001/* ===========================================================
002 * JFreeChart : a free chart library for the Java(tm) platform
003 * ===========================================================
004 *
005 * (C) Copyright 2000-2007, 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 * CategoryItemLabelGenerator.java
029 * -------------------------------
030 * (C) Copyright 2001-2007, by Object Refinery Limited.
031 *
032 * Original Author:  David Gilbert (for Object Refinery Limited);
033 * Contributor(s):   -;
034 *
035 * Changes
036 * -------
037 * 13-Dec-2001 : Version 1 (DG);
038 * 16-Jan-2002 : Completed Javadocs (DG);
039 * 26-Sep-2002 : Fixed errors reported by Checkstyle (DG);
040 * 24-Oct-2002 : Method now specifies category index (DG);
041 * 05-Nov-2002 : Replaced reference to CategoryDataset with TableDataset (DG);
042 * 21-Jan-2003 : TableDataset merged with CategoryDataset (DG);
043 * 10-Apr-2003 : Changed CategoryDataset --> KeyedValues2DDataset (DG);
044 * 01-May-2003 : Added generateValueLabel() method (with a plan to renaming 
045 *               this interface to reflect its more general use) (DG);
046 * 09-Jun-2003 : Renamed CategoryToolTipGenerator 
047 *               --> CategoryItemLabelGenerator (DG);
048 * 13-Aug-2003 : Added clone() method (DG);
049 * 12-Feb-2004 : Removed clone() method (DG);
050 * 15-Apr-2004 : Moved generateToolTip() method into CategoryToolTipGenerator 
051 *               interface (DG);
052 * 11-May-2004 : Renamed CategoryItemLabelGenerator 
053 *               --> CategoryLabelGenerator (DG);
054 * 31-Jan-2005 : Added generateRowLabel() and generateColumnLabel()  
055 *               methods (DG);
056 * 20-Apr-2005 : Reverted name change of 11-May-2004 (DG);
057 * 
058 */
059
060package org.jfree.chart.labels;
061
062import org.jfree.data.category.CategoryDataset;
063
064/**
065 * A <i>category item label generator</i> is an object that can be assigned to a
066 * {@link org.jfree.chart.renderer.category.CategoryItemRenderer} and that 
067 * assumes responsibility for creating text items to be used as labels for the 
068 * items in a {@link org.jfree.chart.plot.CategoryPlot}. 
069 * <p>
070 * To assist with cloning charts, classes that implement this interface should 
071 * also implement the {@link org.jfree.util.PublicCloneable} interface.
072 */
073public interface CategoryItemLabelGenerator {
074
075    /**
076     * Generates a label for the specified row.
077     * 
078     * @param dataset  the dataset (<code>null</code> not permitted).
079     * @param row  the row index (zero-based).
080     * 
081     * @return The label.
082     */
083    public String generateRowLabel(CategoryDataset dataset, int row);
084    
085    /**
086     * Generates a label for the specified row.
087     * 
088     * @param dataset  the dataset (<code>null</code> not permitted).
089     * @param column  the column index (zero-based).
090     * 
091     * @return The label.
092     */
093    public String generateColumnLabel(CategoryDataset dataset, int column);
094    
095    /**
096     * Generates a label for the specified item. The label is typically a 
097     * formatted version of the data value, but any text can be used.
098     *
099     * @param dataset  the dataset (<code>null</code> not permitted).
100     * @param row  the row index (zero-based).
101     * @param column  the column index (zero-based).
102     *
103     * @return The label (possibly <code>null</code>).
104     */
105    public String generateLabel(CategoryDataset dataset, int row, int column);
106    
107}