SPAR/AIModule/BWTA/vendors/CGAL/CGAL/Arr_observer.h

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// Copyright (c) 2005  Tel-Aviv University (Israel).
// All rights reserved.
//
// This file is part of CGAL (www.cgal.org); you may redistribute it under
// the terms of the Q Public License version 1.0.
// See the file LICENSE.QPL distributed with CGAL.
//
// Licensees holding a valid commercial license may use this file in
// accordance with the commercial license agreement provided with the software.
//
// This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
// WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
//
// $URL: svn+ssh://scm.gforge.inria.fr/svn/cgal/branches/CGAL-3.5-branch/Arrangement_on_surface_2/include/CGAL/Arr_observer.h $
// $Id: Arr_observer.h 41108 2007-12-06 15:26:30Z efif $
// 
//
// Author(s)     : Ron Wein          <wein@post.tau.ac.il>

#ifndef CGAL_ARR_OBSERVER_H
#define CGAL_ARR_OBSERVER_H

#include <CGAL/Arr_enums.h>

CGAL_BEGIN_NAMESPACE

template <class Arrangement_>
class Arr_observer
{
public:

  typedef Arrangement_                                     Arrangement_2;
  typedef Arr_observer<Arrangement_2>                      Self;

  typedef typename Arrangement_2::Point_2                  Point_2;
  typedef typename Arrangement_2::X_monotone_curve_2       X_monotone_curve_2;

  typedef typename Arrangement_2::Vertex_handle            Vertex_handle;
  typedef typename Arrangement_2::Halfedge_handle          Halfedge_handle;
  typedef typename Arrangement_2::Face_handle              Face_handle;
  typedef typename Arrangement_2::Ccb_halfedge_circulator  
                                                      Ccb_halfedge_circulator;

private:

  Arrangement_2  *p_arr;           // The associated arrangement.

  Arr_observer (const Self& );

  Self& operator= (const Self& );

public:



  Arr_observer () :
    p_arr (NULL)
  {}

  Arr_observer (Arrangement_2& arr) :
    p_arr (&arr)
  {
    // Register the observer object in the arrangement.
    p_arr->_register_observer (this);
  }

  virtual ~Arr_observer ()
  {
    // Unregister the observer object from the arrangement.
    if (p_arr != NULL)
      p_arr->_unregister_observer (this);
  }



  const Arrangement_2* arrangement () const
  {
    return (p_arr);
  }

  Arrangement_2* arrangement ()
  {
    return (p_arr);
  }

  void attach (Arrangement_2& arr)
  {
    // Do nothing if the associated arrangement is not changed.
    if (p_arr == &arr)
      return;

    // The observer is not already attached to an arrangement.
    CGAL_precondition (p_arr == NULL);

    if (p_arr != NULL)
      return;

    // Notify the concrete oberver (the sub-class) about the attachment.
    before_attach (arr);

    // Register the observer object in the new arrangement.
    p_arr = &arr;
    p_arr->_register_observer (this);

    // Notify the concrete oberver that the attachment took place.
    after_attach();

    return;
  }

  void detach ()
  {
    if (p_arr == NULL)
      return;

    // Notify the concrete oberver (the sub-class) about the detachment.
    before_detach ();

    // Unregister the observer object from the current arrangement, and mark
    // that the oberver is not attached to an arrangement.
    p_arr->_unregister_observer (this);
    p_arr = NULL;
   
    // Notify the concrete oberver that the detachment took place.
    after_detach();

    return;
  }



  virtual void before_assign (const Arrangement_2& /* arr */)
  {}

  virtual void after_assign ()
  {}

  virtual void before_clear ()
  {}

  virtual void after_clear ()
  {}

  virtual void before_global_change ()
  {}

  virtual void after_global_change ()
  {}



  virtual void before_attach (const Arrangement_2& /* arr */)
  {}

  virtual void after_attach ()
  {}

  virtual void before_detach ()
  {}

  virtual void after_detach ()

  {}



  virtual void before_create_vertex (const Point_2& /* p */)
  {}

  virtual void after_create_vertex (Vertex_handle /* v */)
  {}

  virtual void before_create_boundary_vertex (const X_monotone_curve_2& /*cv*/,
                                              Arr_curve_end /* ind */,
                                              Arr_parameter_space /* ps_x */,
                                              Arr_parameter_space /* ps_y */)
  {}

  virtual void after_create_boundary_vertex (Vertex_handle /* v */)
  {}

  virtual void before_create_edge (const X_monotone_curve_2& /* c */,
                                   Vertex_handle /* v1 */,
                                   Vertex_handle /* v2 */)
  {}

  virtual void after_create_edge (Halfedge_handle /* e */)
  {}

  virtual void before_modify_vertex (Vertex_handle /* v */,
                                     const Point_2& /* p */)
  {}

  virtual void after_modify_vertex (Vertex_handle /* v */)
  {}

  virtual void before_modify_edge (Halfedge_handle /* e */,
                                   const X_monotone_curve_2& /* c */)
  {}

  virtual void after_modify_edge (Halfedge_handle /* e */)
  {}

  virtual void before_split_edge (Halfedge_handle /* e */,
                                  Vertex_handle /* v */,
                                  const X_monotone_curve_2& /* c1 */,
                                  const X_monotone_curve_2& /* c2 */)
  {}

  virtual void after_split_edge (Halfedge_handle /* e1 */,
                                 Halfedge_handle /* e2 */)
  {}

  virtual void before_split_fictitious_edge (Halfedge_handle /* e */,
                                             Vertex_handle /* v */)
  {}

  virtual void after_split_fictitious_edge (Halfedge_handle /* e1 */,
                                            Halfedge_handle /* e2 */)
  {}

  virtual void before_split_face (Face_handle /* f */,
                                  Halfedge_handle /* e */)
  {}

  virtual void after_split_face (Face_handle /* f */,
                                 Face_handle /* new_f */,
                                 bool /* is_hole */)
  {}

  virtual void before_split_outer_ccb (Face_handle /* f */,
                                       Ccb_halfedge_circulator /* h */,
                                       Halfedge_handle /* e */)
  {}

  virtual void after_split_outer_ccb (Face_handle /* f */,
                                      Ccb_halfedge_circulator /* h1 */,
                                      Ccb_halfedge_circulator /* h2 */)
  {}

  virtual void before_split_inner_ccb (Face_handle /* f */,
                                       Ccb_halfedge_circulator /* h */,
                                       Halfedge_handle /* e */)
  {}

  virtual void after_split_inner_ccb (Face_handle /* f */,
                                      Ccb_halfedge_circulator /* h1 */,
                                      Ccb_halfedge_circulator /* h2 */)
  {}

  virtual void before_add_outer_ccb (Face_handle /* f */,
                                     Halfedge_handle /* e */)
  {}

  virtual void after_add_outer_ccb (Ccb_halfedge_circulator /* h */)
  {}

  virtual void before_add_inner_ccb (Face_handle /* f */,
                                     Halfedge_handle /* e */)
  {}

  virtual void after_add_inner_ccb (Ccb_halfedge_circulator /* h */)
  {}

  virtual void before_add_isolated_vertex (Face_handle /* f */,
                                           Vertex_handle /* v */)
  {}

  virtual void after_add_isolated_vertex (Vertex_handle /* v */)
  {}

  virtual void before_merge_edge (Halfedge_handle /* e1 */,
                                  Halfedge_handle /* e2 */,
                                  const X_monotone_curve_2& /* c */)
  {}

  virtual void after_merge_edge (Halfedge_handle /* e */)
  {}

  virtual void before_merge_fictitious_edge (Halfedge_handle /* e1 */,
                                             Halfedge_handle /* e2 */)
  {}

  virtual void after_merge_fictitious_edge (Halfedge_handle /* e */)
  {}

  virtual void before_merge_face (Face_handle /* f1 */,
                                  Face_handle /* f2 */,
                                  Halfedge_handle /* e */)
  {}

  virtual void after_merge_face (Face_handle /* f */)
  {}

  virtual void before_merge_outer_ccb (Face_handle /* f */,
                                       Ccb_halfedge_circulator /* h1 */,
                                       Ccb_halfedge_circulator /* h2 */,
                                       Halfedge_handle /* e */)
  {}

  virtual void after_merge_outer_ccb (Face_handle /* f */,
                                      Ccb_halfedge_circulator /* h */)
  {}

  virtual void before_merge_inner_ccb (Face_handle /* f */,
                                       Ccb_halfedge_circulator /* h1 */,
                                       Ccb_halfedge_circulator /* h2 */,
                                       Halfedge_handle /* e */)
  {}

  virtual void after_merge_inner_ccb (Face_handle /* f */,
                                      Ccb_halfedge_circulator /* h */)
  {}

  virtual void before_move_outer_ccb (Face_handle /* from_f */,
                                      Face_handle /* to_f */,
                                      Ccb_halfedge_circulator /* h */)
  {}

  virtual void after_move_outer_ccb (Ccb_halfedge_circulator /* h */)
  {}


  virtual void before_move_inner_ccb (Face_handle /* from_f */,
                                      Face_handle /* to_f */,
                                      Ccb_halfedge_circulator /* h */)
  {}

  virtual void after_move_inner_ccb (Ccb_halfedge_circulator /* h */)
  {}

  virtual void before_move_isolated_vertex (Face_handle /* from_f */,
                                            Face_handle /* to_f */,
                                            Vertex_handle /* v */)
  {}

  virtual void after_move_isolated_vertex (Vertex_handle /* v */)
  {}

  virtual void before_remove_vertex (Vertex_handle /* v */)
  {}

  virtual void after_remove_vertex ()
  {}

  virtual void before_remove_edge (Halfedge_handle /* e */)
  {}

  virtual void after_remove_edge ()
  {}

  virtual void before_remove_outer_ccb (Face_handle /* f */,
                                        Ccb_halfedge_circulator /* h */)
  {}

  virtual void after_remove_outer_ccb (Face_handle /* f */)
  {}

  virtual void before_remove_inner_ccb (Face_handle /* f */,
                                        Ccb_halfedge_circulator /* h */)
  {}

  virtual void after_remove_inner_ccb (Face_handle /* f */)
  {}


};

CGAL_END_NAMESPACE

#endif