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Java > Open Source Codes > org > apache > commons > jxpath > ri > model > jdom > JDOMNamespaceIterator


1 /*
2  * Copyright 1999-2004 The Apache Software Foundation
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  * http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 package org.apache.commons.jxpath.ri.model.jdom;
17
18 import java.util.ArrayList JavaDoc;
19 import java.util.HashSet JavaDoc;
20 import java.util.List JavaDoc;
21 import java.util.Set JavaDoc;
22
23 import org.apache.commons.jxpath.ri.model.NodeIterator;
24 import org.apache.commons.jxpath.ri.model.NodePointer;
25 import org.jdom.Document;
26 import org.jdom.Element;
27 import org.jdom.Namespace;
28
29 /**
30  * An iterator of namespaces of a DOM Node.
31  *
32  * @author Dmitri Plotnikov
33  * @version $Revision: 1.9 $ $Date: 2004/04/01 02:55:31 $
34  */
35 public class JDOMNamespaceIterator implements NodeIterator {
36     private NodePointer parent;
37     private List JavaDoc namespaces;
38     private Set JavaDoc prefixes;
39     private int position = 0;
40
41     public JDOMNamespaceIterator(NodePointer parent) {
42         this.parent = parent;
43         Object JavaDoc node = parent.getNode();
44         if (node instanceof Document) {
45             node = ((Document)node).getRootElement();
46         }
47         if (node instanceof Element) {
48             namespaces = new ArrayList JavaDoc();
49             prefixes = new HashSet JavaDoc();
50             collectNamespaces((Element) node);
51         }
52     }
53
54     private void collectNamespaces(Element element) {
55         Namespace ns = element.getNamespace();
56         if (ns != null && !prefixes.contains(ns.getPrefix())) {
57             namespaces.add(ns);
58             prefixes.add(ns.getPrefix());
59         }
60         List JavaDoc others = element.getAdditionalNamespaces();
61         for (int i = 0; i < others.size(); i++) {
62             ns = (Namespace) others.get(i);
63             if (ns != null && !prefixes.contains(ns.getPrefix())) {
64                 namespaces.add(ns);
65                 prefixes.add(ns.getPrefix());
66             }
67         }
68         Object JavaDoc parent = element.getParent();
69         if (parent instanceof Element) {
70             collectNamespaces((Element)parent);
71         }
72     }
73
74     public NodePointer getNodePointer() {
75         if (position == 0) {
76             if (!setPosition(1)) {
77                 return null;
78             }
79             position = 0;
80         }
81         int index = position - 1;
82         if (index < 0) {
83             index = 0;
84         }
85         Namespace ns = (Namespace) namespaces.get(index);
86         return new JDOMNamespacePointer(parent, ns.getPrefix(), ns.getURI());
87     }
88
89     public int getPosition() {
90         return position;
91     }
92
93     public boolean setPosition(int position) {
94         if (namespaces == null) {
95             return false;
96         }
97         this.position = position;
98         return position >= 1 && position <= namespaces.size();
99     }
100 }
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