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1
61 package org.jaxen.expr;
62
63 import java.util.Comparator  ;
64 import java.util.Iterator ;
65
66 import org.jaxen.Navigator;
67 import org.jaxen.UnsupportedAxisException;
68
69
70 class NodeComparator implements Comparator {
71
72 private Navigator navigator;
73
74
75 NodeComparator(Navigator navigator) {
76 this.navigator = navigator;
77 }
78
79 public int compare(Object o1, Object o2) {
80
81 if (navigator == null) return 0;
82
83 if (isNonChild(o1) && isNonChild(o2)) {
84
85 try {
86 Object p1 = navigator.getParentNode(o1);
87 Object p2 = navigator.getParentNode(o2);
88
89 if (p1 == p2) {
90 if (navigator.isNamespace(o1) && navigator.isAttribute(o2)) {
91 return -1;
92 }
93 else if (navigator.isNamespace(o2) && navigator.isAttribute(o1)) {
94 return 1;
95 }
96 }
97
98 return compare(p1, p2);
99 }
100 catch (UnsupportedAxisException ex) {
101 return 0;
102 }
103
104 }
105
106 try {
107 int depth1 = getDepth(o1);
108 int depth2 = getDepth(o2);
109
110 Object a1 = o1;
111 Object a2 = o2;
112
113 while (depth1 > depth2) {
114 a1 = navigator.getParentNode(a1);
115 depth1--;
116 }
117 if (a1 == o2) return 1;
118
119 while (depth2 > depth1) {
120 a2 = navigator.getParentNode(a2);
121 depth2--;
122 }
123 if (a2 == o1) return -1;
124
125 while (true) {
127 Object p1 = navigator.getParentNode(a1);
128 Object p2 = navigator.getParentNode(a2);
129 if (p1 == p2) {
130 return compareSiblings(a1, a2);
131 }
132 a1 = p1;
133 a2 = p2;
134 }
135
136 }
137 catch (UnsupportedAxisException ex) {
138 return 0; }
140 }
141
142
143 private boolean isNonChild(Object o) {
144 return navigator.isAttribute(o) || navigator.isNamespace(o);
145 }
146
147 private int compareSiblings(Object sib1, Object sib2)
148 throws UnsupportedAxisException {
149
150 Iterator following = navigator.getFollowingSiblingAxisIterator(sib1);
151 while (following.hasNext()) {
152 Object next = following.next();
153 if (next.equals(sib2)) return -1;
154 }
155 return 1;
156
157 }
158
159 private int getDepth(Object o) throws UnsupportedAxisException {
160
161 int depth = 0;
162 Object parent = o;
163
164 while ((parent = navigator.getParentNode(parent)) != null) {
165 depth++;
166 }
167 return depth;
168
169 }
170
171 }
172 |
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