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 "parent::" axis.
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 ParentContext extends EvalContext {
030 private NodeTest nodeTest;
031 private boolean setStarted = false;
032 private NodePointer currentNodePointer;
033
034 /**
035 * Create a new ParentContext.
036 * @param parentContext parent context
037 * @param nodeTest test
038 */
039 public ParentContext(EvalContext parentContext, NodeTest nodeTest) {
040 super(parentContext);
041 this.nodeTest = nodeTest;
042 }
043
044 public NodePointer getCurrentNodePointer() {
045 return currentNodePointer;
046 }
047
048 public int getCurrentPosition() {
049 return 1;
050 }
051
052 public int getDocumentOrder() {
053 return -1;
054 }
055
056 public void reset() {
057 super.reset();
058 setStarted = false;
059 }
060
061 public boolean setPosition(int position) {
062 super.setPosition(position);
063 return position == 1;
064 }
065
066 public boolean nextNode() {
067 // Each set contains exactly one node: the parent
068 if (setStarted) {
069 return false;
070 }
071 setStarted = true;
072 NodePointer thisLocation = parentContext.getCurrentNodePointer();
073 currentNodePointer = thisLocation.getImmediateParentPointer();
074 while (currentNodePointer != null
075 && currentNodePointer.isContainer()) {
076 currentNodePointer = currentNodePointer.getImmediateParentPointer();
077 }
078 if (currentNodePointer != null
079 && currentNodePointer.testNode(nodeTest)) {
080 position++;
081 return true;
082 }
083 return false;
084 }
085 }