import java.awt.*;
import java.applet.Applet;
import java.awt.event.*;

public class DrawTriangles extends Applet
{
     private Graphics g;
     private Triangle redTriangle;
 
     public void init ()
     {
          g = getGraphics ();
          addMouseListener (new PointListener ());
     } // method init
 
     // PointListener is an inner class that listens for the mouse to be pressed.
     class PointListener implements MouseListener
     {
          public void mousePressed (MouseEvent e)
          {
               int xval, yval;
               xval = e.getX ();
                yval = e.getY ();
                redTriangle = new Triangle (Color.red, xval, yval);
                redTriangle.drawTriangle (g);
           } // mousePressed
 
       public void mouseEntered (MouseEvent e)  {}
       public void mouseExited (MouseEvent e) {}
      public void mouseReleased (MouseEvent e) {}
      public void mouseClicked (MouseEvent e) {}
     } // class PointListener
} // class DrawTriangles

// Triangle draws triangles wherever the mouse has been pressed.
class Triangle
{
     private int x, y;
     private Polygon poly;
     private Color color;
 
     Triangle (Color c, int xPosition, int yPosition)
     {
          color = c;
          x = xPosition;
          y = yPosition;
     } // constructor
 
     /* drawTriangle creates two lists of points centered around x and y.
          It then creates a new polygon and draws it. */
     public void drawTriangle (Graphics g)
     {
          g.setColor (color);
          int [] xList = {x-20, x, x+20};
          int [] yList = {y, y-20, y};
          poly = new Polygon (xList, yList, 3);
          g.fillPolygon (poly);
     } // method drawTriangle
} // class Triangle