import javax.swing.*; 
import java.awt.*; 
import java.awt.event.*;

class One extends JFrame {
  One() {
    Two b = new Two();
    Container c = this.getContentPane(); 
    c.add(b); 
    this.setVisible(true); 
    this.setSize(400, 400); 
    this.setDefaultCloseOperation( 3 ); 
  } 
  public static void main(String[] args) {
    One a = new One(); 
  } 
}

class Two extends JComponent implements MouseMotionListener {
  Circle eye; 
  Line line; 
  Two() {
    this.eye = new Circle( new Point(150, 150), 30 ); 
    this.addMouseMotionListener(this); 
  } 
  public void mouseMoved(MouseEvent e) {
    int x = e.getX(), y = e.getY(); 
    System.out.println( "(" + x + ", " + y + ")" ); 
    this.line = new Line( this.eye.center, new Point( x, y ) ); 
    this.repaint(); 
  }
  public void mouseDragged(MouseEvent e) {
    System.out.println("Mouse dragged..."); 
  }
  public void paintComponent(Graphics g) {
    this.eye.draw(g); 
    if (line != null) {
      this.line.draw(g);
      this.line.drawPupil(g, this.eye.radius); 
    } 
  }
}

class Circle {
  Point center;
  int radius;
  Circle(Point c, int r) {
    this.center = c;
    this.radius = r; 
  }  
  void draw(Graphics g) {
    g.drawOval(this.center.x - this.radius, 
               this.center.y - this.radius, 
               this.radius * 2, 
               this.radius * 2); 
  }
}

class Point {
  int x, y;
  Point(int x, int y) {
    this.x = x; 
    this.y = y; 
  }
  double distanceTo(Point another) {
    int dx = this.x - another.x; 
    int dy = this.y - another.y; 
    return Math.sqrt( dx * dx + dy * dy );
  }
}

class Line {
  Point a, b; 
  Line(Point a, Point b) {
    this.a = a; 
    this.b = b; 
  }
  void draw(Graphics g) {
    // g.drawLine(a.x, a.y, b.x, b.y); 
    for (int i = 0; i <= 10; i++) {
      int x, y;
      double t = (double) i / 10;  
      x = (int) (a.x + t * (b.x - a.x)); 
      y = (int) (a.y + t * (b.y - a.y)); 
      g.fillOval( x-3, y-3, 6, 6 ); 
    }   
  } 
  double length() {
   return this.a.distanceTo(this.b); 
  }
  void drawPupil(Graphics g, int r) {
    int x, y;
    double t = (double) r / this.length();  
    x = (int) (a.x + t * (b.x - a.x)); 
    y = (int) (a.y + t * (b.y - a.y)); 
    g.setColor(Color.RED); 
    g.fillOval( x-6, y-6, 12, 12 ); 
  }
}