SWING: JPopupMenu Class Cheat Sheet - A quick cheatsheet for beginners, with examples

Following is the declaration for javax.swing.JPopupMenu class

public class JPopupMenu
   extends JComponent
      implements Accessible, MenuElement

# Constructors

`JPopupMenu()`	Constructs a JPopupMenu without an “invoker”.
`JPopupMenu(String label)`	Constructs a JPopupMenu with the specified title.

# Methods

`JMenuItem add(Action a)`	Appends a new menu item to the end of the menu which dispatches the specified Action object.
`JMenuItem add(JMenuItem menuItem)`	Appends the specified menu item to the end of this menu.
`JMenuItem add(String s)`	Creates a new menu item with the specified text and appends it to the end of this menu.
`void addMenuKeyListener(MenuKeyListener l)`	Adds a MenuKeyListener to the popup menu.
`void addPopupMenuListener(PopupMenuListener l)`	Adds a PopupMenu listener.
`void addSeparator()`	Appends a new separator at the end of the menu.
`protected PropertyChangeListener createActionChangeListener(JMenuItem b)`	Returns a properly configured PropertyChangeListener which updates the control as changes to the Action occur.
`protected JMenuItem createActionComponent(Action a)`	Factory method which creates the JMenuItem for Actions added to the JPopupMenu.
`protected void firePopupMenuCanceled()`	Notifies PopupMenuListeners that this popup menu is canceled.
`protected void firePopupMenuWillBecomeInvisible()`	Notifies PopupMenuListeners that this popup menu will become invisible.
`protected void firePopupMenuWillBecomeVisible()`	Notifies PopupMenuListeners that this popup menu will become visible.
`AccessibleContext getAccessibleContext()`	Gets the AccessibleContext associated with this JPopupMenu.
`Component getComponent()`	Returns this JPopupMenu component.
`Component getComponentAtIndex(int i)`	Deprecated. Replaced by Container.getComponent(int)
`int getComponentIndex(Component c)`	Returns the index of the specified component.
`static boolean getDefaultLightWeightPopupEnabled()`	Gets the defaultLightWeightPopupEnabled property, which by default is true.
`Component getInvoker()`	Returns the component which is the ‘invoker’ of this popup menu.
`String getLabel()`	Returns the popup menu’s label.
`Insets getMargin()`	Returns the margin, in pixels, between the popup menu’s border and its containers.
`MenuKeyListener[]getMenuKeyListeners()`	Returns an array of all the MenuKeyListeners added to this JPopupMenu with addMenuKeyListener().
`PopupMenuListener[] getPopupMenuListeners()`	Returns an array of all the PopupMenuListeners added to this JMenuItem with addPopupMenuListener().
`SingleSelectionModel getSelectionModel()`	Returns the model object that handles single selections.
`MenuElement[] getSubElements()`	Returns an array of MenuElements containing the submenu for this menu component.
`PopupMenuUI getUI()`	Returns the look and feel (L&F) object that renders this component.
`String getUIClassID()`	Returns the name of the L&F class that renders this component.
`void insert(Action a, int index)`	Inserts a menu item for the specified Action object at a given position.
`void insert(Component component, int index)`	Inserts the specified component into the menu at a given position.
`boolean isBorderPainted()`	Checks whether the border should be painted.
boolean isLightWeightPopupEnabled()	Gets the lightWeightPopupEnabled property.
`boolean isPopupTrigger(MouseEvent e)`	Returns true if the MouseEvent is considered a popup trigger by the JPopupMenu’s currently installed UI.
`boolean isVisible()`	Returns true if the popup menu is visible (currently being displayed).
`void menuSelectionChanged(boolean isIncluded)`	Message when the menubar selection changes to activate or deactivate this menu.
`void pack()`	Lays out the container so that it uses the minimum space needed to display its contents.
`protected void paintBorder(Graphics g)`	Paints the popup menu’s border if the borderPainted property is true.
`protected String paramString()`	Returns a string representation of this JPopupMenu.
`protected void processFocusEvent(FocusEvent evt)`	Processes focus events occurring on this component by dispatching them to any registered FocusListener objects.
`protected void processKeyEvent(KeyEvent evt)`	Processes keystroke events such as mnemonics and accelerators.
`void processKeyEvent(KeyEvent e, MenuElement[] path, MenuSelectionManager manager)`	Processes a key event forwarded from the MenuSelectionManager and changes the menu selection, if necessary, by using MenuSelectionManager’s API.
`void processMouseEvent(MouseEvent event, MenuElement[] path, MenuSelectionManager manager)`	This method is required to conform to the MenuElement interface, but it not implemented.
`void remove(int pos)`	Removes the component at the specified index from this popup menu.
`void removeMenuKeyListener(MenuKeyListener l)`	Removes a MenuKeyListener from the popup menu.
`void removePopupMenuListener(PopupMenuListener l)`	Removes a PopupMenu listener.
`void setBorderPainted(boolean b)`	Sets whether the border should be painted.
`static void setDefaultLightWeightPopupEnabled(boolean aFlag)`	Sets the default value of the lightWeightPopupEnabled property.
`void setInvoker(Component invoker)`	Sets the invoker of this popup menu the component in which the popup menu is to be displayed.
`void setLabel(String label)`	Sets the popup menu’s label.
`void setLightWeightPopupEnabled(boolean aFlag)`	Sets the value of the lightWeightPopupEnabled property, which by default is true.
`void setLocation(int x, int y)`	Sets the location of the upper left corner of the popup menu using x, y coordinates.
`void setPopupSize(Dimension d)`	Sets the size of the Popup window using a Dimension object.
`void setPopupSize(int width, int height)`	Sets the size of the Popup window to the specified width and height.
`void setSelected(Component sel)`	Sets the currently selected component, This will result in a change in the selection model.
`void setSelectionModel(SingleSelectionModel model)`	Sets the model object to handle single selections.
`void setUI(PopupMenuUI ui)`	Sets the L&F object that renders this component.
`void setVisible(boolean b)`	Sets the visibility of the popup menu.
`void show(Component invoker, int x, int y)`	Displays the popup menu at the position x,y in the coordinate space of the component invoker.
`void updateUI()`	Resets the UI property to a value from the current look and feel.

# Methods Inherited

javax.swing.JComponent
java.awt.Container
java.awt.Component
java.lang.Object

# JPopupMenu Example

SwingMenuDemo.java

import java.awt.*;
import java.awt.event.*;

import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JMenuItem;
import javax.swing.JPanel;
import javax.swing.JPopupMenu;

public class SwingJpopupMenu{
   private JFrame mainFrame;
   private JLabel headerLabel;
   private JLabel statusLabel;
   private JPanel controlPanel; 

   public SwingJpopupMenu(){
      prepareGUI();
   }
   public static void main(String[] args){
      SwingJpopupMenu  swingMenuDemo = new SwingJpopupMenu();     
      swingMenuDemo.showPopupMenuDemo();
   }
   private void prepareGUI(){
      mainFrame = new JFrame("Java SWING Examples");
      mainFrame.setSize(400,400);
      mainFrame.setLayout(new GridLayout(3, 1));

      headerLabel = new JLabel("",JLabel.CENTER );
      statusLabel = new JLabel("",JLabel.CENTER);        
      statusLabel.setSize(350,100);
      
      mainFrame.addWindowListener(new WindowAdapter() {
         public void windowClosing(WindowEvent windowEvent){
            System.exit(0);
         }        
      });
      controlPanel = new JPanel();
      controlPanel.setLayout(new FlowLayout());

      mainFrame.add(headerLabel);
      mainFrame.add(controlPanel);
      mainFrame.add(statusLabel);
      mainFrame.setVisible(true);  
   }
   private void showPopupMenuDemo(){
      final JPopupMenu editMenu = new JPopupMenu("Edit"); 

      JMenuItem cutMenuItem = new JMenuItem("Cut");
      cutMenuItem.setActionCommand("Cut");

      JMenuItem copyMenuItem = new JMenuItem("Copy");
      copyMenuItem.setActionCommand("Copy");

      JMenuItem pasteMenuItem = new JMenuItem("Paste");
      pasteMenuItem.setActionCommand("Paste");

      MenuItemListener menuItemListener = new MenuItemListener();

      cutMenuItem.addActionListener(menuItemListener);
      copyMenuItem.addActionListener(menuItemListener);
      pasteMenuItem.addActionListener(menuItemListener);

      editMenu.add(cutMenuItem);
      editMenu.add(copyMenuItem);
      editMenu.add(pasteMenuItem);   

      mainFrame.addMouseListener(new MouseAdapter() {
         public void mouseClicked(MouseEvent e) {            
            editMenu.show(mainFrame, e.getX(), e.getY());
         }               
      });
      mainFrame.add(editMenu); 
      mainFrame.setVisible(true);
   }
   class MenuItemListener implements ActionListener {
      public void actionPerformed(ActionEvent e) {            
         statusLabel.setText(e.getActionCommand() + " MenuItem clicked.");
      }    
   }   
}

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