/*
    * Redistribution and use of this software and associated documentation
    * ("Software"), with or without modification, are permitted provided
    * that the following conditions are met:
    *
    * 1. Redistributions of source code must retain copyright
    *    statements and notices.  Redistributions must also contain a
    *    copy of this document.
    *
   * 2. Redistributions in binary form must reproduce the
   *    above copyright notice, this list of conditions and the
   *    following disclaimer in the documentation and/or other
   *    materials provided with the distribution.
   *
   * 3. The name "Exolab" must not be used to endorse or promote
   *    products derived from this Software without prior written
   *    permission of Intalio, Inc.  For written permission,
   *    please contact info@exolab.org.
   *
   * 4. Products derived from this Software may not be called "Exolab"
   *    nor may "Exolab" appear in their names without prior written
   *    permission of Intalio, Inc. Exolab is a registered
   *    trademark of Intalio, Inc.
   *
   * 5. Due credit should be given to the Exolab Project
   *    (http://www.exolab.org/).
   *
   * THIS SOFTWARE IS PROVIDED BY INTALIO, INC. AND CONTRIBUTORS
   * ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT
   * NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
   * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
   * INTALIO, INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
   * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
   * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
   * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
   * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
   * OF THE POSSIBILITY OF SUCH DAMAGE.
   *
   * Copyright 2004 (C) Intalio, Inc. All Rights Reserved.
   *
   *
   */
  package org.exolab.castor.xml.util;
  
  import org.exolab.castor.xml.Namespaces;
  import org.exolab.castor.xml.NamespacesStack;
  import org.xml.sax.Attributes;
  import org.xml.sax.ContentHandler;
  import org.xml.sax.DocumentHandler;
  import org.xml.sax.Locator;
  import org.xml.sax.SAXException;
  import org.xml.sax.helpers.AttributeListImpl;
  
  /**
   * A ContentHandler implementation that wraps a DocumentHandler. This
   * ContentHandler was written for the Marshaller and expects that QNames
   * are non-null in calls to startElement and endElement methods as well
   * as inside the Attributes list.
   *
   * @author <a href="mailto:kvisco@intalio.com">Keith Visco</a>
   * @version $Revision$ $Date: 2004-09-10 12:15:10 -0600 (Fri, 10 Sep 2004) $
   */
  public class DocumentHandlerAdapter implements ContentHandler {
  
      private static final String CDATA = "CDATA";
  
      private DocumentHandler _handler = null;
  
      /**
       * Represents the namespaces stack.
       */
      private NamespacesStack namespacesStack = null;
  
      private boolean _createNamespaceScope = true;
  
      /**
       * Creates a new DocumentHandlerAdapter
       *
       * @param handler the DocumentHandler to wrap (non-null).
       */
      public DocumentHandlerAdapter(DocumentHandler handler) {
          if (handler == null) {
              throw new IllegalArgumentException("The argument 'handler' must not be null.");
          }
          _handler = handler;
          namespacesStack = new NamespacesStack();
      }
  
      /**
       * @see org.xml.sax.ContentHandler#characters(char[], int, int)
       */
      public void characters(char[] chars, int start, int length)
          throws SAXException
      {
          _handler.characters(chars, start, length);
      }
  
     /**
      * @see org.xml.sax.ContentHandler#endDocument()
      */
     public void endDocument()
         throws SAXException
     {
         _handler.endDocument();
     }
 
     /**
      * @see org.xml.sax.ContentHandler#endElement(java.lang.String, java.lang.String,
      *      java.lang.String)
      */
     public void endElement(String uri, String localName, String qName)
         throws SAXException
     {
         _handler.endElement(qName);
         namespacesStack.removeNamespaceScope();
     }
 
     /**
      * @see org.xml.sax.ContentHandler#endPrefixMapping(java.lang.String)
      */
     public void endPrefixMapping(String prefix)
         throws SAXException
     {
         //-- do nothing here, this is handled in endElement
         //-- by simply removing the current namespace scope
 
     }
 
     /**
      * @see org.xml.sax.ContentHandler#ignorableWhitespace(char[], int, int)
      */
     public void ignorableWhitespace(char[] chars, int start, int length)
         throws SAXException
     {
         _handler.ignorableWhitespace(chars, start, length);
     }
 
     /**
      * @see org.xml.sax.ContentHandler#processingInstruction(java.lang.String, java.lang.String)
      */
     public void processingInstruction(String target, String data)
             throws SAXException
     {
         _handler.processingInstruction(target, data);
     }
 
     /**
      * @see org.xml.sax.ContentHandler#setDocumentLocator(org.xml.sax.Locator)
      */
     public void setDocumentLocator(Locator locator)
     {
         _handler.setDocumentLocator(locator);
     }
 
     /**
      * @see org.xml.sax.ContentHandler#skippedEntity(java.lang.String)
      */
     public void skippedEntity(String arg0)
         throws SAXException
     {
         //-- do nothing
     }
 
     /**
      * @see org.xml.sax.ContentHandler#startDocument()
      */
     public void startDocument()
         throws SAXException
     {
         _handler.startDocument();
     }
 
     /**
      * @see org.xml.sax.ContentHandler#startElement(java.lang.String, java.lang.String, java.lang.String, org.xml.sax.Attributes)
      */
     public void startElement(String uri, String localName, String qName, Attributes atts)
         throws SAXException
     {
         AttributeListImpl attList = new AttributeListImpl();
 
         //-- Create a new namespace scope if necessary and
         //-- make sure the flag is reset to true
         if (_createNamespaceScope) {
             //-- no current namespaces, but we create a new scope
             //-- to make things easier in the endElement method
             namespacesStack.addNewNamespaceScope();
         }
         else {
             _createNamespaceScope = true;
             namespacesStack.declareAsAttributes(attList, true);
         }
 
         //-- copy Attributes to AttributeList
         for (int i = 0; i < atts.getLength(); i++) {
             attList.addAttribute(atts.getQName(i), CDATA, atts.getValue(i));
         }
 
         _handler.startElement(qName, attList);
 
     }
 
     /**
      * @see org.xml.sax.ContentHandler#startPrefixMapping(java.lang.String, java.lang.String)
      */
     public void startPrefixMapping(String prefix, String uri)
         throws SAXException
     {
         if (_createNamespaceScope) {
             namespacesStack.addNewNamespaceScope();
             _createNamespaceScope = false;
         }
 
         namespacesStack.addNamespace(prefix, uri);
     }
 }