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 * CategoryToolTipGenerator.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 tool tip 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 tooltips 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 {@code org.jfree.util.PublicCloneable} interface (in
049 * JCommon).
050 */
051public interface CategoryToolTipGenerator {
052
053    /**
054     * Generates the tool tip text for an item in a dataset.  Note: in the
055     * current dataset implementation, each row is a series, and each column
056     * contains values for a particular category.
057     *
058     * @param dataset  the dataset ({@code null} not permitted).
059     * @param row  the row index (zero-based).
060     * @param column  the column index (zero-based).
061     *
062     * @return The tooltip text (possibly {@code null}).
063     */
064    String generateToolTip(CategoryDataset dataset, int row, int column);
065
066}