ListIterator.h

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/*
 * Copyright (C) 2015 Niek Linnenbank
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
#ifndef __LIBSTD_LISTITERATOR_H
#define __LIBSTD_LISTITERATOR_H
 
#include "Macros.h"
#include "Iterator.h"
#include "List.h"
#include "Assert.h"
 
template <class T> class ListIterator : public Iterator<T>
{
  public:
 
    ListIterator(List<T> *list)
        : m_list(*list)
    {
 
        m_current = ZERO;
        reset();
    }
 
    ListIterator(List<T> & list)
        : m_list(list)
    {
 
        m_current = ZERO;
        reset();
    }
 
    ListIterator(const List<T> & list)
        : m_list((List<T> &) list)
    {
 
        m_current = ZERO;
        reset();
    }
 
    virtual void reset()
    {
        m_current = m_list.head();
        m_next = m_current;
    }
 
    virtual bool hasNext() const
    {
        return m_next != ZERO;
    }
 
    virtual bool hasCurrent() const
    {
        return m_current != ZERO;
    }
 
    virtual const T & current() const
    {
        return m_current->data;
    }
 
    virtual T & current()
    {
        return m_current->data;
    }
 
    virtual T & next()
    {
 
        m_current = m_next;
        m_next = m_current->next;
        return m_current->data;
    }
 
    virtual bool remove()
    {
        // Do we have a current item?
        if (!m_current)
            return false;
 
        // Update iterator administration
        class List<T>::Node *node = m_current;
        m_current = m_current->next;
        m_next = m_current;
 
        // Delete the node on the List
        m_list.remove(node);
        return true;
    }
 
    virtual void operator++(int num)
    {
        if (m_current)
        {
            m_current = m_current->next;
 
            if (m_current)
                m_next = m_current->next;
            else
                m_next = ZERO;
        }
    }
 
  private:
 
    List<T> & m_list;
 
    class List<T>::Node *m_current;
 
    class List<T>::Node *m_next;
};
 
#endif /* __LIBSTD_LISTITERATOR_H */