/*
 * The Apache Software License, Version 1.1
 *
 *
 * Copyright (c) 1999 The Apache Software Foundation.  All rights 
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer. 
 *
 * 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 end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:  
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Xalan" and "Apache Software Foundation" must
 *    not be used to endorse or promote products derived from this
 *    software without prior written permission. For written 
 *    permission, please contact apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache",
 *    nor may "Apache" appear in their name, without prior written
 *    permission of the Apache Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED ``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 THE APACHE SOFTWARE FOUNDATION 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.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation and was
 * originally based on software copyright (c) 1999, Lotus
 * Development Corporation., http://www.lotus.com.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */
package org.apache.xalan.stree;

import org.w3c.dom.Document;
import org.w3c.dom.DocumentType;
import org.w3c.dom.DOMImplementation;
import org.w3c.dom.DOMException;

import org.apache.xml.utils.UnImplNode;

/**
 * <meta name="usage" content="internal"/>
 * This class provides a number of methods for performing operations that
 * are independent of any particular instance of the document object model.
 */
public class DOMImplementationImpl extends UnImplNode
        implements DOMImplementation
{

  //
  // Data
  //
  // static

  /** Dom implementation singleton. */
  static DOMImplementationImpl singleton = new DOMImplementationImpl();

  //
  // DOMImplementation methods
  //

  /**
   * Test if the DOM implementation supports a specific "feature" --
   * currently meaning language and level thereof.
   *
   * @param feature      The package name of the feature to test.
   * In Level 1, supported values are "HTML" and "XML" (case-insensitive).
   * At this writing, org.apache.xerces.dom supports only XML.
   *
   * @param version      The version number of the feature being tested.
   * This is interpreted as "Version of the DOM API supported for the
   * specified Feature", and in Level 1 should be "1.0"
   *
   * @return    true iff this implementation is compatible with the
   * specified feature and version.
   *
   */
  public boolean hasFeature(String feature, String version)
  {

    // Currently, we support only XML Level 1 version 1.0
    return (feature.equalsIgnoreCase(
      "XML") && (version == null || version.equals("1.0") || version.equals(
      "2.0"))) || (feature.equalsIgnoreCase(
        "Events") && (version == null || version.equals(
        "2.0"))) || (feature.equalsIgnoreCase(
          "MutationEvents") && (version == null || version.equals(
          "2.0"))) || (feature.equalsIgnoreCase(
            "Traversal") && (version == null || version.equals("2.0")));
  }  // hasFeature(String,String):boolean

  //
  // Public methods
  //

  /**
   * NON-DOM: Obtain and return the single shared object 
   *
   * @return this DOMImplementation
   */
  public static DOMImplementation getDOMImplementation()
  {
    return singleton;
  }

  /**
   * Introduced in DOM Level 2. <p>
   *
   * Creates an empty DocumentType node.
   *
   * @param qualifiedName The qualified name of the document type to be created.
   * @param publicID The document type public identifier.
   * @param systemID The document type system identifier.
   * @since WD-DOM-Level-2-19990923
   *
   * @return an empty DocumentType node
   */
  public DocumentType createDocumentType(String qualifiedName,
                                         String publicID, String systemID)
  {

    // return new DocumentTypeImpl(null, qualifiedName, publicID, systemID);
    return null;
  }

  /**
   * Introduced in DOM Level 2. <p>
   *
   * Creates an XML Document object of the specified type with its document
   * element.
   *
   * @param namespaceURI     The namespace URI of the document
   *                         element to create, or null.
   * @param qualifiedName    The qualified name of the document
   *                         element to create, or null.
   * @param doctype          The type of document to be created or null.<p>
   *
   *                         When doctype is not null, its
   *                         Node.ownerDocument attribute is set to
   *                         the document being created.
   * @return Document        A new Document object.
   * @throws DOMException    WRONG_DOCUMENT_ERR: Raised if doctype has
   *                         already been used with a different document.
   * @since WD-DOM-Level-2-19990923
   */
  public Document createDocument(
          String namespaceURI, String qualifiedName, DocumentType doctype)
            throws DOMException
  {

    if (doctype != null && doctype.getOwnerDocument() != null)
    {
      throw new DOMException(DOMException.WRONG_DOCUMENT_ERR,
                             "DOM005 Wrong document");
    }

    DocumentImpl doc = new DocumentImpl(doctype);

    return doc;
  }
}