- /*
- * Copyright 2001-2004 The Apache Software Foundation.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
- /*
- * $Id: MatchingIterator.java,v 1.9 2004/02/16 22:54:59 minchau Exp $
- */
-
- package com.sun.org.apache.xalan.internal.xsltc.dom;
-
- import com.sun.org.apache.xalan.internal.xsltc.runtime.BasisLibrary;
- import com.sun.org.apache.xml.internal.dtm.DTMAxisIterator;
- import com.sun.org.apache.xml.internal.dtm.ref.DTMAxisIteratorBase;
-
- /**
- * This is a special kind of iterator that takes a source iterator and a
- * node N. If initialized with a node M (the parent of N) it computes the
- * position of N amongst the children of M. This position can be obtained
- * by calling getPosition().
- * It is an iterator even though next() will never be called. It is used to
- * match patterns with a single predicate like:
- *
- * BOOK[position() = last()]
- *
- * In this example, the source iterator will return elements of type BOOK,
- * a call to position() will return the position of N. Notice that because
- * of the way the pattern matching is implemented, N will always be a node
- * in the source since (i) it is a BOOK or the test sequence would not be
- * considered and (ii) the source iterator is initialized with M which is
- * the parent of N. Also, and still in this example, a call to last() will
- * return the number of elements in the source (i.e. the number of BOOKs).
- * @author Jacek Ambroziak
- * @author Santiago Pericas-Geertsen
- */
- public final class MatchingIterator extends DTMAxisIteratorBase {
-
- /**
- * A reference to a source iterator.
- */
- private DTMAxisIterator _source;
-
- /**
- * The node to match.
- */
- private final int _match;
-
- public MatchingIterator(int match, DTMAxisIterator source) {
- _source = source;
- _match = match;
- }
-
-
- public void setRestartable(boolean isRestartable) {
- _isRestartable = isRestartable;
- _source.setRestartable(isRestartable);
- }
-
- public DTMAxisIterator cloneIterator() {
-
- try {
- final MatchingIterator clone = (MatchingIterator) super.clone();
- clone._source = _source.cloneIterator();
- clone._isRestartable = false;
- return clone.reset();
- }
- catch (CloneNotSupportedException e) {
- BasisLibrary.runTimeError(BasisLibrary.ITERATOR_CLONE_ERR,
- e.toString());
- return null;
- }
- }
-
- public DTMAxisIterator setStartNode(int node) {
- if (_isRestartable) {
- // iterator is not a clone
- _source.setStartNode(node);
-
- // Calculate the position of the node in the set
- _position = 1;
- while ((node = _source.next()) != END && node != _match) {
- _position++;
- }
- }
- return this;
- }
-
- public DTMAxisIterator reset() {
- _source.reset();
- return resetPosition();
- }
-
- public int next() {
- return _source.next();
- }
-
- public int getLast() {
- if (_last == -1) {
- _last = _source.getLast();
- }
- return _last;
- }
-
- public int getPosition() {
- return _position;
- }
-
- public void setMark() {
- _source.setMark();
- }
-
- public void gotoMark() {
- _source.gotoMark();
- }
- }