001    /* ===========================================================
002     * JFreeChart : a free chart library for the Java(tm) platform
003     * ===========================================================
004     *
005     * (C) Copyright 2000-2006, 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     * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 
025     * in the United States and other countries.]
026     *
027     * --------------------
028     * PieURLGenerator.java
029     * --------------------
030     * (C) Copyright 2002-2006, by Richard Atkinson and Contributors.
031     *
032     * Original Author:  Richard Atkinson;
033     * Contributors:     David Gilbert (for Object Refinery Limited);
034     *
035     * $Id: PieURLGenerator.java,v 1.3.2.2 2006/11/24 10:47:27 mungady Exp $
036     *
037     * Changes:
038     * --------
039     * 05-Aug-2002 : Version 1, contributed by Richard Atkinson;
040     * 09-Oct-2002 : Fixed errors reported by Checkstyle (DG);
041     * 07-Mar-2003 : Modified to use KeyedValuesDataset and added pieIndex 
042     *               parameter (DG);
043     * 24-Apr-2003 : Switched around PieDataset and KeyedValuesDataset (DG);
044     * ------------- JFREECHART 1.0.x ---------------------------------------------
045     * 24-Nov-2006 : Updated API docs (DG);
046     *
047     */
048    package org.jfree.chart.urls;
049    
050    import org.jfree.data.general.PieDataset;
051    
052    /**
053     * Interface for a URL generator for plots that use data from a 
054     * {@link PieDataset}.
055     * <P>
056     * Classes that implement this interface should be either (a) immutable, or
057     * (b) cloneable via the <code>PublicCloneable</code> interface (defined in 
058     * the JCommon class library).  This provides a mechanism for the referring
059     * plot to clone the generator if necessary.
060     */
061    public interface PieURLGenerator {
062    
063        /**
064         * Generates a URL for one item in a {@link PieDataset}. As a guideline, 
065         * the URL should be valid within the context of an XHTML 1.0 document.
066         *
067         * @param dataset  the dataset (<code>null</code> not permitted).
068         * @param key  the item key (<code>null</code> not permitted).
069         * @param pieIndex  the pie index (differentiates between pies in a 
070         *                  'multi' pie chart).
071         *
072         * @return A string containing the URL.
073         */
074        public String generateURL(PieDataset dataset, Comparable key, int pieIndex);
075    
076    }