/*

   Copyright 2001,2003  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.svggen;

import java.awt.Composite;

import org.apache.batik.ext.awt.g2d.GraphicContext;
import org.w3c.dom.Element;

/**
 * Utility class that converts an custom Composite object into
 * a set of SVG properties and definitions.
 *
 * @author <a href="mailto:vincent.hardy@eng.sun.com">Vincent Hardy</a>
 * @version $Id: SVGCustomComposite.java,v 1.9 2004/08/18 07:14:59 vhardy Exp $
 * @see                org.apache.batik.svggen.SVGComposite
 */
public class SVGCustomComposite extends AbstractSVGConverter {
    /**
     * @param generatorContext for use by SVGCustomComposite to build Elements
     */
    public SVGCustomComposite(final SVGGeneratorContext generatorContext) {
        super(generatorContext);
    }

    /**
     * Converts part or all of the input GraphicContext into
     * a set of attribute/value pairs and related definitions
     *
     * @param gc GraphicContext to be converted
     * @return descriptor of the attributes required to represent
     *         some or all of the GraphicContext state, along
     *         with the related definitions
     * @see org.apache.batik.svggen.SVGDescriptor
     */
    public SVGDescriptor toSVG(final GraphicContext gc) {
        return this.toSVG(gc.getComposite());
    }

    /**
     * @param composite the Composite object to convert to SVG
     * @return an SVGCompositeDescriptor mapping the SVG
     *         composite equivalent to the input Composite.
     */
    public SVGCompositeDescriptor toSVG(final Composite composite) {
        if (composite == null)
            throw new NullPointerException();
        final SVGCompositeDescriptor compositeDesc =
            (SVGCompositeDescriptor)this.descMap.get(composite);

        if (compositeDesc == null) {
            // First time this composite is used. Request handler
            // to do the convertion
            final SVGCompositeDescriptor desc =
                this.generatorContext.
                extensionHandler.handleComposite(composite,
                                                 this.generatorContext);

            if (desc != null) {
                final Element def = desc.getDef();
                if(def != null)
                    this.defSet.add(def);
                this.descMap.put(composite, desc);
            }
        }

        return compositeDesc;
    }
}
