import java.awt.*;
import java.awt.event.*;
import javax.swing.JPopupMenu;
import javax.swing.JMenu;
import javax.swing.JMenuItem;
import javax.swing.JCheckBoxMenuItem;
import javax.swing.JRadioButtonMenuItem;
import javax.swing.ButtonGroup;
import javax.swing.JMenuBar;
import javax.swing.KeyStroke;
import javax.swing.ImageIcon;import javax.swing.JPanel;
import javax.swing.JTextArea;
import javax.swing.JScrollPane;
import javax.swing.JFrame;/* PopupMenuDemo.java is a 1.4 application that requires images/middle.gif. *//*
* Like MenuDemo, but with popup menus added.
*/
public class PopupMenuDemo implements ActionListener, ItemListener {
JTextArea output;
JScrollPane scrollPane;
String newline = "\n"; public JMenuBar createMenuBar() {
JMenuBar menuBar;
JMenu menu, submenu;
JMenuItem menuItem;
JRadioButtonMenuItem rbMenuItem;
JCheckBoxMenuItem cbMenuItem; //Create the menu bar.
menuBar = new JMenuBar(); //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); ImageIcon icon = createImageIcon("images/middle.gif");
menuItem = new JMenuItem("Both text and icon", icon);
menuItem.setMnemonic(KeyEvent.VK_B);
menuItem.addActionListener(this);
menu.add(menuItem); menuItem = new JMenuItem(icon);
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); return menuBar;
}
import java.awt.event.*;
import javax.swing.JPopupMenu;
import javax.swing.JMenu;
import javax.swing.JMenuItem;
import javax.swing.JCheckBoxMenuItem;
import javax.swing.JRadioButtonMenuItem;
import javax.swing.ButtonGroup;
import javax.swing.JMenuBar;
import javax.swing.KeyStroke;
import javax.swing.ImageIcon;import javax.swing.JPanel;
import javax.swing.JTextArea;
import javax.swing.JScrollPane;
import javax.swing.JFrame;/* PopupMenuDemo.java is a 1.4 application that requires images/middle.gif. *//*
* Like MenuDemo, but with popup menus added.
*/
public class PopupMenuDemo implements ActionListener, ItemListener {
JTextArea output;
JScrollPane scrollPane;
String newline = "\n"; public JMenuBar createMenuBar() {
JMenuBar menuBar;
JMenu menu, submenu;
JMenuItem menuItem;
JRadioButtonMenuItem rbMenuItem;
JCheckBoxMenuItem cbMenuItem; //Create the menu bar.
menuBar = new JMenuBar(); //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); ImageIcon icon = createImageIcon("images/middle.gif");
menuItem = new JMenuItem("Both text and icon", icon);
menuItem.setMnemonic(KeyEvent.VK_B);
menuItem.addActionListener(this);
menu.add(menuItem); menuItem = new JMenuItem(icon);
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); return menuBar;
}
//Create the content-pane-to-be.
JPanel contentPane = new JPanel(new BorderLayout());
contentPane.setOpaque(true); //Create a scrolled text area.
output = new JTextArea(5, 30);
output.setEditable(false);
scrollPane = new JScrollPane(output); //Add the text area to the content pane.
contentPane.add(scrollPane, BorderLayout.CENTER); return contentPane;
} public void createPopupMenu() {
JMenuItem menuItem; //Create the popup menu.
JPopupMenu 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 the text area so the popup menu can come up.
MouseListener popupListener = new PopupListener(popup);
output.addMouseListener(popupListener);
} public void actionPerformed(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);
output.setCaretPosition(output.getDocument().getLength());
} public void itemStateChanged(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);
output.setCaretPosition(output.getDocument().getLength());
} // Returns just the class name -- no package info.
protected String getClassName(Object o) {
String classString = o.getClass().getName();
int dotIndex = classString.lastIndexOf(".");
return classString.substring(dotIndex+1);
} /** Returns an ImageIcon, or null if the path was invalid. */
protected static ImageIcon createImageIcon(String path) {
java.net.URL imgURL = PopupMenuDemo.class.getResource(path);
if (imgURL != null) {
return new ImageIcon(imgURL);
} else {
System.err.println("Couldn't find file: " + path);
return null;
}
} /**
* Create the GUI and show it. For thread safety,
* this method should be invoked from the
* event-dispatching thread.
*/
private static void createAndShowGUI() {
//Make sure we have nice window decorations.
JFrame.setDefaultLookAndFeelDecorated(true); //Create and set up the window.
JFrame frame = new JFrame("PopupMenuDemo");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); //Create/set menu bar and content pane.
PopupMenuDemo demo = new PopupMenuDemo();
frame.setJMenuBar(demo.createMenuBar());
frame.setContentPane(demo.createContentPane()); //Create and set up the popup menu.
demo.createPopupMenu(); //Display the window.
frame.setSize(450, 260);
frame.setVisible(true);
} public static void main(String[] args) {
//Schedule a job for the event-dispatching thread:
//creating and showing this application's GUI.
javax.swing.SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGUI();
}
});
} class PopupListener extends MouseAdapter {
JPopupMenu popup; PopupListener(JPopupMenu popupMenu) {
popup = popupMenu;
} public void mousePressed(MouseEvent e) {
maybeShowPopup(e);
} public void mouseReleased(MouseEvent e) {
maybeShowPopup(e);
} private void maybeShowPopup(MouseEvent e) {
if (e.isPopupTrigger()) {
popup.show(e.getComponent(),
e.getX(), e.getY());
}
}
}
}//tut上面的例子