Mouse Motion Problem

Question

I have a JFrame which I have added a MouseMotion Listener to it, it contains many JPanels with border layout manager. I want to detect a MouseMotion in the whole Frame. But I found that only the menu bar area could fire a MouseMotionEvent when the cursor moves there. There are no mouse motion event be fired when the mouse moves on other area on the Frame. What should I do to make it works? Or should I do anything to those insided JPanels ?

Answer 1

Add your MouseMotionListener to the frame's glass pane. Be sure to set the glass pane visible in order to retrieve the mouse moved events. See attached sample working code.
import java.awt.event.*;
import java.awt.*;
import javax.swing.*;
public class GlassMotion
  public static void main(String args[])
    new GlassMotionFrame();
class GlassMotionFrame extends JFrame implements ActionListener
  JMenuBar mb = new JMenuBar();
  JMenu file = new JMenu("File");
  JMenu edit = new JMenu("Edit");
  JMenu view = new JMenu("View");
  JMenu help = new JMenu("Help");
  JSeparator separator = new JSeparator();
  JMenuItem fileOpen = new JMenuItem("Open...");
  JMenuItem fileSaveAs = new JMenuItem("Save As...");
  JMenuItem editCut = new JMenuItem("Cut");
  JMenuItem editCopy = new JMenuItem("Copy");
  JMenuItem editPaste = new JMenuItem("Paste");
  JMenuItem helpAbout = new JMenuItem("About...");
  JPanel north = new JPanel();
  JPanel south = new JPanel();
  JPanel center = new JPanel();
  JTextField jtf = new JTextField(20);
  JTextArea jta = new JTextArea(20,30);
  JScrollPane jsp = new JScrollPane(jta);
  JButton ok = new JButton("OK");
  GlassMotionFrame()
    super();
    /* Components should be added to the container's content pane */
    Container cp = getContentPane();
    Component glassPane = getGlassPane();
    glassPane.addMouseMotionListener(new MouseMotionAdapter() {
      public void mouseMoved(MouseEvent evt) {
        System.out.println("Mouse motion event!");
    glassPane.setVisible(true);
    north.add(new JLabel("Last Name:"));
    north.add(jtf);
    center.add(jsp);
    south.add(ok);
    cp.add(BorderLayout.NORTH,north);
    cp.add(BorderLayout.CENTER,center);
    cp.add(BorderLayout.SOUTH,south);
    /* Add menu items to menus */
    file.add(fileOpen);
    file.add(separator);
    file.add(fileSaveAs);
    edit.add(editCut);
    edit.add(editCopy);
    edit.add(editPaste);
    help.add(helpAbout);
    /* Add menus to menubar */
    mb.add(file);
    mb.add(edit);
    mb.add(view);
    mb.add(help);
    /* Set menubar */
    setJMenuBar(mb);
    /* Add the action listeners */
    fileOpen.addActionListener(this);
    fileSaveAs.addActionListener(this);
    editCut.addActionListener(this);
    editCopy.addActionListener(this);
    editPaste.addActionListener(this);
    helpAbout.addActionListener(this);
    /* Add the window listener */
    addWindowListener(new WindowAdapter()
      public void windowClosing(WindowEvent evt)
        dispose();
        System.exit(0);
    /* Size the frame */
    pack();
    /* Center the frame */
    Dimension screenDim = Toolkit.getDefaultToolkit().getScreenSize();
    Rectangle frameDim = getBounds();
    setLocation((screenDim.width - frameDim.width) / 2,(screenDim.height - frameDim.height) / 2);
    /* Show the frame */
    setVisible(true);
  public void actionPerformed(ActionEvent evt)
    Object obj = evt.getSource();
    if (obj == fileOpen);
    else if (obj == fileSaveAs);
    else if (obj == editCut);
    else if (obj == editCopy);
    else if (obj == editPaste);
    else if (obj == helpAbout);
}