001/* ===========================================================
002 * JFreeChart : a free chart library for the Java(tm) platform
003 * ===========================================================
004 *
005 * (C) Copyright 2000-present, by David Gilbert 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 * [Oracle and Java are registered trademarks of Oracle and/or its affiliates. 
025 * Other names may be trademarks of their respective owners.]
026 *
027 */
028
029package org.jfree.chart.ui;
030
031import java.io.ObjectStreamException;
032import java.io.Serializable;
033
034/**
035 * An enumeration of the vertical alignment types ({@code TOP}, 
036 * {@code BOTTOM} and {@code CENTER}).
037 */
038public final class VerticalAlignment implements Serializable {
039
040    /** For serialization. */
041    private static final long serialVersionUID = 7272397034325429853L;
042    
043    /** Top alignment. */
044    public static final VerticalAlignment TOP 
045        = new VerticalAlignment("VerticalAlignment.TOP");
046
047    /** Bottom alignment. */
048    public static final VerticalAlignment BOTTOM 
049        = new VerticalAlignment("VerticalAlignment.BOTTOM");
050
051    /** Center alignment. */
052    public static final VerticalAlignment CENTER 
053        = new VerticalAlignment("VerticalAlignment.CENTER");
054
055    /** The name. */
056    private final String name;
057
058    /**
059     * Private constructor.
060     *
061     * @param name  the name.
062     */
063    private VerticalAlignment(String name) {
064        this.name = name;
065    }
066
067    /**
068     * Returns a string representing the object.
069     *
070     * @return the string.
071     */
072    @Override
073    public String toString() {
074        return this.name;
075    }
076
077    /**
078     * Returns {@code true} if this object is equal to the specified 
079     * object, and {@code false} otherwise.
080     *
081     * @param o  the other object.
082     *
083     * @return a boolean.
084     */
085    @Override
086    public boolean equals(Object o) {
087
088        if (this == o) {
089            return true;
090        }
091        if (!(o instanceof VerticalAlignment)) {
092            return false;
093        }
094
095        VerticalAlignment alignment = (VerticalAlignment) o;
096        if (!this.name.equals(alignment.name)) {
097            return false;
098        }
099
100        return true;
101    }
102    
103    /**
104     * Returns a hash code value for the object.
105     *
106     * @return the hashcode
107     */
108    @Override
109    public int hashCode() {
110        return this.name.hashCode();
111    }
112
113    /**
114     * Ensures that serialization returns the unique instances.
115     * 
116     * @return The object.
117     * 
118     * @throws ObjectStreamException if there is a problem.
119     */
120    private Object readResolve() throws ObjectStreamException {
121        if (this.equals(VerticalAlignment.TOP)) {
122            return VerticalAlignment.TOP;
123        }
124        else if (this.equals(VerticalAlignment.BOTTOM)) {
125            return VerticalAlignment.BOTTOM;
126        }
127        else if (this.equals(VerticalAlignment.CENTER)) {
128            return VerticalAlignment.CENTER;
129        }
130        else {
131            return null;  // this should never happen
132        }
133    }
134    
135}
136