/*

   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.

 */
package org.apache.batik.svggen;

import java.awt.Rectangle;
import java.awt.image.BufferedImageOp;

import org.w3c.dom.Element;

/**
 * Utility class that converts an custom BufferedImageOp object into
 * an equivalent SVG filter.
 *
 * @author <a href="mailto:vincent.hardy@eng.sun.com">Vincent Hardy</a>
 * @version $Id$
 * @see                org.apache.batik.svggen.SVGBufferedImageOp
 */
public class SVGCustomBufferedImageOp extends AbstractSVGFilterConverter {
    private static final String ERROR_EXTENSION =
        "SVGCustomBufferedImageOp:: ExtensionHandler could not convert filter";

    /**
     * @param generatorContext for use by SVGCustomBufferedImageOp to
     * build Elements.
     */
    public SVGCustomBufferedImageOp(SVGGeneratorContext generatorContext) {
        super(generatorContext);
    }

    /**
     * @param filter the BufferedImageOp object to convert to SVG
     * @param filterRect Rectangle, in device space, that defines the area
     *        to which filtering applies. May be null, meaning that the
     *        area is undefined.
     * @return an SVGFilterDescriptor mapping the SVG
     *         BufferedImageOp equivalent to the input BufferedImageOp.
     */
    public SVGFilterDescriptor toSVG(BufferedImageOp filter,
                                     Rectangle filterRect) {
        SVGFilterDescriptor filterDesc =
            (SVGFilterDescriptor)descMap.get(filter);

        if (filterDesc == null) {
            // First time this filter is used. Request handler
            // to do the convertion
            filterDesc =
                generatorContext.extensionHandler.
                handleFilter(filter, filterRect, generatorContext);

            if (filterDesc != null) {
                Element def = filterDesc.getDef();
                if(def != null)
                    defSet.add(def);
                descMap.put(filter, filterDesc);
            } else {
                System.err.println(ERROR_EXTENSION);
            }
        }

        return filterDesc;
    }

}