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1   /*
2    * Copyright 1999-2004 The Apache Software Foundation
3    *
4    * Licensed under the Apache License, Version 2.0 (the "License");
5    * you may not use this file except in compliance with the License.
6    * You may obtain a copy of the License at
7    *
8    *     http://www.apache.org/licenses/LICENSE-2.0
9    *
10   * Unless required by applicable law or agreed to in writing, software
11   * distributed under the License is distributed on an "AS IS" BASIS,
12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13   * See the License for the specific language governing permissions and
14   * limitations under the License.
15   */
16  package org.apache.commons.jxpath.ri.axes;
17  
18  import org.apache.commons.jxpath.ri.EvalContext;
19  import org.apache.commons.jxpath.ri.compiler.NodeTest;
20  import org.apache.commons.jxpath.ri.model.NodePointer;
21  
22  /***
23   * EvalContext that walks the "parent::" axis.
24   *
25   * @author Dmitri Plotnikov
26   * @version $Revision: 1.15 $ $Date: 2004/03/25 03:49:50 $
27   */
28  public class ParentContext extends EvalContext {
29      private NodeTest nodeTest;
30      private boolean setStarted = false;
31      private NodePointer currentNodePointer;
32  
33      public ParentContext(EvalContext parentContext, NodeTest nodeTest) {
34          super(parentContext);
35          this.nodeTest = nodeTest;
36      }
37  
38      public NodePointer getCurrentNodePointer() {
39          return currentNodePointer;
40      }
41  
42      public int getCurrentPosition() {
43          return 1;
44      }
45  
46      public int getDocumentOrder() {
47          return -1;
48      }
49  
50      public void reset() {
51          super.reset();
52          setStarted = false;
53      }
54  
55      public boolean setPosition(int position) {
56          super.setPosition(position);
57          return position == 1;
58      }
59  
60      public boolean nextNode() {
61          // Each set contains exactly one node: the parent
62          if (setStarted) {
63              return false;
64          }
65          setStarted = true;
66          NodePointer thisLocation = parentContext.getCurrentNodePointer();
67          currentNodePointer = thisLocation.getImmediateParentPointer();
68          while (currentNodePointer != null
69              && currentNodePointer.isContainer()) {
70              currentNodePointer = currentNodePointer.getImmediateParentPointer();
71          }
72          if (currentNodePointer != null
73              && currentNodePointer.testNode(nodeTest)) {
74              position++;
75              return true;
76          }
77          return false;
78      }
79  }