//: c13:Menus.java
// From 'Thinking in Java, 2nd ed.' by Bruce Eckel
// www.BruceEckel.com. See copyright notice in CopyRight.txt.
// Submenus, checkbox menu items, swapping menus,
// mnemonics (shortcuts) and action commands.
// <applet code=Menus width=300
// height=100> </applet>
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import com.bruceeckel.swing.*;
public class Menus extends JApplet {
String[] flavors = { "Chocolate", "Strawberry",
"Vanilla Fudge Swirl", "Mint Chip",
"Mocha Almond Fudge", "Rum Raisin",
"Praline Cream", "Mud Pie" };
JTextField t = new JTextField("No flavor", 30);
JMenuBar mb1 = new JMenuBar();
JMenu
f = new JMenu("File"),
m = new JMenu("Flavors"),
s = new JMenu("Safety");
// Alternative approach:
JCheckBoxMenuItem[] safety = {
new JCheckBoxMenuItem("Guard"),
new JCheckBoxMenuItem("Hide")
};
JMenuItem[] file = {
new JMenuItem("Open"),
};
// A second menu bar to swap to:
JMenuBar mb2 = new JMenuBar();
JMenu fooBar = new JMenu("fooBar");
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"),
};
JButton b = new JButton("Swap Menus");
class BL implements ActionListener {
public void actionPerformed(ActionEvent e) {
JMenuBar m = getJMenuBar();
setJMenuBar(m == mb1 ? mb2 : mb1);
validate(); // Refresh the frame
}
}
class ML implements ActionListener {
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(int i = 0; i < flavors.length; i++)
if(s.equals(flavors[i])) chosen = true;
if(!chosen)
t.setText("Choose a flavor first!");
else
t.setText("Opening "+ s +". Mmm, mm!");
}
}
}
class FL implements ActionListener {
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 {
public void actionPerformed(ActionEvent e) {
t.setText("Foo selected");
}
}
class BarL implements ActionListener {
public void actionPerformed(ActionEvent e) {
t.setText("Bar selected");
}
}
class BazL implements ActionListener {
public void actionPerformed(ActionEvent e) {
t.setText("Baz selected");
}
}
class CMIL implements ItemListener {
public void itemStateChanged(ItemEvent e) {
JCheckBoxMenuItem target =
(JCheckBoxMenuItem)e.getSource();
String actionCommand =
target.getActionCommand();
if(actionCommand.equals("Guard"))
t.setText("Guard the Ice Cream! " +
"Guarding is " + target.getState());
else if(actionCommand.equals("Hide"))
t.setText("Hide the Ice Cream! " +
"Is it cold? " + target.getState());
}
}
public void init() {
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[0].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();
for(int i = 0; i < flavors.length; i++) {
JMenuItem mi = new JMenuItem(flavors[i]);
mi.addActionListener(fl);
m.add(mi);
// Add separators at intervals:
if((i+1) % 3 == 0)
m.addSeparator();
}
for(int i = 0; i < safety.length; i++)
s.add(safety[i]);
s.setMnemonic(KeyEvent.VK_A);
f.add(s);
f.setMnemonic(KeyEvent.VK_F);
for(int i = 0; i < file.length; i++) {
file[i].addActionListener(fl);
f.add(file[i]);
}
mb1.add(f);
mb1.add(m);
setJMenuBar(mb1);
t.setEditable(false);
Container cp = getContentPane();
cp.add(t, BorderLayout.CENTER);
// Set up the system for swapping menus:
b.addActionListener(new BL());
b.setMnemonic(KeyEvent.VK_S);
cp.add(b, BorderLayout.NORTH);
for(int i = 0; i < other.length; i++)
fooBar.add(other[i]);
fooBar.setMnemonic(KeyEvent.VK_B);
mb2.add(fooBar);
}
public static void main(String[] args) {
Console.run(new Menus(), 300, 100);
}
} ///:~