pxs.java

import javax.swing.*;
import java.awt.*;
import java.awt.image.BufferedImage;

public class pxs extends JFrame {
    private static final long SLEEP_DELAY = 500L;
    private static JLabel label;

    public static void main(String[] args) {
        JFrame frame = new pxs();
        final JPanel panel = new JPanel();
        frame.setAlwaysOnTop(true);
        panel.setLayout(new BorderLayout());
        frame.setResizable(false);
        Dimension screenSize = new Dimension(Toolkit.getDefaultToolkit().getScreenSize());

        label = new JLabel("Hello World");
        label.setOpaque(true);
        frame.getContentPane().add(label);
        label.setBackground(Color.black);
        label.setForeground(Color.gray);
        label.setHorizontalAlignment(SwingConstants.RIGHT);
        frame.setDefaultCloseOperation(EXIT_ON_CLOSE);
        frame.setUndecorated(true);
        frame.setLocation(screenSize.width-80,screenSize.height-label.getHeight()-60);

        frame.pack();
        frame.setVisible(true);
        pix();
    }

    private static void pix() {
        Point coord;
        Robot robot = null;

        try {
            robot = new Robot();
        } catch (AWTException e) {
            e.printStackTrace();
            System.exit(-1);
        }

        Color pixColor = null;
        Color color = null;
        int _w = 0;
        int _h = 0;

        while (true) {
            try {
            coord = MouseInfo.getPointerInfo().getLocation();
            Rectangle screenRect = new Rectangle(0, 0, Toolkit.getDefaultToolkit()
                    .getScreenSize().width, Toolkit.getDefaultToolkit()
                    .getScreenSize().height);
            BufferedImage grid = robot.createScreenCapture(screenRect);

                int x = coord.x;
                int y = coord.y;
                int x0 = x;
                int y0 = y;
                int rgb = grid.getRGB(x0, y0);
                //System.out.println(rgb);

                int w = 0;
                int h = 0;
                x = x0 - 1;
                do {
                    x--;
                    w++;
                } while (grid.getRGB(x, y) == rgb || x <= 0);

                x = x0;
                do {
                    x++;
                    w++;
                } while (grid.getRGB(x, y) == rgb || x >= screenRect.width);

                x = x0;
                y = y0 - 1;
                do {
                    y--;
                    h++;
                } while (grid.getRGB(x, y) == rgb || y <= 0);

                y = y0;
                do {
                    y++;
                    h++;
                } while (grid.getRGB(x, y) == rgb || y >= screenRect.height);

                if ((_w != w) || (_h != h)) {
                    //System.out.println(w + " " + h);
                    label.setText(w + " x " + h);
                }
                _w = w;
                _h = h;

            } catch (Exception e) {

            }
            try {
                Thread.sleep(SLEEP_DELAY);
            } catch (InterruptedException e) {
            }

        }

    }


}