001    /* ===========================================================
002     * JFreeChart : a free chart library for the Java(tm) platform
003     * ===========================================================
004     *
005     * (C) Copyright 2000-2008, by Object Refinery Limited and Contributors.
006     *
007     * Project Info:  http://www.jfree.org/jfreechart/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     * CategoryAnchor.java
029     * -------------------
030     * (C) Copyright 2003-2008, by Object Refinery Limited.
031     *
032     * Original Author:  David Gilbert (for Object Refinery Limited);
033     * Contributor(s):   -;
034     *
035     * Changes:
036     * --------
037     * 04-Jul-2003 : Version 1 (DG);
038     *
039     */
040    
041    package org.jfree.chart.axis;
042    
043    import java.io.ObjectStreamException;
044    import java.io.Serializable;
045    
046    /**
047     * Used to indicate one of three positions within a category:
048     * <code>START</code>, <code>MIDDLE</code> and <code>END</code>.
049     */
050    public final class CategoryAnchor implements Serializable {
051    
052        /** For serialization. */
053        private static final long serialVersionUID = -2604142742210173810L;
054    
055        /** Start of period. */
056        public static final CategoryAnchor START
057            = new CategoryAnchor("CategoryAnchor.START");
058    
059        /** Middle of period. */
060        public static final CategoryAnchor MIDDLE
061            = new CategoryAnchor("CategoryAnchor.MIDDLE");
062    
063        /** End of period. */
064        public static final CategoryAnchor END
065            = new CategoryAnchor("CategoryAnchor.END");
066    
067        /** The name. */
068        private String name;
069    
070        /**
071         * Private constructor.
072         *
073         * @param name  the name.
074         */
075        private CategoryAnchor(String name) {
076            this.name = name;
077        }
078    
079        /**
080         * Returns a string representing the object.
081         *
082         * @return The string.
083         */
084        public String toString() {
085            return this.name;
086        }
087    
088        /**
089         * Returns <code>true</code> if this object is equal to the specified
090         * object, and <code>false</code> otherwise.
091         *
092         * @param obj  the other object.
093         *
094         * @return A boolean.
095         */
096        public boolean equals(Object obj) {
097    
098            if (this == obj) {
099                return true;
100            }
101            if (!(obj instanceof CategoryAnchor)) {
102                return false;
103            }
104            CategoryAnchor position = (CategoryAnchor) obj;
105            if (!this.name.equals(position.toString())) {
106                return false;
107            }
108            return true;
109    
110        }
111    
112        /**
113         * Ensures that serialization returns the unique instances.
114         *
115         * @return The object.
116         *
117         * @throws ObjectStreamException if there is a problem.
118         */
119        private Object readResolve() throws ObjectStreamException {
120            if (this.equals(CategoryAnchor.START)) {
121                return CategoryAnchor.START;
122            }
123            else if (this.equals(CategoryAnchor.MIDDLE)) {
124                return CategoryAnchor.MIDDLE;
125            }
126            else if (this.equals(CategoryAnchor.END)) {
127                return CategoryAnchor.END;
128            }
129            return null;
130        }
131    
132    }