// would like to say: 
// Shape {
//   traversal-pp Integer gp1x(){ 
//     bypassing {-> *,p2,*, -> *,y,*} to Integer;
//       (@ return this; @) } }
// will check that path is unique
// it is ok to traverse to terminal class
//
// will create traversal function, create visitor class and object, 
// and call function
//
// Instead of
//     bypassing {-> *,p2,*, -> *,y,*} to Integer;} 
// would like to say
//     ordered-through {-> *,p1,*, -> *,x,*} to Integer;} 


DrawingVisitor { // BAD STYLE
  before Shape (@
    System.out.println("drawing object of "
	  + host.getClass().toString()); @)

  before ScrollDecorator (@ System.out.println(" draw scroll bar "); @)
  before BorderDecorator (@ System.out.println(" draw border "); @)
  before Line (@ 
    // Cursor.move(host.get_p1x(), host.get_p1y());
    Cursor.move(host.get_coords().get_p1().get_x(), host.get_coords().get_p1().get_y());
    Cursor.line(host.get_coords().get_p2().get_x(),host.get_coords().get_p2().get_y());
  @)
  before Box (@
    Cursor.move(host.get_coords().get_p1().get_x(), host.get_coords().get_p1().get_y());
    Cursor.line(host.get_coords().get_p1().get_x(),host.get_coords().get_p2().get_y());
    Cursor.line(host.get_coords().get_p2().get_x(),host.get_coords().get_p2().get_y());
    Cursor.line(host.get_coords().get_p2().get_x(),host.get_coords().get_p1().get_y());
    Cursor.line(host.get_coords().get_p1().get_x(),host.get_coords().get_p1().get_y());
  @)
}
Sketch {
  traversal allShapes(DrawingVisitor d) {
    bypassing -> *,mode,*
    to {Box, Line};} // go to subclasses of Shape
  (@ void draw(Color c) {
       DrawingVisitor d = new DrawingVisitor(c);
       this.allShapes(d);
     }
  @)
}
Cursor { (@ 
  static void move(Integer x, Integer y) 
    { System.out.println(" move to " + x + " , " + y);} 
  static void line(Integer x, Integer y)
    { System.out.println(" line to " + x + " , " + y);} 
  
@) }

Main {
(@
  public static void main(String args[]) throws Exception {

      System.out.println(" *** START *** ");     
      Sketch s = Sketch.parse(System.in);
      s.draw(new Black());
  }
@)
}