JFX 7.7

package bounceballcontrol;

import javafx.application.Application;
import javafx.stage.Stage;
import javafx.scene.Scene;
import javafx.scene.input.KeyCode;

public class BounceBallControl extends Application {
  @Override // Override the start method in the Application class
  public void start(Stage primaryStage) {
    BallPane ballPane = new BallPane(); // Create a ball pane

    // Pause and resume animation
    ballPane.setOnMousePressed(e -> ballPane.pause());
    ballPane.setOnMouseReleased(e -> ballPane.play());

    // Increase and decrease animation
    ballPane.setOnKeyPressed(e -> {
      if (e.getCode() == KeyCode.UP) {
        ballPane.increaseSpeed();
      }
      else if (e.getCode() == KeyCode.DOWN) {
        ballPane.decreaseSpeed();
      }
    });

    // Create a scene and place it in the stage
    Scene scene = new Scene(ballPane, 250, 150);
    primaryStage.setTitle("BounceBallControl"); // Set the stage title
    primaryStage.setScene(scene); // Place the scene in the stage
    primaryStage.show(); // Display the stage

    // Must request focus after the primary stage is displayed
    ballPane.requestFocus();
  }

  /**
   * The main method is only needed for the IDE with limited
   * JavaFX support. Not needed for running from the command line.
   */
  public static void main(String[] args) {
    launch(args);
  }
}

=======================================================================================================================================

package bounceballcontrol;

import javafx.animation.KeyFrame;
import javafx.animation.Timeline;
import javafx.beans.property.DoubleProperty;
import javafx.scene.layout.Pane;
import javafx.scene.paint.Color;
import javafx.scene.shape.Circle;
import javafx.util.Duration;

public class BallPane extends Pane {
  public final double radius = 20;
  private double x = radius, y = radius;
  private double dx = 5, dy = 2;
  private Circle circle = new Circle(x, y, radius);
  private Timeline animation;

  public BallPane() {
    circle.setFill(Color.ORANGE); // Set ball color
    getChildren().add(circle); // Place a ball into this pane

    // Create an animation for moving the ball
    animation = new Timeline(
      new KeyFrame(Duration.millis(50), e -> moveBall()));
    animation.setCycleCount(Timeline.INDEFINITE);
    animation.play(); // Start animation
  }

  public void play() {
    animation.play();
  }

  public void pause() {
    animation.pause();
  }

  public void increaseSpeed() {
    animation.setRate(animation.getRate() + 0.1);
  }

  public void decreaseSpeed() {
    animation.setRate(
      animation.getRate() > 0 ? animation.getRate() - 0.1 : 0);
  }

  public DoubleProperty rateProperty() {
    return animation.rateProperty();
  }

  protected void moveBall() {
    // Check boundaries
    if (x < radius || x > getWidth() - radius) {
      dx *= -1; // Change ball move direction
    }
    if (y < radius || y > getHeight() - radius) {
      dy *= -1; // Change ball move direction
    }

    // Adjust ball position
    x += dx;
    y += dy;
    circle.setCenterX(x);
    circle.setCenterY(y);
  }
}