/*
 *    GeoTools - The Open Source Java GIS Toolkit
 *    http://geotools.org
 *
 *    (C) 2002-2008, Open Source Geospatial Foundation (OSGeo)
 *
 *    This library 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;
 *    version 2.1 of the License.
 *
 *    This library 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.
 */
package org.geotools.xml.impl.jxpath;

import org.apache.commons.jxpath.ri.model.NodeIterator;
import org.apache.commons.jxpath.ri.model.NodePointer;
import org.opengis.feature.simple.SimpleFeature;


/**
 * Iterates over a single property of a feature.
 * <p>
 * Will "iterate" over fid if index is set to -1.
 * </p>
 *
 * @author Justin Deoliveira, The Open Planning Project
 *
 *
 * @source $URL$
 */
public class SingleFeaturePropertyIterator implements NodeIterator {
    /**
     * The feature node pointer
     */
    FeaturePointer pointer;

    /**
     * The feature.
     */
    SimpleFeature feature;

    /**
     * indedx of property
     */
    int index;

    /**
     * Creates the iteartor.
     *
     * @param pointer The pointer to the feature.
     * @param index The index of the property to iterate over, or -1 for the feature id.
     */
    public SingleFeaturePropertyIterator(FeaturePointer pointer, int index) {
        this.pointer = pointer;
        this.index = index;
        feature = (SimpleFeature) pointer.getImmediateNode();
    }

    /**
     * Always return 1, only a single property.
     */
    public int getPosition() {
        return 1;
    }

    /**
     * Return true if position == 1.
     */
    public boolean setPosition(int position) {
        return position < 2;
    }

    /**
     * Return a pointer to the property at the set index.
     */
    public NodePointer getNodePointer() {
        return new FeaturePropertyPointer(pointer, index);
    }
}