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import java.awt.Canvas;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseMotionListener;
import javax.swing.JFrame;
public class Test extends JFrame {
public Test() {
getContentPane().add(new MyCanvas());
setSize(200, 200);
}
class MyCanvas extends Canvas implements MouseListener, MouseMotionListener {
int x1, y1, x2, y2;
public MyCanvas() {
setBackground(Color.white);
addMouseListener(this);
addMouseMotionListener(this);
}
@Override
public void paint(Graphics g) {
g.setColor(Color.red);
g.drawLine(x1, y1, x2, y2);
}
public void mouseClicked(MouseEvent e) {
}
public void mouseEntered(MouseEvent e) {
}
public void mouseExited(MouseEvent e) {
}
public void mousePressed(MouseEvent e) {
x2 = e.getX();
y2 = e.getY();
}
public void mouseReleased(MouseEvent e) {
}
public void mouseDragged(MouseEvent e) {
x1 = x2;
y1 = y2;
x2 = e.getX();
y2 = e.getY();
paint(getGraphics());
}
public void mouseMoved(MouseEvent e) {
}
}
public static void main(String[] args){
Test frame = new Test();
frame.setVisible(true);
}
}