FileDocCategorySizeDatePackage
PopupMenuDemo.javaAPI DocExample6899Tue Dec 12 18:59:18 GMT 2000None

PopupMenuDemo

public class PopupMenuDemo extends JFrame implements ActionListener, ItemListener

Fields Summary
JTextArea
output
JScrollPane
scrollPane
String
newline
JPopupMenu
popup
Constructors Summary
public PopupMenuDemo()


      
        JMenuBar menuBar;
        JMenu menu, submenu;
        JMenuItem menuItem;
        JRadioButtonMenuItem rbMenuItem;
        JCheckBoxMenuItem cbMenuItem;

        addWindowListener(new WindowAdapter() {
            public void windowClosing(WindowEvent e) {
                System.exit(0);
            }
        });

        //Add regular components to the window, using the default BorderLayout.
        Container contentPane = getContentPane();
        output = new JTextArea(5, 30);
        output.setEditable(false);
        scrollPane = new JScrollPane(output);
        contentPane.add(scrollPane, BorderLayout.CENTER);

        //Create the menu bar.
        menuBar = new JMenuBar();
        setJMenuBar(menuBar);

        //Build the first menu.
        menu = new JMenu("A Menu");
        menu.setMnemonic(KeyEvent.VK_A);
        menu.getAccessibleContext().setAccessibleDescription(
                "The only menu in this program that has menu items");
        menuBar.add(menu);

        //a group of JMenuItems
        menuItem = new JMenuItem("A text-only menu item",
                                 KeyEvent.VK_T);
        //menuItem.setMnemonic(KeyEvent.VK_T); //used constructor instead
        menuItem.setAccelerator(KeyStroke.getKeyStroke(
                KeyEvent.VK_1, ActionEvent.ALT_MASK));
        menuItem.getAccessibleContext().setAccessibleDescription(
                "This doesn't really do anything");
        menuItem.addActionListener(this);
        menu.add(menuItem);
        menuItem = new JMenuItem("Both text and icon", 
                                 new ImageIcon("images/middle.gif"));
        menuItem.setMnemonic(KeyEvent.VK_B);
        menuItem.addActionListener(this);
        menu.add(menuItem);
        menuItem = new JMenuItem(new ImageIcon("images/middle.gif"));
        menuItem.setMnemonic(KeyEvent.VK_D);
        menuItem.addActionListener(this);
        menu.add(menuItem);

        //a group of radio button menu items
        menu.addSeparator();
        ButtonGroup group = new ButtonGroup();
        rbMenuItem = new JRadioButtonMenuItem("A radio button menu item");
        rbMenuItem.setSelected(true);
        rbMenuItem.setMnemonic(KeyEvent.VK_R);
        group.add(rbMenuItem);
        rbMenuItem.addActionListener(this);
        menu.add(rbMenuItem);
        rbMenuItem = new JRadioButtonMenuItem("Another one");
        rbMenuItem.setMnemonic(KeyEvent.VK_O);
        group.add(rbMenuItem);
        rbMenuItem.addActionListener(this);
        menu.add(rbMenuItem);

        //a group of check box menu items
        menu.addSeparator();
        cbMenuItem = new JCheckBoxMenuItem("A check box menu item");
        cbMenuItem.setMnemonic(KeyEvent.VK_C);
        cbMenuItem.addItemListener(this);
        menu.add(cbMenuItem);
        cbMenuItem = new JCheckBoxMenuItem("Another one");
        cbMenuItem.setMnemonic(KeyEvent.VK_H);
        cbMenuItem.addItemListener(this);
        menu.add(cbMenuItem);

        //a submenu
        menu.addSeparator();
        submenu = new JMenu("A submenu");
        submenu.setMnemonic(KeyEvent.VK_S);

        menuItem = new JMenuItem("An item in the submenu");
        menuItem.setAccelerator(KeyStroke.getKeyStroke(
                KeyEvent.VK_2, ActionEvent.ALT_MASK));
        menuItem.addActionListener(this);
        submenu.add(menuItem);

        menuItem = new JMenuItem("Another item");
        menuItem.addActionListener(this);
        submenu.add(menuItem);
        menu.add(submenu);

        //Build second menu in the menu bar.
        menu = new JMenu("Another Menu");
        menu.setMnemonic(KeyEvent.VK_N);
        menu.getAccessibleContext().setAccessibleDescription(
                "This menu does nothing");
        menuBar.add(menu);

        //Create the popup menu.
        popup = new JPopupMenu();
        menuItem = new JMenuItem("A popup menu item");
        menuItem.addActionListener(this);
        popup.add(menuItem);
        menuItem = new JMenuItem("Another popup menu item");
        menuItem.addActionListener(this);
        popup.add(menuItem);

        //Add listener to components that can bring up popup menus.
        MouseListener popupListener = new PopupListener();
        output.addMouseListener(popupListener);
        scrollPane.addMouseListener(popupListener);
        menuBar.addMouseListener(popupListener);
    
Methods Summary
public voidactionPerformed(java.awt.event.ActionEvent e)

        JMenuItem source = (JMenuItem)(e.getSource());
        String s = "Action event detected."
                   + newline
                   + "    Event source: " + source.getText()
                   + " (an instance of " + getClassName(source) + ")";
        output.append(s + newline);
    
protected java.lang.StringgetClassName(java.lang.Object o)

        String classString = o.getClass().getName();
        int dotIndex = classString.lastIndexOf(".");
        return classString.substring(dotIndex+1);
    
public voiditemStateChanged(java.awt.event.ItemEvent e)

        JMenuItem source = (JMenuItem)(e.getSource());
        String s = "Item event detected."
                   + newline
                   + "    Event source: " + source.getText()
                   + " (an instance of " + getClassName(source) + ")"
                   + newline
                   + "    New state: " 
                   + ((e.getStateChange() == ItemEvent.SELECTED) ?
                     "selected":"unselected");
        output.append(s + newline);
    
public static voidmain(java.lang.String[] args)

        PopupMenuDemo window = new PopupMenuDemo();

        window.setTitle("PopupMenuDemo");
        window.setSize(450, 260);
        window.setVisible(true);