001 /* ========================================================================
002 * JCommon : a free general purpose class 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/jcommon/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 * KeyedComboBoxModel.java
029 * ------------------
030 * (C) Copyright 2004, by Thomas Morgner and Contributors.
031 *
032 * Original Author: Thomas Morgner;
033 * Contributor(s): David Gilbert (for Object Refinery Limited);
034 *
035 * $Id: KeyedComboBoxModel.java,v 1.6 2006/12/03 15:33:33 taqua Exp $
036 *
037 * Changes
038 * -------
039 * 07-Jun-2004 : Added JCommon header (DG);
040 *
041 */
042 package org.jfree.ui;
043
044 import java.util.ArrayList;
045 import javax.swing.ComboBoxModel;
046 import javax.swing.event.ListDataEvent;
047 import javax.swing.event.ListDataListener;
048
049 /**
050 * The KeyedComboBox model allows to define an internal key (the data element)
051 * for every entry in the model.
052 * <p/>
053 * This class is usefull in all cases, where the public text differs from the
054 * internal view on the data. A separation between presentation data and
055 * processing data is a prequesite for localizing combobox entries. This model
056 * does not allow selected elements, which are not in the list of valid
057 * elements.
058 *
059 * @author Thomas Morgner
060 */
061 public class KeyedComboBoxModel implements ComboBoxModel
062 {
063
064 /**
065 * The internal data carrier to map keys to values and vice versa.
066 */
067 private static class ComboBoxItemPair
068 {
069 /**
070 * The key.
071 */
072 private Object key;
073 /**
074 * The value for the key.
075 */
076 private Object value;
077
078 /**
079 * Creates a new item pair for the given key and value. The value can be
080 * changed later, if needed.
081 *
082 * @param key the key
083 * @param value the value
084 */
085 public ComboBoxItemPair(final Object key, final Object value)
086 {
087 this.key = key;
088 this.value = value;
089 }
090
091 /**
092 * Returns the key.
093 *
094 * @return the key.
095 */
096 public Object getKey()
097 {
098 return key;
099 }
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 }