A Java MouseEvent, MouseMotionListener example with mouseMoved and mouseDragged

The following source code comes from Sun Microsystems, and shows various things related to handling mouse events, including MouseEvent, MouseMotionListener, and the mouseDragged and mouseMoved methods that accept MouseEvent objects.

/**
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 * be used to endorse or promote products derived from this software without
 * specific prior written permission.
 *
 * This software is provided "AS IS," without a warranty of any kind. ALL
 * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING
 * ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE
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/**
 * SwingMouseMotionEventDemo.java is a 1.2/1.3/1.4 example that requires the
 * following file: BlankArea.java
 */

import java.awt.Color;
import java.awt.Dimension;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionListener;

import javax.swing.BorderFactory;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;

public class SwingMouseMotionEventDemo extends JPanel implements MouseMotionListener {
  BlankArea blankArea;

  JTextArea textArea;

  static final String newline = "\n";

  public SwingMouseMotionEventDemo() {
    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,
        JScrollPane.VERTICAL_SCROLLBAR_ALWAYS,
        JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED);
    scrollPane.setPreferredSize(new Dimension(200, 75));
    gridbag.setConstraints(scrollPane, c);
    add(scrollPane);

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

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

  public void mouseMoved(MouseEvent e) {
    saySomething("Mouse moved", e);
  }

  public void mouseDragged(MouseEvent e) {
    saySomething("Mouse dragged", e);
  }

  void saySomething(String eventDescription, MouseEvent e) {
    textArea.append(eventDescription + " (" + e.getX() + "," + e.getY()
        + ")" + " 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("SwingMouseMotionEventDemo");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    //Create and set up the content pane.
    JComponent newContentPane = new SwingMouseMotionEventDemo();
    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();
      }
    });
  }
}

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;
  }
}