import java.awt.*; import java.awt.event.*; import javax.swing.*; /** * Shows an animated bouncing ball. * @version 1.33 2007-05-17 * @author Cay Horstmann */ public class Bounce { public static void main(String[] args) { EventQueue.invokeLater(new Runnable() { public void run() { JFrame frame = new BounceFrame(); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setVisible(true); } }); } } /** * The frame with ball component and buttons. */ class BounceFrame extends JFrame { /** * Constructs the frame with the component for showing the bouncing ball and Start and Close * buttons */ public BounceFrame() { setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT); setTitle("Bounce"); comp = new BallComponent(); add(comp, BorderLayout.CENTER); JPanel buttonPanel = new JPanel(); addButton(buttonPanel, "Start", new ActionListener() { public void actionPerformed(ActionEvent event) { addBall(); } }); addButton(buttonPanel, "Close", new ActionListener() { public void actionPerformed(ActionEvent event) { System.exit(0); } }); add(buttonPanel, BorderLayout.SOUTH); } /** * Adds a button to a container. * @param c the container * @param title the button title * @param listener the action listener for the button */ public void addButton(Container c, String title, ActionListener listener) { JButton button = new JButton(title); c.add(button); button.addActionListener(listener); } /** * Adds a bouncing ball to the panel and makes it bounce 1,000 times. */ public void addBall() { try { Ball ball = new Ball(); comp.add(ball); for (int i = 1; i <= STEPS; i++) { ball.move(comp.getBounds()); comp.paint(comp.getGraphics()); Thread.sleep(DELAY); } } catch (InterruptedException e) { } } private BallComponent comp; public static final int DEFAULT_WIDTH = 450; public static final int DEFAULT_HEIGHT = 350; public static final int STEPS = 1000; public static final int DELAY = 3; }