package howto;

import java.awt.*;
import java.util.*;

public class LineShape extends Shape implements Observer
{
   HotSpot _hs1, _hs2;

   int _x1, _y1, _x2, _y2;

   public LineShape(int x1, int y1, int x2, int y2)
   {
      _x1 = x1;
      _y1 = y1;
      _x2 = x2;
      _y2 = y2;

      _hs1 = new HotSpot(new Coordinates(x1, y1));
      _hs2 = new HotSpot(new Coordinates(x2, y2));

      _hs1.addObserver(this);
      _hs2.addObserver(this);
   }

   public Vector getHotSpots()
   {
      Vector vec = new Vector();

      vec.addElement(_hs1);
      vec.addElement(_hs2);

      return vec;
   }

   public void paint(Graphics g)
   {
      g.drawLine(_x1, _y1, _x2, _y2);
   }

   public void update(Observable obs, Object obj)
   {
      Coordinates coord1 = _hs1.getCoordinates();
      Coordinates coord2 = _hs2.getCoordinates();

      if (obs == _hs1)
      {
         _x1 = coord1.x;
         _y1 = coord1.y;
      }
      else if (obs == _hs2)
      {
         _x2 = coord2.x;
         _y2 = coord2.y;
      }

      _hs1.setCoordinates(new Coordinates(_x1, _y1));
      _hs2.setCoordinates(new Coordinates(_x2, _y2));
   }
}