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 * DomainOrder.java
029 * ----------------
030 * (C) Copyright 2004-2008, by Object Refinery Limited.
031 *
032 * Original Author: David Gilbert (for Object Refinery Limited);
033 * Contributor(s): -;
034 *
035 * Changes:
036 * --------
037 * 29-Jul-2004 : Version 1 (DG);
038 *
039 */
040
041 package org.jfree.data;
042
043 import java.io.ObjectStreamException;
044 import java.io.Serializable;
045
046 /**
047 * Used to indicate sorting order if any (ascending, descending or none).
048 */
049 public final class DomainOrder implements Serializable {
050
051 /** For serialization. */
052 private static final long serialVersionUID = 4902774943512072627L;
053
054 /** No order. */
055 public static final DomainOrder NONE = new DomainOrder("DomainOrder.NONE");
056
057 /** Ascending order. */
058 public static final DomainOrder ASCENDING
059 = new DomainOrder("DomainOrder.ASCENDING");
060
061 /** Descending order. */
062 public static final DomainOrder DESCENDING
063 = new DomainOrder("DomainOrder.DESCENDING");
064
065 /** The name. */
066 private String name;
067
068 /**
069 * Private constructor.
070 *
071 * @param name the name.
072 */
073 private DomainOrder(String name) {
074 this.name = name;
075 }
076
077 /**
078 * Returns a string representing the object.
079 *
080 * @return The string.
081 */
082 public String toString() {
083 return this.name;
084 }
085
086 /**
087 * Returns <code>true</code> if this object is equal to the specified
088 * object, and <code>false</code> otherwise.
089 *
090 * @param obj the other object.
091 *
092 * @return A boolean.
093 */
094 public boolean equals(Object obj) {
095
096 if (this == obj) {
097 return true;
098 }
099 if (!(obj instanceof DomainOrder)) {
100 return false;
101 }
102 DomainOrder that = (DomainOrder) obj;
103 if (!this.name.equals(that.toString())) {
104 return false;
105 }
106 return true;
107 }
108
109 /**
110 * Returns a hash code value for the object.
111 *
112 * @return The hashcode
113 */
114 public int hashCode() {
115 return this.name.hashCode();
116 }
117
118 /**
119 * Ensures that serialization returns the unique instances.
120 *
121 * @return The object.
122 *
123 * @throws ObjectStreamException if there is a problem.
124 */
125 private Object readResolve() throws ObjectStreamException {
126 if (this.equals(DomainOrder.ASCENDING)) {
127 return DomainOrder.ASCENDING;
128 }
129 else if (this.equals(DomainOrder.DESCENDING)) {
130 return DomainOrder.DESCENDING;
131 }
132 else if (this.equals(DomainOrder.NONE)) {
133 return DomainOrder.NONE;
134 }
135 return null;
136 }
137
138 }