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.xml.dtm.DTMAxisIterator;
  import org.apache.xml.dtm.ref.DTMAxisIteratorBase;
  
  /**
   * @author Jacek Ambroziak
   * @author Santiago Pericas-Geertsen
   */
  public class SingletonIterator extends DTMAxisIteratorBase {
      private int _node;
      private final boolean _isConstant;
  
      public SingletonIterator() {
  	this(Integer.MIN_VALUE, false);
      }
  
      public SingletonIterator(int node) {
  	this(node, false);
      }
  
      public SingletonIterator(int node, boolean constant) {
  	_node = _startNode = node;
  	_isConstant = constant;
      }
      
      /**
       * Override the value of <tt>_node</tt> only when this
       * object was constructed using the empty constructor.
       */
      public DTMAxisIterator setStartNode(int node) {
  	if (_isConstant) {
  	    _node = _startNode;
  	    return resetPosition();
  	}
  	else if (_isRestartable) {
  	    if (_node <= 0)
  		_node = _startNode = node;
  	    return resetPosition();
  	}
  	return this;
      }
  	
      public DTMAxisIterator reset() {
  	if (_isConstant) {
  	    _node = _startNode;
  	    return resetPosition();
  	}
  	else {
  	    final boolean temp = _isRestartable;
  	    _isRestartable = true;
  	    setStartNode(_startNode);
  	    _isRestartable = temp;
  	}
  	return this;
      }
      
      public int next() {
  	final int result = _node;
  	_node = DTMAxisIterator.END;
  	return returnNode(result);
      }
  
      public void setMark() {
  	_markedNode = _node;
      }
  
      public void gotoMark() {
  	_node = _markedNode;
      }
  }
  