001/* ===========================================================
002 * JFreeChart : a free chart library for the Java(tm) platform
003 * ===========================================================
004 *
005 * (C) Copyright 2000-present, by David Gilbert 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 * CategoryItemLabelGenerator.java
029 * -------------------------------
030 * (C) Copyright 2001-present, by David Gilbert.
031 *
032 * Original Author:  David Gilbert;
033 * Contributor(s):   -;
034 *
035 */
036
037package org.jfree.chart.labels;
038
039import org.jfree.data.category.CategoryDataset;
040
041/**
042 * A <i>category item label generator</i> is an object that can be assigned to a
043 * {@link org.jfree.chart.renderer.category.CategoryItemRenderer} and that
044 * assumes responsibility for creating text items to be used as labels for the
045 * items in a {@link org.jfree.chart.plot.CategoryPlot}.
046 * <p>
047 * To assist with cloning charts, classes that implement this interface should
048 * also implement the {@link org.jfree.chart.util.PublicCloneable} interface.
049 */
050public interface CategoryItemLabelGenerator {
051
052    /**
053     * Generates a label for the specified row.
054     *
055     * @param dataset  the dataset ({@code null} not permitted).
056     * @param row  the row index (zero-based).
057     *
058     * @return The label.
059     */
060    String generateRowLabel(CategoryDataset dataset, int row);
061
062    /**
063     * Generates a label for the specified row.
064     *
065     * @param dataset  the dataset ({@code null} not permitted).
066     * @param column  the column index (zero-based).
067     *
068     * @return The label.
069     */
070    String generateColumnLabel(CategoryDataset dataset, int column);
071
072    /**
073     * Generates a label for the specified item. The label is typically a
074     * formatted version of the data value, but any text can be used.
075     *
076     * @param dataset  the dataset ({@code null} not permitted).
077     * @param row  the row index (zero-based).
078     * @param column  the column index (zero-based).
079     *
080     * @return The label (possibly {@code null}).
081     */
082    String generateLabel(CategoryDataset dataset, int row, int column);
083
084}