Hi friend,


use this code.

import javax.swing.*;
import javax.swing.event.MouseInputAdapter;
import java.awt.*;
import java.awt.event.*;
import java.util.*;

public class ImageDisplay extends JPanel implements MouseListener {
private Dimension area; //indicates area taken up by graphics
private Vector<Rectangle> circles;
private JPanel drawingPane;

private final Color colors[] = {
Color.red, Color.blue, Color.green, Color.orange,
Color.cyan, Color.magenta, Color.darkGray, Color.yellow};
private final int color_n = colors.length;

public ImageDisplay() {
super(new BorderLayout());
area = new Dimension(0,0);
circles = new Vector<Rectangle>();

//Set up the instructions.
JLabel jlableLeft = new JLabel("Click left mouse button to place a circle.");
JLabel jlableRight = new JLabel("Click right mouse button to clear drawing area.");
JPanel jpane = new JPanel(new GridLayout(0,1));
jpane.setFocusable(true);
jpane.add(jlableLeft);
jpane.add(jlableRight);

//Set up the drawing area.
drawingPane = new DrawingPane();
drawingPane.setBackground(Color.white);
drawingPane.addMouseListener(this);

//Put the drawing area in a scroll pane.
JScrollPane scroller = new JScrollPane(drawingPane);
scroller.setPreferredSize(new Dimension(200,200));

//Lay out this demo.
add(jpane, BorderLayout.PAGE_START);
add(scroller, BorderLayout.CENTER);
}

/** The component inside the scroll pane. */
public class DrawingPane extends JPanel {
protected void paintComponent(Graphics g) {
super.paintComponent(g);

Rectangle rect;
for (int i = 0; i < circles.size(); i++) {
System.out.println("circle size: " + circles.size());
rect = circles.elementAt(i);
g.setColor(colors[(i % color_n)]);
g.fillOval(rect.x, rect.y, rect.width, rect.height);
}
}
}

//Handle mouse events.
public void mouseReleased(MouseEvent e) {
final int W = 100;
final int H = 100;
boolean changed = false;
if (SwingUtilities.isRightMouseButton(e)) {
//This will clear the graphic objects.
circles.removeAllElements();
area.width=0;
area.height=0;
changed = true;
} else {
int x = e.getX() - W/2;
int y = e.getY() - H/2;
if (x < 0) x = 0;
if (y < 0) y = 0;
Rectangle rect = new Rectangle(x, y, W, H);
circles.addElement(rect);
drawingPane.scrollRectToVisible(rect);

int this_width = (x + W + 2);
if (this_width > area.width) {
area.width = this_width; changed=true;
}

int this_height = (y + H + 2);
if (this_height > area.height) {
area.height = this_height; changed=true;
}
}
if (changed) {
drawingPane.setPreferredSize(area);
//Let the scroll pane know to update itself
//and its scrollbars.
drawingPane.revalidate();
}
drawingPane.repaint();
}
public void mouseClicked(MouseEvent e){}
public void mouseEntered(MouseEvent e){}
public void mouseExited(MouseEvent e){}
public void mousePressed(MouseEvent e){}

private static void createAndShowGUI() {
//Create and set up the window.
JFrame frame = new JFrame("Scroll example");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

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

//Display the window.
frame.setSize(300,300);
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();
}
});
}
}
------------------------------

Thanks

Amardeep