    001    /* ===========================================================
    002     * JFreeChart : a free chart library for the Java(tm) platform
    003     * ===========================================================
    004     *
    005     * (C) Copyright 2000-2008, 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     * StandardXYSeriesLabelGenerator.java
    029     * -----------------------------------
    030     * (C) Copyright 2004-2008, by Object Refinery Limited.
    031     *
    032     * Original Author:  David Gilbert (for Object Refinery Limited);
    033     * Contributor(s):   -;
    034     *
    035     * Changes
    036     * -------
    037     * 16-Nov-2004 : Version 1 (DG);
    038     * ------------- JFREECHART 1.0.x ---------------------------------------------
    039     * 24-Nov-2006 : Fixed equals() method and updated API docs (DG);
    040     * 31-Mar-2008 : Added hashCode() method to appease FindBugs (DG);
    041     *
    042     */
    043
    044    package org.jfree.chart.labels;
    045
    046    import java.io.Serializable;
    047    import java.text.MessageFormat;
    048
    049    import org.jfree.chart.HashUtilities;
    050    import org.jfree.data.xy.XYDataset;
    051    import org.jfree.util.PublicCloneable;
    052
    053    /**
    054     * A standard series label generator for plots that use data from
    055     * an {@link org.jfree.data.xy.XYDataset}.
    056     * <br><br>
    057     * This class implements <code>PublicCloneable</code> by mistake but we retain
    058     * this for the sake of backward compatibility.
    059     */
    060    public class StandardXYSeriesLabelGenerator implements XYSeriesLabelGenerator,
    061            Cloneable, PublicCloneable, Serializable {
    062
    063        /** For serialization. */
    064        private static final long serialVersionUID = 1916017081848400024L;
    065
    066        /** The default item label format. */
    067        public static final String DEFAULT_LABEL_FORMAT = "{0}";
    068
    069        /** The format pattern. */
    070        private String formatPattern;
    071
    072        /**
    073         * Creates a default series label generator (uses
    074         * {@link #DEFAULT_LABEL_FORMAT}).
    075         */
    076        public StandardXYSeriesLabelGenerator() {
    077            this(DEFAULT_LABEL_FORMAT);
    078        }
    079
    080        /**
    081         * Creates a new series label generator.
    082         *
    083         * @param format  the format pattern (<code>null</code> not permitted).
    084         */
    085        public StandardXYSeriesLabelGenerator(String format) {
    086            if (format == null) {
    087                throw new IllegalArgumentException("Null 'format' argument.");
    088            }
    089            this.formatPattern = format;
    090        }
    091
    092        /**
    093         * Generates a label for the specified series.  This label will be
    094         * used for the chart legend.
    095         *
    096         * @param dataset  the dataset (<code>null</code> not permitted).
    097         * @param series  the series.
    098         *
    099         * @return A series label.
    100         */
    101        public String generateLabel(XYDataset dataset, int series) {
    102            if (dataset == null) {
    103                throw new IllegalArgumentException("Null 'dataset' argument.");
    104            }
    105            String label = MessageFormat.format(
    106                this.formatPattern, createItemArray(dataset, series)
    107            );
    108            return label;
    109        }
    110
    111        /**
    112         * Creates the array of items that can be passed to the
    113         * {@link MessageFormat} class for creating labels.
    114         *
    115         * @param dataset  the dataset (<code>null</code> not permitted).
    116         * @param series  the series (zero-based index).
    117         *
    118         * @return The items (never <code>null</code>).
    119         */
    120        protected Object[] createItemArray(XYDataset dataset, int series) {
    121            Object[] result = new Object[1];
    122            result[0] = dataset.getSeriesKey(series).toString();
    123            return result;
    124        }
    125
    126        /**
    127         * Returns an independent copy of the generator.  This is unnecessary,
    128         * because instances are immutable anyway, but we retain this
    129         * behaviour for backwards compatibility.
    130         *
    131         * @return A clone.
    132         *
    133         * @throws CloneNotSupportedException if cloning is not supported.
    134         */
    135        public Object clone() throws CloneNotSupportedException {
    136            return super.clone();
    137        }
    138
    139        /**
    140         * Tests this object for equality with an arbitrary object.
    141         *
    142         * @param obj  the other object (<code>null</code> permitted).
    143         *
    144         * @return A boolean.
    145         */
    146        public boolean equals(Object obj) {
    147            if (obj == this) {
    148                return true;
    149            }
    150            if (!(obj instanceof StandardXYSeriesLabelGenerator)) {
    151                return false;
    152            }
    153            StandardXYSeriesLabelGenerator that
    154                    = (StandardXYSeriesLabelGenerator) obj;
    155            if (!this.formatPattern.equals(that.formatPattern)) {
    156                return false;
    157            }
    158            return true;
    159        }
    160
    161        /**
    162         * Returns a hash code for this instance.
    163         *
    164         * @return A hash code.
    165         */
    166        public int hashCode() {
    167            int result = 127;
    168            result = HashUtilities.hashCode(result, this.formatPattern);
    169            return result;
    170        }
    171
    172    }