1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255
| 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;
}
public Container createContentPane() {
//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());
}
}
}
} |