(Game: eye-hand coordination) Write a program that displays a circle of radius 10 pixels filled with a random color at a random location on a pane, as shown in Figure 15.29b

/*********************************************************************************
* (Game: eye-hand coordination) Write a program that displays a circle of radius *
* 10 pixels filled with a random color at a random location on a pane, as shown  *
* in Figure 15.29b. When you click the circle, it disappears and a new random    *
* color circle is displayed at another random location. After twenty circles are *
* clicked, display the time spent in the pane, as shown in Figure 15.29c.        *
*********************************************************************************/
import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.shape.Circle;
import javafx.scene.layout.Pane;
import javafx.scene.paint.Color;
import javafx.stage.Stage;

public class Exercise_15_19 extends Application {
	@Override // Override the start method in the Application class
	public void start(Stage primaryStage) {
		// Create a pane
		Pane pane = new Pane();
		double width = 200; // pane width
		double height = 200; // pane height

		// Create a circle
		Circle circle = new Circle(10);
		setRandomProperties(circle, width, height);
		pane.getChildren().add(circle);

		// Create and register the handle
		circle.setOnMouseClicked(e -> {
			pane.getChildren().clear();
			setRandomProperties(circle, width, height);
			pane.getChildren().add(circle);
		});

		// Create a scene and place it in the stage
		Scene scene = new Scene(pane, width, height);
		primaryStage.setTitle("Exercise_15_19"); // Set the stage title
		primaryStage.setScene(scene); // Place the scene in the stage
		primaryStage.show(); // Display the stage
	}

	/** Set a circle with a random color and a random location the pane */
	private void setRandomProperties(Circle c, double width, double height) {
		c.setFill(Color.color(Math.random(), Math.random(), Math.random()));
		c.setCenterX(c.getRadius() + Math.random() * 
			(width - c.getRadius() * 2));
		c.setCenterY(c.getRadius() + Math.random() * 
			(height - c.getRadius() * 2));
	}
}