Mouse events are generated by the following types of user interaction:

  • A mouse click
  • A mouse entering a component's area
  • A mouse leaving a component's area

Any component can generate these events, and a class must implement MouseListener interface to support them.

The following example shows how to use mouse events in Swing:

 import javax.swing.*;

import java.awt.GridBagLayout;
import java.awt.GridBagConstraints;
import java.awt.Insets;
import java.awt.Color;
import java.awt.Dimension;

import java.awt.event.MouseListener;
import java.awt.event.MouseEvent;

public class MouseEventDemo extends JPanel 
                            implements MouseListener {
    BlankArea blankArea;
    JTextArea textArea;
    final static String newline = "\n";

    public MouseEventDemo() {
        super(new GridBagLayout());
        GridBagLayout gridbag = (GridBagLayout)getLayout();
        GridBagConstraints c = new GridBagConstraints();

        c.fill = GridBagConstraints.BOTH;
        c.gridwidth = GridBagConstraints.REMAINDER;
        c.weightx = 1.0;
        c.weighty = 1.0;

        c.insets = new Insets(1, 1, 1, 1);
        blankArea = new BlankArea(new Color(0.98f, 0.97f, 0.85f));
        gridbag.setConstraints(blankArea, c);
        add(blankArea);

        c.insets = new Insets(0, 0, 0, 0);
        textArea = new JTextArea();
        textArea.setEditable(false);
        JScrollPane scrollPane = new JScrollPane(textArea);
        scrollPane.setVerticalScrollBarPolicy(
                JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
        scrollPane.setPreferredSize(new Dimension(200, 75));
        gridbag.setConstraints(scrollPane, c);
        add(scrollPane);

        //Register for mouse events on blankArea and the panel.
        blankArea.addMouseListener(this);
        addMouseListener(this);

        setPreferredSize(new Dimension(450, 450));
        setBorder(BorderFactory.createEmptyBorder(20,20,20,20));
    }

    public void mousePressed(MouseEvent e) {
       saySomething("Mouse pressed (# of clicks: "
                    + e.getClickCount() + ")", e);
    }

    public void mouseReleased(MouseEvent e) {
       saySomething("Mouse released (# of clicks: "
                    + e.getClickCount() + ")", e);
    }

    public void mouseEntered(MouseEvent e) {
       saySomething("Mouse entered", e);
    }

    public void mouseExited(MouseEvent e) {
       saySomething("Mouse exited", e);
    }

    public void mouseClicked(MouseEvent e) {
       saySomething("Mouse clicked (# of clicks: "
                    + e.getClickCount() + ")", e);
    }

    void saySomething(String eventDescription, MouseEvent e) {
        textArea.append(eventDescription + " detected on "
                        + e.getComponent().getClass().getName()
                        + "." + newline);
        textArea.setCaretPosition(textArea.getDocument().getLength());
    }

    /**
     * Create the GUI and show it.  For thread safety,
     * this method should be invoked from the
     * event-dispatching thread.
     */
    private static void createAndShowGUI() {
        //Make sure we have nice window decorations.
        JFrame.setDefaultLookAndFeelDecorated(true);

        //Create and set up the window.
        JFrame frame = new JFrame("MouseEventDemo");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        //Create and set up the content pane.
        JComponent newContentPane = new MouseEventDemo();
        newContentPane.setOpaque(true); //content panes must be opaque
        frame.setContentPane(newContentPane);

        //Display the window.
        frame.pack();
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        //Schedule a job for the event-dispatching thread:
        //creating and showing this application's GUI.
        javax.swing.SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                createAndShowGUI();
            }
        });
    }
}


import javax.swing.*;
import java.awt.Dimension;
import java.awt.Color;
import java.awt.Graphics;

public class BlankArea extends JLabel {
    Dimension minSize = new Dimension(100, 100);

    public BlankArea(Color color) {
        setBackground(color);
        setOpaque(true);
        setBorder(BorderFactory.createLineBorder(Color.black));
    }

    public Dimension getMinimumSize() {
        return minSize;
    }

    public Dimension getPreferredSize() {
        return minSize;
    }
}