001 /* ===========================================================
002 * JFreeChart : a free chart 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/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 * TickUnit.java
029 * -------------
030 * (C) Copyright 2001-2005, by Object Refinery Limited.
031 *
032 * Original Author: David Gilbert (for Object Refinery Limited);
033 * Contributor(s): -;
034 *
035 * $Id: TickUnit.java,v 1.3.2.2 2005/10/25 20:37:34 mungady Exp $
036 *
037 * Changes (from 19-Dec-2001)
038 * --------------------------
039 * 19-Dec-2001 : Added standard header (DG);
040 * 01-May-2002 : Changed the unit size from Number to double (DG);
041 * 26-Sep-2002 : Fixed errors reported by Checkstyle (DG);
042 * 08-Nov-2002 : Moved to new package com.jrefinery.chart.axis (DG);
043 * 26-Mar-2003 : Implemented Serializable (DG);
044 * 05-Sep-2005 : Implemented hashCode(), thanks to Thomas Morgner (DG);
045 *
046 */
047
048 package org.jfree.chart.axis;
049
050 import java.io.Serializable;
051
052 /**
053 * Base class representing a tick unit. This determines the spacing of the
054 * tick marks on an axis.
055 * <P>
056 * This class (and any subclasses) should be immutable, the reason being that
057 * ORDERED collections of tick units are maintained and if one instance can be
058 * changed, it may destroy the order of the collection that it belongs to.
059 * In addition, if the implementations are immutable, they can belong to
060 * multiple collections.
061 *
062 * @see ValueAxis
063 */
064 public abstract class TickUnit implements Comparable, Serializable {
065
066 /** For serialization. */
067 private static final long serialVersionUID = 510179855057013974L;
068
069 /** The size of the tick unit. */
070 private double size;
071
072 /**
073 * Constructs a new tick unit.
074 *
075 * @param size the tick unit size.
076 */
077 public TickUnit(double size) {
078 this.size = size;
079 }
080
081 /**
082 * Returns the size of the tick unit.
083 *
084 * @return The size of the tick unit.
085 */
086 public double getSize() {
087 return this.size;
088 }
089
090 /**
091 * Converts the supplied value to a string.
092 * <P>
093 * Subclasses may implement special formatting by overriding this method.
094 *
095 * @param value the data value.
096 *
097 * @return Value as string.
098 */
099 public String valueToString(double value) {
100 return String.valueOf(value);
101 }
102
103 /**
104 * Compares this tick unit to an arbitrary object.
105 *
106 * @param object the object to compare against.
107 *
108 * @return <code>1</code> if the size of the other object is less than this,
109 * <code>0</code> if both have the same size and <code>-1</code> this
110 * size is less than the others.
111 */
112 public int compareTo(Object object) {
113
114 if (object instanceof TickUnit) {
115 TickUnit other = (TickUnit) object;
116 if (this.size > other.getSize()) {
117 return 1;
118 }
119 else if (this.size < other.getSize()) {
120 return -1;
121 }
122 else {
123 return 0;
124 }
125 }
126 else {
127 return -1;
128 }
129
130 }
131
132 /**
133 * Tests this unit for equality with another object.
134 *
135 * @param obj the object.
136 *
137 * @return <code>true</code> or <code>false</code>.
138 */
139 public boolean equals(Object obj) {
140
141 if (obj == null) {
142 return false;
143 }
144 if (obj == this) {
145 return true;
146 }
147 if (obj instanceof TickUnit) {
148 TickUnit tu = (TickUnit) obj;
149 return this.size == tu.size;
150 }
151 return false;
152
153 }
154
155 /**
156 * Returns a hash code for this instance.
157 *
158 * @return A hash code.
159 */
160 public int hashCode() {
161 final long temp = size != +0.0d ? Double.doubleToLongBits(size) : 0L;
162 return (int) (temp ^ (temp >>> 32));
163 }
164
165 }