Chapter 15 Exercise 26, Introduction to Java Programming, Tenth Edition Y. Daniel LiangY.

15.26 (Change opacity)
Rewrite Programming Exercise 15.24 so that the
ball’s opacity is changed as it swings.

import javafx.animation.FadeTransition;
import javafx.animation.PathTransition;
import javafx.animation.PathTransition.OrientationType;
import javafx.animation.Timeline;
import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.layout.Pane;
import javafx.scene.paint.Color;
import javafx.scene.shape.Arc;
import javafx.scene.shape.Circle;
import javafx.stage.Stage;
import javafx.util.Duration;

public class Exercise_26 extends Application {

    private static double WIDTH = 400;
    private static double HEIGHT = 400;

    @Override
    public void start(Stage primaryStage) throws Exception {
        Pane pane = new Pane();
        Arc arc = new Arc(WIDTH / 2, HEIGHT * 0.8, WIDTH * 0.25, HEIGHT * 0.1, 180, 180);
        arc.setFill(Color.TRANSPARENT);
        arc.setStroke(Color.BLACK);
        Circle c = new Circle(arc.getCenterX() - arc.getRadiusX(), arc.getCenterY(), 10);

        pane.getChildren().addAll(arc, c);

        PathTransition path = new PathTransition();
        path.setDuration(Duration.millis(3000));
        path.setPath(arc);
        path.setNode(c);
        path.setOrientation(OrientationType.NONE);
        path.setCycleCount(Timeline.INDEFINITE);
        path.setAutoReverse(true);
        FadeTransition fade = new FadeTransition(Duration.millis(3000), c);
        fade.setAutoReverse(true);
        fade.setFromValue(1.0);
        fade.setToValue(0.1);
        fade.setCycleCount(Timeline.INDEFINITE);
        c.setOnMouseClicked(e -> {
            path.play();
            fade.play();
        });

        Scene scene = new Scene(pane, WIDTH, HEIGHT);
        primaryStage.setScene(scene);
        primaryStage.setTitle("Swing");
        primaryStage.show();
    }


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