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.xml.utils;
  
  import java.io.File;
  
  import org.w3c.dom.Comment;
  import org.w3c.dom.Element;
  import org.w3c.dom.EntityReference;
  import org.w3c.dom.NamedNodeMap;
  import org.w3c.dom.Node;
  import org.w3c.dom.ProcessingInstruction;
  import org.w3c.dom.Text;
  
  import org.xml.sax.ContentHandler;
  import org.xml.sax.Locator;
  import org.xml.sax.ext.LexicalHandler;
  import org.xml.sax.helpers.LocatorImpl;
  
  /**
   * This class does a pre-order walk of the DOM tree, calling a ContentHandler
   * interface as it goes.
   * @xsl.usage advanced
   */
  
  public class TreeWalker
  {
  
    /** Local reference to a ContentHandler          */
    private ContentHandler m_contentHandler = null;
  
    // ARGHH!!  JAXP Uses Xerces without setting the namespace processing to ON!
    // DOM2Helper m_dh = new DOM2Helper();
  
    /** DomHelper for this TreeWalker          */
    protected DOMHelper m_dh;
          
          /** Locator object for this TreeWalker          */
          private LocatorImpl m_locator = new LocatorImpl();
  
    /**
     * Get the ContentHandler used for the tree walk.
     *
     * @return the ContentHandler used for the tree walk
     */
    public ContentHandler getContentHandler()
    {
      return m_contentHandler;
    }
  
    /**
     * Get the ContentHandler used for the tree walk.
     *
     * @return the ContentHandler used for the tree walk
     */
    public void setContentHandler(ContentHandler ch)
    {
      m_contentHandler = ch;
    }
          
          /**
     * Constructor.
     * @param   contentHandler The implemention of the
     * @param   systemId System identifier for the document.
     * contentHandler operation (toXMLString, digest, ...)
     */
    public TreeWalker(ContentHandler contentHandler, DOMHelper dh, String systemId)
    {
      this.m_contentHandler = contentHandler;
      m_contentHandler.setDocumentLocator(m_locator);
      if (systemId != null)
          m_locator.setSystemId(systemId);
      else {
          try {
            // Bug see Bugzilla  26741
            m_locator.setSystemId(System.getProperty("user.dir") + File.separator + "dummy.xsl");
           }
           catch (SecurityException se) {// user.dir not accessible from applet             
           }
      }
      m_dh = dh;
    }
  
    /**
     * Constructor.
     * @param   contentHandler The implemention of the
     * contentHandler operation (toXMLString, digest, ...)
     */
    public TreeWalker(ContentHandler contentHandler, DOMHelper dh)
    {
      this.m_contentHandler = contentHandler;
      m_contentHandler.setDocumentLocator(m_locator);
      try {
         // Bug see Bugzilla  26741
        m_locator.setSystemId(System.getProperty("user.dir") + File.separator + "dummy.xsl");
      } 
      catch (SecurityException se){// user.dir not accessible from applet      
      }
      m_dh = dh;
    }
    
    /**
     * Constructor.
     * @param   contentHandler The implemention of the
     * contentHandler operation (toXMLString, digest, ...)
     */
    public TreeWalker(ContentHandler contentHandler)
    {
      this.m_contentHandler = contentHandler;
                  if (m_contentHandler != null)
                          m_contentHandler.setDocumentLocator(m_locator);
                  try {
                     // Bug see Bugzilla  26741
                    m_locator.setSystemId(System.getProperty("user.dir") + File.separator + "dummy.xsl");
                  } 
                  catch (SecurityException se){// user.dir not accessible from applet
                    
      }
      m_dh = new DOM2Helper();
    }
  
    /**
     * Perform a pre-order traversal non-recursive style.  
     *
     * Note that TreeWalker assumes that the subtree is intended to represent 
     * a complete (though not necessarily well-formed) document and, during a 
     * traversal, startDocument and endDocument will always be issued to the 
     * SAX listener.
     *  
     * @param pos Node in the tree where to start traversal
     *
     * @throws TransformerException
     */
    public void traverse(Node pos) throws org.xml.sax.SAXException
    {
          this.m_contentHandler.startDocument();
          
          traverseFragment(pos);
  
          this.m_contentHandler.endDocument();
    }
      
    /**
     * Perform a pre-order traversal non-recursive style.  
     *
     * In contrast to the traverse() method this method will not issue 
     * startDocument() and endDocument() events to the SAX listener.
     *  
     * @param pos Node in the tree where to start traversal
     *
     * @throws TransformerException
     */
    public void traverseFragment(Node pos) throws org.xml.sax.SAXException
    {
      Node top = pos;
  
      while (null != pos)
      {
        startNode(pos);
  
        Node nextNode = pos.getFirstChild();
  
        while (null == nextNode)
        {
          endNode(pos);
  
          if (top.equals(pos))
            break;
  
          nextNode = pos.getNextSibling();
  
          if (null == nextNode)
          {
            pos = pos.getParentNode();
  
            if ((null == pos) || (top.equals(pos)))
            {
              if (null != pos)
                endNode(pos);
  
              nextNode = null;
  
              break;
            }
          }
        }
  
        pos = nextNode;
      }
    }
  
    /**
     * Perform a pre-order traversal non-recursive style.
  
     * Note that TreeWalker assumes that the subtree is intended to represent 
     * a complete (though not necessarily well-formed) document and, during a 
     * traversal, startDocument and endDocument will always be issued to the 
     * SAX listener.
     *
     * @param pos Node in the tree where to start traversal
     * @param top Node in the tree where to end traversal
     *
     * @throws TransformerException
     */
    public void traverse(Node pos, Node top) throws org.xml.sax.SAXException
    {
  
  	this.m_contentHandler.startDocument();
  	
      while (null != pos)
      {
        startNode(pos);
  
        Node nextNode = pos.getFirstChild();
  
        while (null == nextNode)
        {
          endNode(pos);
  
          if ((null != top) && top.equals(pos))
            break;
  
          nextNode = pos.getNextSibling();
  
          if (null == nextNode)
          {
            pos = pos.getParentNode();
  
            if ((null == pos) || ((null != top) && top.equals(pos)))
            {
              nextNode = null;
  
              break;
            }
          }
        }
  
        pos = nextNode;
      }
      this.m_contentHandler.endDocument();
    }
  
    /** Flag indicating whether following text to be processed is raw text          */
    boolean nextIsRaw = false;
    
    /**
     * Optimized dispatch of characters.
     */
    private final void dispatachChars(Node node)
       throws org.xml.sax.SAXException
    {
      if(m_contentHandler instanceof org.apache.xml.dtm.ref.dom2dtm.DOM2DTM.CharacterNodeHandler)
      {
        ((org.apache.xml.dtm.ref.dom2dtm.DOM2DTM.CharacterNodeHandler)m_contentHandler).characters(node);
      }
      else
      {
        String data = ((Text) node).getData();
        this.m_contentHandler.characters(data.toCharArray(), 0, data.length());
      }
    }
  
    /**
     * Start processing given node
     *
     *
     * @param node Node to process
     *
     * @throws org.xml.sax.SAXException
     */
    protected void startNode(Node node) throws org.xml.sax.SAXException
    {
  
      if (m_contentHandler instanceof NodeConsumer)
      {
        ((NodeConsumer) m_contentHandler).setOriginatingNode(node);
      }
                  
                  if (node instanceof Locator)
                  {
                          Locator loc = (Locator)node;
                          m_locator.setColumnNumber(loc.getColumnNumber());
                          m_locator.setLineNumber(loc.getLineNumber());
                          m_locator.setPublicId(loc.getPublicId());
                          m_locator.setSystemId(loc.getSystemId());
                  }
                  else
                  {
                          m_locator.setColumnNumber(0);
        m_locator.setLineNumber(0);
                  }
  
      switch (node.getNodeType())
      {
      case Node.COMMENT_NODE :
      {
        String data = ((Comment) node).getData();
  
        if (m_contentHandler instanceof LexicalHandler)
        {
          LexicalHandler lh = ((LexicalHandler) this.m_contentHandler);
  
          lh.comment(data.toCharArray(), 0, data.length());
        }
      }
      break;
      case Node.DOCUMENT_FRAGMENT_NODE :
  
        // ??;
        break;
      case Node.DOCUMENT_NODE :
      
        break;
      case Node.ELEMENT_NODE :
        NamedNodeMap atts = ((Element) node).getAttributes();
        int nAttrs = atts.getLength();
        // System.out.println("TreeWalker#startNode: "+node.getNodeName());
  
        for (int i = 0; i < nAttrs; i++)
        {
          Node attr = atts.item(i);
          String attrName = attr.getNodeName();
  
          // System.out.println("TreeWalker#startNode: attr["+i+"] = "+attrName+", "+attr.getNodeValue());
          if (attrName.equals("xmlns") || attrName.startsWith("xmlns:"))
          {
            // System.out.println("TreeWalker#startNode: attr["+i+"] = "+attrName+", "+attr.getNodeValue());
            int index;
            // Use "" instead of null, as Xerces likes "" for the 
            // name of the default namespace.  Fix attributed 
            // to "Steven Murray" <smurray@ebt.com>.
            String prefix = (index = attrName.indexOf(":")) < 0
                            ? "" : attrName.substring(index + 1);
  
            this.m_contentHandler.startPrefixMapping(prefix,
                                                     attr.getNodeValue());
          }
          
        }
  
        // System.out.println("m_dh.getNamespaceOfNode(node): "+m_dh.getNamespaceOfNode(node));
        // System.out.println("m_dh.getLocalNameOfNode(node): "+m_dh.getLocalNameOfNode(node));
        String ns = m_dh.getNamespaceOfNode(node);
        if(null == ns)
          ns = "";
        this.m_contentHandler.startElement(ns,
                                           m_dh.getLocalNameOfNode(node),
                                           node.getNodeName(),
                                           new AttList(atts, m_dh));
        break;
      case Node.PROCESSING_INSTRUCTION_NODE :
      {
        ProcessingInstruction pi = (ProcessingInstruction) node;
        String name = pi.getNodeName();
  
        // String data = pi.getData();
        if (name.equals("xslt-next-is-raw"))
        {
          nextIsRaw = true;
        }
        else
        {
          this.m_contentHandler.processingInstruction(pi.getNodeName(),
                                                      pi.getData());
        }
      }
      break;
      case Node.CDATA_SECTION_NODE :
      {
        boolean isLexH = (m_contentHandler instanceof LexicalHandler);
        LexicalHandler lh = isLexH
                            ? ((LexicalHandler) this.m_contentHandler) : null;
  
        if (isLexH)
        {
          lh.startCDATA();
        }
        
        dispatachChars(node);
  
        {
          if (isLexH)
          {
            lh.endCDATA();
          }
        }
      }
      break;
      case Node.TEXT_NODE :
      {
        //String data = ((Text) node).getData();
  
        if (nextIsRaw)
        {
          nextIsRaw = false;
  
          m_contentHandler.processingInstruction(javax.xml.transform.Result.PI_DISABLE_OUTPUT_ESCAPING, "");
          dispatachChars(node);
          m_contentHandler.processingInstruction(javax.xml.transform.Result.PI_ENABLE_OUTPUT_ESCAPING, "");
        }
        else
        {
          dispatachChars(node);
        }
      }
      break;
      case Node.ENTITY_REFERENCE_NODE :
      {
        EntityReference eref = (EntityReference) node;
  
        if (m_contentHandler instanceof LexicalHandler)
        {
          ((LexicalHandler) this.m_contentHandler).startEntity(
            eref.getNodeName());
        }
        else
        {
  
          // warning("Can not output entity to a pure SAX ContentHandler");
        }
      }
      break;
      default :
      }
    }
  
    /**
     * End processing of given node 
     *
     *
     * @param node Node we just finished processing
     *
     * @throws org.xml.sax.SAXException
     */
    protected void endNode(Node node) throws org.xml.sax.SAXException
    {
  
      switch (node.getNodeType())
      {
      case Node.DOCUMENT_NODE :
        break;
        
      case Node.ELEMENT_NODE :
        String ns = m_dh.getNamespaceOfNode(node);
        if(null == ns)
          ns = "";
        this.m_contentHandler.endElement(ns,
                                           m_dh.getLocalNameOfNode(node),
                                           node.getNodeName());
  
        NamedNodeMap atts = ((Element) node).getAttributes();
        int nAttrs = atts.getLength();
  
        for (int i = 0; i < nAttrs; i++)
        {
          Node attr = atts.item(i);
          String attrName = attr.getNodeName();
  
          if (attrName.equals("xmlns") || attrName.startsWith("xmlns:"))
          {
            int index;
            // Use "" instead of null, as Xerces likes "" for the 
            // name of the default namespace.  Fix attributed 
            // to "Steven Murray" <smurray@ebt.com>.
            String prefix = (index = attrName.indexOf(":")) < 0
                            ? "" : attrName.substring(index + 1);
  
            this.m_contentHandler.endPrefixMapping(prefix);
          }
        }
        break;
      case Node.CDATA_SECTION_NODE :
        break;
      case Node.ENTITY_REFERENCE_NODE :
      {
        EntityReference eref = (EntityReference) node;
  
        if (m_contentHandler instanceof LexicalHandler)
        {
          LexicalHandler lh = ((LexicalHandler) this.m_contentHandler);
  
          lh.endEntity(eref.getNodeName());
        }
      }
      break;
      default :
      }
    }
  }  //TreeWalker
  
  