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 * XYDataItem.java
029 * ---------------
030 * (C) Copyright 2003-2005, by Object Refinery Limited.
031 *
032 * Original Author: David Gilbert (for Object Refinery Limited);
033 * Contributor(s): -;
034 *
035 * $Id: XYDataItem.java,v 1.6.2.1 2005/10/25 21:36:51 mungady Exp $
036 *
037 * Changes
038 * -------
039 * 05-Aug-2003 : Renamed XYDataPair --> XYDataItem (DG);
040 * 03-Feb-2004 : Fixed bug in equals() method (DG);
041 * 21-Feb-2005 : Added setY(double) method (DG);
042 *
043 */
044
045 package org.jfree.data.xy;
046
047 import java.io.Serializable;
048
049 import org.jfree.util.ObjectUtilities;
050
051 /**
052 * Represents one (x, y) data item for an {@link XYSeries}.
053 */
054 public class XYDataItem implements Cloneable, Comparable, Serializable {
055
056 private static final long serialVersionUID = 2751513470325494890L;
057
058 /** The x-value. */
059 private Number x;
060
061 /** The y-value. */
062 private Number y;
063
064 /**
065 * Constructs a new data item.
066 *
067 * @param x the x-value (<code>null</code> NOT permitted).
068 * @param y the y-value (<code>null</code> permitted).
069 */
070 public XYDataItem(Number x, Number y) {
071 if (x == null) {
072 throw new IllegalArgumentException("Null 'x' argument.");
073 }
074 this.x = x;
075 this.y = y;
076 }
077
078 /**
079 * Constructs a new data item.
080 *
081 * @param x the x-value.
082 * @param y the y-value.
083 */
084 public XYDataItem(double x, double y) {
085 this(new Double(x), new Double(y));
086 }
087
088 /**
089 * Returns the x-value.
090 *
091 * @return The x-value (never <code>null</code>).
092 */
093 public Number getX() {
094 return this.x;
095 }
096
097 /**
098 * Returns the y-value.
099 *
100 * @return The y-value (possibly <code>null</code>).
101 */
102 public Number getY() {
103 return this.y;
104 }
105
106 /**
107 * Sets the y-value for this data item. Note that there is no
108 * corresponding method to change the x-value.
109 *
110 * @param y the new y-value.
111 */
112 public void setY(double y) {
113 setY(new Double(y));
114 }
115
116 /**
117 * Sets the y-value for this data item. Note that there is no
118 * corresponding method to change the x-value.
119 *
120 * @param y the new y-value (<code>null</code> permitted).
121 */
122 public void setY(Number y) {
123 this.y = y;
124 }
125
126 /**
127 * Returns an integer indicating the order of this object relative to
128 * another object.
129 * <P>
130 * For the order we consider only the x-value:
131 * negative == "less-than", zero == "equal", positive == "greater-than".
132 *
133 * @param o1 the object being compared to.
134 *
135 * @return An integer indicating the order of this data pair object
136 * relative to another object.
137 */
138 public int compareTo(Object o1) {
139
140 int result;
141
142 // CASE 1 : Comparing to another TimeSeriesDataPair object
143 // -------------------------------------------------------
144 if (o1 instanceof XYDataItem) {
145 XYDataItem dataItem = (XYDataItem) o1;
146 double compare = this.x.doubleValue()
147 - dataItem.getX().doubleValue();
148 if (compare > 0.0) {
149 result = 1;
150 }
151 else {
152 if (compare < 0.0) {
153 result = -1;
154 }
155 else {
156 result = 0;
157 }
158 }
159 }
160
161 // CASE 2 : Comparing to a general object
162 // ---------------------------------------------
163 else {
164 // consider time periods to be ordered after general objects
165 result = 1;
166 }
167
168 return result;
169
170 }
171
172 /**
173 * Returns a clone of this object.
174 *
175 * @return A clone.
176 *
177 * @throws CloneNotSupportedException not thrown by this class, but
178 * subclasses may differ.
179 */
180 public Object clone() throws CloneNotSupportedException {
181 return super.clone();
182 }
183
184 /**
185 * Tests if this object is equal to another.
186 *
187 * @param obj the object to test against for equality (<code>null</code>
188 * permitted).
189 *
190 * @return A boolean.
191 */
192 public boolean equals(Object obj) {
193 if (obj == this) {
194 return true;
195 }
196 if (!(obj instanceof XYDataItem)) {
197 return false;
198 }
199 XYDataItem that = (XYDataItem) obj;
200 if (!this.x.equals(that.x)) {
201 return false;
202 }
203 if (!ObjectUtilities.equal(this.y, that.y)) {
204 return false;
205 }
206 return true;
207 }
208
209 /**
210 * Returns a hash code.
211 *
212 * @return A hash code.
213 */
214 public int hashCode() {
215 int result;
216 result = this.x.hashCode();
217 result = 29 * result + (this.y != null ? this.y.hashCode() : 0);
218 return result;
219 }
220
221 }