Mouse clicks inside image in applet

Question

How can I respond to mouse clicks inside particular regions in an image loaded as part of an applet in a browser? ie, I want to send these clicks onto the server for the server to handle it and the server should change the image according to the mouse clicks.
Thanks,

Answer 1

/*  <applet code="ImageMouse" width="400" height="400"></applet>
*  use: >appletviewer ImageMouse.java
import java.awt.*;
import java.awt.event.*;
import java.awt.image.BufferedImage;
import java.io.*;
import java.net.*;
import javax.imageio.ImageIO;
import javax.swing.*;
public class ImageMouse extends JApplet
    JLabel label;
    public void init()
        ImageMousePanel panel = new ImageMousePanel();
        ImageMouser mouser = new ImageMouser(panel, this);
        panel.addMouseMotionListener(mouser);
        getContentPane().add(panel);
        getContentPane().add(getLabel(), "South");
    private JLabel getLabel()
        label = new JLabel(" ");
        label.setHorizontalAlignment(JLabel.CENTER);
        label.setBorder(BorderFactory.createTitledBorder("image coordinates"));
        Dimension d = label.getPreferredSize();
        d.height = 35;
        label.setPreferredSize(d);
        return label;
    public static void main(String[] args)
        JApplet applet = new ImageMouse();
        JFrame f = new JFrame();
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.getContentPane().add(applet);
        f.setSize(400,400);
        f.setLocation(200,200);
        applet.init();
        f.setVisible(true);
class ImageMousePanel extends JPanel
    BufferedImage image;
    Rectangle r;
    public ImageMousePanel()
        loadImage();
        r = new Rectangle(getPreferredSize());
    protected void paintComponent(Graphics g)
        super.paintComponent(g);
        Graphics2D g2 = (Graphics2D)g;
        g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                            RenderingHints.VALUE_ANTIALIAS_ON);
        int w = getWidth();
        int h = getHeight();
        int imageWidth = image.getWidth();
        int imageHeight = image.getHeight();
        r.x = (w - imageWidth)/2;
        r.y = (h - imageHeight)/2;
        g2.drawImage(image, r.x, r.y, this);
        //g2.setPaint(Color.red);
        //g2.draw(r);
    public Dimension getPreferredSize()
        return new Dimension(image.getWidth(), image.getHeight());
    private void loadImage()
        String s = "images/greathornedowl.jpg";
        try
            URL url = getClass().getResource(s);
            image = ImageIO.read(url);
        catch(MalformedURLException mue)
            System.err.println("url: " + mue.getMessage());
        catch(IOException ioe)
            System.err.println("read: " + ioe.getMessage());
class ImageMouser extends MouseMotionAdapter
    ImageMousePanel panel;
    ImageMouse applet;
    boolean outsideImage;
    public ImageMouser(ImageMousePanel imp, ImageMouse applet)
        panel = imp;
        this.applet = applet;
        outsideImage = true;
    public void mouseMoved(MouseEvent e)
        Point p = e.getPoint();
        if(panel.r.contains(p))
            int x = p.x - panel.r.x;
            int y = p.y - panel.r.y;
            applet.label.setText("x = " + x + "  y = " + y);
            if(outsideImage)
                outsideImage = false;
        else if(!outsideImage)
            outsideImage = true;
            applet.label.setText("outside image");
}