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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    *
9    *     http://www.apache.org/licenses/LICENSE-2.0
10   *
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
15   * limitations under the License.
16   */
17  
18  package org.apache.commons.jxpath.ri.axes;
19  
20  import org.apache.commons.jxpath.ri.EvalContext;
21  import org.apache.commons.jxpath.ri.compiler.NodeTest;
22  import org.apache.commons.jxpath.ri.model.NodePointer;
23  
24  /**
25   * EvalContext that walks the "ancestor::" and "ancestor-or-self::" axes.
26   */
27  public class AncestorContext extends EvalContext {
28  
29      private final NodeTest nodeTest;
30      private boolean setStarted;
31      private NodePointer currentNodePointer;
32      private final boolean includeSelf;
33  
34      /**
35       * Constructs a new AncestorContext.
36       *
37       * @param parentContext represents the previous step on the path
38       * @param includeSelf   differentiates between "ancestor::" and "ancestor-or-self::" axes
39       * @param nodeTest      is the name of the element(s) we are looking for
40       */
41      public AncestorContext(final EvalContext parentContext, final boolean includeSelf, final NodeTest nodeTest) {
42          super(parentContext);
43          this.includeSelf = includeSelf;
44          this.nodeTest = nodeTest;
45      }
46  
47      @Override
48      public NodePointer getCurrentNodePointer() {
49          return currentNodePointer;
50      }
51  
52      @Override
53      public int getDocumentOrder() {
54          return -1;
55      }
56  
57      @Override
58      public boolean nextNode() {
59          if (!setStarted) {
60              setStarted = true;
61              currentNodePointer = parentContext.getCurrentNodePointer();
62              if (includeSelf && currentNodePointer.testNode(nodeTest)) {
63                  position++;
64                  return true;
65              }
66          }
67          while (true) {
68              currentNodePointer = currentNodePointer.getImmediateParentPointer();
69              if (currentNodePointer == null) {
70                  return false;
71              }
72              if (currentNodePointer.testNode(nodeTest)) {
73                  position++;
74                  return true;
75              }
76          }
77      }
78  
79      @Override
80      public void reset() {
81          super.reset();
82          setStarted = false;
83      }
84  
85      @Override
86      public boolean setPosition(final int position) {
87          if (position < getCurrentPosition()) {
88              reset();
89          }
90          while (getCurrentPosition() < position) {
91              if (!nextNode()) {
92                  return false;
93              }
94          }
95          return true;
96      }
97  }