Java/Event/Mouse

Detecting Double and Triple Clicks

   <source lang="java">
 

import java.awt.event.MouseAdapter; import java.awt.event.MouseEvent; import javax.swing.JFrame; import javax.swing.JTextField; public class Main {

 public static void main(String[] argv) throws Exception {
   JTextField component = new JTextField();
   component.addMouseListener(new MyMouseListener());
   JFrame f = new JFrame();
   f.add(component);
   f.setSize(300, 300);
   f.setVisible(true);
   component.addMouseListener(new MyMouseListener());
 }

} class MyMouseListener extends MouseAdapter {

 public void mouseClicked(MouseEvent evt) {
   if (evt.getClickCount() == 3) {
     System.out.println("triple-click");
   } else if (evt.getClickCount() == 2) {
     System.out.println("double-click");
   }
 }

}

 </source>
   
  
 
  

Drags within the image

   <source lang="java">
 

/* From http://java.sun.ru/docs/books/tutorial/index.html */ /*

* Copyright (c) 2006 Sun Microsystems, Inc. All Rights Reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* -Redistribution of source code must retain the above copyright notice, this
*  list of conditions and the following disclaimer.
*
* -Redistribution in binary form must reproduce the above copyright notice,
*  this list of conditions and the following disclaimer in the documentation
*  and/or other materials provided with the distribution.
*
* Neither the name of Sun Microsystems, Inc. or the names of contributors may
* 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
* OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN MIDROSYSTEMS, INC. ("SUN")
* AND ITS LICENSORS SHALL NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE
* AS A RESULT OF USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS
* DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS BE LIABLE FOR ANY LOST
* REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT, SPECIAL, CONSEQUENTIAL,
* INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER CAUSED AND REGARDLESS OF THE THEORY
* OF LIABILITY, ARISING OUT OF THE USE OF OR INABILITY TO USE THIS SOFTWARE,
* EVEN IF SUN HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
*
* You acknowledge that this software is not designed, licensed or intended
* for use in the design, construction, operation or maintenance of any
* nuclear facility.
*/

/*

* SelectionDemo.java is a 1.4 application that requires one other file:
* images/starfield.gif
*/

import javax.swing.BoxLayout; import javax.swing.ImageIcon; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.event.MouseInputAdapter; import java.awt.*; import java.awt.event.MouseEvent; /*

* This displays an image. When the user drags within the image, this program
* displays a rectangle and a string indicating the bounds of the rectangle.
*/

public class SelectionDemo {

 JLabel label;
 static String starFile = "starfield.gif";
 private void buildUI(Container container, ImageIcon image) {
   container.setLayout(new BoxLayout(container, BoxLayout.PAGE_AXIS));
   SelectionArea area = new SelectionArea(image, this);
   container.add(area);
   label = new JLabel("Drag within the image.");
   label.setLabelFor(area);
   container.add(label);
   //Align the left edges of the components.
   area.setAlignmentX(Component.LEFT_ALIGNMENT);
   label.setAlignmentX(Component.LEFT_ALIGNMENT); //redundant
 }
 public void updateLabel(Rectangle rect) {
   int width = rect.width;
   int height = rect.height;
   //Make the coordinates look OK if a dimension is 0.
   if (width == 0) {
     width = 1;
   }
   if (height == 0) {
     height = 1;
   }
   label.setText("Rectangle goes from (" + rect.x + ", " + rect.y
       + ") to (" + (rect.x + width - 1) + ", "
       + (rect.y + height - 1) + ").");
 }
 /** Returns an ImageIcon, or null if the path was invalid. */
 protected static ImageIcon createImageIcon(String path) {
   java.net.URL imgURL = SelectionDemo.class.getResource(path);
   if (imgURL != null) {
     return new ImageIcon(imgURL);
   } else {
     System.err.println("Couldn"t find file: " + path);
     return null;
   }
 }
 /**
  * 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("SelectionDemo");
   frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
   //Set up the content pane.
   SelectionDemo controller = new SelectionDemo();
   controller.buildUI(frame.getContentPane(), createImageIcon(starFile));
   //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();
     }
   });
 }
 private class SelectionArea extends JLabel {
   Rectangle currentRect = null;
   Rectangle rectToDraw = null;
   Rectangle previousRectDrawn = new Rectangle();
   SelectionDemo controller;
   public SelectionArea(ImageIcon image, SelectionDemo controller) {
     super(image); //This component displays an image.
     this.controller = controller;
     setOpaque(true);
     setMinimumSize(new Dimension(10, 10)); //don"t hog space
     MyListener myListener = new MyListener();
     addMouseListener(myListener);
     addMouseMotionListener(myListener);
   }
   private class MyListener extends MouseInputAdapter {
     public void mousePressed(MouseEvent e) {
       int x = e.getX();
       int y = e.getY();
       currentRect = new Rectangle(x, y, 0, 0);
       updateDrawableRect(getWidth(), getHeight());
       repaint();
     }
     public void mouseDragged(MouseEvent e) {
       updateSize(e);
     }
     public void mouseReleased(MouseEvent e) {
       updateSize(e);
     }
     /*
      * Update the size of the current rectangle and call repaint.
      * Because currentRect always has the same origin, translate it if
      * the width or height is negative.
      * 
      * For efficiency (though that isn"t an issue for this program),
      * specify the painting region using arguments to the repaint()
      * call.
      *  
      */
     void updateSize(MouseEvent e) {
       int x = e.getX();
       int y = e.getY();
       currentRect.setSize(x - currentRect.x, y - currentRect.y);
       updateDrawableRect(getWidth(), getHeight());
       Rectangle totalRepaint = rectToDraw.union(previousRectDrawn);
       repaint(totalRepaint.x, totalRepaint.y, totalRepaint.width,
           totalRepaint.height);
     }
   }
   protected void paintComponent(Graphics g) {
     super.paintComponent(g); //paints the background and image
     //If currentRect exists, paint a box on top.
     if (currentRect != null) {
       //Draw a rectangle on top of the image.
       g.setXORMode(Color.white); //Color of line varies
       //depending on image colors
       g.drawRect(rectToDraw.x, rectToDraw.y, rectToDraw.width - 1,
           rectToDraw.height - 1);
       controller.updateLabel(rectToDraw);
     }
   }
   private void updateDrawableRect(int compWidth, int compHeight) {
     int x = currentRect.x;
     int y = currentRect.y;
     int width = currentRect.width;
     int height = currentRect.height;
     //Make the width and height positive, if necessary.
     if (width < 0) {
       width = 0 - width;
       x = x - width + 1;
       if (x < 0) {
         width += x;
         x = 0;
       }
     }
     if (height < 0) {
       height = 0 - height;
       y = y - height + 1;
       if (y < 0) {
         height += y;
         y = 0;
       }
     }
     //The rectangle shouldn"t extend past the drawing area.
     if ((x + width) > compWidth) {
       width = compWidth - x;
     }
     if ((y + height) > compHeight) {
       height = compHeight - y;
     }
     //Update rectToDraw after saving old value.
     if (rectToDraw != null) {
       previousRectDrawn.setBounds(rectToDraw.x, rectToDraw.y,
           rectToDraw.width, rectToDraw.height);
       rectToDraw.setBounds(x, y, width, height);
     } else {
       rectToDraw = new Rectangle(x, y, width, height);
     }
   }
 }

}

 </source>
   
  
 
  

Handle mouse button click event?

   <source lang="java">
 

import java.awt.event.MouseAdapter; import java.awt.event.MouseEvent; import javax.swing.JFrame; import javax.swing.JTextArea; public class Main extends JFrame {

 public Main() {
   setSize(300, 300);
   setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
   final JTextArea textArea = new JTextArea();
   textArea.setText("Click Me!");
   textArea.addMouseListener(new MouseAdapter() {
     public void mouseClicked(MouseEvent e) {
       if (e.getButton() == MouseEvent.NOBUTTON) {
         textArea.setText("No button clicked...");
       } else if (e.getButton() == MouseEvent.BUTTON1) {
         textArea.setText("Button 1 clicked...");
       } else if (e.getButton() == MouseEvent.BUTTON2) {
         textArea.setText("Button 2 clicked...");
       } else if (e.getButton() == MouseEvent.BUTTON3) {
         textArea.setText("Button 3 clicked...");
       }
       System.out.println("Number of click: " + e.getClickCount());
       System.out.println("Click position (X, Y):  " + e.getX() + ", " + e.getY());
     }
   });
   getContentPane().add(textArea);
 }
 public static void main(String[] args) {
   new Main().setVisible(true);
 }

}

 </source>
   
  
 
  

Handle mouse motion event

   <source lang="java">
 

import java.awt.event.MouseEvent; import java.awt.event.MouseMotionAdapter; import javax.swing.JFrame; import javax.swing.JTextArea; public class Main extends JFrame {

 public Main() {
   setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
   setSize(400, 400);
   JTextArea textArea = new JTextArea("drag it...");
   textArea.addMouseMotionListener(new MouseMotionAdapter() {
     public void mouseDragged(MouseEvent e) {
       System.out.println("Mouse Dragged...");
     }
     public void mouseMoved(MouseEvent e) {
       System.out.println("Mouse Moved...");
     }
   });
   getContentPane().add(textArea);
 }
 public static void main(String[] args) {
   new Main().setVisible(true);
 }

}

 </source>
   
  
 
  

Handling Mouse Clicks

   <source lang="java">
 

import java.awt.event.InputEvent; import java.awt.event.MouseAdapter; import java.awt.event.MouseEvent; import javax.swing.JFrame; import javax.swing.JTextField; public class Main {

 public static void main(String[] argv) throws Exception {
   JTextField component = new JTextField();
   component.addMouseListener(new MyMouseListener());
   JFrame f = new JFrame();
   f.add(component);
   f.setSize(300, 300);
   f.setVisible(true);
 }

} class MyMouseListener extends MouseAdapter {

 public void mouseClicked(MouseEvent evt) {
   if ((evt.getModifiers() & InputEvent.BUTTON1_MASK) != 0) {
     System.out.println("left" + (evt.getPoint()));
   }
   if ((evt.getModifiers() & InputEvent.BUTTON2_MASK) != 0) {
     System.out.println("middle" + (evt.getPoint()));
   }
   if ((evt.getModifiers() & InputEvent.BUTTON3_MASK) != 0) {
     System.out.println("right" + (evt.getPoint()));
   }
 }

}

 </source>
   
  
 
  

Handling Mouse Motion

   <source lang="java">
 

import java.awt.event.MouseEvent; import java.awt.event.MouseMotionAdapter; import javax.swing.JFrame; import javax.swing.JTextField; public class Main {

 public static void main(String[] argv) throws Exception {
   JTextField component = new JTextField();
   component.addMouseMotionListener(new MyMouseMotionListener());
   JFrame f = new JFrame();
   f.add(component);
   f.setSize(300, 300);
   f.setVisible(true);
 }

} class MyMouseMotionListener extends MouseMotionAdapter {

 public void mouseMoved(MouseEvent evt) {
   System.out.println("moved:" + evt.getPoint());
 }
 public void mouseDragged(MouseEvent evt) {
   System.out.println("dragged:" + evt.getPoint());
 }

}

 </source>
   
  
 
  

InputEvent.BUTTON1_MASK (for left mouse button)

   <source lang="java">
 

import java.awt.event.InputEvent; import java.awt.event.MouseAdapter; import java.awt.event.MouseEvent; import javax.swing.JFrame; import javax.swing.JTextField; public class Main {

 public static void main(String[] argv) throws Exception {
   JTextField component = new JTextField();
   component.addMouseListener(new MyMouseListener());
   JFrame f = new JFrame();
   f.add(component);
   f.setSize(300, 300);
   f.setVisible(true);
 }

} class MyMouseListener extends MouseAdapter {

 public void mouseClicked(MouseEvent evt) {
   if ((evt.getModifiers() & InputEvent.BUTTON1_MASK) != 0) {
     System.out.println("left" + (evt.getPoint()));
   }
   if ((evt.getModifiers() & InputEvent.BUTTON2_MASK) != 0) {
     System.out.println("middle" + (evt.getPoint()));
   }
   if ((evt.getModifiers() & InputEvent.BUTTON3_MASK) != 0) {
     System.out.println("right" + (evt.getPoint()));
   }
 }

}

 </source>
   
  
 
  

InputEvent.BUTTON2_MASK (for middle mouse button)

   <source lang="java">
 

import java.awt.event.InputEvent; import java.awt.event.MouseAdapter; import java.awt.event.MouseEvent; import javax.swing.JFrame; import javax.swing.JTextField; public class Main {

 public static void main(String[] argv) throws Exception {
   JTextField component = new JTextField();
   component.addMouseListener(new MyMouseListener());
   JFrame f = new JFrame();
   f.add(component);
   f.setSize(300, 300);
   f.setVisible(true);
 }

} class MyMouseListener extends MouseAdapter {

 public void mouseClicked(MouseEvent evt) {
   if ((evt.getModifiers() & InputEvent.BUTTON1_MASK) != 0) {
     System.out.println("left" + (evt.getPoint()));
   }
   if ((evt.getModifiers() & InputEvent.BUTTON2_MASK) != 0) {
     System.out.println("middle" + (evt.getPoint()));
   }
   if ((evt.getModifiers() & InputEvent.BUTTON3_MASK) != 0) {
     System.out.println("right" + (evt.getPoint()));
   }
 }

}

 </source>
   
  
 
  

InputEvent.BUTTON3_MASK (for right mouse button)

   <source lang="java">
 

import java.awt.event.InputEvent; import java.awt.event.MouseAdapter; import java.awt.event.MouseEvent; import javax.swing.JFrame; import javax.swing.JTextField; public class Main {

 public static void main(String[] argv) throws Exception {
   JTextField component = new JTextField();
   component.addMouseListener(new MyMouseListener());
   JFrame f = new JFrame();
   f.add(component);
   f.setSize(300, 300);
   f.setVisible(true);
 }

} class MyMouseListener extends MouseAdapter {

 public void mouseClicked(MouseEvent evt) {
   if ((evt.getModifiers() & InputEvent.BUTTON1_MASK) != 0) {
     System.out.println("left" + (evt.getPoint()));
   }
   if ((evt.getModifiers() & InputEvent.BUTTON2_MASK) != 0) {
     System.out.println("middle" + (evt.getPoint()));
   }
   if ((evt.getModifiers() & InputEvent.BUTTON3_MASK) != 0) {
     System.out.println("right" + (evt.getPoint()));
   }
 }

}

 </source>
   
  
 
  

Mouse drag and draw

   <source lang="java">
 

import java.awt.Container; import java.awt.Cursor; import java.awt.Graphics; import java.awt.Graphics2D; import java.awt.Point; import java.awt.Rectangle; import java.awt.event.MouseAdapter; import java.awt.event.MouseEvent; import java.awt.event.MouseMotionListener; import java.awt.event.WindowAdapter; import java.awt.event.WindowEvent; import javax.swing.JFrame; import javax.swing.JPanel; public class MouseDragActionPanel extends JPanel implements MouseMotionListener {

 private static final int SquareWidth = 10;
 private static final int Max = 100;
 private Rectangle[] squares = new Rectangle[Max];
 private int squareCount = 0;
 private int currentSquareIndex = -1;
 public MouseDragActionPanel() {
   addMouseListener(new MouseAdapter() {
     public void mousePressed(MouseEvent evt) {
       int x = evt.getX();
       int y = evt.getY();
       currentSquareIndex = getSquare(x, y);
       if (currentSquareIndex < 0) // not inside a square
         add(x, y);
     }
     public void mouseClicked(MouseEvent evt) {
       int x = evt.getX();
       int y = evt.getY();
       if (evt.getClickCount() >= 2) {
         remove(currentSquareIndex);
       }
     }
   });
   addMouseMotionListener(this);
 }
 public void paintComponent(Graphics g) {
   super.paintComponent(g);
   for (int i = 0; i < squareCount; i++)
     ((Graphics2D)g).draw(squares[i]);
 }
 public int getSquare(int x, int y) {
   for (int i = 0; i < squareCount; i++)
     if(squares[i].contains(x,y))
       return i;
   return -1;
 }
 public void add(int x, int y) {
   if (squareCount < Max) {
     squares[squareCount] = new Rectangle(x, y,SquareWidth,SquareWidth);
     currentSquareIndex = squareCount;
     squareCount++;
     repaint();
   }
 }
 public void remove(int n) {
   if (n < 0 || n >= squareCount)
     return;
   squareCount--;
   squares[n] = squares[squareCount];
   if (currentSquareIndex == n)
     currentSquareIndex = -1;
   repaint();
 }
 public void mouseMoved(MouseEvent evt) {
   int x = evt.getX();
   int y = evt.getY();
   if (getSquare(x, y) >= 0)
     setCursor(Cursor.getPredefinedCursor(Cursor.CROSSHAIR_CURSOR));
   else
     setCursor(Cursor.getDefaultCursor());
 }
 public void mouseDragged(MouseEvent evt) {
   int x = evt.getX();
   int y = evt.getY();
   if (currentSquareIndex >= 0) {
     Graphics g = getGraphics();
     g.setXORMode(getBackground());
     ((Graphics2D)g).draw(squares[currentSquareIndex]);
     squares[currentSquareIndex].x = x;
     squares[currentSquareIndex].y = y;
     ((Graphics2D)g).draw(squares[currentSquareIndex]);
     g.dispose();
   }
 }
 public static void main(String[] args) {
   JFrame frame = new JFrame();
   frame.setTitle("MouseTest");
   frame.setSize(300, 200);
   frame.addWindowListener(new WindowAdapter() {
     public void windowClosing(WindowEvent e) {
       System.exit(0);
     }
   });
   Container contentPane = frame.getContentPane();
   contentPane.add(new MouseDragActionPanel());
   frame.show();
 }

}

 </source>
   
  
 
  

MouseDragClip -- implement simple mouse drag in a window. Speed up by using clipping regions

   <source lang="java">
 

/*

* Copyright (c) Ian F. Darwin, http://www.darwinsys.ru/, 1996-2002.
* All rights reserved. Software written by Ian F. Darwin and others.
* $Id: LICENSE,v 1.8 2004/02/09 03:33:38 ian Exp $
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
*    notice, this list of conditions and the following disclaimer in the
*    documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS""
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
* 
* Java, the Duke mascot, and all variants of Sun"s Java "steaming coffee
* cup" logo are trademarks of Sun Microsystems. Sun"s, and James Gosling"s,
* pioneering role in inventing and promulgating (and standardizing) the Java 
* language and environment is gratefully acknowledged.
* 
* The pioneering role of Dennis Ritchie and Bjarne Stroustrup, of AT&T, for
* inventing predecessor languages C and C++ is also gratefully acknowledged.
*/

//// import java.awt.BorderLayout; import java.awt.Canvas; import java.awt.Color; import java.awt.Container; import java.awt.Dimension; import java.awt.Graphics; import java.awt.Image; import java.awt.Label; import java.awt.Point; import java.awt.Toolkit; import java.awt.event.MouseEvent; import java.awt.event.MouseListener; import java.awt.event.MouseMotionListener; import javax.swing.JFrame; /**

* MouseDragClip -- implement simple mouse drag in a window. Speed up by using
* clipping regions.

*

* This version "works" for very simple cases (only drag down and to the right, * never move up or back :-) ). * * @author Ian Darwin, http://www.darwinsys.ru/ */ public class MouseDragClip extends Canvas implements MouseListener, MouseMotionListener { /** The Image we are to paint */ Image curImage; /** Kludge for showStatus */ static Label status; /** true if we are in drag */ boolean inDrag = false; /** starting location of a drag */ int startX = -1, startY = -1; /** current location of a drag */ int curX = -1, curY = -1; /** Previous ending of current drag */ int oldX, oldY; /** Start of previous selection, if completed, else -1 */ int oldStartX = -1, oldStartY = -1; /** Size of previous selection, if completed, else -1 */ int oldWidth = -1, oldHeight = -1; // "main" method public static void main(String[] av) { JFrame f = new JFrame("Mouse Dragger"); Container cp = f.getContentPane(); if (av.length < 1) { System.err.println("Usage: MouseDragClip imagefile"); System.exit(1); } Image im = Toolkit.getDefaultToolkit().getImage(av[0]); // create a MouseDragClip object MouseDragClip j = new MouseDragClip(im); cp.setLayout(new BorderLayout()); cp.add(BorderLayout.NORTH, new Label( "Hello, and welcome to the world of Java")); cp.add(BorderLayout.CENTER, j); cp.add(BorderLayout.SOUTH, status = new Label()); status.setSize(f.getSize().width, status.getSize().height); f.pack(); f.setVisible(true); f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); } /** Construct the MouseDragClip object, given an Image */ public MouseDragClip(Image i) { super(); curImage = i; setSize(300, 200); addMouseListener(this); addMouseMotionListener(this); } public void showStatus(String s) { status.setText(s); } // Five methods from MouseListener: /** Called when the mouse has been clicked on a component. */ public void mouseClicked(MouseEvent e) { } /** Called when the mouse enters a component. */ public void mouseEntered(MouseEvent e) { } /** Called when the mouse exits a component. */ public void mouseExited(MouseEvent e) { } /** Called when the mouse has been pressed. */ public void mousePressed(MouseEvent e) { Point p = e.getPoint(); System.err.println("mousePressed at " + p); startX = p.x; startY = p.y; inDrag = true; } /** Called when the mouse has been released. */ public void mouseReleased(MouseEvent e) { inDrag = false; System.err.println("SELECTION IS " + startX + "," + startY + " to " + curX + "," + curY); oldX = -1; oldStartX = startX; oldStartY = startY; oldWidth = curX - startX; oldHeight = curY - startY; } // And two methods from MouseMotionListener: public void mouseDragged(MouseEvent e) { Point p = e.getPoint(); // showStatus("mouse dragged to " + p); curX = p.x; curY = p.y; if (inDrag) { repaint(); } } /** * This update() overrides Component"s, to call paint() without * clearing the screen (which has our main image on it, after all! */ public void update(Graphics g) { paint(g); } public void paint(Graphics g) { int w = curX - startX, h = curY - startY; Dimension d = getSize(); if (!inDrag) { // probably first time through(?) g.drawImage(curImage, 0, 0, d.width, d.height, this); return; } System.err.println("paint:drawRect @[" + startX + "," + startY + "] size " + w + "x" + h); // Restore the old background, if previous selection if (oldStartX != -1) { g.setClip(oldStartX, oldStartY, oldWidth + 1, oldHeight + 1); g.drawImage(curImage, 0, 0, d.width, d.height, this); oldStartX = -1; } // Restore the background from previous motions of current drag if (oldX != -1) { g.setClip(startX, startY, w, h); g.drawImage(curImage, 0, 0, d.width + 1, d.height + 1, this); } // Draw the new rectangle g.setClip(0, 0, d.width, d.height); g.setColor(Color.red); g.drawRect(startX, startY, w, h); oldX = curX; oldY = curY; } /** * Invoked when the mouse moves; just update the status line with the new * coordinates. */ public void mouseMoved(MouseEvent e) { showStatus("[" + e.getPoint().x + "," + e.getPoint().y + "]"); } } </source>

MouseDrag -- implement simple mouse drag in a window

   <source lang="java">
 

/*

* Copyright (c) Ian F. Darwin, http://www.darwinsys.ru/, 1996-2002.
* All rights reserved. Software written by Ian F. Darwin and others.
* $Id: LICENSE,v 1.8 2004/02/09 03:33:38 ian Exp $
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
*    notice, this list of conditions and the following disclaimer in the
*    documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS""
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
* 
* Java, the Duke mascot, and all variants of Sun"s Java "steaming coffee
* cup" logo are trademarks of Sun Microsystems. Sun"s, and James Gosling"s,
* pioneering role in inventing and promulgating (and standardizing) the Java 
* language and environment is gratefully acknowledged.
* 
* The pioneering role of Dennis Ritchie and Bjarne Stroustrup, of AT&T, for
* inventing predecessor languages C and C++ is also gratefully acknowledged.
*/

import java.awt.BorderLayout; import java.awt.Color; import java.awt.ruponent; import java.awt.Container; import java.awt.Dimension; import java.awt.Graphics; import java.awt.Image; import java.awt.Label; import java.awt.Point; import java.awt.Toolkit; import java.awt.event.MouseEvent; import java.awt.event.MouseListener; import java.awt.event.MouseMotionListener; import javax.swing.JFrame; /**

* MouseDrag -- implement simple mouse drag in a window.
*/

public class MouseDrag extends Component implements MouseListener,

   MouseMotionListener {
 /** The Image we are to paint */
 Image curImage;
 /** Kludge for showStatus */
 static Label status;
 /** true if we are in drag */
 boolean inDrag = false;
 /** starting location of a drag */
 int startX = -1, startY = -1;
 /** current location of a drag */
 int curX = -1, curY = -1;
 // "main" method
 public static void main(String[] av) {
   JFrame f = new JFrame("Mouse Dragger");
   Container cp = f.getContentPane();
   if (av.length < 1) {
     System.err.println("Usage: MouseDrag imagefile");
     System.exit(1);
   }
   Image im = Toolkit.getDefaultToolkit().getImage(av[0]);
   // create a MouseDrag object
   MouseDrag j = new MouseDrag(im);
   cp.setLayout(new BorderLayout());
   cp.add(BorderLayout.NORTH, new Label(
       "Hello, and welcome to the world of Java"));
   cp.add(BorderLayout.CENTER, j);
   cp.add(BorderLayout.SOUTH, status = new Label());
   status.setSize(f.getSize().width, status.getSize().height);
   f.pack();
   f.setVisible(true);
   f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
 }
 // "Constructor" - creates the object
 public MouseDrag(Image i) {
   super();
   curImage = i;
   setSize(300, 200);
   addMouseListener(this);
   addMouseMotionListener(this);
 }
 public void showStatus(String s) {
   status.setText(s);
 }
 // Five methods from MouseListener:
 /** Called when the mouse has been clicked on a component. */
 public void mouseClicked(MouseEvent e) {
 }
 /** Called when the mouse enters a component. */
 public void mouseEntered(MouseEvent e) {
 }
 /** Called when the mouse exits a component. */
 public void mouseExited(MouseEvent e) {
 }
 /** Called when the mouse has been pressed. */
 public void mousePressed(MouseEvent e) {
   Point p = e.getPoint();
   System.err.println("mousePressed at " + p);
   startX = p.x;
   startY = p.y;
   inDrag = true;
 }
 /** Called when the mouse has been released. */
 public void mouseReleased(MouseEvent e) {
   inDrag = false;
   System.err.println("SELECTION IS " + startX + "," + startY + " to "
       + curX + "," + curY);
 }
 // And two methods from MouseMotionListener:
 public void mouseDragged(MouseEvent e) {
   Point p = e.getPoint();
   // System.err.println("mouse drag to " + p);
   showStatus("mouse Dragged to " + p);
   curX = p.x;
   curY = p.y;
   if (inDrag) {
     repaint();
   }
 }
 public void paint(Graphics g) {
   int w = curX - startX, h = curY - startY;
   Dimension d = getSize();
   g.drawImage(curImage, 0, 0, d.width, d.height, this);
   if (startX < 0 || startY < 0)
     return;
   System.err.println("paint:drawRect @[" + startX + "," + startY
       + "] size " + w + "x" + h);
   g.setColor(Color.red);
   g.fillRect(startX, startY, w, h);
 }
 public void mouseMoved(MouseEvent e) {
   showStatus("mouse Moved to " + e.getPoint());
 }

}

 </source>
   
  
 
  

Mouse Event Demo

   <source lang="java">
 

/* From http://java.sun.ru/docs/books/tutorial/index.html */ /*

* Copyright (c) 2006 Sun Microsystems, Inc. All Rights Reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* -Redistribution of source code must retain the above copyright notice, this
*  list of conditions and the following disclaimer.
*
* -Redistribution in binary form must reproduce the above copyright notice,
*  this list of conditions and the following disclaimer in the documentation
*  and/or other materials provided with the distribution.
*
* Neither the name of Sun Microsystems, Inc. or the names of contributors may
* 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
* OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN MIDROSYSTEMS, INC. ("SUN")
* AND ITS LICENSORS SHALL NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE
* AS A RESULT OF USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS
* DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS BE LIABLE FOR ANY LOST
* REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT, SPECIAL, CONSEQUENTIAL,
* INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER CAUSED AND REGARDLESS OF THE THEORY
* OF LIABILITY, ARISING OUT OF THE USE OF OR INABILITY TO USE THIS SOFTWARE,
* EVEN IF SUN HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
*
* You acknowledge that this software is not designed, licensed or intended
* for use in the design, construction, operation or maintenance of any
* nuclear facility.
*/

/*

* MouseEventDemo.java is a 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.MouseListener; 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 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();
     }
   });
 }

} 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;
 }

}

 </source>
   
  
 
  

MouseMotion Event: mouse move and drag

   <source lang="java">
 

import java.awt.Color; import java.awt.Graphics; import java.awt.event.MouseEvent; import java.awt.event.MouseMotionListener; import javax.swing.JFrame; import javax.swing.JPanel; public class MouseMotionEventDemo extends JPanel implements MouseMotionListener {

 private int mX, mY;
 public MouseMotionEventDemo() {
   addMouseMotionListener(this);
   setVisible(true);
 }
 public void mouseMoved(MouseEvent me) {
   mX = (int) me.getPoint().getX();
   mY = (int) me.getPoint().getY();
   repaint();
 }
 public void mouseDragged(MouseEvent me) {
   mouseMoved(me);
 }
 public void paint(Graphics g) {
   g.setColor(Color.blue);
   g.fillRect(mX, mY, 5, 5);
 }
 public static void main(String[] args) {
   JFrame f = new JFrame();
   f.getContentPane().add(new MouseMotionEventDemo());
   f.setSize(200, 200);
   f.show();
 }

}

 </source>
   
  
 
  

Mouse Wheel Event Demo

   <source lang="java">
 

/* From http://java.sun.ru/docs/books/tutorial/index.html */ /*

* Copyright (c) 2006 Sun Microsystems, Inc. All Rights Reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* -Redistribution of source code must retain the above copyright notice, this
*  list of conditions and the following disclaimer.
*
* -Redistribution in binary form must reproduce the above copyright notice,
*  this list of conditions and the following disclaimer in the documentation
*  and/or other materials provided with the distribution.
*
* Neither the name of Sun Microsystems, Inc. or the names of contributors may
* 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
* OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN MIDROSYSTEMS, INC. ("SUN")
* AND ITS LICENSORS SHALL NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE
* AS A RESULT OF USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS
* DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS BE LIABLE FOR ANY LOST
* REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT, SPECIAL, CONSEQUENTIAL,
* INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER CAUSED AND REGARDLESS OF THE THEORY
* OF LIABILITY, ARISING OUT OF THE USE OF OR INABILITY TO USE THIS SOFTWARE,
* EVEN IF SUN HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
*
* You acknowledge that this software is not designed, licensed or intended
* for use in the design, construction, operation or maintenance of any
* nuclear facility.
*/

/*

* MouseWheelEventDemo.java is a 1.4 example that requires no other files.
*/

import java.awt.BorderLayout; import java.awt.Dimension; import java.awt.event.MouseWheelEvent; import java.awt.event.MouseWheelListener; import javax.swing.BorderFactory; import javax.swing.JComponent; import javax.swing.JFrame; import javax.swing.JPanel; import javax.swing.JScrollPane; import javax.swing.JTextArea; public class MouseWheelEventDemo extends JPanel implements MouseWheelListener {

 JTextArea textArea;
 JScrollPane scrollPane;
 final static String newline = "\n";
 public MouseWheelEventDemo() {
   super(new BorderLayout());
   textArea = new JTextArea();
   textArea.setEditable(false);
   scrollPane = new JScrollPane(textArea);
   scrollPane
       .setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
   scrollPane.setPreferredSize(new Dimension(400, 250));
   add(scrollPane, BorderLayout.CENTER);
   textArea.append("This text area displays information "
       + "about its mouse wheel events." + newline);
   //Register for mouse-wheel events on the text area.
   textArea.addMouseWheelListener(this);
   setPreferredSize(new Dimension(450, 350));
   setBorder(BorderFactory.createEmptyBorder(20, 20, 20, 20));
 }
 public void mouseWheelMoved(MouseWheelEvent e) {
   String message;
   int notches = e.getWheelRotation();
   if (notches < 0) {
     message = "Mouse wheel moved UP " + -notches + " notch(es)"
         + newline;
   } else {
     message = "Mouse wheel moved DOWN " + notches + " notch(es)"
         + newline;
   }
   if (e.getScrollType() == MouseWheelEvent.WHEEL_UNIT_SCROLL) {
     message += "    Scroll type: WHEEL_UNIT_SCROLL" + newline;
     message += "    Scroll amount: " + e.getScrollAmount()
         + " unit increments per notch" + newline;
     message += "    Units to scroll: " + e.getUnitsToScroll()
         + " unit increments" + newline;
     message += "    Vertical unit increment: "
         + scrollPane.getVerticalScrollBar().getUnitIncrement(1)
         + " pixels" + newline;
   } else { //scroll type == MouseWheelEvent.WHEEL_BLOCK_SCROLL
     message += "    Scroll type: WHEEL_BLOCK_SCROLL" + newline;
     message += "    Vertical block increment: "
         + scrollPane.getVerticalScrollBar().getBlockIncrement(1)
         + " pixels" + newline;
   }
   saySomething(message, e);
 }
 //Append to the text area and make sure the new text is visible.
 void saySomething(String eventDescription, MouseWheelEvent e) {
   textArea.append(e.getComponent().getClass().getName() + ": "
       + eventDescription);
   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("MouseWheelEventDemo");
   frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
   //Create and set up the content pane.
   JComponent newContentPane = new MouseWheelEventDemo();
   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();
     }
   });
 }

}

 </source>
   
  
 
  

Move and scale graphical objects with a mouse on the panel

   <source lang="java">
 

import java.awt.Color; import java.awt.Graphics; import java.awt.Graphics2D; import java.awt.RenderingHints; import java.awt.event.MouseAdapter; import java.awt.event.MouseEvent; import java.awt.event.MouseWheelEvent; import java.awt.event.MouseWheelListener; import java.awt.geom.Rectangle2D; import javax.swing.JFrame; import javax.swing.JPanel; public class MouseMoveScale extends JPanel {

 private Rectangle2D.Float myRect = new Rectangle2D.Float(50, 50, 50, 50);
 MovingAdapter ma = new MovingAdapter();
 public MouseMoveScale() {
   addMouseMotionListener(ma);
   addMouseListener(ma);
   addMouseWheelListener(new ScaleHandler());
 }
 public void paint(Graphics g) {
   super.paint(g);
   Graphics2D g2d = (Graphics2D) g;
   g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
   g2d.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING,
       RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
   g2d.setColor(new Color(0, 0, 200));
   g2d.fill(myRect);
 }
 class MovingAdapter extends MouseAdapter {
   private int x;
   private int y;
   public void mousePressed(MouseEvent e) {
     x = e.getX();
     y = e.getY();
   }
   public void mouseDragged(MouseEvent e) {
     int dx = e.getX() - x;
     int dy = e.getY() - y;
     if (myRect.getBounds2D().contains(x, y)) {
       myRect.x += dx;
       myRect.y += dy;
       repaint();
     }
     x += dx;
     y += dy;
   }
 }
 class ScaleHandler implements MouseWheelListener {
   public void mouseWheelMoved(MouseWheelEvent e) {
     int x = e.getX();
     int y = e.getY();
     if (e.getScrollType() == MouseWheelEvent.WHEEL_UNIT_SCROLL) {
       if (myRect.getBounds2D().contains(x, y)) {
         float amount = e.getWheelRotation() * 5f;
         myRect.width += amount;
         myRect.height += amount;
         repaint();
       }
     }
   }
 }
 public static void main(String[] args) {
   JFrame frame = new JFrame("Moving and Scaling");
   MouseMoveScale m = new MouseMoveScale();
   m.setDoubleBuffered(true);
   frame.add(m);
   frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
   frame.setSize(300, 300);
   frame.setLocationRelativeTo(null);
   frame.setVisible(true);
 }

}

 </source>
   
  
 
  

Move Shape with mouse

   <source lang="java">
 

import java.applet.Applet; import java.awt.BasicStroke; import java.awt.BorderLayout; import java.awt.Canvas; import java.awt.Color; import java.awt.Dimension; import java.awt.Frame; import java.awt.Graphics; import java.awt.Graphics2D; import java.awt.Label; import java.awt.Rectangle; import java.awt.event.MouseEvent; import java.awt.event.MouseListener; import java.awt.event.MouseMotionListener; import java.awt.event.WindowAdapter; import java.awt.event.WindowEvent; import javax.swing.JApplet; //Use double buffering to remove rectangle flickers and make it repaint faster. public class ShapeMover extends JApplet {

 static protected Label label = new Label(
     "Drag rectangle around within the area");
 public void init() {
   getContentPane().setLayout(new BorderLayout());
   getContentPane().add(new MyCanvas());
   getContentPane().add("South", label);
 }
 public static void main(String s[]) {
   Frame f = new Frame("ShapeMover");
   f.addWindowListener(new WindowAdapter() {
     public void windowClosing(WindowEvent e) {
       System.exit(0);
     }
   });
   Applet applet = new ShapeMover();
   f.add("Center", applet);
   applet.init();
   f.pack();
   f.setSize(new Dimension(550, 250));
   f.show();
 }

} class MyCanvas extends Canvas implements MouseListener, MouseMotionListener {

 Rectangle rect = new Rectangle(0, 0, 100, 50);
 Graphics2D g2;
 int preX, preY;
 boolean isFirstTime = true;
 Rectangle area;
 boolean pressOut = false;
 public MyCanvas() {
   setBackground(Color.white);
   addMouseMotionListener(this);
   addMouseListener(this);
 }
 public void mousePressed(MouseEvent e) {
   preX = rect.x - e.getX();
   preY = rect.y - e.getY();
   if (rect.contains(e.getX(), e.getY()))
     updateLocation(e);
   else {
     ShapeMover.label.setText("Drag it.");
     pressOut = true;
   }
 }
 public void mouseDragged(MouseEvent e) {
   if (!pressOut)
     updateLocation(e);
   else
     ShapeMover.label.setText("Drag it.");
 }
 public void mouseReleased(MouseEvent e) {
   if (rect.contains(e.getX(), e.getY()))
     updateLocation(e);
   else {
     ShapeMover.label.setText("Drag it.");
     pressOut = false;
   }
 }
 public void mouseMoved(MouseEvent e) {
 }
 public void mouseClicked(MouseEvent e) {
 }
 public void mouseExited(MouseEvent e) {
 }
 public void mouseEntered(MouseEvent e) {
 }
 public void updateLocation(MouseEvent e) {
   rect.setLocation(preX + e.getX(), preY + e.getY());
   if (checkRect()) {
     ShapeMover.label.setText(rect.getX() + ", " + rect.getY());
   } else {
     ShapeMover.label.setText("drag inside the area.");
   }
   repaint();
 }
 public void paint(Graphics g) {
   update(g);
 }
 public void update(Graphics g) {
   Graphics2D g2 = (Graphics2D) g;
   Dimension dim = getSize();
   int w = (int) dim.getWidth();
   int h = (int) dim.getHeight();
   g2.setStroke(new BasicStroke(8.0f));
   if (isFirstTime) {
     area = new Rectangle(dim);
     rect.setLocation(w / 2 - 50, h / 2 - 25);
     isFirstTime = false;
   }
   // Clears the rectangle that was previously drawn.
   g2.setPaint(Color.white);
   g2.fillRect(0, 0, w, h);
   g2.setColor(Color.red);
   g2.draw(rect);
   g2.setColor(Color.black);
   g2.fill(rect);
 }
 boolean checkRect() {
   if (area == null) {
     return false;
   }
   if (area.contains(rect.x, rect.y, 100, 50)) {
     return true;
   }
   int new_x = rect.x;
   int new_y = rect.y;
   if ((rect.x + 100) > area.getWidth()) {
     new_x = (int) area.getWidth() - 99;
   }
   if (rect.x < 0) {
     new_x = -1;
   }
   if ((rect.y + 50) > area.getHeight()) {
     new_y = (int) area.getHeight() - 49;
   }
   if (rect.y < 0) {
     new_y = -1;
   }
   rect.setLocation(new_x, new_y);
   return false;
 }

}

 </source>
   
  
 
  

Swing Mouse Motion Event Demo

   <source lang="java">
 

/* From http://java.sun.ru/docs/books/tutorial/index.html */ /*

* Copyright (c) 2006 Sun Microsystems, Inc. All Rights Reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* -Redistribution of source code must retain the above copyright notice, this
*  list of conditions and the following disclaimer.
*
* -Redistribution in binary form must reproduce the above copyright notice,
*  this list of conditions and the following disclaimer in the documentation
*  and/or other materials provided with the distribution.
*
* Neither the name of Sun Microsystems, Inc. or the names of contributors may
* 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
* OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN MIDROSYSTEMS, INC. ("SUN")
* AND ITS LICENSORS SHALL NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE
* AS A RESULT OF USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS
* DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS BE LIABLE FOR ANY LOST
* REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT, SPECIAL, CONSEQUENTIAL,
* INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER CAUSED AND REGARDLESS OF THE THEORY
* OF LIABILITY, ARISING OUT OF THE USE OF OR INABILITY TO USE THIS SOFTWARE,
* EVEN IF SUN HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
*
* You acknowledge that this software is not designed, licensed or intended
* for use in the design, construction, operation or maintenance of any
* nuclear facility.
*/

/*

* 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;
 }

}

 </source>