1 /*
2 * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25 package javax.swing;
26
27 import java.beans.PropertyChangeEvent;
28 import java.beans.PropertyChangeListener;
29 import java.beans.Transient;
30 import java.util.*;
31
32 import java.awt.*;
33 import java.awt.event.*;
34
35 import java.io.Serializable;
36 import java.io.ObjectOutputStream;
37 import java.io.IOException;
38
39 import javax.swing.event.*;
40 import javax.swing.plaf.*;
41
42 import javax.accessibility.*;
43
44 /**
45 * A component that combines a button or editable field and a drop-down list.
46 * The user can select a value from the drop-down list, which appears at the
47 * user's request. If you make the combo box editable, then the combo box
48 * includes an editable field into which the user can type a value.
49 * <p>
50 * <strong>Warning:</strong> Swing is not thread safe. For more
51 * information see <a
52 * href="package-summary.html#threading">Swing's Threading
53 * Policy</a>.
54 * <p>
55 * <strong>Warning:</strong>
56 * Serialized objects of this class will not be compatible with
57 * future Swing releases. The current serialization support is
58 * appropriate for short term storage or RMI between applications running
59 * the same version of Swing. As of 1.4, support for long term storage
60 * of all JavaBeans™
61 * has been added to the <code>java.beans</code> package.
62 * Please see {@link java.beans.XMLEncoder}.
63 *
64 * <p>
65 * See <a href="https://docs.oracle.com/javase/tutorial/uiswing/components/combobox.html">How to Use Combo Boxes</a>
66 * in <a href="https://docs.oracle.com/javase/tutorial/"><em>The Java Tutorial</em></a>
67 * for further information.
68 * <p>
69 * @see ComboBoxModel
70 * @see DefaultComboBoxModel
71 *
72 * @param <E> the type of the elements of this combo box
73 *
74 * @beaninfo
75 * attribute: isContainer false
76 * description: A combination of a text field and a drop-down list.
77 *
78 * @author Arnaud Weber
79 * @author Mark Davidson
80 */
81 public class JComboBox<E> extends JComponent
82 implements ItemSelectable,ListDataListener,ActionListener, Accessible {
83 /**
84 * @see #getUIClassID
85 * @see #readObject
86 */
87 private static final String uiClassID = "ComboBoxUI";
88
89 /**
90 * This protected field is implementation specific. Do not access directly
91 * or override. Use the accessor methods instead.
92 *
93 * @see #getModel
94 * @see #setModel
95 */
96 protected ComboBoxModel<E> dataModel;
97 /**
98 * This protected field is implementation specific. Do not access directly
99 * or override. Use the accessor methods instead.
100 *
101 * @see #getRenderer
102 * @see #setRenderer
103 */
104 protected ListCellRenderer<? super E> renderer;
105 /**
106 * This protected field is implementation specific. Do not access directly
107 * or override. Use the accessor methods instead.
108 *
109 * @see #getEditor
110 * @see #setEditor
111 */
112 protected ComboBoxEditor editor;
113 /**
114 * This protected field is implementation specific. Do not access directly
115 * or override. Use the accessor methods instead.
116 *
117 * @see #getMaximumRowCount
118 * @see #setMaximumRowCount
119 */
120 protected int maximumRowCount = 8;
121
122 /**
123 * This protected field is implementation specific. Do not access directly
124 * or override. Use the accessor methods instead.
125 *
126 * @see #isEditable
127 * @see #setEditable
128 */
129 protected boolean isEditable = false;
130 /**
131 * This protected field is implementation specific. Do not access directly
132 * or override. Use the accessor methods instead.
133 *
134 * @see #setKeySelectionManager
135 * @see #getKeySelectionManager
136 */
137 protected KeySelectionManager keySelectionManager = null;
138 /**
139 * This protected field is implementation specific. Do not access directly
140 * or override. Use the accessor methods instead.
141 *
142 * @see #setActionCommand
143 * @see #getActionCommand
144 */
145 protected String actionCommand = "comboBoxChanged";
146 /**
147 * This protected field is implementation specific. Do not access directly
148 * or override. Use the accessor methods instead.
149 *
150 * @see #setLightWeightPopupEnabled
151 * @see #isLightWeightPopupEnabled
152 */
153 protected boolean lightWeightPopupEnabled = JPopupMenu.getDefaultLightWeightPopupEnabled();
154
155 /**
156 * This protected field is implementation specific. Do not access directly
157 * or override.
158 */
159 protected Object selectedItemReminder = null;
160
161 private E prototypeDisplayValue;
162
163 // Flag to ensure that infinite loops do not occur with ActionEvents.
164 private boolean firingActionEvent = false;
165
166 // Flag to ensure the we don't get multiple ActionEvents on item selection.
167 private boolean selectingItem = false;
168
169 /**
170 * Creates a <code>JComboBox</code> that takes its items from an
171 * existing <code>ComboBoxModel</code>. Since the
172 * <code>ComboBoxModel</code> is provided, a combo box created using
173 * this constructor does not create a default combo box model and
174 * may impact how the insert, remove and add methods behave.
175 *
176 * @param aModel the <code>ComboBoxModel</code> that provides the
177 * displayed list of items
178 * @see DefaultComboBoxModel
179 */
180 public JComboBox(ComboBoxModel<E> aModel) {
181 super();
182 setModel(aModel);
183 init();
184 }
185
186 /**
187 * Creates a <code>JComboBox</code> that contains the elements
188 * in the specified array. By default the first item in the array
189 * (and therefore the data model) becomes selected.
190 *
191 * @param items an array of objects to insert into the combo box
192 * @see DefaultComboBoxModel
193 */
194 public JComboBox(E[] items) {
195 super();
196 setModel(new DefaultComboBoxModel<E>(items));
197 init();
198 }
199
200 /**
201 * Creates a <code>JComboBox</code> that contains the elements
202 * in the specified Vector. By default the first item in the vector
203 * (and therefore the data model) becomes selected.
204 *
205 * @param items an array of vectors to insert into the combo box
206 * @see DefaultComboBoxModel
207 */
208 public JComboBox(Vector<E> items) {
209 super();
210 setModel(new DefaultComboBoxModel<E>(items));
211 init();
212 }
213
214 /**
215 * Creates a <code>JComboBox</code> with a default data model.
216 * The default data model is an empty list of objects.
217 * Use <code>addItem</code> to add items. By default the first item
218 * in the data model becomes selected.
219 *
220 * @see DefaultComboBoxModel
221 */
222 public JComboBox() {
223 super();
224 setModel(new DefaultComboBoxModel<E>());
225 init();
226 }
227
228 private void init() {
229 installAncestorListener();
230 setUIProperty("opaque",true);
231 updateUI();
232 }
233
234 protected void installAncestorListener() {
235 addAncestorListener(new AncestorListener(){
236 public void ancestorAdded(AncestorEvent event){ hidePopup();}
237 public void ancestorRemoved(AncestorEvent event){ hidePopup();}
238 public void ancestorMoved(AncestorEvent event){
239 if (event.getSource() != JComboBox.this)
240 hidePopup();
241 }});
242 }
243
244 /**
245 * Sets the L&F object that renders this component.
246 *
247 * @param ui the <code>ComboBoxUI</code> L&F object
248 * @see UIDefaults#getUI
249 *
250 * @beaninfo
251 * bound: true
252 * hidden: true
253 * attribute: visualUpdate true
254 * description: The UI object that implements the Component's LookAndFeel.
255 */
256 public void setUI(ComboBoxUI ui) {
257 super.setUI(ui);
258 }
259
260 /**
261 * Resets the UI property to a value from the current look and feel.
262 *
263 * @see JComponent#updateUI
264 */
265 public void updateUI() {
266 setUI((ComboBoxUI)UIManager.getUI(this));
267
268 ListCellRenderer<? super E> renderer = getRenderer();
269 if (renderer instanceof Component) {
270 SwingUtilities.updateComponentTreeUI((Component)renderer);
271 }
272 }
273
274
275 /**
276 * Returns the name of the L&F class that renders this component.
277 *
278 * @return the string "ComboBoxUI"
279 * @see JComponent#getUIClassID
280 * @see UIDefaults#getUI
281 */
282 public String getUIClassID() {
283 return uiClassID;
284 }
285
286
287 /**
288 * Returns the L&F object that renders this component.
289 *
290 * @return the ComboBoxUI object that renders this component
291 */
292 public ComboBoxUI getUI() {
293 return(ComboBoxUI)ui;
294 }
295
296 /**
297 * Sets the data model that the <code>JComboBox</code> uses to obtain
298 * the list of items.
299 *
300 * @param aModel the <code>ComboBoxModel</code> that provides the
301 * displayed list of items
302 *
303 * @beaninfo
304 * bound: true
305 * description: Model that the combo box uses to get data to display.
306 */
307 public void setModel(ComboBoxModel<E> aModel) {
308 ComboBoxModel<E> oldModel = dataModel;
309 if (oldModel != null) {
310 oldModel.removeListDataListener(this);
311 }
312 dataModel = aModel;
313 dataModel.addListDataListener(this);
314
315 // set the current selected item.
316 selectedItemReminder = dataModel.getSelectedItem();
317
318 firePropertyChange( "model", oldModel, dataModel);
319 }
320
321 /**
322 * Returns the data model currently used by the <code>JComboBox</code>.
323 *
324 * @return the <code>ComboBoxModel</code> that provides the displayed
325 * list of items
326 */
327 public ComboBoxModel<E> getModel() {
328 return dataModel;
329 }
330
331 /*
332 * Properties
333 */
334
335 /**
336 * Sets the <code>lightWeightPopupEnabled</code> property, which
337 * provides a hint as to whether or not a lightweight
338 * <code>Component</code> should be used to contain the
339 * <code>JComboBox</code>, versus a heavyweight
340 * <code>Component</code> such as a <code>Panel</code>
341 * or a <code>Window</code>. The decision of lightweight
342 * versus heavyweight is ultimately up to the
343 * <code>JComboBox</code>. Lightweight windows are more
344 * efficient than heavyweight windows, but lightweight
345 * and heavyweight components do not mix well in a GUI.
346 * If your application mixes lightweight and heavyweight
347 * components, you should disable lightweight popups.
348 * The default value for the <code>lightWeightPopupEnabled</code>
349 * property is <code>true</code>, unless otherwise specified
350 * by the look and feel. Some look and feels always use
351 * heavyweight popups, no matter what the value of this property.
352 * <p>
353 * See the article <a href="http://www.oracle.com/technetwork/articles/java/mixing-components-433992.html">Mixing Heavy and Light Components</a>
354 * This method fires a property changed event.
355 *
356 * @param aFlag if <code>true</code>, lightweight popups are desired
357 *
358 * @beaninfo
359 * bound: true
360 * expert: true
361 * description: Set to <code>false</code> to require heavyweight popups.
362 */
363 public void setLightWeightPopupEnabled(boolean aFlag) {
364 boolean oldFlag = lightWeightPopupEnabled;
365 lightWeightPopupEnabled = aFlag;
366 firePropertyChange("lightWeightPopupEnabled", oldFlag, lightWeightPopupEnabled);
367 }
368
369 /**
370 * Gets the value of the <code>lightWeightPopupEnabled</code>
371 * property.
372 *
373 * @return the value of the <code>lightWeightPopupEnabled</code>
374 * property
375 * @see #setLightWeightPopupEnabled
376 */
377 public boolean isLightWeightPopupEnabled() {
378 return lightWeightPopupEnabled;
379 }
380
381 /**
382 * Determines whether the <code>JComboBox</code> field is editable.
383 * An editable <code>JComboBox</code> allows the user to type into the
384 * field or selected an item from the list to initialize the field,
385 * after which it can be edited. (The editing affects only the field,
386 * the list item remains intact.) A non editable <code>JComboBox</code>
387 * displays the selected item in the field,
388 * but the selection cannot be modified.
389 *
390 * @param aFlag a boolean value, where true indicates that the
391 * field is editable
392 *
393 * @beaninfo
394 * bound: true
395 * preferred: true
396 * description: If true, the user can type a new value in the combo box.
397 */
398 public void setEditable(boolean aFlag) {
399 boolean oldFlag = isEditable;
400 isEditable = aFlag;
401 firePropertyChange( "editable", oldFlag, isEditable );
402 }
403
404 /**
405 * Returns true if the <code>JComboBox</code> is editable.
406 * By default, a combo box is not editable.
407 *
408 * @return true if the <code>JComboBox</code> is editable, else false
409 */
410 public boolean isEditable() {
411 return isEditable;
412 }
413
414 /**
415 * Sets the maximum number of rows the <code>JComboBox</code> displays.
416 * If the number of objects in the model is greater than count,
417 * the combo box uses a scrollbar.
418 *
419 * @param count an integer specifying the maximum number of items to
420 * display in the list before using a scrollbar
421 * @beaninfo
422 * bound: true
423 * preferred: true
424 * description: The maximum number of rows the popup should have
425 */
426 public void setMaximumRowCount(int count) {
427 int oldCount = maximumRowCount;
428 maximumRowCount = count;
429 firePropertyChange( "maximumRowCount", oldCount, maximumRowCount );
430 }
431
432 /**
433 * Returns the maximum number of items the combo box can display
434 * without a scrollbar
435 *
436 * @return an integer specifying the maximum number of items that are
437 * displayed in the list before using a scrollbar
438 */
439 public int getMaximumRowCount() {
440 return maximumRowCount;
441 }
442
443 /**
444 * Sets the renderer that paints the list items and the item selected from the list in
445 * the JComboBox field. The renderer is used if the JComboBox is not
446 * editable. If it is editable, the editor is used to render and edit
447 * the selected item.
448 * <p>
449 * The default renderer displays a string or an icon.
450 * Other renderers can handle graphic images and composite items.
451 * <p>
452 * To display the selected item,
453 * <code>aRenderer.getListCellRendererComponent</code>
454 * is called, passing the list object and an index of -1.
455 *
456 * @param aRenderer the <code>ListCellRenderer</code> that
457 * displays the selected item
458 * @see #setEditor
459 * @beaninfo
460 * bound: true
461 * expert: true
462 * description: The renderer that paints the item selected in the list.
463 */
464 public void setRenderer(ListCellRenderer<? super E> aRenderer) {
465 ListCellRenderer<? super E> oldRenderer = renderer;
466 renderer = aRenderer;
467 firePropertyChange( "renderer", oldRenderer, renderer );
468 invalidate();
469 }
470
471 /**
472 * Returns the renderer used to display the selected item in the
473 * <code>JComboBox</code> field.
474 *
475 * @return the <code>ListCellRenderer</code> that displays
476 * the selected item.
477 */
478 public ListCellRenderer<? super E> getRenderer() {
479 return renderer;
480 }
481
482 /**
483 * Sets the editor used to paint and edit the selected item in the
484 * <code>JComboBox</code> field. The editor is used only if the
485 * receiving <code>JComboBox</code> is editable. If not editable,
486 * the combo box uses the renderer to paint the selected item.
487 *
488 * @param anEditor the <code>ComboBoxEditor</code> that
489 * displays the selected item
490 * @see #setRenderer
491 * @beaninfo
492 * bound: true
493 * expert: true
494 * description: The editor that combo box uses to edit the current value
495 */
496 public void setEditor(ComboBoxEditor anEditor) {
497 ComboBoxEditor oldEditor = editor;
498
499 if ( editor != null ) {
500 editor.removeActionListener(this);
501 }
502 editor = anEditor;
503 if ( editor != null ) {
504 editor.addActionListener(this);
505 }
506 firePropertyChange( "editor", oldEditor, editor );
507 }
508
509 /**
510 * Returns the editor used to paint and edit the selected item in the
511 * <code>JComboBox</code> field.
512 *
513 * @return the <code>ComboBoxEditor</code> that displays the selected item
514 */
515 public ComboBoxEditor getEditor() {
516 return editor;
517 }
518
519 //
520 // Selection
521 //
522
523 /**
524 * Sets the selected item in the combo box display area to the object in
525 * the argument.
526 * If <code>anObject</code> is in the list, the display area shows
527 * <code>anObject</code> selected.
528 * <p>
529 * If <code>anObject</code> is <i>not</i> in the list and the combo box is
530 * uneditable, it will not change the current selection. For editable
531 * combo boxes, the selection will change to <code>anObject</code>.
532 * <p>
533 * If this constitutes a change in the selected item,
534 * <code>ItemListener</code>s added to the combo box will be notified with
535 * one or two <code>ItemEvent</code>s.
536 * If there is a current selected item, an <code>ItemEvent</code> will be
537 * fired and the state change will be <code>ItemEvent.DESELECTED</code>.
538 * If <code>anObject</code> is in the list and is not currently selected
539 * then an <code>ItemEvent</code> will be fired and the state change will
540 * be <code>ItemEvent.SELECTED</code>.
541 * <p>
542 * <code>ActionListener</code>s added to the combo box will be notified
543 * with an <code>ActionEvent</code> when this method is called.
544 *
545 * @param anObject the list object to select; use <code>null</code> to
546 clear the selection
547 * @beaninfo
548 * preferred: true
549 * description: Sets the selected item in the JComboBox.
550 */
551 public void setSelectedItem(Object anObject) {
552 Object oldSelection = selectedItemReminder;
553 Object objectToSelect = anObject;
554 if (oldSelection == null || !oldSelection.equals(anObject)) {
555
556 if (anObject != null && !isEditable()) {
557 // For non editable combo boxes, an invalid selection
558 // will be rejected.
559 boolean found = false;
560 for (int i = 0; i < dataModel.getSize(); i++) {
561 E element = dataModel.getElementAt(i);
562 if (anObject.equals(element)) {
563 found = true;
564 objectToSelect = element;
565 break;
566 }
567 }
568 if (!found) {
569 return;
570 }
571 }
572
573 // Must toggle the state of this flag since this method
574 // call may result in ListDataEvents being fired.
575 selectingItem = true;
576 dataModel.setSelectedItem(objectToSelect);
577 selectingItem = false;
578
579 if (selectedItemReminder != dataModel.getSelectedItem()) {
580 // in case a users implementation of ComboBoxModel
581 // doesn't fire a ListDataEvent when the selection
582 // changes.
583 selectedItemChanged();
584 }
585 }
586 fireActionEvent();
587 }
588
589 /**
590 * Returns the current selected item.
591 * <p>
592 * If the combo box is editable, then this value may not have been added
593 * to the combo box with <code>addItem</code>, <code>insertItemAt</code>
594 * or the data constructors.
595 *
596 * @return the current selected Object
597 * @see #setSelectedItem
598 */
599 public Object getSelectedItem() {
600 return dataModel.getSelectedItem();
601 }
602
603 /**
604 * Selects the item at index <code>anIndex</code>.
605 *
606 * @param anIndex an integer specifying the list item to select,
607 * where 0 specifies the first item in the list and -1 indicates no selection
608 * @exception IllegalArgumentException if <code>anIndex</code> < -1 or
609 * <code>anIndex</code> is greater than or equal to size
610 * @beaninfo
611 * preferred: true
612 * description: The item at index is selected.
613 */
614 public void setSelectedIndex(int anIndex) {
615 int size = dataModel.getSize();
616
617 if ( anIndex == -1 ) {
618 setSelectedItem( null );
619 } else if ( anIndex < -1 || anIndex >= size ) {
620 throw new IllegalArgumentException("setSelectedIndex: " + anIndex + " out of bounds");
621 } else {
622 setSelectedItem(dataModel.getElementAt(anIndex));
623 }
624 }
625
626 /**
627 * Returns the first item in the list that matches the given item.
628 * The result is not always defined if the <code>JComboBox</code>
629 * allows selected items that are not in the list.
630 * Returns -1 if there is no selected item or if the user specified
631 * an item which is not in the list.
632
633 * @return an integer specifying the currently selected list item,
634 * where 0 specifies
635 * the first item in the list;
636 * or -1 if no item is selected or if
637 * the currently selected item is not in the list
638 */
639 @Transient
640 public int getSelectedIndex() {
641 Object sObject = dataModel.getSelectedItem();
642 int i,c;
643 E obj;
644
645 for ( i=0,c=dataModel.getSize();i<c;i++ ) {
646 obj = dataModel.getElementAt(i);
647 if ( obj != null && obj.equals(sObject) )
648 return i;
649 }
650 return -1;
651 }
652
653 /**
654 * Returns the "prototypical display" value - an Object used
655 * for the calculation of the display height and width.
656 *
657 * @return the value of the <code>prototypeDisplayValue</code> property
658 * @see #setPrototypeDisplayValue
659 * @since 1.4
660 */
661 public E getPrototypeDisplayValue() {
662 return prototypeDisplayValue;
663 }
664
665 /**
666 * Sets the prototype display value used to calculate the size of the display
667 * for the UI portion.
668 * <p>
669 * If a prototype display value is specified, the preferred size of
670 * the combo box is calculated by configuring the renderer with the
671 * prototype display value and obtaining its preferred size. Specifying
672 * the preferred display value is often useful when the combo box will be
673 * displaying large amounts of data. If no prototype display value has
674 * been specified, the renderer must be configured for each value from
675 * the model and its preferred size obtained, which can be
676 * relatively expensive.
677 *
678 * @param prototypeDisplayValue
679 * @see #getPrototypeDisplayValue
680 * @since 1.4
681 * @beaninfo
682 * bound: true
683 * attribute: visualUpdate true
684 * description: The display prototype value, used to compute display width and height.
685 */
686 public void setPrototypeDisplayValue(E prototypeDisplayValue) {
687 Object oldValue = this.prototypeDisplayValue;
688 this.prototypeDisplayValue = prototypeDisplayValue;
689 firePropertyChange("prototypeDisplayValue", oldValue, prototypeDisplayValue);
690 }
691
692 /**
693 * Adds an item to the item list.
694 * This method works only if the <code>JComboBox</code> uses a
695 * mutable data model.
696 * <p>
697 * <strong>Warning:</strong>
698 * Focus and keyboard navigation problems may arise if you add duplicate
699 * String objects. A workaround is to add new objects instead of String
700 * objects and make sure that the toString() method is defined.
701 * For example:
702 * <pre>
703 * comboBox.addItem(makeObj("Item 1"));
704 * comboBox.addItem(makeObj("Item 1"));
705 * ...
706 * private Object makeObj(final String item) {
707 * return new Object() { public String toString() { return item; } };
708 * }
709 * </pre>
710 *
711 * @param item the item to add to the list
712 * @see MutableComboBoxModel
713 */
714 public void addItem(E item) {
715 checkMutableComboBoxModel();
716 ((MutableComboBoxModel<E>)dataModel).addElement(item);
717 }
718
719 /**
720 * Inserts an item into the item list at a given index.
721 * This method works only if the <code>JComboBox</code> uses a
722 * mutable data model.
723 *
724 * @param item the item to add to the list
725 * @param index an integer specifying the position at which
726 * to add the item
727 * @see MutableComboBoxModel
728 */
729 public void insertItemAt(E item, int index) {
730 checkMutableComboBoxModel();
731 ((MutableComboBoxModel<E>)dataModel).insertElementAt(item,index);
732 }
733
734 /**
735 * Removes an item from the item list.
736 * This method works only if the <code>JComboBox</code> uses a
737 * mutable data model.
738 *
739 * @param anObject the object to remove from the item list
740 * @see MutableComboBoxModel
741 */
742 public void removeItem(Object anObject) {
743 checkMutableComboBoxModel();
744 ((MutableComboBoxModel)dataModel).removeElement(anObject);
745 }
746
747 /**
748 * Removes the item at <code>anIndex</code>
749 * This method works only if the <code>JComboBox</code> uses a
750 * mutable data model.
751 *
752 * @param anIndex an int specifying the index of the item to remove,
753 * where 0
754 * indicates the first item in the list
755 * @see MutableComboBoxModel
756 */
757 public void removeItemAt(int anIndex) {
758 checkMutableComboBoxModel();
759 ((MutableComboBoxModel<E>)dataModel).removeElementAt( anIndex );
760 }
761
762 /**
763 * Removes all items from the item list.
764 */
765 public void removeAllItems() {
766 checkMutableComboBoxModel();
767 MutableComboBoxModel<E> model = (MutableComboBoxModel<E>)dataModel;
768 int size = model.getSize();
769
770 if ( model instanceof DefaultComboBoxModel ) {
771 ((DefaultComboBoxModel)model).removeAllElements();
772 }
773 else {
774 for ( int i = 0; i < size; ++i ) {
775 E element = model.getElementAt( 0 );
776 model.removeElement( element );
777 }
778 }
779 selectedItemReminder = null;
780 if (isEditable()) {
781 editor.setItem(null);
782 }
783 }
784
785 /**
786 * Checks that the <code>dataModel</code> is an instance of
787 * <code>MutableComboBoxModel</code>. If not, it throws an exception.
788 * @exception RuntimeException if <code>dataModel</code> is not an
789 * instance of <code>MutableComboBoxModel</code>.
790 */
791 void checkMutableComboBoxModel() {
792 if ( !(dataModel instanceof MutableComboBoxModel) )
793 throw new RuntimeException("Cannot use this method with a non-Mutable data model.");
794 }
795
796 /**
797 * Causes the combo box to display its popup window.
798 * @see #setPopupVisible
799 */
800 public void showPopup() {
801 setPopupVisible(true);
802 }
803
804 /**
805 * Causes the combo box to close its popup window.
806 * @see #setPopupVisible
807 */
808 public void hidePopup() {
809 setPopupVisible(false);
810 }
811
812 /**
813 * Sets the visibility of the popup.
814 */
815 public void setPopupVisible(boolean v) {
816 getUI().setPopupVisible(this, v);
817 }
818
819 /**
820 * Determines the visibility of the popup.
821 *
822 * @return true if the popup is visible, otherwise returns false
823 */
824 public boolean isPopupVisible() {
825 return getUI().isPopupVisible(this);
826 }
827
828 /** Selection **/
829
830 /**
831 * Adds an <code>ItemListener</code>.
832 * <p>
833 * <code>aListener</code> will receive one or two <code>ItemEvent</code>s when
834 * the selected item changes.
835 *
836 * @param aListener the <code>ItemListener</code> that is to be notified
837 * @see #setSelectedItem
838 */
839 public void addItemListener(ItemListener aListener) {
840 listenerList.add(ItemListener.class,aListener);
841 }
842
843 /** Removes an <code>ItemListener</code>.
844 *
845 * @param aListener the <code>ItemListener</code> to remove
846 */
847 public void removeItemListener(ItemListener aListener) {
848 listenerList.remove(ItemListener.class,aListener);
849 }
850
851 /**
852 * Returns an array of all the <code>ItemListener</code>s added
853 * to this JComboBox with addItemListener().
854 *
855 * @return all of the <code>ItemListener</code>s added or an empty
856 * array if no listeners have been added
857 * @since 1.4
858 */
859 public ItemListener[] getItemListeners() {
860 return listenerList.getListeners(ItemListener.class);
861 }
862
863 /**
864 * Adds an <code>ActionListener</code>.
865 * <p>
866 * The <code>ActionListener</code> will receive an <code>ActionEvent</code>
867 * when a selection has been made. If the combo box is editable, then
868 * an <code>ActionEvent</code> will be fired when editing has stopped.
869 *
870 * @param l the <code>ActionListener</code> that is to be notified
871 * @see #setSelectedItem
872 */
873 public void addActionListener(ActionListener l) {
874 listenerList.add(ActionListener.class,l);
875 }
876
877 /** Removes an <code>ActionListener</code>.
878 *
879 * @param l the <code>ActionListener</code> to remove
880 */
881 public void removeActionListener(ActionListener l) {
882 if ((l != null) && (getAction() == l)) {
883 setAction(null);
884 } else {
885 listenerList.remove(ActionListener.class, l);
886 }
887 }
888
889 /**
890 * Returns an array of all the <code>ActionListener</code>s added
891 * to this JComboBox with addActionListener().
892 *
893 * @return all of the <code>ActionListener</code>s added or an empty
894 * array if no listeners have been added
895 * @since 1.4
896 */
897 public ActionListener[] getActionListeners() {
898 return listenerList.getListeners(ActionListener.class);
899 }
900
901 /**
902 * Adds a <code>PopupMenu</code> listener which will listen to notification
903 * messages from the popup portion of the combo box.
904 * <p>
905 * For all standard look and feels shipped with Java, the popup list
906 * portion of combo box is implemented as a <code>JPopupMenu</code>.
907 * A custom look and feel may not implement it this way and will
908 * therefore not receive the notification.
909 *
910 * @param l the <code>PopupMenuListener</code> to add
911 * @since 1.4
912 */
913 public void addPopupMenuListener(PopupMenuListener l) {
914 listenerList.add(PopupMenuListener.class,l);
915 }
916
917 /**
918 * Removes a <code>PopupMenuListener</code>.
919 *
920 * @param l the <code>PopupMenuListener</code> to remove
921 * @see #addPopupMenuListener
922 * @since 1.4
923 */
924 public void removePopupMenuListener(PopupMenuListener l) {
925 listenerList.remove(PopupMenuListener.class,l);
926 }
927
928 /**
929 * Returns an array of all the <code>PopupMenuListener</code>s added
930 * to this JComboBox with addPopupMenuListener().
931 *
932 * @return all of the <code>PopupMenuListener</code>s added or an empty
933 * array if no listeners have been added
934 * @since 1.4
935 */
936 public PopupMenuListener[] getPopupMenuListeners() {
937 return listenerList.getListeners(PopupMenuListener.class);
938 }
939
940 /**
941 * Notifies <code>PopupMenuListener</code>s that the popup portion of the
942 * combo box will become visible.
943 * <p>
944 * This method is public but should not be called by anything other than
945 * the UI delegate.
946 * @see #addPopupMenuListener
947 * @since 1.4
948 */
949 public void firePopupMenuWillBecomeVisible() {
950 Object[] listeners = listenerList.getListenerList();
951 PopupMenuEvent e=null;
952 for (int i = listeners.length-2; i>=0; i-=2) {
953 if (listeners[i]==PopupMenuListener.class) {
954 if (e == null)
955 e = new PopupMenuEvent(this);
956 ((PopupMenuListener)listeners[i+1]).popupMenuWillBecomeVisible(e);
957 }
958 }
959 }
960
961 /**
962 * Notifies <code>PopupMenuListener</code>s that the popup portion of the
963 * combo box has become invisible.
964 * <p>
965 * This method is public but should not be called by anything other than
966 * the UI delegate.
967 * @see #addPopupMenuListener
968 * @since 1.4
969 */
970 public void firePopupMenuWillBecomeInvisible() {
971 Object[] listeners = listenerList.getListenerList();
972 PopupMenuEvent e=null;
973 for (int i = listeners.length-2; i>=0; i-=2) {
974 if (listeners[i]==PopupMenuListener.class) {
975 if (e == null)
976 e = new PopupMenuEvent(this);
977 ((PopupMenuListener)listeners[i+1]).popupMenuWillBecomeInvisible(e);
978 }
979 }
980 }
981
982 /**
983 * Notifies <code>PopupMenuListener</code>s that the popup portion of the
984 * combo box has been canceled.
985 * <p>
986 * This method is public but should not be called by anything other than
987 * the UI delegate.
988 * @see #addPopupMenuListener
989 * @since 1.4
990 */
991 public void firePopupMenuCanceled() {
992 Object[] listeners = listenerList.getListenerList();
993 PopupMenuEvent e=null;
994 for (int i = listeners.length-2; i>=0; i-=2) {
995 if (listeners[i]==PopupMenuListener.class) {
996 if (e == null)
997 e = new PopupMenuEvent(this);
998 ((PopupMenuListener)listeners[i+1]).popupMenuCanceled(e);
999 }
1000 }
1001 }
1002
1003 /**
1004 * Sets the action command that should be included in the event
1005 * sent to action listeners.
1006 *
1007 * @param aCommand a string containing the "command" that is sent
1008 * to action listeners; the same listener can then
1009 * do different things depending on the command it
1010 * receives
1011 */
1012 public void setActionCommand(String aCommand) {
1013 actionCommand = aCommand;
1014 }
1015
1016 /**
1017 * Returns the action command that is included in the event sent to
1018 * action listeners.
1019 *
1020 * @return the string containing the "command" that is sent
1021 * to action listeners.
1022 */
1023 public String getActionCommand() {
1024 return actionCommand;
1025 }
1026
1027 private Action action;
1028 private PropertyChangeListener actionPropertyChangeListener;
1029
1030 /**
1031 * Sets the <code>Action</code> for the <code>ActionEvent</code> source.
1032 * The new <code>Action</code> replaces any previously set
1033 * <code>Action</code> but does not affect <code>ActionListeners</code>
1034 * independently added with <code>addActionListener</code>.
1035 * If the <code>Action</code> is already a registered
1036 * <code>ActionListener</code> for the <code>ActionEvent</code> source,
1037 * it is not re-registered.
1038 * <p>
1039 * Setting the <code>Action</code> results in immediately changing
1040 * all the properties described in <a href="Action.html#buttonActions">
1041 * Swing Components Supporting <code>Action</code></a>.
1042 * Subsequently, the combobox's properties are automatically updated
1043 * as the <code>Action</code>'s properties change.
1044 * <p>
1045 * This method uses three other methods to set
1046 * and help track the <code>Action</code>'s property values.
1047 * It uses the <code>configurePropertiesFromAction</code> method
1048 * to immediately change the combobox's properties.
1049 * To track changes in the <code>Action</code>'s property values,
1050 * this method registers the <code>PropertyChangeListener</code>
1051 * returned by <code>createActionPropertyChangeListener</code>. The
1052 * default {@code PropertyChangeListener} invokes the
1053 * {@code actionPropertyChanged} method when a property in the
1054 * {@code Action} changes.
1055 *
1056 * @param a the <code>Action</code> for the <code>JComboBox</code>,
1057 * or <code>null</code>.
1058 * @since 1.3
1059 * @see Action
1060 * @see #getAction
1061 * @see #configurePropertiesFromAction
1062 * @see #createActionPropertyChangeListener
1063 * @see #actionPropertyChanged
1064 * @beaninfo
1065 * bound: true
1066 * attribute: visualUpdate true
1067 * description: the Action instance connected with this ActionEvent source
1068 */
1069 public void setAction(Action a) {
1070 Action oldValue = getAction();
1071 if (action==null || !action.equals(a)) {
1072 action = a;
1073 if (oldValue!=null) {
1074 removeActionListener(oldValue);
1075 oldValue.removePropertyChangeListener(actionPropertyChangeListener);
1076 actionPropertyChangeListener = null;
1077 }
1078 configurePropertiesFromAction(action);
1079 if (action!=null) {
1080 // Don't add if it is already a listener
1081 if (!isListener(ActionListener.class, action)) {
1082 addActionListener(action);
1083 }
1084 // Reverse linkage:
1085 actionPropertyChangeListener = createActionPropertyChangeListener(action);
1086 action.addPropertyChangeListener(actionPropertyChangeListener);
1087 }
1088 firePropertyChange("action", oldValue, action);
1089 }
1090 }
1091
1092 private boolean isListener(Class c, ActionListener a) {
1093 boolean isListener = false;
1094 Object[] listeners = listenerList.getListenerList();
1095 for (int i = listeners.length-2; i>=0; i-=2) {
1096 if (listeners[i]==c && listeners[i+1]==a) {
1097 isListener=true;
1098 }
1099 }
1100 return isListener;
1101 }
1102
1103 /**
1104 * Returns the currently set <code>Action</code> for this
1105 * <code>ActionEvent</code> source, or <code>null</code> if no
1106 * <code>Action</code> is set.
1107 *
1108 * @return the <code>Action</code> for this <code>ActionEvent</code>
1109 * source; or <code>null</code>
1110 * @since 1.3
1111 * @see Action
1112 * @see #setAction
1113 */
1114 public Action getAction() {
1115 return action;
1116 }
1117
1118 /**
1119 * Sets the properties on this combobox to match those in the specified
1120 * <code>Action</code>. Refer to <a href="Action.html#buttonActions">
1121 * Swing Components Supporting <code>Action</code></a> for more
1122 * details as to which properties this sets.
1123 *
1124 * @param a the <code>Action</code> from which to get the properties,
1125 * or <code>null</code>
1126 * @since 1.3
1127 * @see Action
1128 * @see #setAction
1129 */
1130 protected void configurePropertiesFromAction(Action a) {
1131 AbstractAction.setEnabledFromAction(this, a);
1132 AbstractAction.setToolTipTextFromAction(this, a);
1133 setActionCommandFromAction(a);
1134 }
1135
1136 /**
1137 * Creates and returns a <code>PropertyChangeListener</code> that is
1138 * responsible for listening for changes from the specified
1139 * <code>Action</code> and updating the appropriate properties.
1140 * <p>
1141 * <b>Warning:</b> If you subclass this do not create an anonymous
1142 * inner class. If you do the lifetime of the combobox will be tied to
1143 * that of the <code>Action</code>.
1144 *
1145 * @param a the combobox's action
1146 * @since 1.3
1147 * @see Action
1148 * @see #setAction
1149 */
1150 protected PropertyChangeListener createActionPropertyChangeListener(Action a) {
1151 return new ComboBoxActionPropertyChangeListener(this, a);
1152 }
1153
1154 /**
1155 * Updates the combobox's state in response to property changes in
1156 * associated action. This method is invoked from the
1157 * {@code PropertyChangeListener} returned from
1158 * {@code createActionPropertyChangeListener}. Subclasses do not normally
1159 * need to invoke this. Subclasses that support additional {@code Action}
1160 * properties should override this and
1161 * {@code configurePropertiesFromAction}.
1162 * <p>
1163 * Refer to the table at <a href="Action.html#buttonActions">
1164 * Swing Components Supporting <code>Action</code></a> for a list of
1165 * the properties this method sets.
1166 *
1167 * @param action the <code>Action</code> associated with this combobox
1168 * @param propertyName the name of the property that changed
1169 * @since 1.6
1170 * @see Action
1171 * @see #configurePropertiesFromAction
1172 */
1173 protected void actionPropertyChanged(Action action, String propertyName) {
1174 if (propertyName == Action.ACTION_COMMAND_KEY) {
1175 setActionCommandFromAction(action);
1176 } else if (propertyName == "enabled") {
1177 AbstractAction.setEnabledFromAction(this, action);
1178 } else if (Action.SHORT_DESCRIPTION == propertyName) {
1179 AbstractAction.setToolTipTextFromAction(this, action);
1180 }
1181 }
1182
1183 private void setActionCommandFromAction(Action a) {
1184 setActionCommand((a != null) ?
1185 (String)a.getValue(Action.ACTION_COMMAND_KEY) :
1186 null);
1187 }
1188
1189
1190 private static class ComboBoxActionPropertyChangeListener
1191 extends ActionPropertyChangeListener<JComboBox<?>> {
1192 ComboBoxActionPropertyChangeListener(JComboBox<?> b, Action a) {
1193 super(b, a);
1194 }
1195 protected void actionPropertyChanged(JComboBox<?> cb,
1196 Action action,
1197 PropertyChangeEvent e) {
1198 if (AbstractAction.shouldReconfigure(e)) {
1199 cb.configurePropertiesFromAction(action);
1200 } else {
1201 cb.actionPropertyChanged(action, e.getPropertyName());
1202 }
1203 }
1204 }
1205
1206 /**
1207 * Notifies all listeners that have registered interest for
1208 * notification on this event type.
1209 * @param e the event of interest
1210 *
1211 * @see EventListenerList
1212 */
1213 protected void fireItemStateChanged(ItemEvent e) {
1214 // Guaranteed to return a non-null array
1215 Object[] listeners = listenerList.getListenerList();
1216 // Process the listeners last to first, notifying
1217 // those that are interested in this event
1218 for ( int i = listeners.length-2; i>=0; i-=2 ) {
1219 if ( listeners[i]==ItemListener.class ) {
1220 // Lazily create the event:
1221 // if (changeEvent == null)
1222 // changeEvent = new ChangeEvent(this);
1223 ((ItemListener)listeners[i+1]).itemStateChanged(e);
1224 }
1225 }
1226 }
1227
1228 /**
1229 * Notifies all listeners that have registered interest for
1230 * notification on this event type.
1231 *
1232 * @see EventListenerList
1233 */
1234 protected void fireActionEvent() {
1235 if (!firingActionEvent) {
1236 // Set flag to ensure that an infinite loop is not created
1237 firingActionEvent = true;
1238 ActionEvent e = null;
1239 // Guaranteed to return a non-null array
1240 Object[] listeners = listenerList.getListenerList();
1241 long mostRecentEventTime = EventQueue.getMostRecentEventTime();
1242 int modifiers = 0;
1243 AWTEvent currentEvent = EventQueue.getCurrentEvent();
1244 if (currentEvent instanceof InputEvent) {
1245 modifiers = ((InputEvent)currentEvent).getModifiers();
1246 } else if (currentEvent instanceof ActionEvent) {
1247 modifiers = ((ActionEvent)currentEvent).getModifiers();
1248 }
1249 // Process the listeners last to first, notifying
1250 // those that are interested in this event
1251 for ( int i = listeners.length-2; i>=0; i-=2 ) {
1252 if ( listeners[i]==ActionListener.class ) {
1253 // Lazily create the event:
1254 if ( e == null )
1255 e = new ActionEvent(this,ActionEvent.ACTION_PERFORMED,
1256 getActionCommand(),
1257 mostRecentEventTime, modifiers);
1258 ((ActionListener)listeners[i+1]).actionPerformed(e);
1259 }
1260 }
1261 firingActionEvent = false;
1262 }
1263 }
1264
1265 /**
1266 * This protected method is implementation specific. Do not access directly
1267 * or override.
1268 */
1269 protected void selectedItemChanged() {
1270 if (selectedItemReminder != null ) {
1271 fireItemStateChanged(new ItemEvent(this,ItemEvent.ITEM_STATE_CHANGED,
1272 selectedItemReminder,
1273 ItemEvent.DESELECTED));
1274 }
1275
1276 // set the new selected item.
1277 selectedItemReminder = dataModel.getSelectedItem();
1278
1279 if (selectedItemReminder != null ) {
1280 fireItemStateChanged(new ItemEvent(this,ItemEvent.ITEM_STATE_CHANGED,
1281 selectedItemReminder,
1282 ItemEvent.SELECTED));
1283 }
1284 }
1285
1286 /**
1287 * Returns an array containing the selected item.
1288 * This method is implemented for compatibility with
1289 * <code>ItemSelectable</code>.
1290 *
1291 * @return an array of <code>Objects</code> containing one
1292 * element -- the selected item
1293 */
1294 public Object[] getSelectedObjects() {
1295 Object selectedObject = getSelectedItem();
1296 if ( selectedObject == null )
1297 return new Object[0];
1298 else {
1299 Object result[] = new Object[1];
1300 result[0] = selectedObject;
1301 return result;
1302 }
1303 }
1304
1305 /**
1306 * This method is public as an implementation side effect.
1307 * do not call or override.
1308 */
1309 public void actionPerformed(ActionEvent e) {
1310 ComboBoxEditor editor = getEditor();
1311 if ((editor != null) && (e != null) && (editor == e.getSource()
1312 || editor.getEditorComponent() == e.getSource())) {
1313 setPopupVisible(false);
1314 getModel().setSelectedItem(editor.getItem());
1315 String oldCommand = getActionCommand();
1316 setActionCommand("comboBoxEdited");
1317 fireActionEvent();
1318 setActionCommand(oldCommand);
1319 }
1320 }
1321
1322 /**
1323 * This method is public as an implementation side effect.
1324 * do not call or override.
1325 */
1326 public void contentsChanged(ListDataEvent e) {
1327 Object oldSelection = selectedItemReminder;
1328 Object newSelection = dataModel.getSelectedItem();
1329 if (oldSelection == null || !oldSelection.equals(newSelection)) {
1330 selectedItemChanged();
1331 if (!selectingItem) {
1332 fireActionEvent();
1333 }
1334 }
1335 }
1336
1337 /**
1338 * This method is public as an implementation side effect.
1339 * do not call or override.
1340 */
1341 public void intervalAdded(ListDataEvent e) {
1342 if (selectedItemReminder != dataModel.getSelectedItem()) {
1343 selectedItemChanged();
1344 }
1345 }
1346
1347 /**
1348 * This method is public as an implementation side effect.
1349 * do not call or override.
1350 */
1351 public void intervalRemoved(ListDataEvent e) {
1352 contentsChanged(e);
1353 }
1354
1355 /**
1356 * Selects the list item that corresponds to the specified keyboard
1357 * character and returns true, if there is an item corresponding
1358 * to that character. Otherwise, returns false.
1359 *
1360 * @param keyChar a char, typically this is a keyboard key
1361 * typed by the user
1362 */
1363 public boolean selectWithKeyChar(char keyChar) {
1364 int index;
1365
1366 if ( keySelectionManager == null )
1367 keySelectionManager = createDefaultKeySelectionManager();
1368
1369 index = keySelectionManager.selectionForKey(keyChar,getModel());
1370 if ( index != -1 ) {
1371 setSelectedIndex(index);
1372 return true;
1373 }
1374 else
1375 return false;
1376 }
1377
1378 /**
1379 * Enables the combo box so that items can be selected. When the
1380 * combo box is disabled, items cannot be selected and values
1381 * cannot be typed into its field (if it is editable).
1382 *
1383 * @param b a boolean value, where true enables the component and
1384 * false disables it
1385 * @beaninfo
1386 * bound: true
1387 * preferred: true
1388 * description: Whether the combo box is enabled.
1389 */
1390 public void setEnabled(boolean b) {
1391 super.setEnabled(b);
1392 firePropertyChange( "enabled", !isEnabled(), isEnabled() );
1393 }
1394
1395 /**
1396 * Initializes the editor with the specified item.
1397 *
1398 * @param anEditor the <code>ComboBoxEditor</code> that displays
1399 * the list item in the
1400 * combo box field and allows it to be edited
1401 * @param anItem the object to display and edit in the field
1402 */
1403 public void configureEditor(ComboBoxEditor anEditor, Object anItem) {
1404 anEditor.setItem(anItem);
1405 }
1406
1407 /**
1408 * Handles <code>KeyEvent</code>s, looking for the Tab key.
1409 * If the Tab key is found, the popup window is closed.
1410 *
1411 * @param e the <code>KeyEvent</code> containing the keyboard
1412 * key that was pressed
1413 */
1414 public void processKeyEvent(KeyEvent e) {
1415 if ( e.getKeyCode() == KeyEvent.VK_TAB ) {
1416 hidePopup();
1417 }
1418 super.processKeyEvent(e);
1419 }
1420
1421 /**
1422 * {@inheritDoc}
1423 */
1424 @Override
1425 protected boolean processKeyBinding(KeyStroke ks, KeyEvent e, int condition, boolean pressed) {
1426 if (super.processKeyBinding(ks, e, condition, pressed)) {
1427 return true;
1428 }
1429
1430 if (!isEditable() || condition != WHEN_FOCUSED || getEditor() == null
1431 || !Boolean.TRUE.equals(getClientProperty("JComboBox.isTableCellEditor"))) {
1432 return false;
1433 }
1434
1435 Component editorComponent = getEditor().getEditorComponent();
1436 if (editorComponent instanceof JComponent) {
1437 JComponent component = (JComponent) editorComponent;
1438 return component.processKeyBinding(ks, e, WHEN_FOCUSED, pressed);
1439 }
1440 return false;
1441 }
1442
1443 /**
1444 * Sets the object that translates a keyboard character into a list
1445 * selection. Typically, the first selection with a matching first
1446 * character becomes the selected item.
1447 *
1448 * @beaninfo
1449 * expert: true
1450 * description: The objects that changes the selection when a key is pressed.
1451 */
1452 public void setKeySelectionManager(KeySelectionManager aManager) {
1453 keySelectionManager = aManager;
1454 }
1455
1456 /**
1457 * Returns the list's key-selection manager.
1458 *
1459 * @return the <code>KeySelectionManager</code> currently in use
1460 */
1461 public KeySelectionManager getKeySelectionManager() {
1462 return keySelectionManager;
1463 }
1464
1465 /* Accessing the model */
1466 /**
1467 * Returns the number of items in the list.
1468 *
1469 * @return an integer equal to the number of items in the list
1470 */
1471 public int getItemCount() {
1472 return dataModel.getSize();
1473 }
1474
1475 /**
1476 * Returns the list item at the specified index. If <code>index</code>
1477 * is out of range (less than zero or greater than or equal to size)
1478 * it will return <code>null</code>.
1479 *
1480 * @param index an integer indicating the list position, where the first
1481 * item starts at zero
1482 * @return the item at that list position; or
1483 * <code>null</code> if out of range
1484 */
1485 public E getItemAt(int index) {
1486 return dataModel.getElementAt(index);
1487 }
1488
1489 /**
1490 * Returns an instance of the default key-selection manager.
1491 *
1492 * @return the <code>KeySelectionManager</code> currently used by the list
1493 * @see #setKeySelectionManager
1494 */
1495 protected KeySelectionManager createDefaultKeySelectionManager() {
1496 return new DefaultKeySelectionManager();
1497 }
1498
1499
1500 /**
1501 * The interface that defines a <code>KeySelectionManager</code>.
1502 * To qualify as a <code>KeySelectionManager</code>,
1503 * the class needs to implement the method
1504 * that identifies the list index given a character and the
1505 * combo box data model.
1506 */
1507 public interface KeySelectionManager {
1508 /** Given <code>aKey</code> and the model, returns the row
1509 * that should become selected. Return -1 if no match was
1510 * found.
1511 *
1512 * @param aKey a char value, usually indicating a keyboard key that
1513 * was pressed
1514 * @param aModel a ComboBoxModel -- the component's data model, containing
1515 * the list of selectable items
1516 * @return an int equal to the selected row, where 0 is the
1517 * first item and -1 is none.
1518 */
1519 int selectionForKey(char aKey,ComboBoxModel aModel);
1520 }
1521
1522 class DefaultKeySelectionManager implements KeySelectionManager, Serializable {
1523 public int selectionForKey(char aKey,ComboBoxModel aModel) {
1524 int i,c;
1525 int currentSelection = -1;
1526 Object selectedItem = aModel.getSelectedItem();
1527 String v;
1528 String pattern;
1529
1530 if ( selectedItem != null ) {
1531 for ( i=0,c=aModel.getSize();i<c;i++ ) {
1532 if ( selectedItem == aModel.getElementAt(i) ) {
1533 currentSelection = i;
1534 break;
1535 }
1536 }
1537 }
1538
1539 pattern = ("" + aKey).toLowerCase();
1540 aKey = pattern.charAt(0);
1541
1542 for ( i = ++currentSelection, c = aModel.getSize() ; i < c ; i++ ) {
1543 Object elem = aModel.getElementAt(i);
1544 if (elem != null && elem.toString() != null) {
1545 v = elem.toString().toLowerCase();
1546 if ( v.length() > 0 && v.charAt(0) == aKey )
1547 return i;
1548 }
1549 }
1550
1551 for ( i = 0 ; i < currentSelection ; i ++ ) {
1552 Object elem = aModel.getElementAt(i);
1553 if (elem != null && elem.toString() != null) {
1554 v = elem.toString().toLowerCase();
1555 if ( v.length() > 0 && v.charAt(0) == aKey )
1556 return i;
1557 }
1558 }
1559 return -1;
1560 }
1561 }
1562
1563
1564 /**
1565 * See <code>readObject</code> and <code>writeObject</code> in
1566 * <code>JComponent</code> for more
1567 * information about serialization in Swing.
1568 */
1569 private void writeObject(ObjectOutputStream s) throws IOException {
1570 s.defaultWriteObject();
1571 if (getUIClassID().equals(uiClassID)) {
1572 byte count = JComponent.getWriteObjCounter(this);
1573 JComponent.setWriteObjCounter(this, --count);
1574 if (count == 0 && ui != null) {
1575 ui.installUI(this);
1576 }
1577 }
1578 }
1579
1580
1581 /**
1582 * Returns a string representation of this <code>JComboBox</code>.
1583 * This method is intended to be used only for debugging purposes,
1584 * and the content and format of the returned string may vary between
1585 * implementations. The returned string may be empty but may not
1586 * be <code>null</code>.
1587 *
1588 * @return a string representation of this <code>JComboBox</code>
1589 */
1590 protected String paramString() {
1591 String selectedItemReminderString = (selectedItemReminder != null ?
1592 selectedItemReminder.toString() :
1593 "");
1594 String isEditableString = (isEditable ? "true" : "false");
1595 String lightWeightPopupEnabledString = (lightWeightPopupEnabled ?
1596 "true" : "false");
1597
1598 return super.paramString() +
1599 ",isEditable=" + isEditableString +
1600 ",lightWeightPopupEnabled=" + lightWeightPopupEnabledString +
1601 ",maximumRowCount=" + maximumRowCount +
1602 ",selectedItemReminder=" + selectedItemReminderString;
1603 }
1604
1605
1606 ///////////////////
1607 // Accessibility support
1608 ///////////////////
1609
1610 /**
1611 * Gets the AccessibleContext associated with this JComboBox.
1612 * For combo boxes, the AccessibleContext takes the form of an
1613 * AccessibleJComboBox.
1614 * A new AccessibleJComboBox instance is created if necessary.
1615 *
1616 * @return an AccessibleJComboBox that serves as the
1617 * AccessibleContext of this JComboBox
1618 */
1619 public AccessibleContext getAccessibleContext() {
1620 if ( accessibleContext == null ) {
1621 accessibleContext = new AccessibleJComboBox();
1622 }
1623 return accessibleContext;
1624 }
1625
1626 /**
1627 * This class implements accessibility support for the
1628 * <code>JComboBox</code> class. It provides an implementation of the
1629 * Java Accessibility API appropriate to Combo Box user-interface elements.
1630 * <p>
1631 * <strong>Warning:</strong>
1632 * Serialized objects of this class will not be compatible with
1633 * future Swing releases. The current serialization support is
1634 * appropriate for short term storage or RMI between applications running
1635 * the same version of Swing. As of 1.4, support for long term storage
1636 * of all JavaBeans™
1637 * has been added to the <code>java.beans</code> package.
1638 * Please see {@link java.beans.XMLEncoder}.
1639 */
1640 protected class AccessibleJComboBox extends AccessibleJComponent
1641 implements AccessibleAction, AccessibleSelection {
1642
1643
1644 private JList popupList; // combo box popup list
1645 private Accessible previousSelectedAccessible = null;
1646
1647 /**
1648 * Returns an AccessibleJComboBox instance
1649 * @since 1.4
1650 */
1651 public AccessibleJComboBox() {
1652 // set the combo box editor's accessible name and description
1653 JComboBox.this.addPropertyChangeListener(new AccessibleJComboBoxPropertyChangeListener());
1654 setEditorNameAndDescription();
1655
1656 // Get the popup list
1657 Accessible a = getUI().getAccessibleChild(JComboBox.this, 0);
1658 if (a instanceof javax.swing.plaf.basic.ComboPopup) {
1659 // Listen for changes to the popup menu selection.
1660 popupList = ((javax.swing.plaf.basic.ComboPopup)a).getList();
1661 popupList.addListSelectionListener(
1662 new AccessibleJComboBoxListSelectionListener());
1663 }
1664 // Listen for popup menu show/hide events
1665 JComboBox.this.addPopupMenuListener(
1666 new AccessibleJComboBoxPopupMenuListener());
1667 }
1668
1669 /*
1670 * JComboBox PropertyChangeListener
1671 */
1672 private class AccessibleJComboBoxPropertyChangeListener
1673 implements PropertyChangeListener {
1674
1675 public void propertyChange(PropertyChangeEvent e) {
1676 if (e.getPropertyName() == "editor") {
1677 // set the combo box editor's accessible name
1678 // and description
1679 setEditorNameAndDescription();
1680 }
1681 }
1682 }
1683
1684 /*
1685 * Sets the combo box editor's accessible name and descripton
1686 */
1687 private void setEditorNameAndDescription() {
1688 ComboBoxEditor editor = JComboBox.this.getEditor();
1689 if (editor != null) {
1690 Component comp = editor.getEditorComponent();
1691 if (comp instanceof Accessible) {
1692 AccessibleContext ac = comp.getAccessibleContext();
1693 if (ac != null) { // may be null
1694 ac.setAccessibleName(getAccessibleName());
1695 ac.setAccessibleDescription(getAccessibleDescription());
1696 }
1697 }
1698 }
1699 }
1700
1701 /*
1702 * Listener for combo box popup menu
1703 * TIGER - 4669379 4894434
1704 */
1705 private class AccessibleJComboBoxPopupMenuListener
1706 implements PopupMenuListener {
1707
1708 /**
1709 * This method is called before the popup menu becomes visible
1710 */
1711 public void popupMenuWillBecomeVisible(PopupMenuEvent e) {
1712 // save the initial selection
1713 if (popupList == null) {
1714 return;
1715 }
1716 int selectedIndex = popupList.getSelectedIndex();
1717 if (selectedIndex < 0) {
1718 return;
1719 }
1720 previousSelectedAccessible =
1721 popupList.getAccessibleContext().getAccessibleChild(selectedIndex);
1722 }
1723
1724 /**
1725 * This method is called before the popup menu becomes invisible
1726 * Note that a JPopupMenu can become invisible any time
1727 */
1728 public void popupMenuWillBecomeInvisible(PopupMenuEvent e) {
1729 // ignore
1730 }
1731
1732 /**
1733 * This method is called when the popup menu is canceled
1734 */
1735 public void popupMenuCanceled(PopupMenuEvent e) {
1736 // ignore
1737 }
1738 }
1739
1740 /*
1741 * Handles changes to the popup list selection.
1742 * TIGER - 4669379 4894434 4933143
1743 */
1744 private class AccessibleJComboBoxListSelectionListener
1745 implements ListSelectionListener {
1746
1747 public void valueChanged(ListSelectionEvent e) {
1748 if (popupList == null) {
1749 return;
1750 }
1751
1752 // Get the selected popup list item.
1753 int selectedIndex = popupList.getSelectedIndex();
1754 if (selectedIndex < 0) {
1755 return;
1756 }
1757 Accessible selectedAccessible =
1758 popupList.getAccessibleContext().getAccessibleChild(selectedIndex);
1759 if (selectedAccessible == null) {
1760 return;
1761 }
1762
1763 // Fire a FOCUSED lost PropertyChangeEvent for the
1764 // previously selected list item.
1765 PropertyChangeEvent pce;
1766
1767 if (previousSelectedAccessible != null) {
1768 pce = new PropertyChangeEvent(previousSelectedAccessible,
1769 AccessibleContext.ACCESSIBLE_STATE_PROPERTY,
1770 AccessibleState.FOCUSED, null);
1771 firePropertyChange(AccessibleContext.ACCESSIBLE_STATE_PROPERTY,
1772 null, pce);
1773 }
1774 // Fire a FOCUSED gained PropertyChangeEvent for the
1775 // currently selected list item.
1776 pce = new PropertyChangeEvent(selectedAccessible,
1777 AccessibleContext.ACCESSIBLE_STATE_PROPERTY,
1778 null, AccessibleState.FOCUSED);
1779 firePropertyChange(AccessibleContext.ACCESSIBLE_STATE_PROPERTY,
1780 null, pce);
1781
1782 // Fire the ACCESSIBLE_ACTIVE_DESCENDANT_PROPERTY event
1783 // for the combo box.
1784 firePropertyChange(AccessibleContext.ACCESSIBLE_ACTIVE_DESCENDANT_PROPERTY,
1785 previousSelectedAccessible, selectedAccessible);
1786
1787 // Save the previous selection.
1788 previousSelectedAccessible = selectedAccessible;
1789 }
1790 }
1791
1792
1793 /**
1794 * Returns the number of accessible children in the object. If all
1795 * of the children of this object implement Accessible, than this
1796 * method should return the number of children of this object.
1797 *
1798 * @return the number of accessible children in the object.
1799 */
1800 public int getAccessibleChildrenCount() {
1801 // Always delegate to the UI if it exists
1802 if (ui != null) {
1803 return ui.getAccessibleChildrenCount(JComboBox.this);
1804 } else {
1805 return super.getAccessibleChildrenCount();
1806 }
1807 }
1808
1809 /**
1810 * Returns the nth Accessible child of the object.
1811 * The child at index zero represents the popup.
1812 * If the combo box is editable, the child at index one
1813 * represents the editor.
1814 *
1815 * @param i zero-based index of child
1816 * @return the nth Accessible child of the object
1817 */
1818 public Accessible getAccessibleChild(int i) {
1819 // Always delegate to the UI if it exists
1820 if (ui != null) {
1821 return ui.getAccessibleChild(JComboBox.this, i);
1822 } else {
1823 return super.getAccessibleChild(i);
1824 }
1825 }
1826
1827 /**
1828 * Get the role of this object.
1829 *
1830 * @return an instance of AccessibleRole describing the role of the
1831 * object
1832 * @see AccessibleRole
1833 */
1834 public AccessibleRole getAccessibleRole() {
1835 return AccessibleRole.COMBO_BOX;
1836 }
1837
1838 /**
1839 * Gets the state set of this object. The AccessibleStateSet of
1840 * an object is composed of a set of unique AccessibleStates.
1841 * A change in the AccessibleStateSet of an object will cause a
1842 * PropertyChangeEvent to be fired for the ACCESSIBLE_STATE_PROPERTY
1843 * property.
1844 *
1845 * @return an instance of AccessibleStateSet containing the
1846 * current state set of the object
1847 * @see AccessibleStateSet
1848 * @see AccessibleState
1849 * @see #addPropertyChangeListener
1850 *
1851 */
1852 public AccessibleStateSet getAccessibleStateSet() {
1853 // TIGER - 4489748
1854 AccessibleStateSet ass = super.getAccessibleStateSet();
1855 if (ass == null) {
1856 ass = new AccessibleStateSet();
1857 }
1858 if (JComboBox.this.isPopupVisible()) {
1859 ass.add(AccessibleState.EXPANDED);
1860 } else {
1861 ass.add(AccessibleState.COLLAPSED);
1862 }
1863 return ass;
1864 }
1865
1866 /**
1867 * Get the AccessibleAction associated with this object. In the
1868 * implementation of the Java Accessibility API for this class,
1869 * return this object, which is responsible for implementing the
1870 * AccessibleAction interface on behalf of itself.
1871 *
1872 * @return this object
1873 */
1874 public AccessibleAction getAccessibleAction() {
1875 return this;
1876 }
1877
1878 /**
1879 * Return a description of the specified action of the object.
1880 *
1881 * @param i zero-based index of the actions
1882 */
1883 public String getAccessibleActionDescription(int i) {
1884 if (i == 0) {
1885 return UIManager.getString("ComboBox.togglePopupText");
1886 }
1887 else {
1888 return null;
1889 }
1890 }
1891
1892 /**
1893 * Returns the number of Actions available in this object. The
1894 * default behavior of a combo box is to have one action.
1895 *
1896 * @return 1, the number of Actions in this object
1897 */
1898 public int getAccessibleActionCount() {
1899 return 1;
1900 }
1901
1902 /**
1903 * Perform the specified Action on the object
1904 *
1905 * @param i zero-based index of actions
1906 * @return true if the the action was performed; else false.
1907 */
1908 public boolean doAccessibleAction(int i) {
1909 if (i == 0) {
1910 setPopupVisible(!isPopupVisible());
1911 return true;
1912 }
1913 else {
1914 return false;
1915 }
1916 }
1917
1918
1919 /**
1920 * Get the AccessibleSelection associated with this object. In the
1921 * implementation of the Java Accessibility API for this class,
1922 * return this object, which is responsible for implementing the
1923 * AccessibleSelection interface on behalf of itself.
1924 *
1925 * @return this object
1926 */
1927 public AccessibleSelection getAccessibleSelection() {
1928 return this;
1929 }
1930
1931 /**
1932 * Returns the number of Accessible children currently selected.
1933 * If no children are selected, the return value will be 0.
1934 *
1935 * @return the number of items currently selected.
1936 * @since 1.3
1937 */
1938 public int getAccessibleSelectionCount() {
1939 Object o = JComboBox.this.getSelectedItem();
1940 if (o != null) {
1941 return 1;
1942 } else {
1943 return 0;
1944 }
1945 }
1946
1947 /**
1948 * Returns an Accessible representing the specified selected child
1949 * in the popup. If there isn't a selection, or there are
1950 * fewer children selected than the integer passed in, the return
1951 * value will be null.
1952 * <p>Note that the index represents the i-th selected child, which
1953 * is different from the i-th child.
1954 *
1955 * @param i the zero-based index of selected children
1956 * @return the i-th selected child
1957 * @see #getAccessibleSelectionCount
1958 * @since 1.3
1959 */
1960 public Accessible getAccessibleSelection(int i) {
1961 // Get the popup
1962 Accessible a =
1963 JComboBox.this.getUI().getAccessibleChild(JComboBox.this, 0);
1964 if (a != null &&
1965 a instanceof javax.swing.plaf.basic.ComboPopup) {
1966
1967 // get the popup list
1968 JList list = ((javax.swing.plaf.basic.ComboPopup)a).getList();
1969
1970 // return the i-th selection in the popup list
1971 AccessibleContext ac = list.getAccessibleContext();
1972 if (ac != null) {
1973 AccessibleSelection as = ac.getAccessibleSelection();
1974 if (as != null) {
1975 return as.getAccessibleSelection(i);
1976 }
1977 }
1978 }
1979 return null;
1980 }
1981
1982 /**
1983 * Determines if the current child of this object is selected.
1984 *
1985 * @return true if the current child of this object is selected;
1986 * else false
1987 * @param i the zero-based index of the child in this Accessible
1988 * object.
1989 * @see AccessibleContext#getAccessibleChild
1990 * @since 1.3
1991 */
1992 public boolean isAccessibleChildSelected(int i) {
1993 return JComboBox.this.getSelectedIndex() == i;
1994 }
1995
1996 /**
1997 * Adds the specified Accessible child of the object to the object's
1998 * selection. If the object supports multiple selections,
1999 * the specified child is added to any existing selection, otherwise
2000 * it replaces any existing selection in the object. If the
2001 * specified child is already selected, this method has no effect.
2002 *
2003 * @param i the zero-based index of the child
2004 * @see AccessibleContext#getAccessibleChild
2005 * @since 1.3
2006 */
2007 public void addAccessibleSelection(int i) {
2008 // TIGER - 4856195
2009 clearAccessibleSelection();
2010 JComboBox.this.setSelectedIndex(i);
2011 }
2012
2013 /**
2014 * Removes the specified child of the object from the object's
2015 * selection. If the specified item isn't currently selected, this
2016 * method has no effect.
2017 *
2018 * @param i the zero-based index of the child
2019 * @see AccessibleContext#getAccessibleChild
2020 * @since 1.3
2021 */
2022 public void removeAccessibleSelection(int i) {
2023 if (JComboBox.this.getSelectedIndex() == i) {
2024 clearAccessibleSelection();
2025 }
2026 }
2027
2028 /**
2029 * Clears the selection in the object, so that no children in the
2030 * object are selected.
2031 * @since 1.3
2032 */
2033 public void clearAccessibleSelection() {
2034 JComboBox.this.setSelectedIndex(-1);
2035 }
2036
2037 /**
2038 * Causes every child of the object to be selected
2039 * if the object supports multiple selections.
2040 * @since 1.3
2041 */
2042 public void selectAllAccessibleSelection() {
2043 // do nothing since multiple selection is not supported
2044 }
2045
2046 // public Accessible getAccessibleAt(Point p) {
2047 // Accessible a = getAccessibleChild(1);
2048 // if ( a != null ) {
2049 // return a; // the editor
2050 // }
2051 // else {
2052 // return getAccessibleChild(0); // the list
2053 // }
2054 // }
2055 private EditorAccessibleContext editorAccessibleContext = null;
2056
2057 private class AccessibleEditor implements Accessible {
2058 public AccessibleContext getAccessibleContext() {
2059 if (editorAccessibleContext == null) {
2060 Component c = JComboBox.this.getEditor().getEditorComponent();
2061 if (c instanceof Accessible) {
2062 editorAccessibleContext =
2063 new EditorAccessibleContext((Accessible)c);
2064 }
2065 }
2066 return editorAccessibleContext;
2067 }
2068 }
2069
2070 /*
2071 * Wrapper class for the AccessibleContext implemented by the
2072 * combo box editor. Delegates all method calls except
2073 * getAccessibleIndexInParent to the editor. The
2074 * getAccessibleIndexInParent method returns the selected
2075 * index in the combo box.
2076 */
2077 private class EditorAccessibleContext extends AccessibleContext {
2078
2079 private AccessibleContext ac;
2080
2081 private EditorAccessibleContext() {
2082 }
2083
2084 /*
2085 * @param a the AccessibleContext implemented by the
2086 * combo box editor
2087 */
2088 EditorAccessibleContext(Accessible a) {
2089 this.ac = a.getAccessibleContext();
2090 }
2091
2092 /**
2093 * Gets the accessibleName property of this object. The accessibleName
2094 * property of an object is a localized String that designates the purpose
2095 * of the object. For example, the accessibleName property of a label
2096 * or button might be the text of the label or button itself. In the
2097 * case of an object that doesn't display its name, the accessibleName
2098 * should still be set. For example, in the case of a text field used
2099 * to enter the name of a city, the accessibleName for the en_US locale
2100 * could be 'city.'
2101 *
2102 * @return the localized name of the object; null if this
2103 * object does not have a name
2104 *
2105 * @see #setAccessibleName
2106 */
2107 public String getAccessibleName() {
2108 return ac.getAccessibleName();
2109 }
2110
2111 /**
2112 * Sets the localized accessible name of this object. Changing the
2113 * name will cause a PropertyChangeEvent to be fired for the
2114 * ACCESSIBLE_NAME_PROPERTY property.
2115 *
2116 * @param s the new localized name of the object.
2117 *
2118 * @see #getAccessibleName
2119 * @see #addPropertyChangeListener
2120 *
2121 * @beaninfo
2122 * preferred: true
2123 * description: Sets the accessible name for the component.
2124 */
2125 public void setAccessibleName(String s) {
2126 ac.setAccessibleName(s);
2127 }
2128
2129 /**
2130 * Gets the accessibleDescription property of this object. The
2131 * accessibleDescription property of this object is a short localized
2132 * phrase describing the purpose of the object. For example, in the
2133 * case of a 'Cancel' button, the accessibleDescription could be
2134 * 'Ignore changes and close dialog box.'
2135 *
2136 * @return the localized description of the object; null if
2137 * this object does not have a description
2138 *
2139 * @see #setAccessibleDescription
2140 */
2141 public String getAccessibleDescription() {
2142 return ac.getAccessibleDescription();
2143 }
2144
2145 /**
2146 * Sets the accessible description of this object. Changing the
2147 * name will cause a PropertyChangeEvent to be fired for the
2148 * ACCESSIBLE_DESCRIPTION_PROPERTY property.
2149 *
2150 * @param s the new localized description of the object
2151 *
2152 * @see #setAccessibleName
2153 * @see #addPropertyChangeListener
2154 *
2155 * @beaninfo
2156 * preferred: true
2157 * description: Sets the accessible description for the component.
2158 */
2159 public void setAccessibleDescription(String s) {
2160 ac.setAccessibleDescription(s);
2161 }
2162
2163 /**
2164 * Gets the role of this object. The role of the object is the generic
2165 * purpose or use of the class of this object. For example, the role
2166 * of a push button is AccessibleRole.PUSH_BUTTON. The roles in
2167 * AccessibleRole are provided so component developers can pick from
2168 * a set of predefined roles. This enables assistive technologies to
2169 * provide a consistent interface to various tweaked subclasses of
2170 * components (e.g., use AccessibleRole.PUSH_BUTTON for all components
2171 * that act like a push button) as well as distinguish between subclasses
2172 * that behave differently (e.g., AccessibleRole.CHECK_BOX for check boxes
2173 * and AccessibleRole.RADIO_BUTTON for radio buttons).
2174 * <p>Note that the AccessibleRole class is also extensible, so
2175 * custom component developers can define their own AccessibleRole's
2176 * if the set of predefined roles is inadequate.
2177 *
2178 * @return an instance of AccessibleRole describing the role of the object
2179 * @see AccessibleRole
2180 */
2181 public AccessibleRole getAccessibleRole() {
2182 return ac.getAccessibleRole();
2183 }
2184
2185 /**
2186 * Gets the state set of this object. The AccessibleStateSet of an object
2187 * is composed of a set of unique AccessibleStates. A change in the
2188 * AccessibleStateSet of an object will cause a PropertyChangeEvent to
2189 * be fired for the ACCESSIBLE_STATE_PROPERTY property.
2190 *
2191 * @return an instance of AccessibleStateSet containing the
2192 * current state set of the object
2193 * @see AccessibleStateSet
2194 * @see AccessibleState
2195 * @see #addPropertyChangeListener
2196 */
2197 public AccessibleStateSet getAccessibleStateSet() {
2198 return ac.getAccessibleStateSet();
2199 }
2200
2201 /**
2202 * Gets the Accessible parent of this object.
2203 *
2204 * @return the Accessible parent of this object; null if this
2205 * object does not have an Accessible parent
2206 */
2207 public Accessible getAccessibleParent() {
2208 return ac.getAccessibleParent();
2209 }
2210
2211 /**
2212 * Sets the Accessible parent of this object. This is meant to be used
2213 * only in the situations where the actual component's parent should
2214 * not be treated as the component's accessible parent and is a method
2215 * that should only be called by the parent of the accessible child.
2216 *
2217 * @param a - Accessible to be set as the parent
2218 */
2219 public void setAccessibleParent(Accessible a) {
2220 ac.setAccessibleParent(a);
2221 }
2222
2223 /**
2224 * Gets the 0-based index of this object in its accessible parent.
2225 *
2226 * @return the 0-based index of this object in its parent; -1 if this
2227 * object does not have an accessible parent.
2228 *
2229 * @see #getAccessibleParent
2230 * @see #getAccessibleChildrenCount
2231 * @see #getAccessibleChild
2232 */
2233 public int getAccessibleIndexInParent() {
2234 return JComboBox.this.getSelectedIndex();
2235 }
2236
2237 /**
2238 * Returns the number of accessible children of the object.
2239 *
2240 * @return the number of accessible children of the object.
2241 */
2242 public int getAccessibleChildrenCount() {
2243 return ac.getAccessibleChildrenCount();
2244 }
2245
2246 /**
2247 * Returns the specified Accessible child of the object. The Accessible
2248 * children of an Accessible object are zero-based, so the first child
2249 * of an Accessible child is at index 0, the second child is at index 1,
2250 * and so on.
2251 *
2252 * @param i zero-based index of child
2253 * @return the Accessible child of the object
2254 * @see #getAccessibleChildrenCount
2255 */
2256 public Accessible getAccessibleChild(int i) {
2257 return ac.getAccessibleChild(i);
2258 }
2259
2260 /**
2261 * Gets the locale of the component. If the component does not have a
2262 * locale, then the locale of its parent is returned.
2263 *
2264 * @return this component's locale. If this component does not have
2265 * a locale, the locale of its parent is returned.
2266 *
2267 * @exception IllegalComponentStateException
2268 * If the Component does not have its own locale and has not yet been
2269 * added to a containment hierarchy such that the locale can be
2270 * determined from the containing parent.
2271 */
2272 public Locale getLocale() throws IllegalComponentStateException {
2273 return ac.getLocale();
2274 }
2275
2276 /**
2277 * Adds a PropertyChangeListener to the listener list.
2278 * The listener is registered for all Accessible properties and will
2279 * be called when those properties change.
2280 *
2281 * @see #ACCESSIBLE_NAME_PROPERTY
2282 * @see #ACCESSIBLE_DESCRIPTION_PROPERTY
2283 * @see #ACCESSIBLE_STATE_PROPERTY
2284 * @see #ACCESSIBLE_VALUE_PROPERTY
2285 * @see #ACCESSIBLE_SELECTION_PROPERTY
2286 * @see #ACCESSIBLE_TEXT_PROPERTY
2287 * @see #ACCESSIBLE_VISIBLE_DATA_PROPERTY
2288 *
2289 * @param listener The PropertyChangeListener to be added
2290 */
2291 public void addPropertyChangeListener(PropertyChangeListener listener) {
2292 ac.addPropertyChangeListener(listener);
2293 }
2294
2295 /**
2296 * Removes a PropertyChangeListener from the listener list.
2297 * This removes a PropertyChangeListener that was registered
2298 * for all properties.
2299 *
2300 * @param listener The PropertyChangeListener to be removed
2301 */
2302 public void removePropertyChangeListener(PropertyChangeListener listener) {
2303 ac.removePropertyChangeListener(listener);
2304 }
2305
2306 /**
2307 * Gets the AccessibleAction associated with this object that supports
2308 * one or more actions.
2309 *
2310 * @return AccessibleAction if supported by object; else return null
2311 * @see AccessibleAction
2312 */
2313 public AccessibleAction getAccessibleAction() {
2314 return ac.getAccessibleAction();
2315 }
2316
2317 /**
2318 * Gets the AccessibleComponent associated with this object that has a
2319 * graphical representation.
2320 *
2321 * @return AccessibleComponent if supported by object; else return null
2322 * @see AccessibleComponent
2323 */
2324 public AccessibleComponent getAccessibleComponent() {
2325 return ac.getAccessibleComponent();
2326 }
2327
2328 /**
2329 * Gets the AccessibleSelection associated with this object which allows its
2330 * Accessible children to be selected.
2331 *
2332 * @return AccessibleSelection if supported by object; else return null
2333 * @see AccessibleSelection
2334 */
2335 public AccessibleSelection getAccessibleSelection() {
2336 return ac.getAccessibleSelection();
2337 }
2338
2339 /**
2340 * Gets the AccessibleText associated with this object presenting
2341 * text on the display.
2342 *
2343 * @return AccessibleText if supported by object; else return null
2344 * @see AccessibleText
2345 */
2346 public AccessibleText getAccessibleText() {
2347 return ac.getAccessibleText();
2348 }
2349
2350 /**
2351 * Gets the AccessibleEditableText associated with this object
2352 * presenting editable text on the display.
2353 *
2354 * @return AccessibleEditableText if supported by object; else return null
2355 * @see AccessibleEditableText
2356 */
2357 public AccessibleEditableText getAccessibleEditableText() {
2358 return ac.getAccessibleEditableText();
2359 }
2360
2361 /**
2362 * Gets the AccessibleValue associated with this object that supports a
2363 * Numerical value.
2364 *
2365 * @return AccessibleValue if supported by object; else return null
2366 * @see AccessibleValue
2367 */
2368 public AccessibleValue getAccessibleValue() {
2369 return ac.getAccessibleValue();
2370 }
2371
2372 /**
2373 * Gets the AccessibleIcons associated with an object that has
2374 * one or more associated icons
2375 *
2376 * @return an array of AccessibleIcon if supported by object;
2377 * otherwise return null
2378 * @see AccessibleIcon
2379 */
2380 public AccessibleIcon [] getAccessibleIcon() {
2381 return ac.getAccessibleIcon();
2382 }
2383
2384 /**
2385 * Gets the AccessibleRelationSet associated with an object
2386 *
2387 * @return an AccessibleRelationSet if supported by object;
2388 * otherwise return null
2389 * @see AccessibleRelationSet
2390 */
2391 public AccessibleRelationSet getAccessibleRelationSet() {
2392 return ac.getAccessibleRelationSet();
2393 }
2394
2395 /**
2396 * Gets the AccessibleTable associated with an object
2397 *
2398 * @return an AccessibleTable if supported by object;
2399 * otherwise return null
2400 * @see AccessibleTable
2401 */
2402 public AccessibleTable getAccessibleTable() {
2403 return ac.getAccessibleTable();
2404 }
2405
2406 /**
2407 * Support for reporting bound property changes. If oldValue and
2408 * newValue are not equal and the PropertyChangeEvent listener list
2409 * is not empty, then fire a PropertyChange event to each listener.
2410 * In general, this is for use by the Accessible objects themselves
2411 * and should not be called by an application program.
2412 * @param propertyName The programmatic name of the property that
2413 * was changed.
2414 * @param oldValue The old value of the property.
2415 * @param newValue The new value of the property.
2416 * @see java.beans.PropertyChangeSupport
2417 * @see #addPropertyChangeListener
2418 * @see #removePropertyChangeListener
2419 * @see #ACCESSIBLE_NAME_PROPERTY
2420 * @see #ACCESSIBLE_DESCRIPTION_PROPERTY
2421 * @see #ACCESSIBLE_STATE_PROPERTY
2422 * @see #ACCESSIBLE_VALUE_PROPERTY
2423 * @see #ACCESSIBLE_SELECTION_PROPERTY
2424 * @see #ACCESSIBLE_TEXT_PROPERTY
2425 * @see #ACCESSIBLE_VISIBLE_DATA_PROPERTY
2426 */
2427 public void firePropertyChange(String propertyName,
2428 Object oldValue,
2429 Object newValue) {
2430 ac.firePropertyChange(propertyName, oldValue, newValue);
2431 }
2432 }
2433
2434 } // innerclass AccessibleJComboBox
2435 }