001/* ===========================================================
002 * JFreeChart : a free chart library for the Java(tm) platform
003 * ===========================================================
004 *
005 * (C) Copyright 2000-2013, by Object Refinery Limited and Contributors.
006 *
007 * Project Info:  http://www.jfree.org/jfreechart/index.html
008 *
009 * This library is free software; you can redistribute it and/or modify it
010 * under the terms of the GNU Lesser General Public License as published by
011 * the Free Software Foundation; either version 2.1 of the License, or
012 * (at your option) any later version.
013 *
014 * This library is distributed in the hope that it will be useful, but
015 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
016 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
017 * License for more details.
018 *
019 * You should have received a copy of the GNU Lesser General Public
020 * License along with this library; if not, write to the Free Software
021 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
022 * USA.
023 *
024 * [Oracle and Java are registered trademarks of Oracle and/or its affiliates. 
025 * Other names may be trademarks of their respective owners.]
026 *
027 * --------------------
028 * ShadowGenerator.java
029 * --------------------
030 * (C) Copyright 2009, 2011, by Object Refinery Limited and Contributors.
031 *
032 * Original Author:  David Gilbert (for Object Refinery Limited);
033 * Contributor(s):   -;
034 *
035 * Changes:
036 * --------
037 * 10-Jul-2009 : Version 1 (DG);
038 *
039 */
040
041package org.jfree.chart.util;
042
043import java.awt.image.BufferedImage;
044
045/**
046 * An interface that defines the API for a shadow generator.  Some plot
047 * classes use this to create drop shadows.
048 *
049 * @since 1.0.14
050 */
051public interface ShadowGenerator {
052
053    /**
054     * Creates and returns an image containing the drop shadow for the
055     * specified source image.
056     *
057     * @param source  the source image.
058     *
059     * @return A new image containing the shadow.
060     */
061    public BufferedImage createDropShadow(BufferedImage source);
062
063    /**
064     * Calculates the x-offset for drawing the shadow image relative to the
065     * source.
066     *
067     * @return The x-offset.
068     */
069    public int calculateOffsetX();
070
071    /**
072     * Calculates the y-offset for drawing the shadow image relative to the
073     * source.
074     *
075     * @return The y-offset.
076     */
077    public int calculateOffsetY();
078
079}