filteriterator.h

/*
 *
 * This file is part of Tulip (www.tulip-software.org)
 *
 * Authors: David Auber and the Tulip development Team
 * from LaBRI, University of Bordeaux 1 and Inria Bordeaux - Sud Ouest
 *
 * Tulip is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License
 * as published by the Free Software Foundation, either version 3
 * of the License, or (at your option) any later version.
 *
 * Tulip 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 General Public License for more details.
 *
 */
///@cond DOXYGEN_HIDDEN

#ifndef FILTERITERATOR_H
#define FILTERITERATOR_H

#include <tulip/memorypool.h>



namespace tlp {
/**
  * @class FilterIterator
  * @brief Iterator that enables to filter an other Iterator
  * @param it the iterator that should be filtered
  * @param filter the functor that enables to test wheter or not an element is filtered
  *
  * The functor function shoul have the following form
  * @code
  * class AFilterFunctor {
  *  bool operator()(TYPE a) {
  *    return true if a should be iterated, false if a should be removed;
  *  }
  * };
  * @endcode
  */
template <typename TYPE, typename FILTER>
class FilterIterator : public Iterator<TYPE> {
public:
  FilterIterator(Iterator<TYPE> *it, FILTER filter):
    _it(it),
    _filter(filter) {
    update();
  }
  ~FilterIterator() {
    delete _it;
  }
  inline TYPE next() {
    TYPE tmp = _curVal;
    update();
    return tmp;
  }
  inline bool hasNext() {
    return _hasNext;
  }

private:
  void update() {
    _hasNext = false;

    while (_it->hasNext()) {
      _curVal = _it->next();

      if (_filter(_curVal)) {
        _hasNext = true;
        break;
      }
    }
  }

  bool _hasNext;
  Iterator<TYPE> *_it;
  TYPE   _curVal;
  FILTER _filter;
  size_t _nbele;
};
/**
  * @class MPFilterIterator
  * @brief MPFilterIterator implements memory pool for FilterIterator
  * @warning never inherit from that class
  * @see FilterIterator
  */
template <typename TYPE, typename FILTER>
class MPFilterIterator : public FilterIterator<TYPE, FILTER>, public MemoryPool<MPFilterIterator<TYPE, FILTER> > {
public:
  MPFilterIterator(Iterator<TYPE> *it, FILTER filter):
    FilterIterator<TYPE, FILTER>(it, filter) {
  }
};

}
#endif // FILTERITERATOR_H
///@endcond