Arr_observer.h
// Copyright (c) 2006,2007,2009,2010,2011 Tel-Aviv University (Israel).
// All rights reserved.
//
// This file is part of CGAL (www.cgal.org).
//
// $URL$
// $Id$
// SPDX-License-Identifier: GPL-3.0-or-later OR LicenseRef-Commercial
//
//
// Author(s) : Ron Wein <wein@post.tau.ac.il>
// Efi Fogel <efif@post.tau.ac.il>
#ifndef CGAL_ARR_OBSERVER_H
#define CGAL_ARR_OBSERVER_H
#include <CGAL/license/Arrangement_on_surface_2.h>
#include <CGAL/disable_warnings.h>
#include <CGAL/Arr_enums.h>
/*! \file
* Definition of the Arr_observer<Arrangement> base class.
*/
namespace CGAL {
/*! \class
* A base class for arrangement observers.
* The Arrangement parameter corresponds to an arrangement instantiation.
*/
template <typename 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.
/*! Copy constructor - not supported. */
Arr_observer(const Self&);
/*! Assignment operator - not supported. */
Self& operator=(const Self&);
public:
/// \name Construction and destruction functions.
//@{
/*! Default constructor. */
Arr_observer() : p_arr(nullptr) {}
/*! Constructor with an associated arrangement. */
Arr_observer(Arrangement_2& arr) : p_arr(&arr)
{
// Register the observer object in the arrangement.
p_arr->_register_observer(this);
}
/*! Destructor. */
virtual ~Arr_observer()
{
// Unregister the observer object from the arrangement.
if (p_arr != nullptr)
p_arr->_unregister_observer(this);
}
//@}
/// \name Modifying the associated arrangement.
//@{
/*! Get the associated arrangement (non-const version). */
const Arrangement_2* arrangement() const { return (p_arr); }
/*! Get the associated arrangement (non-const version). */
Arrangement_2* arrangement() { return (p_arr); }
/*! Attach the observer to an arrangement.
* \pre The observer is not already attached to an arrangement.
*/
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 == nullptr);
if (p_arr != nullptr) return;
// Notify the concrete observer (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 observer that the attachment took place.
after_attach();
}
/*! Detach the observer from the arrangement. */
void detach()
{
if (p_arr == nullptr) return;
// Notify the concrete observer (the sub-class) about the detachment.
before_detach ();
// Unregister the observer object from the current arrangement, and mark
// that the observer is not attached to an arrangement.
p_arr->_unregister_observer(this);
p_arr = nullptr;
// Notify the concrete observer that the detachment took place.
after_detach();
}
//@}
/// \name Notification functions on global arrangement operations.
//@{
/*! Notification before the arrangement is assigned with another
* arrangement.
* \param arr The arrangement to be copied.
*/
virtual void before_assign(const Arrangement_2& /* arr */) {}
/*! Notification after the arrangement has been assigned with another
* arrangement.
*/
virtual void after_assign() {}
/*! Notification before the arrangement is cleared. */
virtual void before_clear() {}
/*! Notification after the arrangement is cleared. */
virtual void after_clear() {}
/*! Notification before a global operation modifies the arrangement. */
virtual void before_global_change() {}
/*! Notification after a global operation is completed. */
virtual void after_global_change() {}
//@}
/// \name Notification functions on observer attachment or detachment.
//@{
/*! Notification before the observer is attached to an arrangement.
* \param arr The arrangement we are about to attach the observer to.
*/
virtual void before_attach(const Arrangement_2& /* arr */) {}
/*! Notification after the observer has been attached to an arrangement. */
virtual void after_attach() {}
/*! Notification before the observer is detached from the arrangement. */
virtual void before_detach() {}
/*! Notification after the observer has been detached to the arrangement. */
virtual void after_detach() {}
//@}
/// \name Notification functions on local changes in the arrangement.
//@{
/*!
* Notification before the creation of a new vertex.
* \param p The point to be associated with the vertex.
* This point cannot lies on the surface boundaries.
*/
virtual void before_create_vertex(const Point_2& /* p */) {}
/*! Notification after the creation of a new vertex.
* \param v A handle to the created vertex.
*/
virtual void after_create_vertex(Vertex_handle /* v */)
{}
/*! Notification before the creation of a new boundary vertex.
* \param p The on the surface boundary.
* \param ps_x The boundary condition of the vertex in x.
* \param ps_y The boundary condition of the vertex in y.
*/
virtual void before_create_boundary_vertex(const Point_2& /* p */,
Arr_parameter_space /* ps_x */,
Arr_parameter_space /* ps_y */)
{}
/*! Notification before the creation of a new boundary vertex.
* \param cv The curve incident to the surface boundary.
* \param ind The relevant curve-end.
* \param ps_x The boundary condition of the vertex in x.
* \param ps_y The boundary condition of the vertex in y.
*/
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 */)
{}
/*! Notification after the creation of a new vertex at infinity.
* \param v A handle to the created vertex.
*/
virtual void after_create_boundary_vertex(Vertex_handle /* v */) {}
/*! Notification before the creation of a new edge.
* \param c The x-monotone curve to be associated with the edge.
* \param v1 A handle to the first end-vertex of the edge.
* \param v2 A handle to the second end-vertex of the edge.
*/
virtual void before_create_edge(const X_monotone_curve_2& /* c */,
Vertex_handle /* v1 */,
Vertex_handle /* v2 */)
{}
/*! Notification after the creation of a new edge.
* \param e A handle to one of the twin halfedges that were created.
*/
virtual void after_create_edge(Halfedge_handle /* e */) {}
/*! Notification before the modification of an existing vertex.
* \param v A handle to the vertex to be updated.
* \param p The point to be associated with the vertex.
*/
virtual void before_modify_vertex(Vertex_handle /* v */,
const Point_2& /* p */)
{}
/*! Notification after a vertex was modified.
* \param v A handle to the updated vertex.
*/
virtual void after_modify_vertex(Vertex_handle /* v */) {}
/*! Notification before the modification of an existing edge.
* \param e A handle to one of the twin halfedges to be updated.
* \param c The x-monotone curve to be associated with the edge.
*/
virtual void before_modify_edge(Halfedge_handle /* e */,
const X_monotone_curve_2& /* c */)
{}
/*! Notification after an edge was modified.
* \param e A handle to one of the twin halfedges that were updated.
*/
virtual void after_modify_edge(Halfedge_handle /* e */) {}
/*! Notification before the splitting of an edge into two.
* \param e A handle to one of the existing halfedges.
* \param v A vertex representing the split point.
* \param c1 The x-monotone curve to be associated with the first edge.
* \param c2 The x-monotone curve to be associated with the second edge.
*/
virtual void before_split_edge(Halfedge_handle /* e */,
Vertex_handle /* v */,
const X_monotone_curve_2& /* c1 */,
const X_monotone_curve_2& /* c2 */)
{}
/*! Notification after an edge was split.
* \param e1 A handle to one of the twin halfedges forming the first edge.
* \param e2 A handle to one of the twin halfedges forming the second edge.
*/
virtual void after_split_edge(Halfedge_handle /* e1 */,
Halfedge_handle /* e2 */)
{}
/*! Notification before the splitting of a fictitious edge into two.
* \param e A handle to one of the existing halfedges.
* \param v A vertex representing the unbounded split point.
*/
virtual void before_split_fictitious_edge(Halfedge_handle /* e */,
Vertex_handle /* v */)
{}
/*! Notification after a fictitious edge was split.
* \param e1 A handle to one of the twin halfedges forming the first edge.
* \param e2 A handle to one of the twin halfedges forming the second edge.
*/
virtual void after_split_fictitious_edge(Halfedge_handle /* e1 */,
Halfedge_handle /* e2 */)
{}
/*! Notification before the splitting of a face into two.
* \param f A handle to the existing face.
* \param e The new edge whose insertion causes the face to split.
*/
virtual void before_split_face(Face_handle /* f */,
Halfedge_handle /* e */)
{}
/*! Notification after a face was split.
* \param f A handle to the face we have just split.
* \param new_f A handle to the new face that has been created.
* \param is_hole Whether the new face forms a hole inside f.
*/
virtual void after_split_face(Face_handle /* f */,
Face_handle /* new_f */,
bool /* is_hole */)
{}
/*! Notification before the splitting of an outer CCB into two.
* \param f A handle to the face that owns the outer CCB.
* \param h A circulator representing the component boundary.
* \param e The new edge whose removal causes the outer CCB to split.
*/
virtual void before_split_outer_ccb(Face_handle /* f */,
Ccb_halfedge_circulator /* h */,
Halfedge_handle /* e */)
{}
/*! Notification after an outer CCB was split.
* \param f A handle to the face that owns the outer CCBs.
* \param h1 A circulator representing the boundary of the first component.
* \param h2 A circulator representing the boundary of the second component.
*/
virtual void after_split_outer_ccb(Face_handle /* f */,
Ccb_halfedge_circulator /* h1 */,
Ccb_halfedge_circulator /* h2 */)
{}
/*! Notification before the splitting of an inner CCB into two.
* \param f A handle to the face containing the inner CCB.
* \param h A circulator representing the component boundary.
* \param e The new edge whose removal causes the inner CCB to split.
*/
virtual void before_split_inner_ccb(Face_handle /* f */,
Ccb_halfedge_circulator /* h */,
Halfedge_handle /* e */)
{}
/*! Notification after an inner CCB was split.
* \param f A handle to the face containing the inner CCBs.
* \param h1 A circulator representing the boundary of the first component.
* \param h2 A circulator representing the boundary of the second component.
*/
virtual void after_split_inner_ccb(Face_handle /* f */,
Ccb_halfedge_circulator /* h1 */,
Ccb_halfedge_circulator /* h2 */)
{}
/*! Notification before the creation of a new outer CCB of a face.
* \param f A handle to the face that owns the outer CCB.
* \param e A halfedge along the new outer CCB.
*/
virtual void before_add_outer_ccb(Face_handle /* f */,
Halfedge_handle /* e */)
{}
/*! Notification after an outer CCB was added to a face.
* \param h A circulator representing the boundary of the new outer CCB.
*/
virtual void after_add_outer_ccb(Ccb_halfedge_circulator /* h */) {}
/*! Notification before the creation of a new inner CCB inside a face.
* \param f A handle to the face containing the inner CCB.
* \param e The new halfedge that forms the new inner CCB.
*/
virtual void before_add_inner_ccb(Face_handle /* f */,
Halfedge_handle /* e */)
{}
/*! Notification after an inner CCB was created inside a face.
* \param h A circulator representing the boundary of the new inner CCB.
*/
virtual void after_add_inner_ccb(Ccb_halfedge_circulator /* h */) {}
/*! Notification before the creation of a new isolated vertex inside a face.
* \param f A handle to the face containing the isolated vertex.
* \param v The isolated vertex.
*/
virtual void before_add_isolated_vertex(Face_handle /* f */,
Vertex_handle /* v */)
{}
/*! Notification after an isolated vertex was created inside a face.
* \param v The isolated vertex.
*/
virtual void after_add_isolated_vertex(Vertex_handle /* v */) {}
/*! Notification before the merging of two edges.
* \param e1 A handle to one of the halfedges forming the first edge.
* \param e2 A handle to one of the halfedges forming the second edge.
* \param c The x-monotone curve to be associated with the merged edge.
*/
virtual void before_merge_edge(Halfedge_handle /* e1 */,
Halfedge_handle /* e2 */,
const X_monotone_curve_2& /* c */)
{}
/*! Notification after an edge was merged.
* \param e A handle to one of the twin halfedges forming the merged edge.
*/
virtual void after_merge_edge(Halfedge_handle /* e */) {}
/*! Notification before the merging of two fictitious edges.
* \param e1 A handle to one of the halfedges forming the first edge.
* \param e2 A handle to one of the halfedges forming the second edge.
*/
virtual void before_merge_fictitious_edge(Halfedge_handle /* e1 */,
Halfedge_handle /* e2 */)
{}
/*! Notification after a fictitious edge was merged.
* \param e A handle to one of the twin halfedges forming the merged edge.
*/
virtual void after_merge_fictitious_edge(Halfedge_handle /* e */) {}
/*! Notification before the merging of two faces.
* \param f1 A handle to the first face.
* \param f2 A handle to the second face.
* \param e The edge whose removal causes the faces to merge.
*/
virtual void before_merge_face(Face_handle /* f1 */,
Face_handle /* f2 */,
Halfedge_handle /* e */)
{}
/*! Notification after a face was merged.
* \param f A handle to the merged face.
*/
virtual void after_merge_face(Face_handle /* f */) {}
/*! Notification before the merging of two outer CCBs.
* \param f A handle to the face that owns the outer CCBs.
* \param h1 A circulator representing the boundary of the first component.
* \param h2 A circulator representing the boundary of the second component.
* \param e The edge whose insertion or removal causes the CCBs to merge.
*/
virtual void before_merge_outer_ccb(Face_handle /* f */,
Ccb_halfedge_circulator /* h1 */,
Ccb_halfedge_circulator /* h2 */,
Halfedge_handle /* e */)
{}
/*! Notification after an outer CCB was merged.
* \param f A handle to the face that owns the outer CCBs.
* \param h A circulator representing the boundary of the merged component.
*/
virtual void after_merge_outer_ccb(Face_handle /* f */,
Ccb_halfedge_circulator /* h */)
{}
/*! Notification before the merging of two inner CCBs (holes).
* \param f A handle to the face that contains the inner CCBs.
* \param h1 A circulator representing the boundary of the first component.
* \param h2 A circulator representing the boundary of the second component.
* \param e The edge whose insertion causes the inner CCBs to merge.
*/
virtual void before_merge_inner_ccb(Face_handle /* f */,
Ccb_halfedge_circulator /* h1 */,
Ccb_halfedge_circulator /* h2 */,
Halfedge_handle /* e */)
{}
/*! Notification after an inner CCB was merged.
* \param f A handle to the face that contains the inner CCBs.
* \param h A circulator representing the boundary of the merged component.
*/
virtual void after_merge_inner_ccb(Face_handle /* f */,
Ccb_halfedge_circulator /* h */)
{}
/*! Notification before an outer CCB is moved from one face to another.
* \param from_f A handle to the face that currently owns the outer CCB.
* \param to_f A handle to the face that should own the outer CCB.
* \param h A circulator representing the boundary of the component.
*/
virtual void before_move_outer_ccb(Face_handle /* from_f */,
Face_handle /* to_f */,
Ccb_halfedge_circulator /* h */)
{}
/*! Notification after an outer CCB is moved from one face to another.
* \param h A circulator representing the boundary of the component.
*/
virtual void after_move_outer_ccb(Ccb_halfedge_circulator /* h */) {}
/*! Notification before an inner CCB is moved from one face to another.
* \param from_f A handle to the face currently containing the inner CCB.
* \param to_f A handle to the face that should contain the inner CCB.
* \param h A circulator representing the boundary of the component.
*/
virtual void before_move_inner_ccb(Face_handle /* from_f */,
Face_handle /* to_f */,
Ccb_halfedge_circulator /* h */)
{}
/*!
* Notification after an inner CCB is moved from one face to another.
* \param h A circulator representing the boundary of the component.
*/
virtual void after_move_inner_ccb(Ccb_halfedge_circulator /* h */) {}
/*! Notification before an isolated vertex is moved from one face to another.
* \param from_f A handle to the face currently containing the vertex.
* \param to_f A handle to the face that should contain the vertex.
* \param v The isolated vertex.
*/
virtual void before_move_isolated_vertex(Face_handle /* from_f */,
Face_handle /* to_f */,
Vertex_handle /* v */)
{}
/*! Notification after an isolated vertex is moved from one face to another.
* \param v The isolated vertex.
*/
virtual void after_move_isolated_vertex(Vertex_handle /* v */) {}
/*! Notificaion before the removal of a vertex.
* \param v A handle to the vertex to be deleted.
*/
virtual void before_remove_vertex(Vertex_handle /* v */) {}
/*! Notificaion after the removal of a vertex. */
virtual void after_remove_vertex() {}
/*! Notification before the removal of an edge.
* \param e A handle to one of the twin halfedges to be deleted.
*/
virtual void before_remove_edge(Halfedge_handle /* e */) {}
/*! Notificaion after the removal of an edge. */
virtual void after_remove_edge() {}
/*! Notification before the removal of an outer CCB.
* \param f The face that owns the outer CCB.
* \param h A circulator representing the boundary of the component.
*/
virtual void before_remove_outer_ccb(Face_handle /* f */,
Ccb_halfedge_circulator /* h */)
{}
/*! Notificaion after the removal of an outer CCB.
* \param f The face that used to own the outer CCB.
*/
virtual void after_remove_outer_ccb(Face_handle /* f */) {}
/*! Notification before the removal of an inner CCB.
* \param f The face containing the inner CCB.
* \param h A circulator representing the boundary of the component.
*/
virtual void before_remove_inner_ccb(Face_handle /* f */,
Ccb_halfedge_circulator /* h */)
{}
/*! Notificaion after the removal of an inner CCB.
* \param f The face that used to contain the inner CCB.
*/
virtual void after_remove_inner_ccb(Face_handle /* f */) {}
//@}
};
} //namespace CGAL
#include <CGAL/enable_warnings.h>
#endif
