Java Programming Tutorial - 64, 65 - JCheckBox

import java.awt.Font;
import java.awt.FlowLayout;
import java.awt.event.ItemListener;
import java.awt.event.ItemEvent;
import javax.swing.JCheckBox;
import javax.swing.JTextField;
import javax.swing.JFrame;

class CheckBox {
   public static void main(String args[ ]) {
      Box window = new Box();
      window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      window.setSize(250, 100);
      window.setVisible(true);
   }
}

class Box extends JFrame {
   private JTextField msg;
   private JCheckBox boldBox, italicBox;

   Box() {
      super("Font changer");
      setLayout(new FlowLayout());

      msg = new JTextField("This is my sentence.", 13);
      msg.setFont(new Font("Serif", Font.PLAIN, 14));
      add(msg);

      boldBox = new JCheckBox("Set bold");
      add(boldBox);
      italicBox = new JCheckBox("Set italic");
      add(italicBox);

      TheHandler handler = new TheHandler();
      boldBox.addItemListener(handler);
      italicBox.addItemListener(handler);

   }

   private class TheHandler implements ItemListener {
      private Font font;

      public void itemStateChanged(ItemEvent event) {
         if(boldBox.isSelected() && italicBox.isSelected())
            font = new Font("Serif", Font.BOLD + Font.ITALIC, 14);
         else if(boldBox.isSelected())
            font = new Font("Serif", Font.BOLD, 14);
         else if(italicBox.isSelected())
            font = new Font("Serif", Font.ITALIC, 14);
         else
            font = new Font("Serif", Font.PLAIN, 14);

         msg.setFont(font);
      }
   }

}