Source for org.jfree.data.DomainOrder

   1: /* ===========================================================
   2:  * JFreeChart : a free chart library for the Java(tm) platform
   3:  * ===========================================================
   4:  *
   5:  * (C) Copyright 2000-2005, by Object Refinery Limited and Contributors.
   6:  *
   7:  * Project Info:  http://www.jfree.org/jfreechart/index.html
   8:  *
   9:  * This library is free software; you can redistribute it and/or modify it 
  10:  * under the terms of the GNU Lesser General Public License as published by 
  11:  * the Free Software Foundation; either version 2.1 of the License, or 
  12:  * (at your option) any later version.
  13:  *
  14:  * This library is distributed in the hope that it will be useful, but 
  15:  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 
  16:  * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public 
  17:  * License for more details.
  18:  *
  19:  * You should have received a copy of the GNU Lesser General Public
  20:  * License along with this library; if not, write to the Free Software
  21:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, 
  22:  * USA.  
  23:  *
  24:  * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 
  25:  * in the United States and other countries.]
  26:  *
  27:  * ----------------
  28:  * DomainOrder.java
  29:  * ----------------
  30:  * (C) Copyright 2004, 2005, by Object Refinery Limited.
  31:  *
  32:  * Original Author:  David Gilbert (for Object Refinery Limited);
  33:  * Contributor(s):   -;
  34:  *
  35:  * $Id: DomainOrder.java,v 1.4.2.1 2005/10/25 21:29:13 mungady Exp $
  36:  *
  37:  * Changes:
  38:  * --------
  39:  * 29-Jul-2004 : Version 1 (DG);
  40:  * 
  41:  */
  42: 
  43: package org.jfree.data;
  44: 
  45: import java.io.ObjectStreamException;
  46: import java.io.Serializable;
  47: 
  48: /**
  49:  * Used to indicate sorting order if any (ascending, descending or none).
  50:  */
  51: public final class DomainOrder implements Serializable {
  52: 
  53:     /** For serialization. */
  54:     private static final long serialVersionUID = 4902774943512072627L;
  55:     
  56:     /** No order. */
  57:     public static final DomainOrder NONE = new DomainOrder("DomainOrder.NONE");
  58: 
  59:     /** Ascending order. */
  60:     public static final DomainOrder ASCENDING 
  61:         = new DomainOrder("DomainOrder.ASCENDING");
  62: 
  63:     /** Descending order. */
  64:     public static final DomainOrder DESCENDING 
  65:         = new DomainOrder("DomainOrder.DESCENDING");
  66: 
  67:     /** The name. */
  68:     private String name;
  69: 
  70:     /**
  71:      * Private constructor.
  72:      *
  73:      * @param name  the name.
  74:      */
  75:     private DomainOrder(String name) {
  76:         this.name = name;
  77:     }
  78: 
  79:     /**
  80:      * Returns a string representing the object.
  81:      *
  82:      * @return The string.
  83:      */
  84:     public String toString() {
  85:         return this.name;
  86:     }
  87: 
  88:     /**
  89:      * Returns <code>true</code> if this object is equal to the specified 
  90:      * object, and <code>false</code> otherwise.
  91:      *
  92:      * @param obj  the other object.
  93:      *
  94:      * @return A boolean.
  95:      */
  96:     public boolean equals(Object obj) {
  97: 
  98:         if (this == obj) {
  99:             return true;
 100:         }
 101:         if (!(obj instanceof DomainOrder)) {
 102:             return false;
 103:         }
 104:         DomainOrder that = (DomainOrder) obj;
 105:         if (!this.name.equals(that.toString())) {
 106:             return false;
 107:         }
 108:         return true;
 109:     }
 110:     
 111:     /**
 112:      * Returns a hash code value for the object.
 113:      *
 114:      * @return The hashcode
 115:      */
 116:     public int hashCode() {
 117:         return this.name.hashCode();
 118:     }
 119: 
 120:     /**
 121:      * Ensures that serialization returns the unique instances.
 122:      * 
 123:      * @return The object.
 124:      * 
 125:      * @throws ObjectStreamException if there is a problem.
 126:      */
 127:     private Object readResolve() throws ObjectStreamException {
 128:         if (this.equals(DomainOrder.ASCENDING)) {
 129:             return DomainOrder.ASCENDING;
 130:         }
 131:         else if (this.equals(DomainOrder.DESCENDING)) {
 132:             return DomainOrder.DESCENDING;
 133:         }
 134:         else if (this.equals(DomainOrder.NONE)) {
 135:             return DomainOrder.NONE;
 136:         }
 137:         return null;
 138:     }
 139:     
 140: }