Source for org.jfree.util.Rotation

   1: /* ========================================================================
   2:  * JCommon : a free general purpose class 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/jcommon/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:  * Rotation.java
  29:  * -------------
  30:  * (C)opyright 2003-2005, by Object Refinery Limited and Contributors.
  31:  *
  32:  * Original Author:  David Gilbert (for Object Refinery Limited);
  33:  * Contributor(s):   -;
  34:  *
  35:  * $Id: Rotation.java,v 1.5 2005/11/16 15:58:41 taqua Exp $
  36:  *
  37:  * Changes
  38:  * -------
  39:  * 19-Aug-2003 : Version 1 (DG);
  40:  * 20-Feb-2004 : Updated Javadocs (DG);
  41:  * 
  42:  */
  43: 
  44: package org.jfree.util;
  45: 
  46: import java.io.ObjectStreamException;
  47: import java.io.Serializable;
  48: 
  49: /**
  50:  * Represents a direction of rotation (<code>CLOCKWISE</code> or 
  51:  * <code>ANTICLOCKWISE</code>).
  52:  * @author David Gilbert
  53:  */
  54: public final class Rotation implements Serializable {
  55: 
  56:     /** For serialization. */
  57:     private static final long serialVersionUID = -4662815260201591676L;
  58:     
  59:     /** Clockwise. */
  60:     public static final Rotation CLOCKWISE 
  61:         = new Rotation("Rotation.CLOCKWISE", -1.0);
  62: 
  63:     /** The reverse order renders the primary dataset first. */
  64:     public static final Rotation ANTICLOCKWISE 
  65:         = new Rotation("Rotation.ANTICLOCKWISE", 1.0);
  66: 
  67:     /** The name. */
  68:     private String name;
  69:     
  70:     /** 
  71:      * The factor (-1.0 for <code>CLOCKWISE</code> and 1.0 for 
  72:      * <code>ANTICLOCKWISE</code>). 
  73:      */
  74:     private double factor;
  75: 
  76:     /**
  77:      * Private constructor.
  78:      *
  79:      * @param name  the name.
  80:      * @param factor  the rotation factor.
  81:      */
  82:     private Rotation(final String name, final double factor) {
  83:         this.name = name;
  84:         this.factor = factor;
  85:     }
  86: 
  87:     /**
  88:      * Returns a string representing the object.
  89:      *
  90:      * @return the string (never <code>null</code>).
  91:      */
  92:     public String toString() {
  93:         return this.name;
  94:     }
  95: 
  96:     /**
  97:      * Returns the rotation factor, which is -1.0 for <code>CLOCKWISE</code> 
  98:      * and 1.0 for <code>ANTICLOCKWISE</code>.
  99:      * 
 100:      * @return the rotation factor.
 101:      */
 102:     public double getFactor() {
 103:         return this.factor;
 104:     }
 105: 
 106:     /**
 107:      * Compares this object for equality with an other object.
 108:      * Implementation note: This simply compares the factor instead
 109:      * of the name.
 110:      *
 111:      * @param o the other object
 112:      * @return true or false
 113:      */
 114:     public boolean equals(final Object o) {
 115:         if (this == o) {
 116:             return true;
 117:         }
 118:         if (!(o instanceof Rotation)) {
 119:             return false;
 120:         }
 121: 
 122:         final Rotation rotation = (Rotation) o;
 123: 
 124:         if (this.factor != rotation.factor) {
 125:             return false;
 126:         }
 127: 
 128:         return true;
 129:     }
 130: 
 131:     /**
 132:      * Returns a hash code value for the object.
 133:      *
 134:      * @return the hashcode
 135:      */
 136:     public int hashCode() {
 137:         final long temp = Double.doubleToLongBits(this.factor);
 138:         return (int) (temp ^ (temp >>> 32));
 139:     }
 140: 
 141:     /**
 142:      * Ensures that serialization returns the unique instances.
 143:      * 
 144:      * @return the object.
 145:      * 
 146:      * @throws ObjectStreamException if there is a problem.
 147:      */
 148:     private Object readResolve() throws ObjectStreamException {
 149:         if (this.equals(Rotation.CLOCKWISE)) {
 150:             return Rotation.CLOCKWISE;
 151:         }
 152:         else if (this.equals(Rotation.ANTICLOCKWISE)) {
 153:             return Rotation.ANTICLOCKWISE;
 154:         }      
 155:         return null;
 156:     }
 157: 
 158: }