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: FilterIterator.java 468651 2006-10-28 07:04:25Z minchau $
020 */
021
022 package org.apache.xalan.xsltc.dom;
023
024 import org.apache.xalan.xsltc.runtime.BasisLibrary;
025 import org.apache.xml.dtm.DTMAxisIterator;
026 import org.apache.xml.dtm.DTMFilter;
027 import org.apache.xml.dtm.DTMIterator;
028 import org.apache.xml.dtm.ref.DTMAxisIteratorBase;
029
030 /**
031 * Similar to a CurrentNodeListIterator except that the filter has a
032 * simpler interface (only needs the node, no position, last, etc.)
033 * It takes a source iterator and a Filter object and returns nodes
034 * from the source after filtering them by calling filter.test(node).
035 * @author Jacek Ambroziak
036 * @author Santiago Pericas-Geertsen
037 */
038 public final class FilterIterator extends DTMAxisIteratorBase {
039
040 /**
041 * Reference to source iterator.
042 */
043 private DTMAxisIterator _source;
044
045 /**
046 * Reference to a filter object that to be applied to each node.
047 */
048 private final DTMFilter _filter;
049
050 /**
051 * A flag indicating if position is reversed.
052 */
053 private final boolean _isReverse;
054
055 public FilterIterator(DTMAxisIterator source, DTMFilter filter) {
056 _source = source;
057 // System.out.println("FI souce = " + source + " this = " + this);
058 _filter = filter;
059 _isReverse = source.isReverse();
060 }
061
062 public boolean isReverse() {
063 return _isReverse;
064 }
065
066
067 public void setRestartable(boolean isRestartable) {
068 _isRestartable = isRestartable;
069 _source.setRestartable(isRestartable);
070 }
071
072 public DTMAxisIterator cloneIterator() {
073
074 try {
075 final FilterIterator clone = (FilterIterator) super.clone();
076 clone._source = _source.cloneIterator();
077 clone._isRestartable = false;
078 return clone.reset();
079 }
080 catch (CloneNotSupportedException e) {
081 BasisLibrary.runTimeError(BasisLibrary.ITERATOR_CLONE_ERR,
082 e.toString());
083 return null;
084 }
085 }
086
087 public DTMAxisIterator reset() {
088 _source.reset();
089 return resetPosition();
090 }
091
092 public int next() {
093 int node;
094 while ((node = _source.next()) != END) {
095 if (_filter.acceptNode(node, DTMFilter.SHOW_ALL) == DTMIterator.FILTER_ACCEPT) {
096 return returnNode(node);
097 }
098 }
099 return END;
100 }
101
102 public DTMAxisIterator setStartNode(int node) {
103 if (_isRestartable) {
104 _source.setStartNode(_startNode = node);
105 return resetPosition();
106 }
107 return this;
108 }
109
110 public void setMark() {
111 _source.setMark();
112 }
113
114 public void gotoMark() {
115 _source.gotoMark();
116 }
117
118 }