Java How to Program, Early Objects, 11th Edition

...  northPanel.add(comboBox); 53
 54    // create array for radio buttons
 55    radio = new JRadioButton[looks.length];
 56
 57    JPanel southPanel = new JPanel();
 58
 59    // use a GridLayout with 3 buttons in each row
 60    int rows = (int) Math.ceil(radio.length / 3.0);
 61    southPanel.setLayout(new GridLayout(rows, 3));
 62
 63    group = new ButtonGroup(); // button group for look-and-feels
 64    ItemHandler handler = new ItemHandler(); // look-and-feel handler
 65
 66    for (int count = 0; count < radio.length; count++)
 67    {
 68     radio[count] = new JRadioButton(lookNames[count]);
 69     radio[count].addItemListener(handler); // add handler
 70     group.add(radio[count]); // add radio button to group
 71     southPanel.add(radio[count]); // add radio button to panel
 72    }
 73
 74 add(northPanel, ...