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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.Pointer;
21  import org.apache.commons.jxpath.ri.EvalContext;
22  import org.apache.commons.jxpath.ri.model.NodePointer;
23  
24  /**
25   * A single-set EvalContext that provides access to the current node of the parent context and nothing else. It does not pass the iteration on to the parent
26   * context.
27   */
28  public class InitialContext extends EvalContext {
29  
30      private boolean started;
31      private boolean collection;
32      private final NodePointer nodePointer;
33  
34      /**
35       * Constructs a new InitialContext.
36       *
37       * @param parentContext parent context
38       */
39      public InitialContext(final EvalContext parentContext) {
40          super(parentContext);
41          nodePointer = (NodePointer) parentContext.getCurrentNodePointer().clone();
42          if (nodePointer != null) {
43              collection = nodePointer.getIndex() == NodePointer.WHOLE_COLLECTION;
44          }
45      }
46  
47      @Override
48      public NodePointer getCurrentNodePointer() {
49          return nodePointer;
50      }
51  
52      @Override
53      public Pointer getSingleNodePointer() {
54          return nodePointer;
55      }
56  
57      @Override
58      public Object getValue() {
59          return nodePointer.getValue();
60      }
61  
62      @Override
63      public boolean nextNode() {
64          return setPosition(position + 1);
65      }
66  
67      @Override
68      public boolean nextSet() {
69          if (started) {
70              return false;
71          }
72          started = true;
73          return true;
74      }
75  
76      @Override
77      public boolean setPosition(final int position) {
78          this.position = position;
79          if (collection) {
80              if (position >= 1 && position <= nodePointer.getLength()) {
81                  nodePointer.setIndex(position - 1);
82                  return true;
83              }
84              return false;
85          }
86          return position == 1;
87      }
88  }