001    /* ===========================================================
002     * JFreeChart : a free chart library for the Java(tm) platform
003     * ===========================================================
004     *
005     * (C) Copyright 2000-2005, 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 2001-2005, by Object Refinery Limited.
031     *
032     * Original Author:  David Gilbert (for Object Refinery Limited);
033     * Contributor(s):   -;
034     *
035     * $Id: CategoryItemLabelGenerator.java,v 1.1.2.1 2005/10/25 20:49:02 mungady Exp $
036     *
037     * Changes
038     * -------
039     * 13-Dec-2001 : Version 1 (DG);
040     * 16-Jan-2002 : Completed Javadocs (DG);
041     * 26-Sep-2002 : Fixed errors reported by Checkstyle (DG);
042     * 24-Oct-2002 : Method now specifies category index (DG);
043     * 05-Nov-2002 : Replaced reference to CategoryDataset with TableDataset (DG);
044     * 21-Jan-2003 : TableDataset merged with CategoryDataset (DG);
045     * 10-Apr-2003 : Changed CategoryDataset --> KeyedValues2DDataset (DG);
046     * 01-May-2003 : Added generateValueLabel() method (with a plan to renaming 
047     *               this interface to reflect its more general use) (DG);
048     * 09-Jun-2003 : Renamed CategoryToolTipGenerator 
049     *               --> CategoryItemLabelGenerator (DG);
050     * 13-Aug-2003 : Added clone() method (DG);
051     * 12-Feb-2004 : Removed clone() method (DG);
052     * 15-Apr-2004 : Moved generateToolTip() method into CategoryToolTipGenerator 
053     *               interface (DG);
054     * 11-May-2004 : Renamed CategoryItemLabelGenerator 
055     *               --> CategoryLabelGenerator (DG);
056     * 31-Jan-2005 : Added generateRowLabel() and generateColumnLabel()  
057     *               methods (DG);
058     * 20-Apr-2005 : Reverted name change of 11-May-2004 (DG);
059     * 
060     */
061    
062    package org.jfree.chart.labels;
063    
064    import org.jfree.data.category.CategoryDataset;
065    
066    /**
067     * A <i>category item label generator</i> is an object that can be assigned to a
068     * {@link org.jfree.chart.renderer.category.CategoryItemRenderer} and that 
069     * assumes responsibility for creating text items to be used as labels for the 
070     * items in a {@link org.jfree.chart.plot.CategoryPlot}. 
071     * <p>
072     * To assist with cloning charts, classes that implement this interface should 
073     * also implement the {@link org.jfree.util.PublicCloneable} interface.
074     */
075    public interface CategoryItemLabelGenerator {
076    
077        /**
078         * Generates a label for the specified row.
079         * 
080         * @param dataset  the dataset (<code>null</code> not permitted).
081         * @param row  the row index (zero-based).
082         * 
083         * @return The label.
084         */
085        public String generateRowLabel(CategoryDataset dataset, int row);
086        
087        /**
088         * Generates a label for the specified row.
089         * 
090         * @param dataset  the dataset (<code>null</code> not permitted).
091         * @param column  the column index (zero-based).
092         * 
093         * @return The label.
094         */
095        public String generateColumnLabel(CategoryDataset dataset, int column);
096        
097        /**
098         * Generates a label for the specified item. The label is typically a 
099         * formatted version of the data value, but any text can be used.
100         *
101         * @param dataset  the dataset (<code>null</code> not permitted).
102         * @param row  the row index (zero-based).
103         * @param column  the column index (zero-based).
104         *
105         * @return The label (possibly <code>null</code>).
106         */
107        public String generateLabel(CategoryDataset dataset, int row, int column);
108        
109    }