/*

   Copyright 2000-2003  The Apache Software Foundation 

   Licensed 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.

 */
package org.apache.batik.dom;

import java.io.Serializable;

import org.apache.batik.dom.events.DocumentEventSupport;
import org.apache.batik.dom.util.HashTable;
import org.w3c.dom.DOMImplementation;

/**
 * This class implements the {@link org.w3c.dom.DOMImplementation},
 * {@link org.w3c.dom.css.DOMImplementationCSS} interfaces.
 *
 * @author <a href="mailto:stephane@hillion.org">Stephane Hillion</a>
 * @version $Id$
 */

public abstract class AbstractDOMImplementation
    implements DOMImplementation,
               Serializable {

    /**
     * The supported features.
     */
    protected final HashTable features = new HashTable();
    {
	registerFeature("XML",            new String[] { "1.0", "2.0" });
	registerFeature("Events",         "2.0");
	registerFeature("MouseEvents",    "2.0");
	registerFeature("MutationEvents", "2.0");
	registerFeature("Traversal",      "2.0");
	registerFeature("UIEvents",       "2.0");
    }
    
    /**
     * Registers a DOM feature.
     */
    protected void registerFeature(String name, Object value) {
        features.put(name.toLowerCase(), value);
    }

    /**
     * Creates a new AbstractDOMImplementation object.
     */
    protected AbstractDOMImplementation() {
    }

    /**
     * <b>DOM</b>: Implements {@link
     * org.w3c.dom.DOMImplementation#hasFeature(String,String)}.
     */
    public boolean hasFeature(String feature, String version) {
	Object v = features.get(feature.toLowerCase());
	if (v == null) {
	    return false;
	}
	if (version == null || version.length() == 0) {
	    return true;
	}
        if (v instanceof String) {
            return version.equals(v);
        } else {
            String[] va = (String[])v;
            for (int i = 0; i < va.length; i++) {
                if (version.equals(va[i])) {
                    return true;
                }
            }
            return false;
        }
    }

    /**
     * Creates an DocumentEventSupport object suitable for use with this implementation.
     */
    public DocumentEventSupport createDocumentEventSupport() {
        return new DocumentEventSupport();
    }
}