Source for org.jfree.data.DomainOrder

   1: /* ===========================================================
   2:  * JFreeChart : a free chart library for the Java(tm) platform
   3:  * ===========================================================
   4:  *
   5:  * (C) Copyright 2000-2007, 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 2004-2007, by Object Refinery Limited.
  31:  *
  32:  * Original Author:  David Gilbert (for Object Refinery Limited);
  33:  * Contributor(s):   -;
  34:  *
  35:  * Changes:
  36:  * --------
  37:  * 29-Jul-2004 : Version 1 (DG);
  38:  * 
  39:  */
  40: 
  41: package org.jfree.data;
  42: 
  43: import java.io.ObjectStreamException;
  44: import java.io.Serializable;
  45: 
  46: /**
  47:  * Used to indicate sorting order if any (ascending, descending or none).
  48:  */
  49: public final class DomainOrder implements Serializable {
  50: 
  51:     /** For serialization. */
  52:     private static final long serialVersionUID = 4902774943512072627L;
  53:     
  54:     /** No order. */
  55:     public static final DomainOrder NONE = new DomainOrder("DomainOrder.NONE");
  56: 
  57:     /** Ascending order. */
  58:     public static final DomainOrder ASCENDING 
  59:         = new DomainOrder("DomainOrder.ASCENDING");
  60: 
  61:     /** Descending order. */
  62:     public static final DomainOrder DESCENDING 
  63:         = new DomainOrder("DomainOrder.DESCENDING");
  64: 
  65:     /** The name. */
  66:     private String name;
  67: 
  68:     /**
  69:      * Private constructor.
  70:      *
  71:      * @param name  the name.
  72:      */
  73:     private DomainOrder(String name) {
  74:         this.name = name;
  75:     }
  76: 
  77:     /**
  78:      * Returns a string representing the object.
  79:      *
  80:      * @return The string.
  81:      */
  82:     public String toString() {
  83:         return this.name;
  84:     }
  85: 
  86:     /**
  87:      * Returns <code>true</code> if this object is equal to the specified 
  88:      * object, and <code>false</code> otherwise.
  89:      *
  90:      * @param obj  the other object.
  91:      *
  92:      * @return A boolean.
  93:      */
  94:     public boolean equals(Object obj) {
  95: 
  96:         if (this == obj) {
  97:             return true;
  98:         }
  99:         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: }