Why isn't my program handles mouse motion? (Java)

Question

I try to make some cool "Mouse tracker" .. It records your mouse positions until you press the "Track" button, and when you click it , It "restores" the mouse position.

It's seems it doesn't handle the mouseMove method. why?

import java.awt.AWTException;
import java.awt.Dimension;
import java.awt.Point;
import java.awt.Robot;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
public class Mouse implements MouseMotionListener {
 JFrame frame = new JFrame();
 JButton move = new JButton("Track");
 Point[] points = new Point[100000];
 int i = 0;
 public Mouse() {
 // restore on track
 move.addActionListener(new ActionListener() {
 @Override
 public void actionPerformed(ActionEvent arg0) {
 try {
 Mouse.this.restore();
 } catch (InterruptedException | AWTException e) {
 // TODO Auto-generated catch block
 e.printStackTrace();
 }
 }
 });
 // initialize component
 frame.setPreferredSize(new Dimension(300, 300));
 frame.getContentPane().add(move);
 frame.addMouseMotionListener(this);
 frame.pack();
 frame.setVisible(true);
 }
 @Override
 public void mouseDragged(MouseEvent e) {}
 @Override
 public void mouseMoved(MouseEvent e) {
 System.out.println("Mouve move");
 if(i < 100000) {
 points[i] = e.getLocationOnScreen();
 i++;
 }
 }
 public void restore() throws InterruptedException, AWTException {
 System.out.println("Mouse restored");
 for(int j = 0; j < i; j++) {
 Robot r = new Robot();
 r.mouseMove(points[j].x, points[j].y);
 Thread.sleep(100);
 }
 }
 public static void main(String[] args) {
 Mouse s = new Mouse();
 }
}

• Nikolay Kuznetsov: so what actually happens after you press the button? what is the value of i, is it > 0? Create Robot outside of for loop.

Answer 1

1. add MouseListener to JFrame or its ContentPane, not to JButton - main reason
2. Run Swing in EDT thread using SwingUtilities.invokeLater()
3. Remove mouseMotionListener from JFrame when you call restore
4. Put Robot creation outside of loop

This

for(int j = 0; j < i; j++) {
 Robot r = new Robot();

to

Robot r = new Robot();
for(int j = 0; j < i; j++) {

• Nikolay Kuznetsov: @user1798362, frame.removeMouseMotionListener(this); docs.oracle.com/javase/1.4.2/docs/api/java/awt/…