001/* ===========================================================
002 * JFreeChart : a free chart library for the Java(tm) platform
003 * ===========================================================
004 *
005 * (C) Copyright 2000-2013, 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 * [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 * StandardXYSeriesLabelGenerator.java
029 * -----------------------------------
030 * (C) Copyright 2004-2013, 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 * 03-Jul-2013 : Use ParamChecks (DG);
042 *
043 */
044
045package org.jfree.chart.labels;
046
047import java.io.Serializable;
048import java.text.MessageFormat;
049
050import org.jfree.chart.HashUtilities;
051import org.jfree.chart.util.ParamChecks;
052import org.jfree.data.xy.XYDataset;
053import org.jfree.util.PublicCloneable;
054
055/**
056 * A standard series label generator for plots that use data from
057 * an {@link org.jfree.data.xy.XYDataset}.
058 * <br><br>
059 * This class implements <code>PublicCloneable</code> by mistake but we retain
060 * this for the sake of backward compatibility.
061 */
062public class StandardXYSeriesLabelGenerator implements XYSeriesLabelGenerator,
063        Cloneable, PublicCloneable, Serializable {
064
065    /** For serialization. */
066    private static final long serialVersionUID = 1916017081848400024L;
067
068    /** The default item label format. */
069    public static final String DEFAULT_LABEL_FORMAT = "{0}";
070
071    /** The format pattern. */
072    private String formatPattern;
073
074    /**
075     * Creates a default series label generator (uses
076     * {@link #DEFAULT_LABEL_FORMAT}).
077     */
078    public StandardXYSeriesLabelGenerator() {
079        this(DEFAULT_LABEL_FORMAT);
080    }
081
082    /**
083     * Creates a new series label generator.
084     *
085     * @param format  the format pattern (<code>null</code> not permitted).
086     */
087    public StandardXYSeriesLabelGenerator(String format) {
088        ParamChecks.nullNotPermitted(format, "format");
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    @Override
102    public String generateLabel(XYDataset dataset, int series) {
103        ParamChecks.nullNotPermitted(dataset, "dataset");
104        String label = MessageFormat.format(
105            this.formatPattern, createItemArray(dataset, series)
106        );
107        return label;
108    }
109
110    /**
111     * Creates the array of items that can be passed to the
112     * {@link MessageFormat} class for creating labels.
113     *
114     * @param dataset  the dataset (<code>null</code> not permitted).
115     * @param series  the series (zero-based index).
116     *
117     * @return The items (never <code>null</code>).
118     */
119    protected Object[] createItemArray(XYDataset dataset, int series) {
120        Object[] result = new Object[1];
121        result[0] = dataset.getSeriesKey(series).toString();
122        return result;
123    }
124
125    /**
126     * Returns an independent copy of the generator.  This is unnecessary,
127     * because instances are immutable anyway, but we retain this
128     * behaviour for backwards compatibility.
129     *
130     * @return A clone.
131     *
132     * @throws CloneNotSupportedException if cloning is not supported.
133     */
134    @Override
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    @Override
147    public boolean equals(Object obj) {
148        if (obj == this) {
149            return true;
150        }
151        if (!(obj instanceof StandardXYSeriesLabelGenerator)) {
152            return false;
153        }
154        StandardXYSeriesLabelGenerator that
155                = (StandardXYSeriesLabelGenerator) obj;
156        if (!this.formatPattern.equals(that.formatPattern)) {
157            return false;
158        }
159        return true;
160    }
161
162    /**
163     * Returns a hash code for this instance.
164     *
165     * @return A hash code.
166     */
167    @Override
168    public int hashCode() {
169        int result = 127;
170        result = HashUtilities.hashCode(result, this.formatPattern);
171        return result;
172    }
173
174}