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.Pointer;
020 import org.apache.commons.jxpath.ri.EvalContext;
021 import org.apache.commons.jxpath.ri.model.NodePointer;
022
023 /**
024 * A single-set EvalContext that provides access to the current node of
025 * the parent context and nothing else. It does not pass the iteration
026 * on to the parent context.
027 *
028 * @author Dmitri Plotnikov
029 * @version $Revision: 652845 $ $Date: 2008-05-02 12:46:46 -0500 (Fri, 02 May 2008) $
030 */
031 public class InitialContext extends EvalContext {
032 private boolean started = false;
033 private boolean collection;
034 private NodePointer nodePointer;
035
036 /**
037 * Create a new InitialContext.
038 * @param parentContext parent context
039 */
040 public InitialContext(EvalContext parentContext) {
041 super(parentContext);
042 nodePointer =
043 (NodePointer) parentContext.getCurrentNodePointer().clone();
044 if (nodePointer != null) {
045 collection =
046 (nodePointer.getIndex() == NodePointer.WHOLE_COLLECTION);
047 }
048 }
049
050 public Pointer getSingleNodePointer() {
051 return nodePointer;
052 }
053
054 public NodePointer getCurrentNodePointer() {
055 return nodePointer;
056 }
057
058 public Object getValue() {
059 return nodePointer.getValue();
060 }
061
062 public boolean nextNode() {
063 return setPosition(position + 1);
064 }
065
066 public boolean setPosition(int position) {
067 this.position = position;
068 if (collection) {
069 if (position >= 1 && position <= nodePointer.getLength()) {
070 nodePointer.setIndex(position - 1);
071 return true;
072 }
073 return false;
074 }
075 return position == 1;
076 }
077
078 public boolean nextSet() {
079 if (started) {
080 return false;
081 }
082 started = true;
083 return true;
084 }
085 }