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.ri.EvalContext;
020 import org.apache.commons.jxpath.ri.compiler.NodeTest;
021 import org.apache.commons.jxpath.ri.model.NodePointer;
022
023 /**
024 * EvalContext that walks the "ancestor::" and "ancestor-or-self::" axes.
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 AncestorContext extends EvalContext {
030 private NodeTest nodeTest;
031 private boolean setStarted = false;
032 private NodePointer currentNodePointer;
033 private boolean includeSelf;
034
035 /**
036 * Create a new AncestorContext.
037 * @param parentContext represents the previous step on the path
038 * @param includeSelf differentiates between "ancestor::" and
039 * "ancestor-or-self::" axes
040 * @param nodeTest is the name of the element(s) we are looking for
041 */
042 public AncestorContext(
043 EvalContext parentContext,
044 boolean includeSelf,
045 NodeTest nodeTest) {
046 super(parentContext);
047 this.includeSelf = includeSelf;
048 this.nodeTest = nodeTest;
049 }
050
051 public NodePointer getCurrentNodePointer() {
052 return currentNodePointer;
053 }
054
055 public int getDocumentOrder() {
056 return -1;
057 }
058
059 public void reset() {
060 super.reset();
061 setStarted = false;
062 }
063
064 public boolean setPosition(int position) {
065 if (position < getCurrentPosition()) {
066 reset();
067 }
068
069 while (getCurrentPosition() < position) {
070 if (!nextNode()) {
071 return false;
072 }
073 }
074 return true;
075 }
076
077 public boolean nextNode() {
078 if (!setStarted) {
079 setStarted = true;
080 currentNodePointer = parentContext.getCurrentNodePointer();
081 if (includeSelf && currentNodePointer.testNode(nodeTest)) {
082 position++;
083 return true;
084 }
085 }
086
087 while (true) {
088 currentNodePointer = currentNodePointer.getImmediateParentPointer();
089
090 if (currentNodePointer == null) {
091 return false;
092 }
093
094 if (currentNodePointer.testNode(nodeTest)) {
095 position++;
096 return true;
097 }
098 }
099 }
100 }