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 * reserved comment block

 * DO NOT REMOVE OR ALTER!

 */

/*

 * 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.

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package com.sun.org.apache.xerces.internal.dom;

import org.w3c.dom.DOMException;

import org.w3c.dom.DOMImplementation;

import org.w3c.dom.Document;

import org.w3c.dom.DocumentType;

import org.w3c.dom.Element;

/**

 * The DOMImplementation class is description of a particular

 * implementation of the Document Object Model. As such its data is

 * static, shared by all instances of this implementation.

 * <P>

 * The DOM API requires that it be a real object rather than static

 * methods. However, there's nothing that says it can't be a singleton,

 * so that's how I've implemented it.

 *

 * @xerces.internal

 *

 * @since  PR-DOM-Level-1-19980818.

 */

public class DOMImplementationImpl extends CoreDOMImplementationImpl

    implements DOMImplementation {

    //

    // Data

    //

    // static

    /** Dom implementation singleton. */

    static DOMImplementationImpl singleton = new DOMImplementationImpl();

    //

    // Public methods

    //

    /** NON-DOM: Obtain and return the single shared object */

    public static DOMImplementation getDOMImplementation() {

        return singleton;

    }

    //

    // 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, com.sun.org.apache.xerces.internal.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 compatable with the

     * specified feature and version.

     */

    public boolean hasFeature(String feature, String version) {

        if (feature == null || feature.length() == 0) {

            return false;

        }

        boolean result = super.hasFeature(feature, version);

        if (!result) {

            boolean anyVersion = version == null || version.length() == 0;

            if (feature.startsWith("+")) {

                feature = feature.substring(1);

            }

            return (

                (feature.equalsIgnoreCase("Events")

                    && (anyVersion || version.equals("2.0")))

                    || (feature.equalsIgnoreCase("MutationEvents")

                        && (anyVersion || version.equals("2.0")))

                    || (feature.equalsIgnoreCase("Traversal")

                        && (anyVersion || version.equals("2.0")))

                    || (feature.equalsIgnoreCase("Range")

                        && (anyVersion || version.equals("2.0")))

                    || (feature.equalsIgnoreCase("MutationEvents")

                        && (anyVersion || version.equals("2.0"))));

        }

        return result;

    } // hasFeature(String,String):boolean

    /**

     * 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.

     * @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(namespaceURI == null && qualifiedName == null && doctype == null){

        //if namespaceURI, qualifiedName and doctype are null, returned document is empty with

        //no document element

            return new DocumentImpl();

        }

        else if (doctype != null && doctype.getOwnerDocument() != null) {

            String msg = DOMMessageFormatter.formatMessage(DOMMessageFormatter.DOM_DOMAIN, "WRONG_DOCUMENT_ERR", null);

            throw new DOMException(DOMException.WRONG_DOCUMENT_ERR, msg);

        }

        DocumentImpl doc = new DocumentImpl(doctype);

        Element e = doc.createElementNS( namespaceURI, qualifiedName);

        doc.appendChild(e);

        return doc;

    }

} // class DOMImplementationImpl