Source for org.jfree.data.xy.XYDataItem

   1: /* ===========================================================
   2:  * JFreeChart : a free chart library for the Java(tm) platform
   3:  * ===========================================================
   4:  *
   5:  * (C) Copyright 2000-2007, by Object Refinery Limited and Contributors.
   6:  *
   7:  * Project Info:  http://www.jfree.org/jfreechart/index.html
   8:  *
   9:  * This library is free software; you can redistribute it and/or modify it 
  10:  * under the terms of the GNU Lesser General Public License as published by 
  11:  * the Free Software Foundation; either version 2.1 of the License, or 
  12:  * (at your option) any later version.
  13:  *
  14:  * This library is distributed in the hope that it will be useful, but 
  15:  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 
  16:  * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public 
  17:  * License for more details.
  18:  *
  19:  * You should have received a copy of the GNU Lesser General Public
  20:  * License along with this library; if not, write to the Free Software
  21:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, 
  22:  * USA.  
  23:  *
  24:  * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 
  25:  * in the United States and other countries.]
  26:  *
  27:  * ---------------
  28:  * XYDataItem.java
  29:  * ---------------
  30:  * (C) Copyright 2003-2007, by Object Refinery Limited.
  31:  *
  32:  * Original Author:  David Gilbert (for Object Refinery Limited);
  33:  * Contributor(s):   -;
  34:  *
  35:  * Changes
  36:  * -------
  37:  * 05-Aug-2003 : Renamed XYDataPair --> XYDataItem (DG);
  38:  * 03-Feb-2004 : Fixed bug in equals() method (DG);
  39:  * 21-Feb-2005 : Added setY(double) method (DG);
  40:  * ------------- JFREECHART 1.0.x ---------------------------------------------
  41:  * 30-Nov-2007 : Implemented getXValue() and getYValue(), plus toString() for 
  42:  *               debugging use (DG);
  43:  * 
  44:  */
  45: 
  46: package org.jfree.data.xy;
  47: 
  48: import java.io.Serializable;
  49: 
  50: import org.jfree.util.ObjectUtilities;
  51: 
  52: /**
  53:  * Represents one (x, y) data item for an {@link XYSeries}.
  54:  */
  55: public class XYDataItem implements Cloneable, Comparable, Serializable {
  56: 
  57:     /** For serialization. */
  58:     private static final long serialVersionUID = 2751513470325494890L;
  59:     
  60:     /** The x-value (<code>null</code> not permitted). */
  61:     private Number x;
  62: 
  63:     /** The y-value. */
  64:     private Number y;
  65: 
  66:     /**
  67:      * Constructs a new data item.
  68:      *
  69:      * @param x  the x-value (<code>null</code> NOT permitted).
  70:      * @param y  the y-value (<code>null</code> permitted).
  71:      */
  72:     public XYDataItem(Number x, Number y) {
  73:         if (x == null) {
  74:             throw new IllegalArgumentException("Null 'x' argument.");
  75:         }
  76:         this.x = x;
  77:         this.y = y;
  78:     }
  79: 
  80:     /**
  81:      * Constructs a new data item.
  82:      *
  83:      * @param x  the x-value.
  84:      * @param y  the y-value.
  85:      */
  86:     public XYDataItem(double x, double y) {
  87:         this(new Double(x), new Double(y));
  88:     }
  89: 
  90:     /**
  91:      * Returns the x-value.
  92:      *
  93:      * @return The x-value (never <code>null</code>).
  94:      */
  95:     public Number getX() {
  96:         return this.x;
  97:     }
  98:     
  99:     /**
 100:      * Returns the x-value as a double primitive.
 101:      * 
 102:      * @return The x-value.
 103:      * 
 104:      * @see #getX()
 105:      * @see #getYValue()
 106:      * 
 107:      * @since 1.0.9
 108:      */
 109:     public double getXValue() {
 110:         // this.x is not allowed to be null...
 111:         return this.x.doubleValue();
 112:     }
 113: 
 114:     /**
 115:      * Returns the y-value.
 116:      *
 117:      * @return The y-value (possibly <code>null</code>).
 118:      */
 119:     public Number getY() {
 120:         return this.y;
 121:     }
 122:     
 123:     /**
 124:      * Returns the y-value as a double primitive.
 125:      * 
 126:      * @return The y-value.
 127:      * 
 128:      * @see #getY()
 129:      * @see #getXValue()
 130:      * 
 131:      * @since 1.0.9
 132:      */
 133:     public double getYValue() {
 134:         double result = Double.NaN;
 135:         if (this.y != null) {
 136:             result = this.y.doubleValue();
 137:         }
 138:         return result;
 139:     }
 140: 
 141:     /**
 142:      * Sets the y-value for this data item.  Note that there is no 
 143:      * corresponding method to change the x-value.
 144:      *
 145:      * @param y  the new y-value.
 146:      */
 147:     public void setY(double y) {
 148:         setY(new Double(y));   
 149:     }
 150:     
 151:     /**
 152:      * Sets the y-value for this data item.  Note that there is no 
 153:      * corresponding method to change the x-value.
 154:      *
 155:      * @param y  the new y-value (<code>null</code> permitted).
 156:      */
 157:     public void setY(Number y) {
 158:         this.y = y;
 159:     }
 160: 
 161:     /**
 162:      * Returns an integer indicating the order of this object relative to 
 163:      * another object.
 164:      * <P>
 165:      * For the order we consider only the x-value:
 166:      * negative == "less-than", zero == "equal", positive == "greater-than".
 167:      *
 168:      * @param o1  the object being compared to.
 169:      *
 170:      * @return An integer indicating the order of this data pair object
 171:      *      relative to another object.
 172:      */
 173:     public int compareTo(Object o1) {
 174: 
 175:         int result;
 176: 
 177:         // CASE 1 : Comparing to another TimeSeriesDataPair object
 178:         // -------------------------------------------------------
 179:         if (o1 instanceof XYDataItem) {
 180:             XYDataItem dataItem = (XYDataItem) o1;
 181:             double compare = this.x.doubleValue() 
 182:                              - dataItem.getX().doubleValue();
 183:             if (compare > 0.0) {
 184:                 result = 1;
 185:             }
 186:             else {
 187:                 if (compare < 0.0) {
 188:                     result = -1;
 189:                 }
 190:                 else {
 191:                     result = 0;
 192:                 }
 193:             }
 194:         }
 195: 
 196:         // CASE 2 : Comparing to a general object
 197:         // ---------------------------------------------
 198:         else {
 199:             // consider time periods to be ordered after general objects
 200:             result = 1;
 201:         }
 202: 
 203:         return result;
 204: 
 205:     }
 206: 
 207:     /**
 208:      * Returns a clone of this object.
 209:      *
 210:      * @return A clone.
 211:      * 
 212:      * @throws CloneNotSupportedException not thrown by this class, but 
 213:      *         subclasses may differ.
 214:      */
 215:     public Object clone() throws CloneNotSupportedException {
 216:         return super.clone();
 217:     }
 218:     
 219:     /**
 220:      * Tests if this object is equal to another.
 221:      *
 222:      * @param obj  the object to test against for equality (<code>null</code>
 223:      *             permitted).
 224:      *
 225:      * @return A boolean.
 226:      */
 227:     public boolean equals(Object obj) {
 228:         if (obj == this) {
 229:             return true;
 230:         }
 231:         if (!(obj instanceof XYDataItem)) {
 232:             return false;
 233:         }
 234:         XYDataItem that = (XYDataItem) obj;
 235:         if (!this.x.equals(that.x)) {
 236:             return false;
 237:         }
 238:         if (!ObjectUtilities.equal(this.y, that.y)) {
 239:             return false;
 240:         }
 241:         return true;        
 242:     }
 243: 
 244:     /**
 245:      * Returns a hash code.
 246:      * 
 247:      * @return A hash code.
 248:      */
 249:     public int hashCode() {
 250:         int result;
 251:         result = this.x.hashCode();
 252:         result = 29 * result + (this.y != null ? this.y.hashCode() : 0);
 253:         return result;
 254:     }
 255:     
 256:     /**
 257:      * Returns a string representing this instance, primarily for debugging
 258:      * use.
 259:      * 
 260:      * @return A string.
 261:      */
 262:     public String toString() {
 263:         return "[" + getXValue() + ", " + getYValue() + "]";
 264:     }
 265:     
 266: }