JPopupMenu Problem

Question

Is there an easier way to code a JPopupMenu?
I keep having trouble with mine. It does not display the Popup menu correctly when I run the Java program.
Here is the code:
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
public class PopupTest {
    private JFrame frame;
    private JPopupMenu popup;
    public PopupTest() {
          frame = new JFrame("My Frame");
          popup = new JPopupMenu();
          popup.add("mi1");
          popup.add("mi2");
          frame.addMouseListener(new MouseAdapter() {
              public void mousePressed(MouseEvent me) {
                    if (me.isPopupTrigger()) {
                       popup.show(me.getComponent(), me.getX(), me.getY());
              public void mouseReleased(MouseEvent me) {
                    if (me.isPopupTrigger()) {
                        popup.show(me.getComponent(), me.getX(), me.getY());
         frame.getContentPane().add(popup);
          frame.pack();
        frame.setVisible(true);
    public static void main(String[] args) {
          new PopupTest();
}Any code samples is much appreciated
I have looked at the Java tutorial, it is too complex or too big for my liking.
Thanks,
Riz

Answer 1

To bring up a popup menu ( JPopupMenu [(in the API reference documentation)] ), you must register a mouse listener on each component that the popup menu should be associated with. The mouse listener must detect user requests that the popup menu be brought up. On Windows and Motif platforms, the user brings up a popup menu by pressing the right mouse button while the cursor is over a component that is popup-enabled.
The mouse listener brings up the popup menu by invoking the show method on the appropriate JPopupMenu instance. The following code, taken from PopupMenuDemo.java [(in a .java source file)] , shows how to create and show popup menus:
//...where instance variables are declared:
JPopupMenu popup;
    //...where the GUI is constructed:
//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);
    menuBar.addMouseListener(popupListener);
class PopupListener extends MouseAdapter {
    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());
}Popup menus have a few interesting implementation details. One is that every menu has an associated popup menu. When the menu is activated, it uses its associated popup menu to show its menu items.
Another detail is that a popup menu itself uses another component to implement the window containing the menu items. Depending on the circumstances under which the popup menu is displayed, the popup menu might implement its "window" using a lightweight component (such as a JPanel), a "mediumweight" component (such as a Panel [(in the API reference documentation)] ), or a heavyweight window (something that inherits from Window [(in the API reference documentation)] ).
Lightweight popup windows are more efficient than heavyweight windows, but they don't work well if you have any heavyweight components inside your GUI. Specifically, when the lightweight popup's display area intersects the heavyweight component's display area, the heavyweight component is drawn on top. This is one of the reasons we recommend against mixing heavyweight and lightweight components. If you absolutely need to use a heavyweight component in your GUI, then you can invoke JPopupMenu.setLightWeightPopupEnabled(false) to disable lightweight popup windows. For details, see Mixing Heavy and Light Components, an article in The Swing Connection.