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 * StandardCategorySeriesLabelGenerator.java
029 * -----------------------------------------
030 * (C) Copyright 2005-2008, by Object Refinery Limited.
031 *
032 * Original Author: David Gilbert (for Object Refinery Limited);
033 * Contributor(s): -;
034 *
035 * Changes
036 * -------
037 * 20-Apr-2005 : Version 1 (DG);
038 * ------------- JFREECHART 1.0.x ---------------------------------------------
039 * 03-May-2006 : Fixed equals() method (bug 1481102) (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.category.CategoryDataset;
051 import org.jfree.util.PublicCloneable;
052
053 /**
054 * A standard series label generator for plots that use data from
055 * a {@link org.jfree.data.category.CategoryDataset}.
056 */
057 public class StandardCategorySeriesLabelGenerator implements
058 CategorySeriesLabelGenerator, Cloneable, PublicCloneable, Serializable {
059
060 /** For serialization. */
061 private static final long serialVersionUID = 4630760091523940820L;
062
063 /** The default item label format. */
064 public static final String DEFAULT_LABEL_FORMAT = "{0}";
065
066 /** The format pattern. */
067 private String formatPattern;
068
069 /**
070 * Creates a default series label generator (uses
071 * {@link #DEFAULT_LABEL_FORMAT}).
072 */
073 public StandardCategorySeriesLabelGenerator() {
074 this(DEFAULT_LABEL_FORMAT);
075 }
076
077 /**
078 * Creates a new series label generator.
079 *
080 * @param format the format pattern (<code>null</code> not permitted).
081 */
082 public StandardCategorySeriesLabelGenerator(String format) {
083 if (format == null) {
084 throw new IllegalArgumentException("Null 'format' argument.");
085 }
086 this.formatPattern = format;
087 }
088
089 /**
090 * Generates a label for the specified series.
091 *
092 * @param dataset the dataset (<code>null</code> not permitted).
093 * @param series the series.
094 *
095 * @return A series label.
096 */
097 public String generateLabel(CategoryDataset dataset, int series) {
098 if (dataset == null) {
099 throw new IllegalArgumentException("Null 'dataset' argument.");
100 }
101 String label = MessageFormat.format(this.formatPattern,
102 createItemArray(dataset, series));
103 return label;
104 }
105
106 /**
107 * Creates the array of items that can be passed to the
108 * {@link MessageFormat} class for creating labels.
109 *
110 * @param dataset the dataset (<code>null</code> not permitted).
111 * @param series the series (zero-based index).
112 *
113 * @return The items (never <code>null</code>).
114 */
115 protected Object[] createItemArray(CategoryDataset dataset, int series) {
116 Object[] result = new Object[1];
117 result[0] = dataset.getRowKey(series).toString();
118 return result;
119 }
120
121 /**
122 * Returns an independent copy of the generator.
123 *
124 * @return A clone.
125 *
126 * @throws CloneNotSupportedException if cloning is not supported.
127 */
128 public Object clone() throws CloneNotSupportedException {
129 return super.clone();
130 }
131
132 /**
133 * Tests this object for equality with an arbitrary object.
134 *
135 * @param obj the other object (<code>null</code> permitted).
136 *
137 * @return A boolean.
138 */
139 public boolean equals(Object obj) {
140 if (obj == this) {
141 return true;
142 }
143 if (!(obj instanceof StandardCategorySeriesLabelGenerator)) {
144 return false;
145 }
146 StandardCategorySeriesLabelGenerator that
147 = (StandardCategorySeriesLabelGenerator) obj;
148 if (!this.formatPattern.equals(that.formatPattern)) {
149 return false;
150 }
151 return true;
152 }
153
154 /**
155 * Returns a hash code for this instance.
156 *
157 * @return A hash code.
158 */
159 public int hashCode() {
160 int result = 127;
161 result = HashUtilities.hashCode(result, this.formatPattern);
162 return result;
163 }
164
165 }