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I'm currently creating a right-click context menu by instantiating a new JMenu on right click and setting its location to that of the mouse's position... Is there a better way?

JavaA
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Wayne
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5 Answers5

145

You are probably manually calling setVisible(true) on the menu. That can cause some nasty buggy behavior in the menu.

The show(Component, int x, int x) method handles all of the things you need to happen, (Highlighting things on mouseover and closing the popup when necessary) where using setVisible(true) just shows the menu without adding any additional behavior.

To make a right click popup menu simply create a JPopupMenu.

class PopUpDemo extends JPopupMenu {
    JMenuItem anItem;
    public PopUpDemo() {
        anItem = new JMenuItem("Click Me!");
        add(anItem);
    }
}

Then, all you need to do is add a custom MouseListener to the components you would like the menu to popup for.

class PopClickListener extends MouseAdapter {
    public void mousePressed(MouseEvent e) {
        if (e.isPopupTrigger())
            doPop(e);
    }

    public void mouseReleased(MouseEvent e) {
        if (e.isPopupTrigger())
            doPop(e);
    }

    private void doPop(MouseEvent e) {
        PopUpDemo menu = new PopUpDemo();
        menu.show(e.getComponent(), e.getX(), e.getY());
    }
}

// Then on your component(s)
component.addMouseListener(new PopClickListener());

Of course, the tutorials have a slightly more in-depth explanation.

Note: If you notice that the popup menu is appearing way off from where the user clicked, try using the e.getXOnScreen() and e.getYOnScreen() methods for the x and y coordinates.

Ahmed Ashour
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jjnguy
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  • After using the above code, I get the error saying that "The method addMouseListener(MouseListener) in the type Figure is not applicable for the arguments (PopClickListener)" Regards, Vinay –  Nov 08 '11 at 15:31
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    @user1035905 Did you make sure that the `PopClickListener` extends `MouseAdapter`? – jjnguy Nov 08 '11 at 15:55
  • How do you get it to work with the context menu key on the keyboard? – Christoffer Hammarström Dec 23 '12 at 14:56
  • the only case in which this solution is better than kleopatra's is when you need some custom logic to happen (e.g. different popup menus under different conditions); still, you have to add keyboard listener to work with context menu key –  Apr 22 '13 at 22:16
  • @PavelRyzhov not on the JPopupMenu class. http://docs.oracle.com/javase/7/docs/api/javax/swing/JPopupMenu.html#show(java.awt.Component, int, int) – jjnguy Jun 17 '13 at 21:50
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    what does `component` stand for? – Loint May 30 '16 at 03:39
124

This question is a bit old - as are the answers (and the tutorial as well)

The current api for setting a popupMenu in Swing is

myComponent.setComponentPopupMenu(myPopupMenu);

This way it will be shown automagically, both for mouse and keyboard triggers (the latter depends on LAF). Plus, it supports re-using the same popup across a container's children. To enable that feature:

myChild.setInheritsPopupMenu(true);
kleopatra
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    @user681159 don't know any - and it's not needed, IMO, simply read the api doc :-) – kleopatra Jan 22 '12 at 15:34
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    How would you use this with a `JTable` so it pops on the selected row or on the row where you right click? Or in this scenario the old method is the one to be chosen? – Alex Burdusel Dec 28 '13 at 20:08
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    @Burfee either that or enhance JTable via subclassing: override getPopupLocation(..) and store the location for later usage, [see a recent QA](http://stackoverflow.com/a/17316876/203657) which is implemented in all SwingX collection components – kleopatra Jan 08 '14 at 16:41
  • @RanjitVamadevan where do you see a need for formatting? – kleopatra Nov 23 '20 at 11:16
18

There's a section on Bringing Up a Popup Menu in the How to Use Menus article of The Java Tutorials which explains how to use the JPopupMenu class.

The example code in the tutorial shows how to add MouseListeners to the components which should display a pop-up menu, and displays the menu accordingly.

(The method you describe is fairly similar to the way the tutorial presents the way to show a pop-up menu on a component.)

coobird
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11

The following code implements a default context menu known from Windows with copy, cut, paste, select all, undo and redo functions. It also works on Linux and Mac OS X:

import javax.swing.*;
import javax.swing.text.JTextComponent;
import javax.swing.undo.UndoManager;
import java.awt.*;
import java.awt.datatransfer.Clipboard;
import java.awt.datatransfer.DataFlavor;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;

public class DefaultContextMenu extends JPopupMenu
{
    private Clipboard clipboard;

    private UndoManager undoManager;

    private JMenuItem undo;
    private JMenuItem redo;
    private JMenuItem cut;
    private JMenuItem copy;
    private JMenuItem paste;
    private JMenuItem delete;
    private JMenuItem selectAll;

    private JTextComponent textComponent;

    public DefaultContextMenu()
    {
        undoManager = new UndoManager();
        clipboard = Toolkit.getDefaultToolkit().getSystemClipboard();

        addPopupMenuItems();
    }

    private void addPopupMenuItems()
    {
        undo = new JMenuItem("Undo");
        undo.setEnabled(false);
        undo.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_Z, Toolkit.getDefaultToolkit().getMenuShortcutKeyMask()));
        undo.addActionListener(event -> undoManager.undo());
        add(undo);

        redo = new JMenuItem("Redo");
        redo.setEnabled(false);
        redo.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_Y, Toolkit.getDefaultToolkit().getMenuShortcutKeyMask()));
        redo.addActionListener(event -> undoManager.redo());
        add(redo);

        add(new JSeparator());

        cut = new JMenuItem("Cut");
        cut.setEnabled(false);
        cut.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_X, Toolkit.getDefaultToolkit().getMenuShortcutKeyMask()));
        cut.addActionListener(event -> textComponent.cut());
        add(cut);

        copy = new JMenuItem("Copy");
        copy.setEnabled(false);
        copy.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_C, Toolkit.getDefaultToolkit().getMenuShortcutKeyMask()));
        copy.addActionListener(event -> textComponent.copy());
        add(copy);

        paste = new JMenuItem("Paste");
        paste.setEnabled(false);
        paste.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_V, Toolkit.getDefaultToolkit().getMenuShortcutKeyMask()));
        paste.addActionListener(event -> textComponent.paste());
        add(paste);

        delete = new JMenuItem("Delete");
        delete.setEnabled(false);
        delete.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_DELETE, Toolkit.getDefaultToolkit().getMenuShortcutKeyMask()));
        delete.addActionListener(event -> textComponent.replaceSelection(""));
        add(delete);

        add(new JSeparator());

        selectAll = new JMenuItem("Select All");
        selectAll.setEnabled(false);
        selectAll.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_A, Toolkit.getDefaultToolkit().getMenuShortcutKeyMask()));
        selectAll.addActionListener(event -> textComponent.selectAll());
        add(selectAll);
    }

    private void addTo(JTextComponent textComponent)
    {
        textComponent.addKeyListener(new KeyAdapter()
        {
            @Override
            public void keyPressed(KeyEvent pressedEvent)
            {
                if ((pressedEvent.getKeyCode() == KeyEvent.VK_Z)
                        && ((pressedEvent.getModifiersEx() & Toolkit.getDefaultToolkit().getMenuShortcutKeyMask()) != 0))
                {
                    if (undoManager.canUndo())
                    {
                        undoManager.undo();
                    }
                }

                if ((pressedEvent.getKeyCode() == KeyEvent.VK_Y)
                        && ((pressedEvent.getModifiersEx() & Toolkit.getDefaultToolkit().getMenuShortcutKeyMask()) != 0))
                {
                    if (undoManager.canRedo())
                    {
                        undoManager.redo();
                    }
                }
            }
        });

        textComponent.addMouseListener(new MouseAdapter()
        {
            @Override
            public void mousePressed(MouseEvent releasedEvent)
            {
                handleContextMenu(releasedEvent);
            }

            @Override
            public void mouseReleased(MouseEvent releasedEvent)
            {
                handleContextMenu(releasedEvent);
            }
        });

        textComponent.getDocument().addUndoableEditListener(event -> undoManager.addEdit(event.getEdit()));
    }

    private void handleContextMenu(MouseEvent releasedEvent)
    {
        if (releasedEvent.getButton() == MouseEvent.BUTTON3)
        {
            processClick(releasedEvent);
        }
    }

    private void processClick(MouseEvent event)
    {
        textComponent = (JTextComponent) event.getSource();
        textComponent.requestFocus();

        boolean enableUndo = undoManager.canUndo();
        boolean enableRedo = undoManager.canRedo();
        boolean enableCut = false;
        boolean enableCopy = false;
        boolean enablePaste = false;
        boolean enableDelete = false;
        boolean enableSelectAll = false;

        String selectedText = textComponent.getSelectedText();
        String text = textComponent.getText();

        if (text != null)
        {
            if (text.length() > 0)
            {
                enableSelectAll = true;
            }
        }

        if (selectedText != null)
        {
            if (selectedText.length() > 0)
            {
                enableCut = true;
                enableCopy = true;
                enableDelete = true;
            }
        }

        if (clipboard.isDataFlavorAvailable(DataFlavor.stringFlavor) && textComponent.isEnabled())
        {
            enablePaste = true;
        }

        undo.setEnabled(enableUndo);
        redo.setEnabled(enableRedo);
        cut.setEnabled(enableCut);
        copy.setEnabled(enableCopy);
        paste.setEnabled(enablePaste);
        delete.setEnabled(enableDelete);
        selectAll.setEnabled(enableSelectAll);

        // Shows the popup menu
        show(textComponent, event.getX(), event.getY());
    }

    public static void addDefaultContextMenu(JTextComponent component)
    {
        DefaultContextMenu defaultContextMenu = new DefaultContextMenu();
        defaultContextMenu.addTo(component);
    }
}

Usage:

JTextArea textArea = new JTextArea();
DefaultContextMenu.addDefaultContextMenu(textArea);

Now the textArea will have a context menu when it is right-clicked on.

BullyWiiPlaza
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    Great solution. One thing: you could/should use `releasedEvent.isPopupTrigger()` instead of `releasedEvent.getButton() == MouseEvent.BUTTON3` to work properly on all platforms. – Frederic Leitenberger Jul 22 '20 at 06:23
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    One more bug in the key-listener: `pressedEvent.getModifiersEx() & Toolkit.getDefaultToolkit().getMenuShortcutKeyMask()` these must be both either `Ex` or not `Ex`. The `Ex` version of `getMenuShortcutKeyMask()` is only available since java 10+. – Frederic Leitenberger Jul 22 '20 at 06:30
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I will correct usage for that method that @BullyWillPlaza suggested. Reason is that when I try to add add textArea to only contextMenu it's not visible, and if i add it to both to contextMenu and some panel it ecounters: Different parent double association if i try to switch to Design editor.

TexetObjcet.addMouseListener(new MouseAdapter() {
        @Override
        public void mouseClicked(MouseEvent e) {
            if (SwingUtilities.isRightMouseButton(e)){
                contextmenu.add(TexetObjcet);
                contextmenu.show(TexetObjcet, 0, 0);
            }
        }
    }); 

Make mouse listener like this for text object you need to have popup on. What this will do is when you right click on your text object it will then add that popup and display it. This way you don't encounter that error. Solution that @BullyWillPlaza made is very good, rich and fast to implement in your program so you should try it our see how you like it.

  • Also don't forget you still need to import that contextMenu and create new instance. – Đumić Branislav Jul 25 '17 at 07:23
  • You might prefer `e.isPopupTrigger()` over `isRightMouseButton` call. On some platforms is it on right mouse click, on some right mouse release. See https://stackoverflow.com/questions/59815792/what-is-the-correct-handling-of-ispopuptrigger-in-mouseadapter – Suma Jan 05 '23 at 16:29