer bat to the Y position of the ball */
timerComponent.runAtInterval(() -> {
    Entity ball = timerComponent.getEntity().getObject("ballEntity");
    timerComponent.getEntity().setY(ball.getY() - timerComponent.getEntity().getHeight() / 2f);
}, Duration.seconds(1 / 60f));

entityBuilder()
        .at(x, y)
        .viewWithBBox(new Rectangle(PADDLE_WIDTH, PADDLE_HEIGHT))
        .with(timerComponent)
        .with("ballEntity", ball)
        .buildAndAttach();

[AlmasB]

Many thanks for this PR, it looks good.

1. Please can you check the comments below.
2. Also the checks seem to be failing, could you take a look please.

[AlmasB]

Should be fine to make it final by default. It can be opened in the future if required

[AlmasB]

super.onUpdate(tpf); calls Component onUpdate(), which I think may be empty. If it is, then we can safely remove this line.

[AlmasB]

Worth noting that the timer's clock will be tied to the entity's clock. So 1 second in this TimerActionComponent will depend on how long 1 second is for the entity, e.g. TimeComponent may alter that behaviour (which is the correct desirable behaviour). Not quite sure exactly the wording for the doc, but something along these lines should do the trick.

[AlmasB]

This formatting is largely inconsistent with the rest of the project's formatting. This will need to be updated to follow the standard Java guidelines. Though I think the fix for the above comment will remove the need for this altogether.

[AlmasB]

Same comment about formatting Line 34 and 35 as above. There is no need to align elements.

[AlmasB]

It's fine to use such a helper class, but best to avoid using the same object from multiple tests in this way. For example, if the test environment runs the tests in parallel (I don't think it does, however we should try best practice where it's easy to do so), there may be an issue with multiple threads writing and reading the same data.

This would mean simply using an int count = 0. If this doesn't work because of lambda functions, you can use var count = new SimpleIntegerProperty(), in each test (like you have done in public void testRunAtIntervalConditionalCancelledEarly()). This should give you more or less the same functionality, but in a relatively safer way.

[michqql]

Commit today:

• Made TimerActionComponent class final
• Removed call to super#onUpdate in TimerActionComponent
• Reworded documentation in TimerActionComponent class
• Fixed formatting in TimerActionComponentTest
• Removed member variables from TimerActionComponentTest to support parallelism