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     * UnitType.java
029     * -------------
030     * (C) Copyright 2004, 2005, by Object Refinery Limited.
031     *
032     * Original Author:  David Gilbert (for Object Refinery Limited);
033     * Contributor(s):   -;
034     *
035     * $Id: UnitType.java,v 1.7 2005/10/18 13:24:19 mungady Exp $
036     *
037     * Changes:
038     * --------
039     * 11-Feb-2004 : Version 1 (DG);
040     * 
041     */
042    
043    package org.jfree.util;
044    
045    import java.io.ObjectStreamException;
046    import java.io.Serializable;
047    
048    /**
049     * Used to indicate absolute or relative units.
050     *
051     * @author David Gilbert
052     */
053    public final class UnitType implements Serializable {
054    
055        /** For serialization. */
056        private static final long serialVersionUID = 6531925392288519884L;    
057        
058        /** Absolute. */
059        public static final UnitType ABSOLUTE = new UnitType("UnitType.ABSOLUTE");
060    
061        /** Relative. */
062        public static final UnitType RELATIVE = new UnitType("UnitType.RELATIVE");
063    
064        /** The name. */
065        private String name;
066    
067        /**
068         * Private constructor.
069         *
070         * @param name  the name.
071         */
072        private UnitType(final String name) {
073            this.name = name;
074        }
075    
076        /**
077         * Returns a string representing the object.
078         *
079         * @return The string.
080         */
081        public String toString() {
082            return this.name;
083        }
084    
085        /**
086         * Returns <code>true</code> if this object is equal to the specified 
087         * object, and <code>false</code> otherwise.
088         *
089         * @param obj  the other object.
090         *
091         * @return A boolean.
092         */
093        public boolean equals(final Object obj) {
094            if (obj == this) {
095                return true;
096            }
097            if (!(obj instanceof UnitType)) {
098                return false;
099            }
100            final UnitType that = (UnitType) obj;
101            if (!this.name.equals(that.name)) {
102                return false;
103            }
104            return true;
105        }
106    
107        /**
108         * Returns a hash code value for the object.
109         *
110         * @return The hashcode
111         */
112        public int hashCode() {
113            return this.name.hashCode();
114        }
115    
116        /**
117         * Ensures that serialization returns the unique instances.
118         * 
119         * @return The object.
120         * 
121         * @throws ObjectStreamException if there is a problem.
122         */
123        private Object readResolve() throws ObjectStreamException {
124            if (this.equals(UnitType.ABSOLUTE)) {
125                return UnitType.ABSOLUTE;
126            }
127            else if (this.equals(UnitType.RELATIVE)) {
128                return UnitType.RELATIVE;
129            }
130            return null;
131        }
132        
133    }