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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.configuration.tree.xpath;
18  
19  import java.util.ArrayList;
20  import java.util.Collections;
21  import java.util.Iterator;
22  import java.util.List;
23  
24  import org.apache.commons.configuration.tree.ConfigurationNode;
25  import org.apache.commons.jxpath.ri.Compiler;
26  import org.apache.commons.jxpath.ri.QName;
27  import org.apache.commons.jxpath.ri.compiler.NodeNameTest;
28  import org.apache.commons.jxpath.ri.compiler.NodeTest;
29  import org.apache.commons.jxpath.ri.compiler.NodeTypeTest;
30  import org.apache.commons.jxpath.ri.model.NodePointer;
31  import org.apache.commons.lang.StringUtils;
32  
33  /***
34   * A specialized iterator implementation for the child nodes of a configuration
35   * node.
36   *
37   * @since 1.3
38   * @author Oliver Heger
39   * @version $Id: ConfigurationNodeIteratorChildren.java 439648 2006-09-02 20:42:10Z oheger $
40   */
41  class ConfigurationNodeIteratorChildren extends ConfigurationNodeIteratorBase
42  {
43      /***
44       * Creates a new instance of <code>ConfigurationNodeIteratorChildren</code>
45       * and initializes it.
46       *
47       * @param parent the parent pointer
48       * @param nodeTest the test selecting the sub nodes
49       * @param reverse the reverse flag
50       * @param startsWith the first element of the iteration
51       */
52      public ConfigurationNodeIteratorChildren(NodePointer parent,
53              NodeTest nodeTest, boolean reverse, NodePointer startsWith)
54      {
55          super(parent, reverse);
56          ConfigurationNode root = (ConfigurationNode) parent.getNode();
57          List childNodes = createSubNodeList(root, nodeTest);
58          initSubNodeList(childNodes);
59          if (startsWith != null)
60          {
61              setStartOffset(findStartIndex(root,
62                      (ConfigurationNode) startsWith.getNode()));
63          }
64      }
65  
66      /***
67       * Creates the list with sub nodes. This method gets called during
68       * initialization phase. It finds out, based on the given test, which nodes
69       * must be iterated over.
70       *
71       * @param node the current node
72       * @param test the test object
73       * @return a list with the matching nodes
74       */
75      protected List createSubNodeList(ConfigurationNode node, NodeTest test)
76      {
77          List children = node.getChildren();
78  
79          if (test == null)
80          {
81              return children;
82          }
83          else
84          {
85              if (test instanceof NodeNameTest)
86              {
87                  NodeNameTest nameTest = (NodeNameTest) test;
88                  QName name = nameTest.getNodeName();
89                  if (name.getPrefix() == null)
90                  {
91                      if (nameTest.isWildcard())
92                      {
93                          return children;
94                      }
95  
96                      List result = new ArrayList();
97                      for (Iterator it = children.iterator(); it.hasNext();)
98                      {
99                          ConfigurationNode child = (ConfigurationNode) it.next();
100                         if (StringUtils.equals(name.getName(), child.getName()))
101                         {
102                             result.add(child);
103                         }
104                     }
105                     return result;
106                 }
107             }
108 
109             else if (test instanceof NodeTypeTest)
110             {
111                 NodeTypeTest typeTest = (NodeTypeTest) test;
112                 if (typeTest.getNodeType() == Compiler.NODE_TYPE_NODE
113                         || typeTest.getNodeType() == Compiler.NODE_TYPE_TEXT)
114                 {
115                     return children;
116                 }
117             }
118         }
119 
120         return Collections.EMPTY_LIST;
121     }
122 
123     /***
124      * Determines the start position of the iteration. Finds the index of the
125      * given start node in the children of the root node.
126      *
127      * @param node the root node
128      * @param startNode the start node
129      * @return the start node's index
130      */
131     protected int findStartIndex(ConfigurationNode node,
132             ConfigurationNode startNode)
133     {
134         for (int index = 0; index < node.getChildrenCount(); index++)
135         {
136             if (node.getChild(index) == startNode)
137             {
138                 return index;
139             }
140         }
141 
142         return -1;
143     }
144 }