In Windows, it is very common to show context menu (with cut, copy, paste etc) on textfields, textareas. I don't know about other operating systems. So any windows user using a swing application expects a popup menu on right click of text components.

When I am in doubt whether this application is swing or not, what I do is find any textfield and right click. if no popup appears then I conclude it as swing application.

How do I provide context menu for text components ?
Solution1: Create a subclass for each text component (JTextField, JPasswordField etc) and implement the logic inside these subclasses.
Solution2: Create a mouse listener which does the work of showing popup and add this to all text components of your applications.

Each of the above solutions have their own drawbacks:

• Changing the complete swing application to use our subclass is a tedious job
• If we use mouse listener, then it is also tedious job to ensure that this mouse listener is registered to all text components of you application
• There is no way to make this work for text components that are not created by the user code such as JTextField in JOptionPane.showInputDialog(...) or JFileChooser dialog.
• If the applications tries to show its own popup menu for a text component we will run into problems

I found a very clean solution for this problem: We install our implmentation of EventQueue.

// @author Santhosh Kumar T - santhosh@in.fiorano.com 
public class MyEventQueue extends EventQueue{ 
    protected void dispatchEvent(AWTEvent event){ 
        super.dispatchEvent(event); 
 
        // interested only in mouseevents 
        if(!(event instanceof MouseEvent)) 
            return; 
 
        MouseEvent me = (MouseEvent)event; 
 
        // interested only in popuptriggers 
        if(!me.isPopupTrigger()) 
            return; 
 
        // me.getComponent(...) retunrs the heavy weight component on which event occured 
        Component comp = SwingUtilities.getDeepestComponentAt(me.getComponent(), me.getX(), me.getY()); 
 
        // interested only in textcomponents 
        if(!(comp instanceof JTextComponent)) 
            return; 
 
        // no popup shown by user code 
        if(MenuSelectionManager.defaultManager().getSelectedPath().length>0) 
            return; 
 
        // create popup menu and show 
        JTextComponent tc = (JTextComponent)comp; 
        JPopupMenu menu = new JPopupMenu(); 
        menu.add(new CutAction(tc)); 
        menu.add(new CopyAction(tc)); 
        menu.add(new PasteAction(tc)); 
        menu.add(new DeleteAction(tc)); 
        menu.addSeparator(); 
        menu.add(new SelectAllAction(tc)); 
 
        Point pt = SwingUtilities.convertPoint(me.getComponent(), me.getPoint(), tc);
        menu.show(tc, pt.x, pt.y);
    } 
} 

The above class is self-explanatory with comments.

The implementation of actions is here:

// @author Santhosh Kumar T - santhosh@in.fiorano.com 
class CutAction extends AbstractAction{ 
    JTextComponent comp; 
 
    public CutAction(JTextComponent comp){ 
        super("Cut"); 
        this.comp = comp; 
    } 
 
    public void actionPerformed(ActionEvent e){ 
        comp.cut(); 
    } 
 
    public boolean isEnabled(){ 
        return comp.isEditable() 
                && comp.isEnabled() 
                && comp.getSelectedText()!=null; 
    } 
} 
 
// @author Santhosh Kumar T - santhosh@in.fiorano.com 
class PasteAction extends AbstractAction{ 
    JTextComponent comp; 
 
    public PasteAction(JTextComponent comp){ 
        super("Paste"); 
        this.comp = comp; 
    } 
 
    public void actionPerformed(ActionEvent e){ 
        comp.paste(); 
    } 
 
    public boolean isEnabled(){ 
        if (comp.isEditable() && comp.isEnabled()){ 
            Transferable contents = Toolkit.getDefaultToolkit().getSystemClipboard().getContents(this); 
            return contents.isDataFlavorSupported(DataFlavor.stringFlavor); 
        }else 
            return false; 
    } 
} 
 
// @author Santhosh Kumar T - santhosh@in.fiorano.com 
class DeleteAction extends AbstractAction{ 
    JTextComponent comp; 
 
    public DeleteAction(JTextComponent comp){ 
        super("Delete"); 
        this.comp = comp; 
    } 
 
    public void actionPerformed(ActionEvent e){ 
        comp.replaceSelection(null); 
    } 
 
    public boolean isEnabled(){ 
        return comp.isEditable() 
                && comp.isEnabled() 
                && comp.getSelectedText()!=null; 
    } 
} 
 
// @author Santhosh Kumar T - santhosh@in.fiorano.com 
class CopyAction extends AbstractAction{ 
    JTextComponent comp; 
 
    public CopyAction(JTextComponent comp){ 
        super("Copy"); 
        this.comp = comp; 
    } 
 
    public void actionPerformed(ActionEvent e){ 
        comp.copy(); 
    } 
 
    public boolean isEnabled(){ 
        return comp.isEnabled() 
                && comp.getSelectedText()!=null; 
    } 
} 
 
// @author Santhosh Kumar T - santhosh@in.fiorano.com 
class SelectAllAction extends AbstractAction{ 
    JTextComponent comp; 
 
    public SelectAllAction(JTextComponent comp){ 
        super("Select All"); 
        this.comp = comp; 
    } 
 
    public void actionPerformed(ActionEvent e){ 
        comp.selectAll(); 
    } 
 
    public boolean isEnabled(){ 
        return comp.isEnabled() 
                && comp.getText().length()>0; 
    } 
} 

How to use it:

    public static void main(String[] args){ 
        Toolkit.getDefaultToolkit().getSystemEventQueue().push(new MyEventQueue()); 
        
        .....
    } 

Just a single line in the beginning of your application's main method. So simple.

I created a webstart demo to show it in action:



There are two textfields in this demo. Second textfield shows a popupmenu in one of its mouse listener.



When click the button [JOptionPane], it shows a input message dialog which again contains a textfield, which is not created the demo.



Thus, this approach is very simple to use, and works perfectly, even if the application has its own popup menu on mouse click.



Your comments are appreciated.

Found a problem when using with JGoodies LNF. and the code now includes the fix;

if(Boolean.getBoolean("swing.text.contextmenu"))
  Toolkit.getDefaultToolkit().getSystemEventQueue().push(new MyEventQueue());

// no popup shown by user code 
if(MenuSelectionManager.defaultManager().getSelectedPath().length>0) 
            return; 

if(MenuSelectionManager.defaultManager().getSelectedPath().length>0) 

// installInFocusManager() {

KeyboardFocusManager focusManager = KeyboardFocusManager.getCurrentKeyboardFocusManager();

focusManager.addPropertyChangeListener("permanentFocusOwner", new ActionEnabler());

/* class ActionEnabler enables Cut/Copy/Paste plus 

 * (with a CaretListener) which is not listed here 

 * but also ensures the a mouse listener for popup menu

 */

class ActionEnabler implements PropertyChangeListener {

        public void propertyChange(PropertyChangeEvent evt) {

            if (evt.getNewValue() instanceof  TextComponent) {

                JTextComponent comp = (JTextComponent) evt.getNewValue();

                MouseListener[] ml = comp.getMouseListeners();

                boolean hasRightClickListener = false;

                for (int i = 0; i 
                    if (ml [ i ] == getMenuPopupListener()) {

                        hasRightClickListener = true;

                        break;

                    }

                }

                if (!hasRightClickListener) {

                    comp.addMouseListener(getMenuPopupListener());

                }

            }

        }

    }