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 * HistogramType.java
029 * ------------------
030 * (C) Copyright 2004-2008, by Object Refinery Limited and Contributors.
031 *
032 * Original Author: David Gilbert (for Object Refinery Limited);
033 * Contributor(s): -;
034 *
035 * Changes
036 * -------
037 * 05-Mar-2004 : Version 1 (DG);
038 *
039 */
040
041 package org.jfree.data.statistics;
042
043 import java.io.ObjectStreamException;
044 import java.io.Serializable;
045
046 /**
047 * A class for creating constants to represent the histogram type. See Bloch's
048 * enum tip in 'Effective Java'.
049 */
050 public class HistogramType implements Serializable {
051
052 /** For serialization. */
053 private static final long serialVersionUID = 2618927186251997727L;
054
055 /** Frequency histogram. */
056 public static final HistogramType FREQUENCY
057 = new HistogramType("FREQUENCY");
058
059 /** Relative frequency. */
060 public static final HistogramType RELATIVE_FREQUENCY
061 = new HistogramType("RELATIVE_FREQUENCY");
062
063 /** Scale area to one. */
064 public static final HistogramType SCALE_AREA_TO_1
065 = new HistogramType("SCALE_AREA_TO_1");
066
067 /** The type name. */
068 private String name;
069
070 /**
071 * Creates a new type.
072 *
073 * @param name the name.
074 */
075 private HistogramType(String name) {
076 this.name = name;
077 }
078
079 /**
080 * Returns a string representing the object.
081 *
082 * @return The string.
083 */
084 public String toString() {
085 return this.name;
086 }
087
088 /**
089 * Tests this type for equality with an arbitrary object.
090 *
091 * @param obj the object to test against.
092 *
093 * @return A boolean.
094 */
095 public boolean equals(Object obj) {
096
097 if (obj == null) {
098 return false;
099 }
100
101 if (obj == this) {
102 return true;
103 }
104
105 if (!(obj instanceof HistogramType)) {
106 return false;
107 }
108
109 HistogramType t = (HistogramType) obj;
110 if (!this.name.equals(t.name)) {
111 return false;
112 }
113
114 return true;
115
116 }
117
118 /**
119 * Returns a hash code value for the object.
120 *
121 * @return The hashcode
122 */
123 public int hashCode() {
124 return this.name.hashCode();
125 }
126
127 /**
128 * Ensures that serialization returns the unique instances.
129 *
130 * @return The object.
131 *
132 * @throws ObjectStreamException if there is a problem.
133 */
134 private Object readResolve() throws ObjectStreamException {
135 if (this.equals(HistogramType.FREQUENCY)) {
136 return HistogramType.FREQUENCY;
137 }
138 else if (this.equals(HistogramType.RELATIVE_FREQUENCY)) {
139 return HistogramType.RELATIVE_FREQUENCY;
140 }
141 else if (this.equals(HistogramType.SCALE_AREA_TO_1)) {
142 return HistogramType.SCALE_AREA_TO_1;
143 }
144 return null;
145 }
146
147 }
148