001    /*
002     * Licensed to the Apache Software Foundation (ASF) under one
003     * or more contributor license agreements. See the NOTICE file
004     * distributed with this work for additional information
005     * regarding copyright ownership. The ASF licenses this file
006     * to you under the Apache License, Version 2.0 (the  "License");
007     * you may not use this file except in compliance with the License.
008     * You may obtain a copy of the License at
009     *
010     *     http://www.apache.org/licenses/LICENSE-2.0
011     *
012     * Unless required by applicable law or agreed to in writing, software
013     * distributed under the License is distributed on an "AS IS" BASIS,
014     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015     * See the License for the specific language governing permissions and
016     * limitations under the License.
017     */
018    /*
019     * $Id: SingletonIterator.java 468651 2006-10-28 07:04:25Z minchau $
020     */
021    
022    package org.apache.xalan.xsltc.dom;
023    
024    import org.apache.xml.dtm.DTMAxisIterator;
025    import org.apache.xml.dtm.ref.DTMAxisIteratorBase;
026    
027    /**
028     * @author Jacek Ambroziak
029     * @author Santiago Pericas-Geertsen
030     */
031    public class SingletonIterator extends DTMAxisIteratorBase {
032        private int _node;
033        private final boolean _isConstant;
034    
035        public SingletonIterator() {
036            this(Integer.MIN_VALUE, false);
037        }
038    
039        public SingletonIterator(int node) {
040            this(node, false);
041        }
042    
043        public SingletonIterator(int node, boolean constant) {
044            _node = _startNode = node;
045            _isConstant = constant;
046        }
047        
048        /**
049         * Override the value of <tt>_node</tt> only when this
050         * object was constructed using the empty constructor.
051         */
052        public DTMAxisIterator setStartNode(int node) {
053            if (_isConstant) {
054                _node = _startNode;
055                return resetPosition();
056            }
057            else if (_isRestartable) {
058                if (_node <= 0)
059                    _node = _startNode = node;
060                return resetPosition();
061            }
062            return this;
063        }
064            
065        public DTMAxisIterator reset() {
066            if (_isConstant) {
067                _node = _startNode;
068                return resetPosition();
069            }
070            else {
071                final boolean temp = _isRestartable;
072                _isRestartable = true;
073                setStartNode(_startNode);
074                _isRestartable = temp;
075            }
076            return this;
077        }
078        
079        public int next() {
080            final int result = _node;
081            _node = DTMAxisIterator.END;
082            return returnNode(result);
083        }
084    
085        public void setMark() {
086            _markedNode = _node;
087        }
088    
089        public void gotoMark() {
090            _node = _markedNode;
091        }
092    }