Source for org.jfree.ui.KeyedComboBoxModel

   1: /* ========================================================================
   2:  * JCommon : a free general purpose class library for the Java(tm) platform
   3:  * ========================================================================
   4:  *
   5:  * (C) Copyright 2000-2005, by Object Refinery Limited and Contributors.
   6:  *
   7:  * Project Info:  http://www.jfree.org/jcommon/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:  * KeyedComboBoxModel.java
  29:  * ------------------
  30:  * (C) Copyright 2004, by Thomas Morgner and Contributors.
  31:  *
  32:  * Original Author:  Thomas Morgner;
  33:  * Contributor(s):   David Gilbert (for Object Refinery Limited);
  34:  *
  35:  * $Id: KeyedComboBoxModel.java,v 1.6 2006/12/03 15:33:33 taqua Exp $
  36:  *
  37:  * Changes
  38:  * -------
  39:  * 07-Jun-2004 : Added JCommon header (DG);
  40:  *
  41:  */
  42: package org.jfree.ui;
  43: 
  44: import java.util.ArrayList;
  45: import javax.swing.ComboBoxModel;
  46: import javax.swing.event.ListDataEvent;
  47: import javax.swing.event.ListDataListener;
  48: 
  49: /**
  50:  * The KeyedComboBox model allows to define an internal key (the data element)
  51:  * for every entry in the model.
  52:  * <p/>
  53:  * This class is usefull in all cases, where the public text differs from the
  54:  * internal view on the data. A separation between presentation data and
  55:  * processing data is a prequesite for localizing combobox entries. This model
  56:  * does not allow selected elements, which are not in the list of valid
  57:  * elements.
  58:  *
  59:  * @author Thomas Morgner
  60:  */
  61: public class KeyedComboBoxModel implements ComboBoxModel
  62: {
  63: 
  64:   /**
  65:    * The internal data carrier to map keys to values and vice versa.
  66:    */
  67:   private static class ComboBoxItemPair
  68:   {
  69:     /**
  70:      * The key.
  71:      */
  72:     private Object key;
  73:     /**
  74:      * The value for the key.
  75:      */
  76:     private Object value;
  77: 
  78:     /**
  79:      * Creates a new item pair for the given key and value. The value can be
  80:      * changed later, if needed.
  81:      *
  82:      * @param key   the key
  83:      * @param value the value
  84:      */
  85:     public ComboBoxItemPair(final Object key, final Object value)
  86:     {
  87:       this.key = key;
  88:       this.value = value;
  89:     }
  90: 
  91:     /**
  92:      * Returns the key.
  93:      *
  94:      * @return the key.
  95:      */
  96:     public Object getKey()
  97:     {
  98:       return key;
  99:     }
 100: 
 101:     /**
 102:      * Returns the value.
 103:      *
 104:      * @return the value for this key.
 105:      */
 106:     public Object getValue()
 107:     {
 108:       return value;
 109:     }
 110: 
 111:     /**
 112:      * Redefines the value stored for that key.
 113:      *
 114:      * @param value the new value.
 115:      */
 116:     public void setValue(final Object value)
 117:     {
 118:       this.value = value;
 119:     }
 120:   }
 121: 
 122:   /**
 123:    * The index of the selected item.
 124:    */
 125:   private int selectedItemIndex;
 126:   private Object selectedItemValue;
 127:   /**
 128:    * The data (contains ComboBoxItemPairs).
 129:    */
 130:   private ArrayList data;
 131:   /**
 132:    * The listeners.
 133:    */
 134:   private ArrayList listdatalistener;
 135:   /**
 136:    * The cached listeners as array.
 137:    */
 138:   private transient ListDataListener[] tempListeners;
 139:   private boolean allowOtherValue;
 140: 
 141:   /**
 142:    * Creates a new keyed combobox model.
 143:    */
 144:   public KeyedComboBoxModel()
 145:   {
 146:     data = new ArrayList();
 147:     listdatalistener = new ArrayList();
 148:   }
 149: 
 150:   /**
 151:    * Creates a new keyed combobox model for the given keys and values. Keys
 152:    * and values must have the same number of items.
 153:    *
 154:    * @param keys   the keys
 155:    * @param values the values
 156:    */
 157:   public KeyedComboBoxModel(final Object[] keys, final Object[] values)
 158:   {
 159:     this();
 160:     setData(keys, values);
 161:   }
 162: 
 163:   /**
 164:    * Replaces the data in this combobox model. The number of keys must be
 165:    * equals to the number of values.
 166:    *
 167:    * @param keys   the keys
 168:    * @param values the values
 169:    */
 170:   public void setData(final Object[] keys, final Object[] values)
 171:   {
 172:     if (values.length != keys.length)
 173:     {
 174:       throw new IllegalArgumentException("Values and text must have the same length.");
 175:     }
 176: 
 177:     data.clear();
 178:     data.ensureCapacity(keys.length);
 179: 
 180:     for (int i = 0; i < values.length; i++)
 181:     {
 182:       add(keys[i], values[i]);
 183:     }
 184: 
 185:     selectedItemIndex = -1;
 186:     final ListDataEvent evt = new ListDataEvent
 187:         (this, ListDataEvent.CONTENTS_CHANGED, 0, data.size() - 1);
 188:     fireListDataEvent(evt);
 189:   }
 190: 
 191:   /**
 192:    * Notifies all registered list data listener of the given event.
 193:    *
 194:    * @param evt the event.
 195:    */
 196:   protected synchronized void fireListDataEvent(final ListDataEvent evt)
 197:   {
 198:     if (tempListeners == null)
 199:     {
 200:       tempListeners = (ListDataListener[]) listdatalistener.toArray
 201:           (new ListDataListener[listdatalistener.size()]);
 202:     }
 203:     for (int i = 0; i < tempListeners.length; i++)
 204:     {
 205:       final ListDataListener l = tempListeners[i];
 206:       l.contentsChanged(evt);
 207:     }
 208:   }
 209: 
 210:   /**
 211:    * Returns the selected item.
 212:    *
 213:    * @return The selected item or <code>null</code> if there is no selection
 214:    */
 215:   public Object getSelectedItem()
 216:   {
 217:     return selectedItemValue;
 218:   }
 219: 
 220:   /**
 221:    * Defines the selected key. If the object is not in the list of values, no
 222:    * item gets selected.
 223:    *
 224:    * @param anItem the new selected item.
 225:    */
 226:   public void setSelectedKey(final Object anItem)
 227:   {
 228:     if (anItem == null)
 229:     {
 230:       selectedItemIndex = -1;
 231:       selectedItemValue = null;
 232:     }
 233:     else
 234:     {
 235:       final int newSelectedItem = findDataElementIndex(anItem);
 236:       if (newSelectedItem == -1)
 237:       {
 238:         selectedItemIndex = -1;
 239:         selectedItemValue = null;
 240:       }
 241:       else
 242:       {
 243:         selectedItemIndex = newSelectedItem;
 244:         selectedItemValue = getElementAt(selectedItemIndex);
 245:       }
 246:     }
 247:     fireListDataEvent(new ListDataEvent(this, ListDataEvent.CONTENTS_CHANGED, -1, -1));
 248:   }
 249: 
 250:   /**
 251:    * Set the selected item. The implementation of this  method should notify
 252:    * all registered <code>ListDataListener</code>s that the contents have
 253:    * changed.
 254:    *
 255:    * @param anItem the list object to select or <code>null</code> to clear the
 256:    *               selection
 257:    */
 258:   public void setSelectedItem(final Object anItem)
 259:   {
 260:     if (anItem == null)
 261:     {
 262:       selectedItemIndex = -1;
 263:       selectedItemValue = null;
 264:     }
 265:     else
 266:     {
 267:       final int newSelectedItem = findElementIndex(anItem);
 268:       if (newSelectedItem == -1)
 269:       {
 270:         if (isAllowOtherValue())
 271:         {
 272:           selectedItemIndex = -1;
 273:           selectedItemValue = anItem;
 274:         }
 275:         else
 276:         {
 277:           selectedItemIndex = -1;
 278:           selectedItemValue = null;
 279:         }
 280:       }
 281:       else
 282:       {
 283:         selectedItemIndex = newSelectedItem;
 284:         selectedItemValue = getElementAt(selectedItemIndex);
 285:       }
 286:     }
 287:     fireListDataEvent(new ListDataEvent(this, ListDataEvent.CONTENTS_CHANGED, -1, -1));
 288:   }
 289: 
 290:   private boolean isAllowOtherValue()
 291:   {
 292:     return allowOtherValue;
 293:   }
 294: 
 295:   public void setAllowOtherValue(final boolean allowOtherValue)
 296:   {
 297:     this.allowOtherValue = allowOtherValue;
 298:   }
 299: 
 300:   /**
 301:    * Adds a listener to the list that's notified each time a change to the data
 302:    * model occurs.
 303:    *
 304:    * @param l the <code>ListDataListener</code> to be added
 305:    */
 306:   public synchronized void addListDataListener(final ListDataListener l)
 307:   {
 308:     listdatalistener.add(l);
 309:     tempListeners = null;
 310:   }
 311: 
 312:   /**
 313:    * Returns the value at the specified index.
 314:    *
 315:    * @param index the requested index
 316:    * @return the value at <code>index</code>
 317:    */
 318:   public Object getElementAt(final int index)
 319:   {
 320:     if (index >= data.size())
 321:     {
 322:       return null;
 323:     }
 324: 
 325:     final ComboBoxItemPair datacon = (ComboBoxItemPair) data.get(index);
 326:     if (datacon == null)
 327:     {
 328:       return null;
 329:     }
 330:     return datacon.getValue();
 331:   }
 332: 
 333:   /**
 334:    * Returns the key from the given index.
 335:    *
 336:    * @param index the index of the key.
 337:    * @return the the key at the specified index.
 338:    */
 339:   public Object getKeyAt(final int index)
 340:   {
 341:     if (index >= data.size())
 342:     {
 343:       return null;
 344:     }
 345: 
 346:     if (index < 0)
 347:     {
 348:       return null;
 349:     }
 350: 
 351:     final ComboBoxItemPair datacon = (ComboBoxItemPair) data.get(index);
 352:     if (datacon == null)
 353:     {
 354:       return null;
 355:     }
 356:     return datacon.getKey();
 357:   }
 358: 
 359:   /**
 360:    * Returns the selected data element or null if none is set.
 361:    *
 362:    * @return the selected data element.
 363:    */
 364:   public Object getSelectedKey()
 365:   {
 366:     return getKeyAt(selectedItemIndex);
 367:   }
 368: 
 369:   /**
 370:    * Returns the length of the list.
 371:    *
 372:    * @return the length of the list
 373:    */
 374:   public int getSize()
 375:   {
 376:     return data.size();
 377:   }
 378: 
 379:   /**
 380:    * Removes a listener from the list that's notified each time a change to
 381:    * the data model occurs.
 382:    *
 383:    * @param l the <code>ListDataListener</code> to be removed
 384:    */
 385:   public void removeListDataListener(final ListDataListener l)
 386:   {
 387:     listdatalistener.remove(l);
 388:     tempListeners = null;
 389:   }
 390: 
 391:   /**
 392:    * Searches an element by its data value. This method is called by the
 393:    * setSelectedItem method and returns the first occurence of the element.
 394:    *
 395:    * @param anItem the item
 396:    * @return the index of the item or -1 if not found.
 397:    */
 398:   private int findDataElementIndex(final Object anItem)
 399:   {
 400:     if (anItem == null)
 401:     {
 402:       throw new NullPointerException("Item to find must not be null");
 403:     }
 404: 
 405:     for (int i = 0; i < data.size(); i++)
 406:     {
 407:       final ComboBoxItemPair datacon = (ComboBoxItemPair) data.get(i);
 408:       if (anItem.equals(datacon.getKey()))
 409:       {
 410:         return i;
 411:       }
 412:     }
 413:     return -1;
 414:   }
 415: 
 416:   /**
 417:    * Tries to find the index of element with the given key. The key must not
 418:    * be null.
 419:    *
 420:    * @param key the key for the element to be searched.
 421:    * @return the index of the key, or -1 if not found.
 422:    */
 423:   public int findElementIndex(final Object key)
 424:   {
 425:     if (key == null)
 426:     {
 427:       throw new NullPointerException("Item to find must not be null");
 428:     }
 429: 
 430:     for (int i = 0; i < data.size(); i++)
 431:     {
 432:       final ComboBoxItemPair datacon = (ComboBoxItemPair) data.get(i);
 433:       if (key.equals(datacon.getValue()))
 434:       {
 435:         return i;
 436:       }
 437:     }
 438:     return -1;
 439:   }
 440: 
 441:   /**
 442:    * Removes an entry from the model.
 443:    *
 444:    * @param key the key
 445:    */
 446:   public void removeDataElement(final Object key)
 447:   {
 448:     final int idx = findDataElementIndex(key);
 449:     if (idx == -1)
 450:     {
 451:       return;
 452:     }
 453: 
 454:     data.remove(idx);
 455:     final ListDataEvent evt = new ListDataEvent
 456:         (this, ListDataEvent.INTERVAL_REMOVED, idx, idx);
 457:     fireListDataEvent(evt);
 458:   }
 459: 
 460:   /**
 461:    * Adds a new entry to the model.
 462:    *
 463:    * @param key    the key
 464:    * @param cbitem the display value.
 465:    */
 466:   public void add(final Object key, final Object cbitem)
 467:   {
 468:     final ComboBoxItemPair con = new ComboBoxItemPair(key, cbitem);
 469:     data.add(con);
 470:     final ListDataEvent evt = new ListDataEvent
 471:         (this, ListDataEvent.INTERVAL_ADDED, data.size() - 2, data.size() - 2);
 472:     fireListDataEvent(evt);
 473:   }
 474: 
 475:   /**
 476:    * Removes all entries from the model.
 477:    */
 478:   public void clear()
 479:   {
 480:     final int size = getSize();
 481:     data.clear();
 482:     final ListDataEvent evt = new ListDataEvent(this, ListDataEvent.INTERVAL_REMOVED, 0, size - 1);
 483:     fireListDataEvent(evt);
 484:   }
 485: 
 486: }