Java by API/java.awt.event/MouseListener

implements MouseListener

   <source lang="java">

import java.awt.Container; import java.awt.Dimension; import java.awt.Graphics; import java.awt.Point; import java.awt.event.MouseEvent; import java.awt.event.MouseListener; import java.awt.event.MouseMotionListener; import javax.swing.JFrame; import javax.swing.JPanel; public class MainClass {

 public static void main(String[] args) {
   JFrame aWindow = new JFrame();
   aWindow.setBounds(200, 200, 200, 200);
   aWindow.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
   Container content = aWindow.getContentPane();
   content.add(new MouseMotionEvents());
   aWindow.setVisible(true);
 }

} class MouseMotionEvents extends JPanel implements MouseListener,

   MouseMotionListener {
 Point p;
 public MouseMotionEvents() {
   addMouseListener(this);
   addMouseMotionListener(this);
 }
 public void mouseClicked(MouseEvent me) {
 }
 public void mouseEntered(MouseEvent me) {
 }
 public void mouseExited(MouseEvent me) {
 }
 public void mousePressed(MouseEvent me) {
   p = me.getPoint();
   repaint();
 }
 public void mouseReleased(MouseEvent me) {
   p = null;
   repaint();
 }
 public void mouseDragged(MouseEvent me) {
   p = me.getPoint();
   repaint();
 }
 public void mouseMoved(MouseEvent me) {
 }
 public void paint(Graphics g) {
   if (p != null) {
     Dimension d = getSize();
     int xc = d.width / 2;
     int yc = d.height / 2;
     g.drawLine(xc, yc, p.x, p.y);
   }
 }

}

      </source>