001 /* ===========================================================
002 * JFreeChart : a free chart library for the Java(tm) platform
003 * ===========================================================
004 *
005 * (C) Copyright 2000-2006, 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 2004-2006, by Object Refinery Limited.
031 *
032 * Original Author: David Gilbert (for Object Refinery Limited);
033 * Contributor(s): -;
034 *
035 * $Id: StandardXYSeriesLabelGenerator.java,v 1.5.2.2 2006/11/24 16:36:33 mungady Exp $
036 *
037 * Changes
038 * -------
039 * 16-Nov-2004 : Version 1 (DG);
040 * ------------- JFREECHART 1.0.x ---------------------------------------------
041 * 24-Nov-2006 : Fixed equals() method and updated API docs (DG);
042 *
043 */
044
045 package org.jfree.chart.labels;
046
047 import java.io.Serializable;
048 import java.text.MessageFormat;
049
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,
062 PublicCloneable,
063 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 if (format == null) {
089 throw new IllegalArgumentException("Null 'format' argument.");
090 }
091 this.formatPattern = format;
092 }
093
094 /**
095 * Generates a label for the specified series. This label will be
096 * used for the chart legend.
097 *
098 * @param dataset the dataset (<code>null</code> not permitted).
099 * @param series the series.
100 *
101 * @return A series label.
102 */
103 public String generateLabel(XYDataset dataset, int series) {
104 if (dataset == null) {
105 throw new IllegalArgumentException("Null 'dataset' argument.");
106 }
107 String label = MessageFormat.format(
108 this.formatPattern, createItemArray(dataset, series)
109 );
110 return label;
111 }
112
113 /**
114 * Creates the array of items that can be passed to the
115 * {@link MessageFormat} class for creating labels.
116 *
117 * @param dataset the dataset (<code>null</code> not permitted).
118 * @param series the series (zero-based index).
119 *
120 * @return The items (never <code>null</code>).
121 */
122 protected Object[] createItemArray(XYDataset dataset, int series) {
123 Object[] result = new Object[1];
124 result[0] = dataset.getSeriesKey(series).toString();
125 return result;
126 }
127
128 /**
129 * Returns an independent copy of the generator. This is unnecessary,
130 * because instances are immutable anyway, but we retain this
131 * behaviour for backwards compatibility.
132 *
133 * @return A clone.
134 *
135 * @throws CloneNotSupportedException if cloning is not supported.
136 */
137 public Object clone() throws CloneNotSupportedException {
138 return super.clone();
139 }
140
141 /**
142 * Tests this object for equality with an arbitrary object.
143 *
144 * @param obj the other object (<code>null</code> permitted).
145 *
146 * @return A boolean.
147 */
148 public boolean equals(Object obj) {
149 if (obj == this) {
150 return true;
151 }
152 if (!(obj instanceof StandardXYSeriesLabelGenerator)) {
153 return false;
154 }
155 StandardXYSeriesLabelGenerator that
156 = (StandardXYSeriesLabelGenerator) obj;
157 if (!this.formatPattern.equals(that.formatPattern)) {
158 return false;
159 }
160 return true;
161 }
162
163 }