    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}