001    /*
002     * Licensed to the Apache Software Foundation (ASF) under one or more
003     * contributor license agreements.  See the NOTICE file distributed with
004     * this work for additional information regarding copyright ownership.
005     * The ASF licenses this file to You under the Apache License, Version 2.0
006     * (the "License"); you may not use this file except in compliance with
007     * the License.  You may obtain a copy of the License at
008     *
009     *     http://www.apache.org/licenses/LICENSE-2.0
010     *
011     * Unless required by applicable law or agreed to in writing, software
012     * distributed under the License is distributed on an "AS IS" BASIS,
013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014     * See the License for the specific language governing permissions and
015     * limitations under the License.
016     */
017    package org.apache.commons.jxpath.ri.model.jdom;
018    
019    import java.util.ArrayList;
020    import java.util.HashSet;
021    import java.util.List;
022    import java.util.Set;
023    
024    import org.apache.commons.jxpath.ri.model.NodeIterator;
025    import org.apache.commons.jxpath.ri.model.NodePointer;
026    import org.jdom.Document;
027    import org.jdom.Element;
028    import org.jdom.Namespace;
029    
030    /**
031     * An iterator of namespaces of a DOM Node.
032     *
033     * @author Dmitri Plotnikov
034     * @version $Revision: 652845 $ $Date: 2008-05-02 12:46:46 -0500 (Fri, 02 May 2008) $
035     */
036    public class JDOMNamespaceIterator implements NodeIterator {
037        private NodePointer parent;
038        private List namespaces;
039        private Set prefixes;
040        private int position = 0;
041    
042        /**
043         * Create a new JDOMNamespaceIterator.
044         * @param parent the parent NodePointer.
045         */
046        public JDOMNamespaceIterator(NodePointer parent) {
047            this.parent = parent;
048            Object node = parent.getNode();
049            if (node instanceof Document) {
050                node = ((Document) node).getRootElement();
051            }
052            if (node instanceof Element) {
053                namespaces = new ArrayList();
054                prefixes = new HashSet();
055                collectNamespaces((Element) node);
056            }
057        }
058    
059        /**
060         * Collect the namespaces from a JDOM Element.
061         * @param element the source Element
062         */
063        private void collectNamespaces(Element element) {
064            Namespace ns = element.getNamespace();
065            if (ns != null && !prefixes.contains(ns.getPrefix())) {
066                namespaces.add(ns);
067                prefixes.add(ns.getPrefix());
068            }
069            List others = element.getAdditionalNamespaces();
070            for (int i = 0; i < others.size(); i++) {
071                ns = (Namespace) others.get(i);
072                if (ns != null && !prefixes.contains(ns.getPrefix())) {
073                    namespaces.add(ns);
074                    prefixes.add(ns.getPrefix());
075                }
076            }
077            Object elementParent = element.getParent();
078            if (elementParent instanceof Element) {
079                collectNamespaces((Element) elementParent);
080            }
081        }
082    
083        public NodePointer getNodePointer() {
084            if (position == 0) {
085                if (!setPosition(1)) {
086                    return null;
087                }
088                position = 0;
089            }
090            int index = position - 1;
091            if (index < 0) {
092                index = 0;
093            }
094            Namespace ns = (Namespace) namespaces.get(index);
095            return new JDOMNamespacePointer(parent, ns.getPrefix(), ns.getURI());
096        }
097    
098        public int getPosition() {
099            return position;
100        }
101    
102        public boolean setPosition(int position) {
103            if (namespaces == null) {
104                return false;
105            }
106            this.position = position;
107            return position >= 1 && position <= namespaces.size();
108        }
109    }