associated_elements_iterator.h

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/*
 * Copyright (c) 2015:  G-CSC, Goethe University Frankfurt
 * Author: Sebastian Reiter
 * 
 * This file is part of UG4.
 * 
 * UG4 is free software: you can redistribute it and/or modify it under the
 * terms of the GNU Lesser General Public License version 3 (as published by the
 * Free Software Foundation) with the following additional attribution
 * requirements (according to LGPL/GPL v3 §7):
 * 
 * (1) The following notice must be displayed in the Appropriate Legal Notices
 * of covered and combined works: "Based on UG4 (www.ug4.org/license)".
 * 
 * (2) The following notice must be displayed at a prominent place in the
 * terminal output of covered works: "Based on UG4 (www.ug4.org/license)".
 * 
 * (3) The following bibliography is recommended for citation and must be
 * preserved in all covered files:
 * "Reiter, S., Vogel, A., Heppner, I., Rupp, M., and Wittum, G. A massively
 *   parallel geometric multigrid solver on hierarchically distributed grids.
 *   Computing and visualization in science 16, 4 (2013), 151-164"
 * "Vogel, A., Reiter, S., Rupp, M., Nägel, A., and Wittum, G. UG4 -- a novel
 *   flexible software system for simulating pde based models on high performance
 *   computers. Computing and visualization in science 16, 4 (2013), 165-179"
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU Lesser General Public License for more details.
 */
 
#ifndef __H__UG_associated_elements_iterator
#define __H__UG_associated_elements_iterator
 
#include <iterator>
#include <limits>
#include "lib_grid/callbacks/basic_callbacks.h"
 
namespace ug{
 
 
template <class TElem, class TAssocElem, bool VSorted = false>
class AssocElemIter : public std::iterator<std::input_iterator_tag, TAssocElem*>
{
    public:
      AssocElemIter(typename Grid::traits<TAssocElem>::callback cbConsiderElem =
              ConsiderAll()) :
        m_i(0),
        m_cbConsiderElem(cbConsiderElem)
      {}
 
      AssocElemIter(Grid& grid, TElem* elem,
              typename Grid::traits<TAssocElem>::callback cbConsiderElem =
              ConsiderAll()) :
        m_i(0),
        m_cbConsiderElem(cbConsiderElem)
      {
        init(grid, elem);
      }
 
      void set_callback(typename Grid::traits<TAssocElem>::callback cbConsiderElem)
      {
        m_cbConsiderElem(cbConsiderElem);
      }
 
      void reinit(Grid& grid, TElem* elem)
      {
        m_i = 0;
        init(grid, elem);
      }
 
      void reinit(Grid& grid, TElem* elem,
            typename Grid::traits<TAssocElem>::callback cb)
      {
        m_i = 0;
        m_cbConsiderElem(cb);
        init(grid, elem);
      }
 
      AssocElemIter end() const
      {
        AssocElemIter e;
        e.m_i = std::numeric_limits<size_t>::max();
        return e;
      }
 
      bool valid() const  {return m_i < m_assElems.size();}
      bool invalid() const  {return m_i >= m_assElems.size();}
 
 
      AssocElemIter& operator ++()      {increment(); return *this;}
      AssocElemIter operator ++(int unused) {AssocElemIter i = *this; increment(); return i;}
 
      bool operator ==(const AssocElemIter& iter) const {return equal(iter);}
      bool operator !=(const AssocElemIter& iter) const {return !equal(iter);}
 
      TAssocElem* operator *()  {return dereference();}
 
    private:
      inline void init(Grid& grid, TElem* elem){
        if(VSorted)
          grid.associated_elements_sorted(m_assElems, elem);
        else
          grid.associated_elements(m_assElems, elem);
        
        if(valid() && (!m_cbConsiderElem(dereference())))
          increment();
      }
 
      inline bool equal(AssocElemIter const& other) const{
        if(valid()){
          if(other.valid()){
            if(dereference() == *other)
              return true;
          }
        }
        else{
          if(!other.valid())
            return true;
        }
        return false;
      }
 
      void increment(){
        while(1){
          ++m_i;
          if(valid()){
            if(m_cbConsiderElem(dereference()))
              break;
          }
          else
            break;
        }
      }
 
      inline TAssocElem* dereference() const{
        return m_assElems[m_i];
      }
 
    private:
      size_t m_i;
      typename Grid::traits<TAssocElem>::secure_container m_assElems;
      typename Grid::traits<TAssocElem>::callback     m_cbConsiderElem;
  };
 
}// end of namespace
 
#endif  //__H__UG_associated_elements_iterator