package buttons2; import javax.swing.*; /** * A frame with a button panel. * @version 1.00 2007-11-02 * @author Cay Horstmann */ public abstract class ButtonFrame extends JFrame { public static final int DEFAULT_WIDTH = 300; public static final int DEFAULT_HEIGHT = 200; protected JPanel panel; protected JButton yellowButton; protected JButton blueButton; protected JButton redButton; protected abstract void addEventHandlers(); public ButtonFrame() { setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT); panel = new JPanel(); add(panel); yellowButton = new JButton("Yellow"); blueButton = new JButton("Blue"); redButton = new JButton("Red"); panel.add(yellowButton); panel.add(blueButton); panel.add(redButton); addEventHandlers(); } }