//: gui/Menus.java // Submenus, check box menu items, swapping menus, // mnemonics (shortcuts) and action commands. import javax.swing.*; import java.awt.*; import java.awt.event.*; import static net.mindview.util.SwingConsole.*; public class Menus extends JFrame { private String[] flavors = { "Chocolate", "Strawberry", "Vanilla Fudge Swirl", "Mint Chip", "Mocha Almond Fudge", "Rum Raisin", "Praline Cream", "Mud Pie" }; private JTextField t = new JTextField("No flavor", 30); private JMenuBar mb1 = new JMenuBar(); private JMenu f = new JMenu("File"), m = new JMenu("Flavors"), s = new JMenu("Safety"); // Alternative approach: private JCheckBoxMenuItem[] safety = { new JCheckBoxMenuItem("Guard"), new JCheckBoxMenuItem("Hide") }; private JMenuItem[] file = { new JMenuItem("Open") }; // A second menu bar to swap to: private JMenuBar mb2 = new JMenuBar(); private JMenu fooBar = new JMenu("fooBar"); private JMenuItem[] other = { // Adding a menu shortcut (mnemonic) is very // simple, but only JMenuItems can have them // in their constructors: new JMenuItem("Foo", KeyEvent.VK_F), new JMenuItem("Bar", KeyEvent.VK_A), // No shortcut: new JMenuItem("Baz"), }; private JButton b = new JButton("Swap Menus"); class BL implements ActionListener { @Override public void actionPerformed(ActionEvent e) { JMenuBar m = getJMenuBar(); setJMenuBar(m == mb1 ? mb2 : mb1); validate(); // Refresh the frame } } class ML implements ActionListener { @Override public void actionPerformed(ActionEvent e) { JMenuItem target = (JMenuItem)e.getSource(); String actionCommand = target.getActionCommand(); if(actionCommand.equals("Open")) { String s = t.getText(); boolean chosen = false; for(String flavor : flavors) if(s.equals(flavor)) chosen = true; if(!chosen) t.setText("Choose a flavor first!"); else t.setText("Opening " + s + ". Mmm, mm!"); } } } class FL implements ActionListener { @Override public void actionPerformed(ActionEvent e) { JMenuItem target = (JMenuItem)e.getSource(); t.setText(target.getText()); } } // Alternatively, you can create a different // class for each different MenuItem. Then you // don't have to figure out which one it is: class FooL implements ActionListener { @Override public void actionPerformed(ActionEvent e) { t.setText("Foo selected"); } } class BarL implements ActionListener { @Override public void actionPerformed(ActionEvent e) { t.setText("Bar selected"); } } class BazL implements ActionListener { @Override public void actionPerformed(ActionEvent e) { t.setText("Baz selected"); } } class CMIL implements ItemListener { @Override public void itemStateChanged(ItemEvent e) { JCheckBoxMenuItem target = (JCheckBoxMenuItem)e.getSource(); String actionCommand = target.getActionCommand(); switch (actionCommand) { case "Guard": t.setText("Guard the Ice Cream! " + "Guarding is " + target.getState()); break; case "Hide": t.setText("Hide the Ice Cream! " + "Is it hidden? " + target.getState()); break; } } } public Menus() { ML ml = new ML(); CMIL cmil = new CMIL(); safety[0].setActionCommand("Guard"); safety[0].setMnemonic(KeyEvent.VK_G); safety[0].addItemListener(cmil); safety[1].setActionCommand("Hide"); safety[1].setMnemonic(KeyEvent.VK_H); safety[1].addItemListener(cmil); other[0].addActionListener(new FooL()); other[1].addActionListener(new BarL()); other[2].addActionListener(new BazL()); FL fl = new FL(); int n = 0; for(String flavor : flavors) { JMenuItem mi = new JMenuItem(flavor); mi.addActionListener(fl); m.add(mi); // Add separators at intervals: if((n++ + 1) % 3 == 0) m.addSeparator(); } for(JCheckBoxMenuItem sfty : safety) s.add(sfty); s.setMnemonic(KeyEvent.VK_A); f.add(s); f.setMnemonic(KeyEvent.VK_F); for(JMenuItem file1 : file) { file1.addActionListener(ml); f.add(file1); } mb1.add(f); mb1.add(m); setJMenuBar(mb1); t.setEditable(false); add(t, BorderLayout.CENTER); // Set up the system for swapping menus: b.addActionListener(new BL()); b.setMnemonic(KeyEvent.VK_S); add(b, BorderLayout.NORTH); for(JMenuItem oth : other) fooBar.add(oth); fooBar.setMnemonic(KeyEvent.VK_B); mb2.add(fooBar); } public static void main(String[] args) { run(new Menus(), 300, 200); } } ///:~