001 /* ===========================================================
002 * JFreeChart : a free chart library for the Java(tm) platform
003 * ===========================================================
004 *
005 * (C) Copyright 2000-2005, 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, 2005, by Object Refinery Limited and Contributors.
031 *
032 * Original Author: David Gilbert (for Object Refinery Limited);
033 * Contributor(s): -;
034 *
035 * $Id: HistogramType.java,v 1.4.2.1 2005/10/25 21:34:46 mungady Exp $
036 *
037 * Changes
038 * -------
039 * 05-Mar-2004 : Version 1 (DG);
040 *
041 */
042
043 package org.jfree.data.statistics;
044
045 import java.io.ObjectStreamException;
046 import java.io.Serializable;
047
048 /**
049 * A class for creating constants to represent the histogram type. See Bloch's
050 * enum tip in 'Effective Java'.
051 */
052 public class HistogramType implements Serializable {
053
054 /** For serialization. */
055 private static final long serialVersionUID = 2618927186251997727L;
056
057 /** Frequency histogram. */
058 public static final HistogramType FREQUENCY
059 = new HistogramType("FREQUENCY");
060
061 /** Relative frequency. */
062 public static final HistogramType RELATIVE_FREQUENCY
063 = new HistogramType("RELATIVE_FREQUENCY");
064
065 /** Scale area to one. */
066 public static final HistogramType SCALE_AREA_TO_1
067 = new HistogramType("SCALE_AREA_TO_1");
068
069 /** The type name. */
070 private String name;
071
072 /**
073 * Creates a new type.
074 *
075 * @param name the name.
076 */
077 private HistogramType(String name) {
078 this.name = name;
079 }
080
081 /**
082 * Returns a string representing the object.
083 *
084 * @return The string.
085 */
086 public String toString() {
087 return this.name;
088 }
089
090 /**
091 * Tests this type for equality with an arbitrary object.
092 *
093 * @param obj the object to test against.
094 *
095 * @return A boolean.
096 */
097 public boolean equals(Object obj) {
098
099 if (obj == null) {
100 return false;
101 }
102
103 if (obj == this) {
104 return true;
105 }
106
107 if (!(obj instanceof HistogramType)) {
108 return false;
109 }
110
111 HistogramType t = (HistogramType) obj;
112 if (!this.name.equals(t.name)) {
113 return false;
114 }
115
116 return true;
117
118 }
119
120 /**
121 * Returns a hash code value for the object.
122 *
123 * @return The hashcode
124 */
125 public int hashCode() {
126 return this.name.hashCode();
127 }
128
129 /**
130 * Ensures that serialization returns the unique instances.
131 *
132 * @return The object.
133 *
134 * @throws ObjectStreamException if there is a problem.
135 */
136 private Object readResolve() throws ObjectStreamException {
137 if (this.equals(HistogramType.FREQUENCY)) {
138 return HistogramType.FREQUENCY;
139 }
140 else if (this.equals(HistogramType.RELATIVE_FREQUENCY)) {
141 return HistogramType.RELATIVE_FREQUENCY;
142 }
143 else if (this.equals(HistogramType.SCALE_AREA_TO_1)) {
144 return HistogramType.SCALE_AREA_TO_1;
145 }
146 return null;
147 }
148
149 }
150