Source for org.jfree.data.KeyedObjects

   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:  * KeyedObjects.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:  * 31-Oct-2002 : Version 1 (DG);
  38:  * 11-Jan-2005 : Minor tidy up (DG);
  39:  * 28-Sep-2007 : Clean up equals() method (DG);
  40:  * 03-Oct-2007 : Make method behaviour consistent with DefaultKeyedValues (DG);
  41:  *
  42:  */
  43: 
  44: package org.jfree.data;
  45: 
  46: import java.io.Serializable;
  47: import java.util.Iterator;
  48: import java.util.List;
  49: 
  50: import org.jfree.util.PublicCloneable;
  51: 
  52: /**
  53:  * A collection of (key, object) pairs.
  54:  */
  55: public class KeyedObjects implements Cloneable, PublicCloneable, Serializable {
  56: 
  57:     /** For serialization. */
  58:     private static final long serialVersionUID = 1321582394193530984L;
  59:     
  60:     /** Storage for the data. */
  61:     private List data;
  62: 
  63:     /**
  64:      * Creates a new collection (initially empty).
  65:      */
  66:     public KeyedObjects() {
  67:         this.data = new java.util.ArrayList();
  68:     }
  69: 
  70:     /**
  71:      * Returns the number of items (values) in the collection.
  72:      *
  73:      * @return The item count.
  74:      */
  75:     public int getItemCount() {
  76:         return this.data.size();
  77:     }
  78: 
  79:     /**
  80:      * Returns an object from the list.
  81:      *
  82:      * @param item  the item index (zero-based).
  83:      *
  84:      * @return The object (possibly <code>null</code>).
  85:      * 
  86:      * @throws IndexOutOfBoundsException if <code>item</code> is out of bounds.
  87:      */
  88:     public Object getObject(int item) {
  89:         Object result = null;
  90:         KeyedObject kobj = (KeyedObject) this.data.get(item);
  91:         if (kobj != null) {
  92:             result = kobj.getObject();
  93:         }
  94:         return result;
  95:     }
  96: 
  97:     /**
  98:      * Returns the key at the specified position in the list.
  99:      *
 100:      * @param index  the item index (zero-based).
 101:      *
 102:      * @return The row key.
 103:      *
 104:      * @throws IndexOutOfBoundsException if <code>item</code> is out of bounds.
 105:      * 
 106:      * @see #getIndex(Comparable)
 107:      */
 108:     public Comparable getKey(int index) {
 109:         Comparable result = null;
 110:         KeyedObject item = (KeyedObject) this.data.get(index);
 111:         if (item != null) {
 112:             result = item.getKey();
 113:         }
 114:         return result;
 115:     }
 116: 
 117:     /**
 118:      * Returns the index for a given key, or <code>-1</code>.
 119:      *
 120:      * @param key  the key (<code>null</code> not permitted).
 121:      *
 122:      * @return The index, or <code>-1</code> if the key is unrecognised.
 123:      * 
 124:      * @see #getKey(int)
 125:      */
 126:     public int getIndex(Comparable key) {
 127:         if (key == null) {
 128:             throw new IllegalArgumentException("Null 'key' argument.");
 129:         }
 130:         int i = 0;
 131:         Iterator iterator = this.data.iterator();
 132:         while (iterator.hasNext()) {
 133:             KeyedObject ko = (KeyedObject) iterator.next();
 134:             if (ko.getKey().equals(key)) {
 135:                 return i;
 136:             }
 137:             i++;
 138:         }
 139:         return -1;
 140:     }
 141: 
 142:     /**
 143:      * Returns a list containing all the keys in the list.
 144:      *
 145:      * @return The keys (never <code>null</code>).
 146:      */
 147:     public List getKeys() {
 148:         List result = new java.util.ArrayList();
 149:         Iterator iterator = this.data.iterator();
 150:         while (iterator.hasNext()) {
 151:             KeyedObject ko = (KeyedObject) iterator.next();
 152:             result.add(ko.getKey());
 153:         }
 154:         return result;
 155:     }
 156: 
 157:     /**
 158:      * Returns the object for a given key. If the key is not recognised, the 
 159:      * method should return <code>null</code>.
 160:      *
 161:      * @param key  the key.
 162:      *
 163:      * @return The object (possibly <code>null</code>).
 164:      * 
 165:      * @see #addObject(Comparable, Object)
 166:      */
 167:     public Object getObject(Comparable key) {
 168:         int index = getIndex(key);
 169:         if (index < 0) {
 170:             throw new UnknownKeyException("The key (" + key 
 171:                     + ") is not recognised.");
 172:         }
 173:         return getObject(index);
 174:     }
 175: 
 176:     /**
 177:      * Adds a new object to the collection, or overwrites an existing object.  
 178:      * This is the same as the {@link #setObject(Comparable, Object)} method.
 179:      *
 180:      * @param key  the key.
 181:      * @param object  the object.
 182:      * 
 183:      * @see #getObject(Comparable)
 184:      */
 185:     public void addObject(Comparable key, Object object) {
 186:         setObject(key, object);
 187:     }
 188: 
 189:     /**
 190:      * Replaces an existing object, or adds a new object to the collection.
 191:      * This is the same as the {@link #addObject(Comparable, Object)} 
 192:      * method.
 193:      *
 194:      * @param key  the key (<code>null</code> not permitted).
 195:      * @param object  the object.
 196:      * 
 197:      * @see #getObject(Comparable)
 198:      */
 199:     public void setObject(Comparable key, Object object) {
 200:         int keyIndex = getIndex(key);
 201:         if (keyIndex >= 0) {
 202:             KeyedObject ko = (KeyedObject) this.data.get(keyIndex);
 203:             ko.setObject(object);
 204:         }
 205:         else {
 206:             KeyedObject ko = new KeyedObject(key, object);
 207:             this.data.add(ko);
 208:         }
 209:     }
 210: 
 211:     /**
 212:      * Inserts a new value at the specified position in the dataset or, if
 213:      * there is an existing item with the specified key, updates the value 
 214:      * for that item and moves it to the specified position.
 215:      * 
 216:      * @param position  the position (in the range <code>0</code> to 
 217:      *                  <code>getItemCount()</code>).
 218:      * @param key  the key (<code>null</code> not permitted).
 219:      * @param value  the value (<code>null</code> permitted).
 220:      * 
 221:      * @since 1.0.7
 222:      */
 223:     public void insertValue(int position, Comparable key, Object value) {
 224:         if (position < 0 || position > this.data.size()) {
 225:             throw new IllegalArgumentException("'position' out of bounds.");
 226:         }
 227:         if (key == null) {
 228:             throw new IllegalArgumentException("Null 'key' argument.");
 229:         }
 230:         int pos = getIndex(key);
 231:         if (pos >= 0) {
 232:             this.data.remove(pos);
 233:         }
 234:         KeyedObject item = new KeyedObject(key, value);
 235:         if (position <= this.data.size()) {
 236:             this.data.add(position, item);
 237:         }
 238:         else {
 239:             this.data.add(item);
 240:         }
 241:     }
 242: 
 243:     /**
 244:      * Removes a value from the collection.
 245:      *
 246:      * @param index  the index of the item to remove.
 247:      * 
 248:      * @see #removeValue(Comparable)
 249:      */
 250:     public void removeValue(int index) {
 251:         this.data.remove(index);
 252:     }
 253: 
 254:     /**
 255:      * Removes a value from the collection.
 256:      *
 257:      * @param key  the key (<code>null</code> not permitted).
 258:      * 
 259:      * @see #removeValue(int)
 260:      * 
 261:      * @throws UnknownKeyException if the key is not recognised.
 262:      */
 263:     public void removeValue(Comparable key) {
 264:         // defer argument checking 
 265:         int index = getIndex(key);
 266:         if (index < 0) {
 267:             throw new UnknownKeyException("The key (" + key.toString() 
 268:                     + ") is not recognised.");
 269:         }
 270:         removeValue(index);
 271:     }
 272:     
 273:     /**
 274:      * Clears all values from the collection.
 275:      * 
 276:      * @since 1.0.7
 277:      */
 278:     public void clear() {
 279:         this.data.clear();
 280:     }
 281: 
 282:     /**
 283:      * Returns a clone of this object.  Keys in the list should be immutable
 284:      * and are not cloned.  Objects in the list are cloned only if they
 285:      * implement {@link PublicCloneable}.
 286:      * 
 287:      * @return A clone.
 288:      * 
 289:      * @throws CloneNotSupportedException if there is a problem cloning.
 290:      */
 291:     public Object clone() throws CloneNotSupportedException {
 292:         KeyedObjects clone = (KeyedObjects) super.clone();
 293:         clone.data = new java.util.ArrayList();
 294:         Iterator iterator = this.data.iterator();
 295:         while (iterator.hasNext()) {
 296:             KeyedObject ko = (KeyedObject) iterator.next();
 297:             clone.data.add(ko.clone());
 298:         }
 299:         return clone;      
 300:     }
 301:     
 302:     /**
 303:      * Tests this object for equality with an arbitrary object.
 304:      *
 305:      * @param obj  the object (<code>null</code> permitted).
 306:      *
 307:      * @return A boolean.
 308:      */
 309:     public boolean equals(Object obj) {
 310: 
 311:         if (obj == this) {
 312:             return true;
 313:         }
 314:         if (!(obj instanceof KeyedObjects)) {
 315:             return false;
 316:         }
 317:         KeyedObjects that = (KeyedObjects) obj;
 318:         int count = getItemCount();
 319:         if (count != that.getItemCount()) {
 320:             return false;
 321:         }
 322: 
 323:         for (int i = 0; i < count; i++) {
 324:             Comparable k1 = getKey(i);
 325:             Comparable k2 = that.getKey(i);
 326:             if (!k1.equals(k2)) {
 327:                 return false;
 328:             }
 329:             Object o1 = getObject(i);
 330:             Object o2 = that.getObject(i);
 331:             if (o1 == null) {
 332:                 if (o2 != null) {
 333:                     return false;
 334:                 }
 335:             }
 336:             else {
 337:                 if (!o1.equals(o2)) {
 338:                     return false;
 339:                 }
 340:             }
 341:         }
 342:         return true;
 343: 
 344:     }
 345:     
 346:     /**
 347:      * Returns a hash code.
 348:      * 
 349:      * @return A hash code.
 350:      */
 351:     public int hashCode() {
 352:         return (this.data != null ? this.data.hashCode() : 0);
 353:     }
 354:   
 355: }