In 2.0, the only equivalent to the action member of Transition from 1.x is to use the onFinished member from Timeline. Problem is that onFinished is only called at the end.

For example, PauseTransition in 2.0 does not behave like it used to do in 1.x. In 2.0, the action associated to the transition is only executed whenever the transition ends. In 1.x it used to be executed every cycle. This prevents using PauseTransition as a timer as it was possible in 1.x.

In 1.x, the following code prints "Hi!" 3 times:

import javafx.animation.transition.PauseTransition;

PauseTransition {
    repeatCount: 3
    duration: 500ms
    action: function():Void {
        println("Hi!");
    }
}.play();


In 2.0, the following code only prints "Hi!" 1 time, when the transition ends:

import javafx.animation.PauseTransition;
import javafx.application.Application;
import javafx.builders.PauseTransitionBuilder;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.stage.Stage;
import javafx.util.Duration;

public class Main extends Application {

    public static void main(String[] args) {
        Application.launch(Main.class, args);
    }

    @Override
    public void start(Stage primaryStage) {
        PauseTransition pauseTransition = new PauseTransitionBuilder()
                .cycleCount(3)
                .duration(Duration.valueOf(500))
                .onFinished(new EventHandler<ActionEvent>() {
                @Override
                    public void handle(ActionEvent event) {
                System.out.println("Hi!");
            }
        })
                .build();
        pauseTransition.play();
    }
}

The way to fix this issue is to reintroduce the action member in Transition and to bind the onFinished member of the last KeyFrame of the Timeline to this value.