001    /* ========================================================================
002     * JCommon : a free general purpose class 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/jcommon/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     * Rotation.java
029     * -------------
030     * (C)opyright 2003-2005, by Object Refinery Limited and Contributors.
031     *
032     * Original Author:  David Gilbert (for Object Refinery Limited);
033     * Contributor(s):   -;
034     *
035     * $Id: Rotation.java,v 1.5 2005/11/16 15:58:41 taqua Exp $
036     *
037     * Changes
038     * -------
039     * 19-Aug-2003 : Version 1 (DG);
040     * 20-Feb-2004 : Updated Javadocs (DG);
041     * 
042     */
043    
044    package org.jfree.util;
045    
046    import java.io.ObjectStreamException;
047    import java.io.Serializable;
048    
049    /**
050     * Represents a direction of rotation (<code>CLOCKWISE</code> or 
051     * <code>ANTICLOCKWISE</code>).
052     * @author David Gilbert
053     */
054    public final class Rotation implements Serializable {
055    
056        /** For serialization. */
057        private static final long serialVersionUID = -4662815260201591676L;
058        
059        /** Clockwise. */
060        public static final Rotation CLOCKWISE 
061            = new Rotation("Rotation.CLOCKWISE", -1.0);
062    
063        /** The reverse order renders the primary dataset first. */
064        public static final Rotation ANTICLOCKWISE 
065            = new Rotation("Rotation.ANTICLOCKWISE", 1.0);
066    
067        /** The name. */
068        private String name;
069        
070        /** 
071         * The factor (-1.0 for <code>CLOCKWISE</code> and 1.0 for 
072         * <code>ANTICLOCKWISE</code>). 
073         */
074        private double factor;
075    
076        /**
077         * Private constructor.
078         *
079         * @param name  the name.
080         * @param factor  the rotation factor.
081         */
082        private Rotation(final String name, final double factor) {
083            this.name = name;
084            this.factor = factor;
085        }
086    
087        /**
088         * Returns a string representing the object.
089         *
090         * @return the string (never <code>null</code>).
091         */
092        public String toString() {
093            return this.name;
094        }
095    
096        /**
097         * Returns the rotation factor, which is -1.0 for <code>CLOCKWISE</code> 
098         * and 1.0 for <code>ANTICLOCKWISE</code>.
099         * 
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    }