Java tutorial
import java.awt.event.MouseEvent; import java.awt.event.MouseListener; import javax.swing.JFrame; public class Main extends JFrame implements MouseListener { public static void main(String[] args) { Main frame = new Main(); frame.setVisible(true); frame.setSize(200, 200); frame.setExtendedState(JFrame.MAXIMIZED_BOTH); frame.addMouseListener(frame); } @Override public void mouseClicked(MouseEvent e) { if (this.getExtendedState() == JFrame.MAXIMIZED_BOTH) { this.setExtendedState(JFrame.NORMAL); } else { this.setExtendedState(JFrame.MAXIMIZED_BOTH); } } @Override public void mousePressed(MouseEvent e) { } @Override public void mouseReleased(MouseEvent e) { } @Override public void mouseEntered(MouseEvent e) { } @Override public void mouseExited(MouseEvent e) { } }