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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  package org.apache.commons.jxpath.ri.axes;
18  
19  import org.apache.commons.jxpath.Pointer;
20  import org.apache.commons.jxpath.ri.EvalContext;
21  import org.apache.commons.jxpath.ri.model.NodePointer;
22  
23  /**
24   * A single-set EvalContext that provides access to the current node of
25   * the parent context and nothing else.  It does not pass the iteration
26   * on to the parent context.
27   *
28   * @author Dmitri Plotnikov
29   * @version $Revision: 652845 $ $Date: 2008-05-02 13:46:46 -0400 (Fri, 02 May 2008) $
30   */
31  public class InitialContext extends EvalContext {
32      private boolean started = false;
33      private boolean collection;
34      private NodePointer nodePointer;
35  
36      /**
37       * Create a new InitialContext.
38       * @param parentContext parent context
39       */
40      public InitialContext(EvalContext parentContext) {
41          super(parentContext);
42          nodePointer =
43              (NodePointer) parentContext.getCurrentNodePointer().clone();
44          if (nodePointer != null) {
45              collection =
46                  (nodePointer.getIndex() == NodePointer.WHOLE_COLLECTION);
47          }
48      }
49  
50      public Pointer getSingleNodePointer() {
51          return nodePointer;
52      }
53  
54      public NodePointer getCurrentNodePointer() {
55          return nodePointer;
56      }
57  
58      public Object getValue() {
59          return nodePointer.getValue();
60      }
61  
62      public boolean nextNode() {
63          return setPosition(position + 1);
64      }
65  
66      public boolean setPosition(int position) {
67          this.position = position;
68          if (collection) {
69              if (position >= 1 && position <= nodePointer.getLength()) {
70                  nodePointer.setIndex(position - 1);
71                  return true;
72              }
73              return false;
74          }
75          return position == 1;
76      }
77  
78      public boolean nextSet() {
79          if (started) {
80              return false;
81          }
82          started = true;
83          return true;
84      }
85  }