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.xpath.functions;
  
  import org.apache.xml.dtm.DTM;
  import org.apache.xml.dtm.DTMIterator;
  import org.apache.xpath.XPathContext;
  import org.apache.xpath.axes.LocPathIterator;
  import org.apache.xpath.axes.PredicatedNodeTest;
  import org.apache.xpath.objects.XNodeSet;
  import org.apache.xpath.objects.XObject;
  import org.apache.xpath.axes.SubContextList;
  import org.apache.xpath.patterns.StepPattern;
  import org.apache.xalan.res.XSLMessages;
  import org.apache.xalan.res.XSLTErrorResources;
  
  
  /**
   * Execute the current() function.
   * @xsl.usage advanced
   */
  public class FuncCurrent extends Function
  {
      static final long serialVersionUID = 5715316804877715008L;
  
    /**
     * Execute the function.  The function must return
     * a valid object.
     * @param xctxt The current execution context.
     * @return A valid XObject.
     *
     * @throws javax.xml.transform.TransformerException
     */
    public XObject execute(XPathContext xctxt) throws javax.xml.transform.TransformerException
    {
     
      SubContextList subContextList = xctxt.getCurrentNodeList();
      int currentNode = DTM.NULL;
  
      if (null != subContextList) {
          if (subContextList instanceof PredicatedNodeTest) {
              LocPathIterator iter = ((PredicatedNodeTest)subContextList)
                                                            .getLocPathIterator();
              currentNode = iter.getCurrentContextNode();
           } else if(subContextList instanceof StepPattern) {
             throw new RuntimeException(XSLMessages.createMessage(
                XSLTErrorResources.ER_PROCESSOR_ERROR,null));
           }
      } else {
          // not predicate => ContextNode == CurrentNode
          currentNode = xctxt.getContextNode();
      }
      return new XNodeSet(currentNode, xctxt.getDTMManager());
    }
    
    /**
     * No arguments to process, so this does nothing.
     */
    public void fixupVariables(java.util.Vector vars, int globalsSize)
    {
      // no-op
    }
  
  }
  