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Java > Open Source Codes > com > caucho > xpath > pattern > SelectedNode


1 /*
2  * Copyright (c) 1998-2006 Caucho Technology -- all rights reserved
3  *
4  * This file is part of Resin(R) Open Source
5  *
6  * Each copy or derived work must preserve the copyright notice and this
7  * notice unmodified.
8  *
9  * Resin Open Source is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License as published by
11  * the Free Software Foundation; either version 2 of the License, or
12  * (at your option) any later version.
13  *
14  * Resin Open Source is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, or any warranty
17  * of NON-INFRINGEMENT. See the GNU General Public License for more
18  * details.
19  *
20  * You should have received a copy of the GNU General Public License
21  * along with Resin Open Source; if not, write to the
22  * Free SoftwareFoundation, Inc.
23  * 59 Temple Place, Suite 330
24  * Boston, MA 02111-1307 USA
25  *
26  * @author Scott Ferguson
27  */
28
29 package com.caucho.xpath.pattern;
30
31 import org.w3c.dom.Node JavaDoc;
32
33 /**
34  * Represents a selected node.
35  */
36 public class SelectedNode {
37   protected Node JavaDoc _node;
38   
39   protected int _depth;
40   protected int _level;
41
42   /**
43    * Creates new selected node, calculating the index.
44    *
45    * @param node the underlying DOM node.
46    */
47   public SelectedNode(Node JavaDoc node)
48   {
49     _node = node;
50
51     _depth = 0;
52     for (Node JavaDoc ptr = node; ptr != null; ptr = ptr.getParentNode()) {
53       _depth++;
54     }
55
56     _level = 0;
57     for (Node JavaDoc ptr = node; ptr != null; ptr = ptr.getPreviousSibling()) {
58       _level++;
59     }
60   }
61
62   /**
63    * Returns the underlying DOM node.
64    */
65   public Node JavaDoc getNode()
66   {
67     return _node;
68   }
69
70   /**
71    * Returns the node's index
72    */
73   public int compareTo(SelectedNode b)
74   {
75     int aDepth = _depth;
76     int bDepth = b._depth;
77
78     Node JavaDoc aPtr = getNode();
79     Node JavaDoc bPtr = b.getNode();
80
81     if (aDepth == bDepth && aPtr.getParentNode() == bPtr.getParentNode())
82       return _level - b._level;
83
84     return compareTo(aPtr, aDepth, bPtr, bDepth);
85   }
86
87   /**
88    * Returns the node's index
89    */
90   static int compareTo(Node JavaDoc aPtr, int aDepth, Node JavaDoc bPtr, int bDepth)
91   {
92     for (int depth = aDepth; bDepth < depth; depth--)
93       aPtr = aPtr.getParentNode();
94     
95     for (int depth = bDepth; aDepth < depth; depth--)
96       bPtr = bPtr.getParentNode();
97
98     Node JavaDoc aParent;
99     Node JavaDoc bParent;
100     while ((aParent = aPtr.getParentNode()) !=
101            (bParent = bPtr.getParentNode())) {
102       aPtr = aParent;
103       bPtr = bParent;
104     }
105
106     if (aPtr == bPtr)
107       return aDepth - bDepth;
108
109     for (; aPtr != null; aPtr = aPtr.getPreviousSibling()) {
110       if (aPtr == bPtr)
111         return 1;
112     }
113
114     return -1;
115   }
116 }
117
118
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