001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *     http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.commons.jxpath.ri.axes;
018
019import org.apache.commons.jxpath.NodeSet;
020import org.apache.commons.jxpath.ri.EvalContext;
021import org.apache.commons.jxpath.ri.model.NodePointer;
022
023/**
024 * A simple context that is based on a {@link NodeSet}.
025 *
026 * @author Dmitri Plotnikov
027 * @version $Revision: 652845 $ $Date: 2008-05-02 13:46:46 -0400 (Fri, 02 May 2008) $
028 */
029public class NodeSetContext extends EvalContext {
030    private boolean startedSet = false;
031    private NodeSet nodeSet;
032
033    /**
034     * Create a new NodeSetContext.
035     * @param parentContext parent context
036     * @param nodeSet associated NodeSet
037     */
038    public NodeSetContext(EvalContext parentContext, NodeSet nodeSet) {
039        super(parentContext);
040        this.nodeSet = nodeSet;
041    }
042
043    public NodeSet getNodeSet() {
044        return nodeSet;
045    }
046
047    public NodePointer getCurrentNodePointer() {
048        if (position == 0 && !setPosition(1)) {
049            return null;
050        }
051        return (NodePointer) nodeSet.getPointers().get(position - 1);
052    }
053
054    public boolean setPosition(int position) {
055        super.setPosition(position);
056        return position >= 1 && position <= nodeSet.getPointers().size();
057    }
058
059    public boolean nextSet() {
060        if (startedSet) {
061            return false;
062        }
063        startedSet = true;
064        return true;
065    }
066
067    public boolean nextNode() {
068        return setPosition(position + 1);
069    }
070}