import java.awt.*;
import java.awt.event.*;
import java.util.Vector;

// A variation of a class that appears in Core Web
// Programming from Prentice Hall. May be freely used
// or adapted.
// 1998 Marty Hall, http://www.apl.jhu.edu/~hall/java/

/** A frame that draws a small circle where you click.*/

 public class DrawCircles extends CloseableAppletFrame {

  private Vector circles;

  /** When you click the mouse, create a SimpleCircle,
   *  put it in the Vector, and tell the system
   *  to repaint (which calls update, which clears
   *  the screen and calls paint).
   */

  private class CircleDrawer extends MouseAdapter {
    public void mousePressed(MouseEvent event) {
      circles.addElement(new SimpleCircle(event.getX(),
                                          event.getY(),
                                          9));
      repaint();
    }
  }
  
  
  public DrawCircles() {
    super("Drawing Circles" );
    circles = new Vector();
    addMouseListener(new CircleDrawer());
    setBackground(Color.white);
    setSize(500, 300);
    setVisible(true);
  }

  /** This loops down the available SimpleCircle objects,
   *  drawing each one.
   */
  public void paint(Graphics g) {
    SimpleCircle circle;
    for(int i=0; i<circles.size(); i++) {
      circle = (SimpleCircle)circles.elementAt(i);
      circle.draw(g);
    }
  }
}