/*
 * Copyright (C) 2005-2010 Alfresco Software Limited.
 *
 * This file is part of Alfresco
 *
 * Alfresco 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.
 *
 * Alfresco 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.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with Alfresco. If not, see <http://www.gnu.org/licenses/>.
 */
package org.alfresco.repo.search;

import org.alfresco.service.cmr.search.ResultSet;
import org.alfresco.service.cmr.search.ResultSetRow;


/**
 * Iterate over the rows in a ResultSet
 * 
 * @author andyh
 * 
 */
public abstract class AbstractResultSetRowIterator implements ResultSetRowIterator
{
    /**
     * The result set
     */
    private ResultSet resultSet;

    /**
     * The current position
     */
    private int position = -1;

    /**
     * The maximum position
     */
    private int max;

    /**
     * Create an iterator over the result set. Follows stadard ListIterator
     * conventions
     * 
     * @param resultSet
     */
    public AbstractResultSetRowIterator(ResultSet resultSet)
    {
        super();
        this.resultSet = resultSet;
        this.max = resultSet.length();
    }

    
    
    public ResultSet getResultSet()
    {
        return resultSet;
    }
    



    /*
     * ListIterator implementation
     */
    public boolean hasNext()
    {
        return position < (max - 1);
    }

    public boolean allowsReverse()
    {
        return true;
    }

    public boolean hasPrevious()
    {
        return position > 0;
    }

    abstract public ResultSetRow next();
    
    protected int moveToNextPosition()
    {
        return ++position;
    }

    abstract public ResultSetRow previous();
    
    protected int moveToPreviousPosition()
    {
        return --position;
    }

    public int nextIndex()
    {
        return position + 1;
    }

    public int previousIndex()
    {
        return position - 1;
    }

    /*
     * Mutation is not supported
     */

    public void remove()
    {
        // TODO Auto-generated method stub
        throw new UnsupportedOperationException();
    }

    public void set(ResultSetRow o)
    {
        // TODO Auto-generated method stub
        throw new UnsupportedOperationException();
    }

    public void add(ResultSetRow o)
    {
        // TODO Auto-generated method stub
        throw new UnsupportedOperationException();
    }

}