source: java-automator/src/nl/rickvanderzwet/farmville/ScreenRecognition.java@ 109

/*
 * Rick van der Zwet <info@rickvanderzwet.nl>
 * License BSDLike http://rickvanderzwet.nl/LICENSE
 */

/* Based after http://ironbark.bendigo.latrobe.edu.au/~mary/DS/lectures/tutorials/ACSWorkshop98.html */
package nl.rickvanderzwet.farmville;

import java.awt.*;
import java.awt.event.*;
import java.awt.image.BufferedImage;
import java.awt.image.RasterFormatException;


public class ScreenRecognition extends Frame implements ActionListener  {
        /**
         * 
         */
        private static final long serialVersionUID = -6742715532913330783L;
        static int mouseSurround = 120;
        Image image;
        static Color pixel;
        static Point mouse;
        static BufferedImage bi;
        static Robot bot;
        
        static boolean freezeImage = false;
        static boolean mouseClickEnabled = true;
        
        private static void pressMouse() throws InterruptedException {
                if (mouseClickEnabled) {
                        bot.mousePress(InputEvent.BUTTON1_MASK);        
                        bot.mouseRelease(InputEvent.BUTTON1_MASK);
                }

        }
        
        public ScreenRecognition() {
                setTitle("Screen Recognition Example");
                
                Panel buttons = new Panel();
                Button redButton = new Button("Red");
                Button blueButton = new Button("Blue");
                Button greenButton = new Button("Green");
                redButton.setName("redButton");
                redButton.setLabel("Freeze Screen");
                redButton.addActionListener(this);
                blueButton.setName("blueButton");
                blueButton.setLabel("Stop clicking");
                blueButton.addActionListener(this);
                buttons.add(redButton);
                buttons.add(blueButton);
                buttons.add(greenButton);
                add(buttons,"South");

                 
                setSize(400,300);
                addWindowListener(new WindowAdapter() {
                        public void windowClosing(WindowEvent e){ 
                                System.exit(0);
                        }
                });
                setVisible(true);
        }

        public void actionPerformed(ActionEvent event) {
                Component c = (Component)event.getSource();
                if (c.getName() == "redButton") {
                        c.getToolkit().beep();
                        try {
                                Thread.sleep(3000);
                        } catch (InterruptedException e) {
                                // TODO Auto-generated catch block
                                e.printStackTrace();
                        }
                        freezeImage = !freezeImage;
                } else if (c.getName() == "blueButton") {
                        mouseClickEnabled =  !mouseClickEnabled;
                        if (mouseClickEnabled) {
                                ((Button) c).setLabel("Stop clicking");
                        } else {
                                ((Button) c).setLabel("Start clicking");        
                        }
                }
        }
        
        public void paint(Graphics g) {
                g.drawString("Mouse:" + mouse.x + "," + mouse.y ,20,40);
                g.drawString("PixelRGB:" + pixel.toString() ,150,40);

                g.drawRect(18, 48, mouseSurround * 2 + 4, mouseSurround * 2 + 4);
                g.setColor(pixel);
                g.fillRect(300,100,20,20);
                g.drawImage(bi,20, 50, this);
        }

        public static void main(String[] args) throws AWTException, InterruptedException  {
                //bot.mouseMove(100, 100);
                bot = new Robot();
                ScreenRecognition foo = new ScreenRecognition();

                while (true) {
                        PointerInfo pointer = MouseInfo.getPointerInfo();
                        mouse = pointer.getLocation();
                        pixel = bot.getPixelColor(mouse.x, mouse.y);
                        try {
                                if (!freezeImage) {
                                bi=bot.createScreenCapture(new Rectangle(mouse.x + mouseSurround,
                                                mouse.y + mouseSurround));
                                bi = bi.getSubimage(mouse.x - mouseSurround, 
                                                mouse.y - mouseSurround, 
                                                mouseSurround * 2, mouseSurround * 2);
                                
                                /* See is enabled */
                                Color target = new Color(255, 170, 0);
                                int pixelTreshold = 10;
                                
                                search: for (int x = 0; x < bi.getWidth(); x++) {
                                        for (int y = 0; y < bi.getHeight(); y++){
                                                if (bi.getRGB(x, y) == target.getRGB()) {
                                                        pixelTreshold--;
                                                        if (pixelTreshold == 0) {
                                                                break search;
                                                        }
                                                }
                                        }
                                }
                                if (pixelTreshold == 0) {
                                        pressMouse();
                                        System.out.println("Button Click at [" + mouse.x + "," + mouse.y + "]");
                                }

                                }
                                foo.repaint();
                        } catch (IllegalArgumentException e) {
                                continue;
                        }  catch (RasterFormatException e) {
                                continue;
                        }
                        // Allow time to focus Firefox window
                        Thread.sleep(100);
                }

        }
}