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.axes;
018    
019    import org.apache.commons.jxpath.ri.EvalContext;
020    import org.apache.commons.jxpath.ri.QName;
021    import org.apache.commons.jxpath.ri.compiler.NodeNameTest;
022    import org.apache.commons.jxpath.ri.compiler.NodeTest;
023    import org.apache.commons.jxpath.ri.model.NodeIterator;
024    import org.apache.commons.jxpath.ri.model.NodePointer;
025    
026    /**
027     * EvalContext that walks the "namespace::" axis.
028     *
029     * @author Dmitri Plotnikov
030     * @version $Revision: 652845 $ $Date: 2008-05-02 12:46:46 -0500 (Fri, 02 May 2008) $
031     */
032    public class NamespaceContext extends EvalContext {
033        private NodeTest nodeTest;
034        private boolean setStarted = false;
035        private NodeIterator iterator;
036        private NodePointer currentNodePointer;
037    
038        /**
039         * @param parentContext represents the previous step on the path
040         * @param nodeTest is the name of the namespace we are looking for
041         */
042        public NamespaceContext(EvalContext parentContext, NodeTest nodeTest) {
043            super(parentContext);
044            this.nodeTest = nodeTest;
045        }
046    
047        public NodePointer getCurrentNodePointer() {
048            return currentNodePointer;
049        }
050    
051        public void reset() {
052            setStarted = false;
053            iterator = null;
054            super.reset();
055        }
056    
057        public boolean setPosition(int position) {
058            if (position < getCurrentPosition()) {
059                reset();
060            }
061    
062            while (getCurrentPosition() < position) {
063                if (!nextNode()) {
064                    return false;
065                }
066            }
067            return true;
068        }
069    
070        public boolean nextNode() {
071            super.setPosition(getCurrentPosition() + 1);
072            if (!setStarted) {
073                setStarted = true;
074                if (!(nodeTest instanceof NodeNameTest)) {
075                    return false;
076                }
077    
078                NodeNameTest nodeNameTest = (NodeNameTest) nodeTest;
079                QName testName = nodeNameTest.getNodeName();
080                if (testName.getPrefix() != null) {
081                    return false;
082                }
083                if (nodeNameTest.isWildcard()) {
084                    iterator =
085                        parentContext.getCurrentNodePointer().namespaceIterator();
086                }
087                else {
088                    currentNodePointer =
089                        parentContext.getCurrentNodePointer().namespacePointer(
090                                testName.getName());
091                    return currentNodePointer != null;
092                }
093            }
094    
095            if (iterator == null) {
096                return false;
097            }
098            if (!iterator.setPosition(iterator.getPosition() + 1)) {
099                return false;
100            }
101            currentNodePointer = iterator.getNodePointer();
102            return true;
103        }
104    }