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 */
017
018package org.apache.commons.jxpath.ri.axes;
019
020import org.apache.commons.jxpath.NodeSet;
021import org.apache.commons.jxpath.ri.EvalContext;
022import org.apache.commons.jxpath.ri.model.NodePointer;
023
024/**
025 * A simple context that is based on a {@link NodeSet}.
026 */
027public class NodeSetContext extends EvalContext {
028
029    private boolean startedSet;
030    private final NodeSet nodeSet;
031
032    /**
033     * Constructs a new NodeSetContext.
034     *
035     * @param parentContext parent context
036     * @param nodeSet       associated NodeSet
037     */
038    public NodeSetContext(final EvalContext parentContext, final NodeSet nodeSet) {
039        super(parentContext);
040        this.nodeSet = nodeSet;
041    }
042
043    @Override
044    public NodePointer getCurrentNodePointer() {
045        if (position == 0 && !setPosition(1)) {
046            return null;
047        }
048        return (NodePointer) nodeSet.getPointers().get(position - 1);
049    }
050
051    @Override
052    public NodeSet getNodeSet() {
053        return nodeSet;
054    }
055
056    @Override
057    public boolean nextNode() {
058        return setPosition(position + 1);
059    }
060
061    @Override
062    public boolean nextSet() {
063        if (startedSet) {
064            return false;
065        }
066        startedSet = true;
067        return true;
068    }
069
070    @Override
071    public boolean setPosition(final int position) {
072        super.setPosition(position);
073        return position >= 1 && position <= nodeSet.getPointers().size();
074    }
075}