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    package org.apache.commons.jxpath.ri.axes;
018    
019    import org.apache.commons.jxpath.NodeSet;
020    import org.apache.commons.jxpath.ri.EvalContext;
021    import 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 12:46:46 -0500 (Fri, 02 May 2008) $
028     */
029    public 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    }