001 /* DefaultCellEditor.java --
002 Copyright (C) 2002, 2004, 2006, Free Software Foundation, Inc.
003
004 This file is part of GNU Classpath.
005
006 GNU Classpath is free software; you can redistribute it and/or modify
007 it under the terms of the GNU General Public License as published by
008 the Free Software Foundation; either version 2, or (at your option)
009 any later version.
010
011 GNU Classpath is distributed in the hope that it will be useful, but
012 WITHOUT ANY WARRANTY; without even the implied warranty of
013 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
014 General Public License for more details.
015
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017 along with GNU Classpath; see the file COPYING. If not, write to the
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019 02110-1301 USA.
020
021 Linking this library statically or dynamically with other modules is
022 making a combined work based on this library. Thus, the terms and
023 conditions of the GNU General Public License cover the whole
024 combination.
025
026 As a special exception, the copyright holders of this library give you
027 permission to link this library with independent modules to produce an
028 executable, regardless of the license terms of these independent
029 modules, and to copy and distribute the resulting executable under
030 terms of your choice, provided that you also meet, for each linked
031 independent module, the terms and conditions of the license of that
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033 or based on this library. If you modify this library, you may extend
034 this exception to your version of the library, but you are not
035 obligated to do so. If you do not wish to do so, delete this
036 exception statement from your version. */
037
038
039 package javax.swing;
040
041 import java.awt.Component;
042 import java.awt.event.ActionEvent;
043 import java.awt.event.ActionListener;
044 import java.awt.event.ItemEvent;
045 import java.awt.event.ItemListener;
046 import java.awt.event.MouseEvent;
047 import java.io.Serializable;
048 import java.util.EventObject;
049
050 import javax.swing.JTable;
051 import javax.swing.JTextField;
052 import javax.swing.event.CellEditorListener;
053 import javax.swing.table.TableCellEditor;
054 import javax.swing.tree.TreeCellEditor;
055
056 /**
057 * The default implementation of {@link TableCellEditor} and
058 * {@link TreeCellEditor}. It provides editor components for
059 * some standard object types.
060 *
061 * @author Andrew Selkirk
062 * @author Audrius Meskauskas
063 */
064 public class DefaultCellEditor
065 extends AbstractCellEditor
066 implements TableCellEditor, TreeCellEditor
067 {
068 private static final long serialVersionUID = 3564035141373880027L;
069
070 /**
071 * This changeable module access the editor component in the component
072 * specific way. For instance, to set the value for JTextField, we need to
073 * call setText(String), and for JCheckBox we need to call
074 * setSelected(boolean). Each default editor has the component specific
075 * derivative of this class. These derivatives are private inner classes of
076 * the DefaultCellEditor.
077 *
078 * The editor delegate is also set for the editor component as the action
079 * listener. It listens for the events that indicate that editing has stopped.
080 */
081 protected class EditorDelegate
082 implements ActionListener, ItemListener, Serializable
083 {
084 /**
085 * Use the serial version UID for interoperability.
086 */
087 private static final long serialVersionUID = -1420007406015481933L;
088
089 /**
090 * The object value (updated when getting and setting the value).
091 */
092 protected Object value;
093
094 /**
095 * Constructor EditorDelegate
096 */
097 protected EditorDelegate()
098 {
099 // Nothing to do here.
100 }
101
102 /**
103 * Set the value for the editor component. This method is normally
104 * overridden to set the value in the way, specific for the text
105 * component, check box or combo box.
106 *
107 * @param aValue the value to set (String, Boolean or Number).
108 */
109 public void setValue(Object aValue)
110 {
111 value = aValue;
112 }
113
114 /**
115 * Get the value for the editor component. This method is normally
116 * overridden to obtain the value in the way, specific for the text
117 * component, check box or combo box.
118 *
119 * @return value the value of the component (String, Boolean or Number).
120 */
121 public Object getCellEditorValue()
122 {
123 return value;
124 }
125
126 /**
127 * The default method returns true for the {@link MouseEvent} and false
128 * for any other events.
129 *
130 * @param event the event to check
131 *
132 * @return true if the passed event is the mouse event and false otherwise.
133 */
134 public boolean isCellEditable(EventObject event)
135 {
136 if (event == null || !(event instanceof MouseEvent) ||
137 (((MouseEvent) event).getClickCount() >= getClickCountToStart()))
138 return true;
139 return false;
140 } // isCellEditable()
141
142 /**
143 * Returns true to indicate that the editing cell can be selected.
144 *
145 * The default method returns true without action but may be overridden
146 * in derived classes for more specific behavior.
147 *
148 * @param event unused in default method
149 *
150 * @return true always
151 */
152 public boolean shouldSelectCell(EventObject event)
153 {
154 // return true to indicate that the editing cell may be selected
155 return true;
156 }
157
158 /**
159 * Finish the cell editing session. This method notifies the registered
160 * cell editor listeners (including the table) that the editing has been
161 * stopped.
162 *
163 * @return boolean
164 */
165 public boolean stopCellEditing()
166 {
167 fireEditingStopped();
168 return true;
169 } // stopCellEditing()
170
171 /**
172 * Cancel the cell editing session. This method notifies the registered
173 * cell editor listeners (including the table) that the editing has been
174 * canceled.
175 */
176 public void cancelCellEditing()
177 {
178 fireEditingCanceled();
179 } // cancelCellEditing()
180
181 /**
182 * Start editing session and returns true to indicate the editing has begun.
183 * The default method returns true without action but may be overridden
184 * in derived classes for more specific behavior.
185 *
186 * @param event the event.
187 *
188 * @return true, always
189 */
190 public boolean startCellEditing(EventObject event)
191 {
192 // return true to indicate that editing has begun
193 return true;
194 } // startCellEditing()
195
196 /**
197 * This event is fired by the editor component (for instance, by pressing
198 * ENTER in the {@link JTextField}. The default method delegates call to
199 * the {@link #stopCellEditing}, finishing the editing session.
200 *
201 * @param event unused in default method
202 */
203 public void actionPerformed(ActionEvent event)
204 {
205 stopCellEditing();
206 } // actionPerformed()
207
208 /**
209 * This event is fired by the editor component.The default method delegates
210 * call to the {@link #stopCellEditing}, finishing the editing session.
211 *
212 * @param event unused in default method
213 */
214 public void itemStateChanged(ItemEvent event)
215 {
216 stopCellEditing();
217 } // itemStateChanged()
218
219 /**
220 * Notify the registered listeners (including the table) that the editing
221 * has been completed.
222 */
223 void fireEditingStopped()
224 {
225 CellEditorListener[] listeners = getCellEditorListeners();
226 for (int index = 0; index < listeners.length; index++)
227 listeners[index].editingStopped(changeEvent);
228
229 }
230
231 /**
232 * Notify the registered listeners (including the table) that the editing
233 * has been canceled.
234 */
235 void fireEditingCanceled()
236 {
237 CellEditorListener[] listeners = getCellEditorListeners();
238 for (int index = 0; index < listeners.length; index++)
239 listeners[index].editingCanceled(changeEvent);
240 }
241 } // EditorDelegate
242
243 /**
244 * Provides getter and setter methods to work with the text component.
245 *
246 * @author Audrius Meskauskas (audriusa@Bioinformatics.org)
247 */
248 private class JTextFieldDelegate extends EditorDelegate
249 {
250 /**
251 * Use the serial version UID for interoperability.
252 */
253 private static final long serialVersionUID = 1;
254
255 /**
256 * Set the value for the editor component.
257 *
258 * @param aValue the value to set (toString() will be called).
259 */
260 public void setValue(Object aValue)
261 {
262 value = aValue;
263 JTextField f = (JTextField) editorComponent;
264 if (value == null)
265 f.setText("");
266 else
267 f.setText(value.toString());
268 }
269
270 /**
271 * Get the value for the editor component.
272 *
273 * @return value the value of the component (String)
274 */
275 public Object getCellEditorValue()
276 {
277 JTextField f = (JTextField) editorComponent;
278 return value = f.getText();
279 }
280 }
281
282 /**
283 * Provides getter and setter methods to work with the combo box.
284 *
285 * @author Audrius Meskauskas (audriusa@Bioinformatics.org)
286 */
287 private class JComboBoxDelegate extends EditorDelegate
288 {
289 /**
290 * Use the serial version UID for interoperability.
291 */
292 private static final long serialVersionUID = 1;
293
294 /**
295 * Set the value for the editor component.
296 *
297 * @param aValue the value to set.
298 */
299 public void setValue(Object aValue)
300 {
301 value = aValue;
302 JComboBox c = (JComboBox) editorComponent;
303 if (value != null)
304 c.setSelectedItem(value);
305 }
306
307 /**
308 * Get the value for the editor component.
309 *
310 * @return value the value of the component (as String)
311 */
312 public Object getCellEditorValue()
313 {
314 JComboBox c = (JComboBox) editorComponent;
315 return value = c.getSelectedItem();
316 }
317
318 /**
319 * Returns true to indicate that the editing cell can be selected. If the
320 * check box is not editable, expands it. If it is editable, brings
321 * focus to the editor field.
322 *
323 * @param event unused in default method
324 *
325 * @return true always
326 */
327 public boolean shouldSelectCell(EventObject event)
328 {
329 JComboBox c = (JComboBox) editorComponent;
330 if (!c.isEditable)
331 c.showPopup();
332 return true;
333 }
334 }
335
336 /**
337 * Provides getter and setter methods to work with the check box.
338 *
339 * @author Audrius Meskauskas (audriusa@Bioinformatics.org)
340 */
341 private class JCheckBoxDelegate extends EditorDelegate
342 {
343 /**
344 * Use the serial version UID for interoperability.
345 */
346 private static final long serialVersionUID = 1;
347
348 /**
349 * Set the value for the editor component.
350 *
351 * @param value the value to set (must be Boolean).
352 */
353 public void setValue(Object value)
354 {
355 JCheckBox c = (JCheckBox) editorComponent;
356
357 if (value == null)
358 c.setSelected(false);
359 else
360 c.setSelected( ((Boolean) value).booleanValue());
361 }
362
363 /**
364 * Get the value for the editor component.
365 *
366 * @return value the value of the component (must be CharSequence)
367 */
368 public Object getCellEditorValue()
369 {
370 JCheckBox c = (JCheckBox) editorComponent;
371 value = c.isSelected() ? Boolean.TRUE : Boolean.FALSE;
372 return value;
373 }
374 }
375
376 /**
377 * The Swing JComponent, performing the editing session.
378 */
379 protected JComponent editorComponent;
380
381 /**
382 * The editor delegate, responsible for listening the {@link #editorComponent}
383 * events and getting/setting its value.
384 */
385 protected EditorDelegate delegate;
386
387 /**
388 * The number of the mouse clicks, required to start the editing session.
389 */
390 protected int clickCountToStart;
391
392 /**
393 * Create the DefaultCellEditor that uses the text field as its editor
394 * component (appropriate for the text content)
395 *
396 * @param textfield the text field as will be used as the editor component
397 */
398 public DefaultCellEditor(JTextField textfield)
399 {
400 editorComponent = textfield;
401 clickCountToStart = 2;
402 delegate = new JTextFieldDelegate();
403 textfield.addActionListener(delegate);
404 } // DefaultCellEditor()
405
406 /**
407 * Constructor DefaultCellEditor that uses the checkbox (appropriate
408 * for boolean values)
409 *
410 * @param checkbox the checkbox that will be used with this editor.
411 */
412 public DefaultCellEditor(JCheckBox checkbox)
413 {
414 editorComponent = checkbox;
415 clickCountToStart = 1;
416 delegate = new JCheckBoxDelegate();
417 checkbox.addActionListener(delegate);
418 } // DefaultCellEditor()
419
420 /**
421 * Constructor DefaultCellEditor that uses the combo box.
422 *
423 * @param combobox the combo box that will be used with this editor.
424 */
425 public DefaultCellEditor(JComboBox combobox)
426 {
427 editorComponent = combobox;
428 clickCountToStart = 1;
429 delegate = new JComboBoxDelegate();
430 combobox.addActionListener(delegate);
431 } // DefaultCellEditor()
432
433 /**
434 * Get the component that performs the editing sessions. It is the same
435 * component that was passed in constructor.
436 *
437 * @return the component, performing the editing sessions.
438 */
439 public Component getComponent()
440 {
441 return editorComponent;
442 } // getComponent()
443
444 /**
445 * Get the number of mouse clicks, required to start the editing session.
446 *
447 * @return int the number of mouse clicks, required to start the session
448 */
449 public int getClickCountToStart()
450 {
451 return clickCountToStart;
452 } // getClickCountToStart()
453
454 /**
455 * Set the number of mouse clicks, required to start the editing session.
456 *
457 * @param count the number of clicks, required to start the session
458 */
459 public void setClickCountToStart(int count)
460 {
461 clickCountToStart = count;
462 } // setClickCountToStart()
463
464 /**
465 * Get the value, currently being displayed by the editor component. The
466 * call is forwarded to the {@link #delegate}.
467 *
468 * @return Object the value (class depends on the editor component)
469 */
470 public Object getCellEditorValue()
471 {
472 return delegate.getCellEditorValue();
473 } // getCellEditorValue()
474
475 /**
476 * Forwards call to the {@link #delegate}.
477 *
478 * @param event forwarded to the delegate.
479 *
480 * @return boolean returned by delegate
481 */
482 public boolean isCellEditable(EventObject event)
483 {
484 return delegate.isCellEditable(event);
485 } // isCellEditable()
486
487 /**
488 * Forwards call to the {@link #delegate}.
489 *
490 * @param event forwarded to the delegate.
491 *
492 * @return boolean returned by delegate
493 */
494 public boolean shouldSelectCell(EventObject event)
495 {
496 return delegate.shouldSelectCell(event);
497 } // shouldSelectCell()
498
499 /**
500 * Forwards call to the {@link #delegate}.
501 *
502 * @return boolean returned by delegate
503 */
504 public boolean stopCellEditing()
505 {
506 return delegate.stopCellEditing();
507 } // stopCellEditing()
508
509 /**
510 * Forwards call to the {@link #delegate}.
511 */
512 public void cancelCellEditing()
513 {
514 delegate.cancelCellEditing();
515 } // cancelCellEditing()
516
517 /**
518 * Sets an initial value for the editor.
519 * This will cause the editor to stopEditing and lose any partially
520 * edited value if the editor is editing when this method is called.
521 * Returns the component that should be added to the client's Component
522 * hierarchy. Once installed in the client's hierarchy this component will
523 * then be able to draw and receive user input.
524 *
525 * @param tree - the JTree that is asking the editor to edit; this
526 * parameter can be null
527 * @param value - the value of the cell to be edited
528 * @param isSelected - true is the cell is to be renderer with selection
529 * highlighting
530 * @param expanded - true if the node is expanded
531 * @param leaf - true if the node is a leaf node
532 * @param row - the row index of the node being edited
533 *
534 * @return Component the component for editing
535 */
536 public Component getTreeCellEditorComponent(JTree tree, Object value,
537 boolean isSelected,
538 boolean expanded, boolean leaf,
539 int row)
540 {
541 delegate.setValue(value);
542 return editorComponent;
543 } // getTreeCellEditorComponent()
544
545 /**
546 * Get the cell editor component that will perform the editing session. If
547 * returned once, the same component is also returned on the repetetive calls
548 * again (reused).
549 *
550 * @param table the table where the editing is performed
551 * @param value the current value of the table. It is set as the initial
552 * component value.
553 * @param isSelected if true, the cell is currently selected
554 * @param row the row of the cell being edited
555 * @param column the column of the cell being edited
556 *
557 * @return Component the component that will perform the editing session
558 */
559 public Component getTableCellEditorComponent(JTable table, Object value,
560 boolean isSelected, int row,
561 int column)
562 {
563 // NOTE: as specified by Sun, we don't call new() everytime, we return
564 // editorComponent on each call to getTableCellEditorComponent or
565 // getTreeCellEditorComponent.
566 delegate.setValue(value);
567 return editorComponent;
568 } // getTableCellEditorComponent()
569
570 }