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
044package org.jfree.util;
045
046import java.io.ObjectStreamException;
047import java.io.Serializable;
048
049/**
050 * Represents a direction of rotation (<code>CLOCKWISE</code> or 
051 * <code>ANTICLOCKWISE</code>).
052 * @author David Gilbert
053 */
054public 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}