import javax.swing.*;

public class TransparentBackground extends JComponent implements
MouseMotionListener, MouseListener, ComponentListener, WindowListener {
/**
*
*/
private static final long serialVersionUID = 1L;

private JFrame frame;

private int x, y;

private Image background;

public TransparentBackground(JFrame frame) {
this.frame = frame;
frame.addWindowListener(this);
addMouseMotionListener(this);
addMouseListener(this);
updateBackground();
}

public void updateBackground() {
try {
Dimension frameDim = frame.getSize();
frame.setSize(0, 0);
Robot rbt = new Robot();
Toolkit tk = Toolkit.getDefaultToolkit();
Dimension dim = tk.getScreenSize();

background = rbt.createScreenCapture(new Rectangle(0, 0, (int) dim
.getWidth(), (int) dim.getHeight()));
frame.setSize(frameDim);
} catch (Exception ex) {
ex.printStackTrace();
}
}

public void paintComponent(Graphics g) {
Point pos = this.getLocationOnScreen();
Point offset = new Point(-pos.x, -pos.y);
g.drawImage(background, offset.x, offset.y, null);
}

public void componentResized(ComponentEvent e) {
Component[] components = ((JFrame) e.getComponent()).getContentPane()
.getComponents();
if (components.length > 0)
components[0].repaint();
}

public void componentMoved(ComponentEvent e) {
componentResized(e);
}

public void componentShown(ComponentEvent e) {
componentResized(e);
}

public void componentHidden(ComponentEvent e) {
componentResized(e);

}

public static void main(String[] args) {
final JFrame frame = new JFrame("Transparent Window");
frame.setUndecorated(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JButton button = new JButton("This is a button");
button.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
frame.dispose();
}
});
TransparentBackground bg = new TransparentBackground(frame);

bg.setLayout(new BorderLayout());
bg.add("North", button);
JLabel label = new JLabel("This is a label");
bg.add("South", label);
frame.getContentPane().add("Center", bg);
frame.setSize(200, 200);

frame.setVisible(true);
}

public void mouseDragged(MouseEvent e) {
frame.setLocation(e.getX() + frame.getX() - x, e.getY() + frame.getY()
- y);
frame.repaint();
}

public void mouseMoved(MouseEvent e) {
}

public void mouseClicked(MouseEvent e) {

}

public void mouseEntered(MouseEvent e) {
}

public void mouseExited(MouseEvent e) {
}

public void mousePressed(MouseEvent e) {
x = e.getX();
y = e.getY();
}

public void mouseReleased(MouseEvent e) {
}

public void windowActivated(WindowEvent e) {
updateBackground();
frame.repaint();
}

public void windowClosed(WindowEvent e) {}

public void windowClosing(WindowEvent e) {}

public void windowDeactivated(WindowEvent e) {
updateBackground();
frame.repaint();
}

public void windowDeiconified(WindowEvent e) {}

public void windowIconified(WindowEvent e) {}