Java tutorial
import java.awt.Graphics; import java.awt.Graphics2D; import java.awt.geom.Line2D; import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JPanel; public class Main extends JFrame { public Main() { JPanel panel = new JPanel(); getContentPane().add(panel); setSize(450, 450); JButton button = new JButton("press"); panel.add(button); } public void paint(Graphics g) { super.paint(g); Graphics2D g2 = (Graphics2D) g; Line2D lin = new Line2D.Float(100, 100, 250, 260); g2.draw(lin); } public static void main(String[] args) { Main s = new Main(); s.setVisible(true); } }