code: /*
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements. See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership. The ASF licenses this file
   * to you 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.
   */
  /*
   * $Id$
   */
  
  package org.apache.xalan.xsltc.dom;
  
  import org.apache.xalan.xsltc.runtime.AbstractTranslet;
  import org.apache.xalan.xsltc.runtime.BasisLibrary;
  import org.apache.xalan.xsltc.util.IntegerArray;
  import org.apache.xml.dtm.DTMAxisIterator;
  import org.apache.xml.dtm.ref.DTMAxisIteratorBase;
  
  /**
   * Iterators of this kind use a CurrentNodeListFilter to filter a subset of 
   * nodes from a source iterator. For each node from the source, the boolean 
   * method CurrentNodeListFilter.test() is called. 
   *
   * All nodes from the source are read into an array upon calling setStartNode() 
   * (this is needed to determine the value of last, a parameter to 
   * CurrentNodeListFilter.test()). The method getLast() returns the last element 
   * after applying the filter.
   * @author Jacek Ambroziak
   * @author Santiago Pericas-Geertsen
   * @author Morten Jorgensen
   */
  
  public final class CurrentNodeListIterator extends DTMAxisIteratorBase {
      /**
       * A flag indicating if nodes are returned in document order.
       */
      private boolean _docOrder;
  
      /**
       * The source for this iterator.
       */
      private DTMAxisIterator _source;
  
      /**
       * A reference to a filter object.
       */
      private final CurrentNodeListFilter _filter;
  
      /**
       * An integer array to store nodes from source iterator.
       */
      private IntegerArray _nodes = new IntegerArray();
  	
      /**
       * Index in _nodes of the next node to filter.
       */
      private int _currentIndex;
  	
      /**
       * The current node in the stylesheet at the time of evaluation.
       */
      private final int _currentNode;
  
      /**
       * A reference to the translet.
       */
      private AbstractTranslet _translet;
  
      public CurrentNodeListIterator(DTMAxisIterator source, 
  				   CurrentNodeListFilter filter,
  				   int currentNode,
  				   AbstractTranslet translet) 
      {
  	this(source, !source.isReverse(), filter, currentNode, translet);
      }
  
      public CurrentNodeListIterator(DTMAxisIterator source, boolean docOrder,
  				   CurrentNodeListFilter filter,
  				   int currentNode,
  				   AbstractTranslet translet) 
      {
  	_source = source;
  	_filter = filter;
  	_translet = translet;
  	_docOrder = docOrder;
  	_currentNode = currentNode;
      }
  
      public DTMAxisIterator forceNaturalOrder() {
  	_docOrder = true;
  	return this;
      }
  
      public void setRestartable(boolean isRestartable) {
  	_isRestartable = isRestartable;
  	_source.setRestartable(isRestartable);
      }
  
      public boolean isReverse() {
  	return !_docOrder;
      }
  
      public DTMAxisIterator cloneIterator() {
  	try {
  	    final CurrentNodeListIterator clone =
  		(CurrentNodeListIterator) super.clone();
  	    clone._nodes = (IntegerArray) _nodes.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 reset() {
  	_currentIndex = 0;
  	return resetPosition();
      }
  
      public int next() {
  	final int last = _nodes.cardinality();
  	final int currentNode = _currentNode;
  	final AbstractTranslet translet = _translet;
  
  	for (int index = _currentIndex; index < last; ) {
  	    final int position = _docOrder ? index + 1 : last - index;
  	    final int node = _nodes.at(index++); 	// note increment
  
  	    if (_filter.test(node, position, last, currentNode, translet,
                               this)) {
  		_currentIndex = index;
  		return returnNode(node);
  	    }
  	}
  	return END;
      }
  
      public DTMAxisIterator setStartNode(int node) {
  	if (_isRestartable) {
  	    _source.setStartNode(_startNode = node);
  
  	    _nodes.clear();
  	    while ((node = _source.next()) != END) {
  		_nodes.add(node);
  	    }
  	    _currentIndex = 0;
  	    resetPosition();
  	}
  	return this;
      }
  	
      public int getLast() {
  	if (_last == -1) {
  	    _last = computePositionOfLast();
  	}
  	return _last;
      }
  
      public void setMark() {
  	_markedNode = _currentIndex;
      }
  
      public void gotoMark() {
  	_currentIndex = _markedNode;
      }
  
      private int computePositionOfLast() {
          final int last = _nodes.cardinality();
          final int currNode = _currentNode;
  	final AbstractTranslet translet = _translet;
  
  	int lastPosition = _position;
  	for (int index = _currentIndex; index < last; ) {
  	    final int position = _docOrder ? index + 1 : last - index;
              int nodeIndex = _nodes.at(index++); 	// note increment
  
              if (_filter.test(nodeIndex, position, last, currNode, translet,
                               this)) {
                  lastPosition++;
              }
          }
  	return lastPosition;
      }
  }
  