Concepts of Programming Languages

14.6 Event Handling with Java 659

private Font plainFont, boldFont, italicFont,
boldItalicFont;
private JRadioButton plain, bold, italic, boldItalic;
private ButtonGroup radioButtons;

// The constructor method is where the display is initially
// built
public RadioB() {

// Create the test text string and set its font
text = new JTextField(
"In what font style should I appear?", 25);
text.setFont(plainFont);

// Create radio buttons for the fonts and add them to
// a new button group
plain = new JRadioButton("Plain", true);
bold = new JRadioButton("Bold");
italic = new JRadioButton("Italic");
boldItalic = new JRadioButton("Bold Italic");
radioButtons = new ButtonGroup();
radioButtons.add(plain);
radioButtons.add(bold);
radioButtons.add(italic);
radioButtons.add(boldItalic);

// Create a panel and put the text and the radio
// buttons in it; then add the panel to the frame
JPanel radioPanel = new JPanel();
radioPanel.add(text);
radioPanel.add(plain);
radioPanel.add(bold);
radioPanel.add(italic);
radioPanel.add(boldItalic);
add(radioPanel, BorderLayout.LINE_START);

// Register the event handlers
plain.addItemListener(this);
bold.addItemListener(this);
italic.addItemListener(this);
boldItalic.addItemListener(this);

// Create the fonts
plainFont = new Font("Serif", Font.PLAIN, 16);
boldFont = new Font("Serif", Font.BOLD, 16);