1 /*
2 * Copyright (c) 1997, 2015, 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.io.Serializable;
28 import java.awt.Component;
29 import java.awt.Adjustable;
30 import java.awt.Dimension;
31 import java.awt.event.AdjustmentListener;
32 import java.awt.event.AdjustmentEvent;
33 import java.beans.JavaBean;
34 import java.beans.BeanProperty;
35
36 import javax.swing.event.*;
37 import javax.swing.plaf.*;
38 import javax.accessibility.*;
39
40 import java.io.ObjectOutputStream;
41 import java.io.IOException;
42
43 /**
44 * An implementation of a scrollbar. The user positions the knob in the
45 * scrollbar to determine the contents of the viewing area. The
46 * program typically adjusts the display so that the end of the
47 * scrollbar represents the end of the displayable contents, or 100%
48 * of the contents. The start of the scrollbar is the beginning of the
49 * displayable contents, or 0%. The position of the knob within
50 * those bounds then translates to the corresponding percentage of
51 * the displayable contents.
52 * <p>
53 * Typically, as the position of the knob in the scrollbar changes
54 * a corresponding change is made to the position of the JViewport on
55 * the underlying view, changing the contents of the JViewport.
56 * <p>
57 * <strong>Warning:</strong> Swing is not thread safe. For more
58 * information see <a
59 * href="package-summary.html#threading">Swing's Threading
60 * Policy</a>.
61 * <p>
62 * <strong>Warning:</strong>
63 * Serialized objects of this class will not be compatible with
64 * future Swing releases. The current serialization support is
65 * appropriate for short term storage or RMI between applications running
66 * the same version of Swing. As of 1.4, support for long term storage
67 * of all JavaBeans™
68 * has been added to the <code>java.beans</code> package.
69 * Please see {@link java.beans.XMLEncoder}.
70 *
71 * @see JScrollPane
72 *
73 * @author David Kloba
74 * @since 1.2
75 */
76 @JavaBean(defaultProperty = "UI", description = "A component that helps determine the visible content range of an area.")
77 @SwingContainer(false)
78 @SuppressWarnings("serial") // Same-version serialization only
79 public class JScrollBar extends JComponent implements Adjustable, Accessible
80 {
81 /**
82 * @see #getUIClassID
83 * @see #readObject
84 */
85 private static final String uiClassID = "ScrollBarUI";
86
87 /**
88 * All changes from the model are treated as though the user moved
89 * the scrollbar knob.
90 */
91 private ChangeListener fwdAdjustmentEvents = new ModelListener();
92
93
94 /**
95 * The model that represents the scrollbar's minimum, maximum, extent
96 * (aka "visibleAmount") and current value.
97 * @see #setModel
98 */
99 protected BoundedRangeModel model;
100
101
102 /**
103 * @see #setOrientation
104 */
105 protected int orientation;
106
107
108 /**
109 * @see #setUnitIncrement
110 */
111 protected int unitIncrement;
112
113
114 /**
115 * @see #setBlockIncrement
116 */
117 protected int blockIncrement;
118
119
120 private void checkOrientation(int orientation) {
121 switch (orientation) {
122 case VERTICAL:
123 case HORIZONTAL:
124 break;
125 default:
126 throw new IllegalArgumentException("orientation must be one of: VERTICAL, HORIZONTAL");
127 }
128 }
129
130
131 /**
132 * Creates a scrollbar with the specified orientation,
133 * value, extent, minimum, and maximum.
134 * The "extent" is the size of the viewable area. It is also known
135 * as the "visible amount".
136 * <p>
137 * Note: Use <code>setBlockIncrement</code> to set the block
138 * increment to a size slightly smaller than the view's extent.
139 * That way, when the user jumps the knob to an adjacent position,
140 * one or two lines of the original contents remain in view.
141 *
142 * @exception IllegalArgumentException if orientation is not one of VERTICAL, HORIZONTAL
143 *
144 * @see #setOrientation
145 * @see #setValue
146 * @see #setVisibleAmount
147 * @see #setMinimum
148 * @see #setMaximum
149 *
150 * @param orientation an orientation of the {@code JScrollBar}
151 * @param value an int giving the current value
152 * @param extent an int giving the amount by which the value can "jump"
153 * @param min an int giving the minimum value
154 * @param max an int giving the maximum value
155 */
156 public JScrollBar(int orientation, int value, int extent, int min, int max)
157 {
158 checkOrientation(orientation);
159 this.unitIncrement = 1;
160 this.blockIncrement = (extent == 0) ? 1 : extent;
161 this.orientation = orientation;
162 this.model = new DefaultBoundedRangeModel(value, extent, min, max);
163 this.model.addChangeListener(fwdAdjustmentEvents);
164 setRequestFocusEnabled(false);
165 updateUI();
166 }
167
168
169 /**
170 * Creates a scrollbar with the specified orientation
171 * and the following initial values:
172 * <pre>
173 * minimum = 0
174 * maximum = 100
175 * value = 0
176 * extent = 10
177 * </pre>
178 *
179 * @param orientation an orientation of the {@code JScrollBar}
180 */
181 public JScrollBar(int orientation) {
182 this(orientation, 0, 10, 0, 100);
183 }
184
185
186 /**
187 * Creates a vertical scrollbar with the following initial values:
188 * <pre>
189 * minimum = 0
190 * maximum = 100
191 * value = 0
192 * extent = 10
193 * </pre>
194 */
195 public JScrollBar() {
196 this(VERTICAL);
197 }
198
199
200 /**
201 * Sets the {@literal L&F} object that renders this component.
202 *
203 * @param ui the <code>ScrollBarUI</code> {@literal L&F} object
204 * @see UIDefaults#getUI
205 * @since 1.4
206 */
207 @BeanProperty(hidden = true, visualUpdate = true, description
208 = "The UI object that implements the Component's LookAndFeel")
209 public void setUI(ScrollBarUI ui) {
210 super.setUI(ui);
211 }
212
213
214 /**
215 * Returns the delegate that implements the look and feel for
216 * this component.
217 *
218 * @return the scroll bar's current UI.
219 * @see JComponent#setUI
220 */
221 public ScrollBarUI getUI() {
222 return (ScrollBarUI)ui;
223 }
224
225
226 /**
227 * Overrides <code>JComponent.updateUI</code>.
228 * @see JComponent#updateUI
229 */
230 public void updateUI() {
231 setUI((ScrollBarUI)UIManager.getUI(this));
232 }
233
234
235 /**
236 * Returns the name of the LookAndFeel class for this component.
237 *
238 * @return "ScrollBarUI"
239 * @see JComponent#getUIClassID
240 * @see UIDefaults#getUI
241 */
242 @BeanProperty(bound = false)
243 public String getUIClassID() {
244 return uiClassID;
245 }
246
247
248
249 /**
250 * Returns the component's orientation (horizontal or vertical).
251 *
252 * @return VERTICAL or HORIZONTAL
253 * @see #setOrientation
254 * @see java.awt.Adjustable#getOrientation
255 */
256 public int getOrientation() {
257 return orientation;
258 }
259
260
261 /**
262 * Set the scrollbar's orientation to either VERTICAL or
263 * HORIZONTAL.
264 *
265 * @param orientation an orientation of the {@code JScrollBar}
266 * @exception IllegalArgumentException if orientation is not one of VERTICAL, HORIZONTAL
267 * @see #getOrientation
268 */
269 @BeanProperty(preferred = true, visualUpdate = true, enumerationValues = {
270 "JScrollBar.VERTICAL",
271 "JScrollBar.HORIZONTAL"}, description
272 = "The scrollbar's orientation.")
273 public void setOrientation(int orientation)
274 {
275 checkOrientation(orientation);
276 int oldValue = this.orientation;
277 this.orientation = orientation;
278 firePropertyChange("orientation", oldValue, orientation);
279
280 if ((oldValue != orientation) && (accessibleContext != null)) {
281 accessibleContext.firePropertyChange(
282 AccessibleContext.ACCESSIBLE_STATE_PROPERTY,
283 ((oldValue == VERTICAL)
284 ? AccessibleState.VERTICAL : AccessibleState.HORIZONTAL),
285 ((orientation == VERTICAL)
286 ? AccessibleState.VERTICAL : AccessibleState.HORIZONTAL));
287 }
288 if (orientation != oldValue) {
289 revalidate();
290 }
291 }
292
293
294 /**
295 * Returns data model that handles the scrollbar's four
296 * fundamental properties: minimum, maximum, value, extent.
297 *
298 * @return the data model
299 *
300 * @see #setModel
301 */
302 public BoundedRangeModel getModel() {
303 return model;
304 }
305
306
307 /**
308 * Sets the model that handles the scrollbar's four
309 * fundamental properties: minimum, maximum, value, extent.
310 *
311 * @param newModel a new model
312 * @see #getModel
313 */
314 @BeanProperty(expert = true, description
315 = "The scrollbar's BoundedRangeModel.")
316 public void setModel(BoundedRangeModel newModel) {
317 Integer oldValue = null;
318 BoundedRangeModel oldModel = model;
319 if (model != null) {
320 model.removeChangeListener(fwdAdjustmentEvents);
321 oldValue = Integer.valueOf(model.getValue());
322 }
323 model = newModel;
324 if (model != null) {
325 model.addChangeListener(fwdAdjustmentEvents);
326 }
327
328 firePropertyChange("model", oldModel, model);
329
330 if (accessibleContext != null) {
331 accessibleContext.firePropertyChange(
332 AccessibleContext.ACCESSIBLE_VALUE_PROPERTY,
333 oldValue, model.getValue());
334 }
335 }
336
337
338 /**
339 * Returns the amount to change the scrollbar's value by,
340 * given a unit up/down request. A ScrollBarUI implementation
341 * typically calls this method when the user clicks on a scrollbar
342 * up/down arrow and uses the result to update the scrollbar's
343 * value. Subclasses my override this method to compute
344 * a value, e.g. the change required to scroll up or down one
345 * (variable height) line text or one row in a table.
346 * <p>
347 * The JScrollPane component creates scrollbars (by default)
348 * that override this method and delegate to the viewports
349 * Scrollable view, if it has one. The Scrollable interface
350 * provides a more specialized version of this method.
351 * <p>
352 * Some look and feels implement custom scrolling behavior
353 * and ignore this property.
354 *
355 * @param direction is -1 or 1 for up/down respectively
356 * @return the value of the unitIncrement property
357 * @see #setUnitIncrement
358 * @see #setValue
359 * @see Scrollable#getScrollableUnitIncrement
360 */
361 public int getUnitIncrement(int direction) {
362 return unitIncrement;
363 }
364
365
366 /**
367 * Sets the unitIncrement property.
368 * <p>
369 * Note, that if the argument is equal to the value of Integer.MIN_VALUE,
370 * the most look and feels will not provide the scrolling to the right/down.
371 * <p>
372 * Some look and feels implement custom scrolling behavior
373 * and ignore this property.
374 *
375 * @see #getUnitIncrement
376 */
377 @BeanProperty(preferred = true, description
378 = "The scrollbar's unit increment.")
379 public void setUnitIncrement(int unitIncrement) {
380 int oldValue = this.unitIncrement;
381 this.unitIncrement = unitIncrement;
382 firePropertyChange("unitIncrement", oldValue, unitIncrement);
383 }
384
385
386 /**
387 * Returns the amount to change the scrollbar's value by,
388 * given a block (usually "page") up/down request. A ScrollBarUI
389 * implementation typically calls this method when the user clicks
390 * above or below the scrollbar "knob" to change the value
391 * up or down by large amount. Subclasses my override this
392 * method to compute a value, e.g. the change required to scroll
393 * up or down one paragraph in a text document.
394 * <p>
395 * The JScrollPane component creates scrollbars (by default)
396 * that override this method and delegate to the viewports
397 * Scrollable view, if it has one. The Scrollable interface
398 * provides a more specialized version of this method.
399 * <p>
400 * Some look and feels implement custom scrolling behavior
401 * and ignore this property.
402 *
403 * @param direction is -1 or 1 for up/down respectively
404 * @return the value of the blockIncrement property
405 * @see #setBlockIncrement
406 * @see #setValue
407 * @see Scrollable#getScrollableBlockIncrement
408 */
409 public int getBlockIncrement(int direction) {
410 return blockIncrement;
411 }
412
413
414 /**
415 * Sets the blockIncrement property.
416 * <p>
417 * Note, that if the argument is equal to the value of Integer.MIN_VALUE,
418 * the most look and feels will not provide the scrolling to the right/down.
419 * <p>
420 * Some look and feels implement custom scrolling behavior
421 * and ignore this property.
422 *
423 * @see #getBlockIncrement()
424 */
425 @BeanProperty(preferred = true, description
426 = "The scrollbar's block increment.")
427 public void setBlockIncrement(int blockIncrement) {
428 int oldValue = this.blockIncrement;
429 this.blockIncrement = blockIncrement;
430 firePropertyChange("blockIncrement", oldValue, blockIncrement);
431 }
432
433
434 /**
435 * For backwards compatibility with java.awt.Scrollbar.
436 * @see Adjustable#getUnitIncrement
437 * @see #getUnitIncrement(int)
438 */
439 public int getUnitIncrement() {
440 return unitIncrement;
441 }
442
443
444 /**
445 * For backwards compatibility with java.awt.Scrollbar.
446 * @see Adjustable#getBlockIncrement
447 * @see #getBlockIncrement(int)
448 */
449 public int getBlockIncrement() {
450 return blockIncrement;
451 }
452
453
454 /**
455 * Returns the scrollbar's value.
456 * @return the model's value property
457 * @see #setValue
458 */
459 public int getValue() {
460 return getModel().getValue();
461 }
462
463
464 /**
465 * Sets the scrollbar's value. This method just forwards the value
466 * to the model.
467 *
468 * @see #getValue
469 * @see BoundedRangeModel#setValue
470 */
471 @BeanProperty(bound = false, preferred = true, description
472 = "The scrollbar's current value.")
473 public void setValue(int value) {
474 BoundedRangeModel m = getModel();
475 int oldValue = m.getValue();
476 m.setValue(value);
477
478 if (accessibleContext != null) {
479 accessibleContext.firePropertyChange(
480 AccessibleContext.ACCESSIBLE_VALUE_PROPERTY,
481 Integer.valueOf(oldValue),
482 Integer.valueOf(m.getValue()));
483 }
484 }
485
486
487 /**
488 * Returns the scrollbar's extent, aka its "visibleAmount". In many
489 * scrollbar look and feel implementations the size of the
490 * scrollbar "knob" or "thumb" is proportional to the extent.
491 *
492 * @return the value of the model's extent property
493 * @see #setVisibleAmount
494 */
495 public int getVisibleAmount() {
496 return getModel().getExtent();
497 }
498
499
500 /**
501 * Set the model's extent property.
502 *
503 * @see #getVisibleAmount
504 * @see BoundedRangeModel#setExtent
505 */
506 @BeanProperty(bound = false, preferred = true, description
507 = "The amount of the view that is currently visible.")
508 public void setVisibleAmount(int extent) {
509 getModel().setExtent(extent);
510 }
511
512
513 /**
514 * Returns the minimum value supported by the scrollbar
515 * (usually zero).
516 *
517 * @return the value of the model's minimum property
518 * @see #setMinimum
519 */
520 public int getMinimum() {
521 return getModel().getMinimum();
522 }
523
524
525 /**
526 * Sets the model's minimum property.
527 *
528 * @see #getMinimum
529 * @see BoundedRangeModel#setMinimum
530 */
531 @BeanProperty(bound = false, preferred = true, description
532 = "The scrollbar's minimum value.")
533 public void setMinimum(int minimum) {
534 getModel().setMinimum(minimum);
535 }
536
537
538 /**
539 * The maximum value of the scrollbar is maximum - extent.
540 *
541 * @return the value of the model's maximum property
542 * @see #setMaximum
543 */
544 public int getMaximum() {
545 return getModel().getMaximum();
546 }
547
548
549 /**
550 * Sets the model's maximum property. Note that the scrollbar's value
551 * can only be set to maximum - extent.
552 *
553 * @see #getMaximum
554 * @see BoundedRangeModel#setMaximum
555 */
556 @BeanProperty(bound = false, preferred = true, description
557 = "The scrollbar's maximum value.")
558 public void setMaximum(int maximum) {
559 getModel().setMaximum(maximum);
560 }
561
562
563 /**
564 * True if the scrollbar knob is being dragged.
565 *
566 * @return the value of the model's valueIsAdjusting property
567 * @see #setValueIsAdjusting
568 */
569 public boolean getValueIsAdjusting() {
570 return getModel().getValueIsAdjusting();
571 }
572
573
574 /**
575 * Sets the model's valueIsAdjusting property. Scrollbar look and
576 * feel implementations should set this property to true when
577 * a knob drag begins, and to false when the drag ends. The
578 * scrollbar model will not generate ChangeEvents while
579 * valueIsAdjusting is true.
580 *
581 * @param b {@code true} if the upcoming changes to the value property are part of a series
582 *
583 * @see #getValueIsAdjusting
584 * @see BoundedRangeModel#setValueIsAdjusting
585 */
586 @BeanProperty(bound = false, expert = true, description
587 = "True if the scrollbar thumb is being dragged.")
588 public void setValueIsAdjusting(boolean b) {
589 BoundedRangeModel m = getModel();
590 boolean oldValue = m.getValueIsAdjusting();
591 m.setValueIsAdjusting(b);
592
593 if ((oldValue != b) && (accessibleContext != null)) {
594 accessibleContext.firePropertyChange(
595 AccessibleContext.ACCESSIBLE_STATE_PROPERTY,
596 ((oldValue) ? AccessibleState.BUSY : null),
597 ((b) ? AccessibleState.BUSY : null));
598 }
599 }
600
601
602 /**
603 * Sets the four BoundedRangeModel properties after forcing
604 * the arguments to obey the usual constraints:
605 * <pre>
606 * minimum ≤ value ≤ value+extent ≤ maximum
607 * </pre>
608 *
609 * @param newValue an int giving the current value
610 * @param newExtent an int giving the amount by which the value can "jump"
611 * @param newMin an int giving the minimum value
612 * @param newMax an int giving the maximum value
613 *
614 * @see BoundedRangeModel#setRangeProperties
615 * @see #setValue
616 * @see #setVisibleAmount
617 * @see #setMinimum
618 * @see #setMaximum
619 */
620 public void setValues(int newValue, int newExtent, int newMin, int newMax)
621 {
622 BoundedRangeModel m = getModel();
623 int oldValue = m.getValue();
624 m.setRangeProperties(newValue, newExtent, newMin, newMax, m.getValueIsAdjusting());
625
626 if (accessibleContext != null) {
627 accessibleContext.firePropertyChange(
628 AccessibleContext.ACCESSIBLE_VALUE_PROPERTY,
629 Integer.valueOf(oldValue),
630 Integer.valueOf(m.getValue()));
631 }
632 }
633
634
635 /**
636 * Adds an AdjustmentListener. Adjustment listeners are notified
637 * each time the scrollbar's model changes. Adjustment events are
638 * provided for backwards compatibility with java.awt.Scrollbar.
639 * <p>
640 * Note that the AdjustmentEvents type property will always have a
641 * placeholder value of AdjustmentEvent.TRACK because all changes
642 * to a BoundedRangeModels value are considered equivalent. To change
643 * the value of a BoundedRangeModel one just sets its value property,
644 * i.e. model.setValue(123). No information about the origin of the
645 * change, e.g. it's a block decrement, is provided. We don't try
646 * fabricate the origin of the change here.
647 *
648 * @param l the AdjustmentLister to add
649 * @see #removeAdjustmentListener
650 * @see BoundedRangeModel#addChangeListener
651 */
652 public void addAdjustmentListener(AdjustmentListener l) {
653 listenerList.add(AdjustmentListener.class, l);
654 }
655
656
657 /**
658 * Removes an AdjustmentEvent listener.
659 *
660 * @param l the AdjustmentLister to remove
661 * @see #addAdjustmentListener
662 */
663 public void removeAdjustmentListener(AdjustmentListener l) {
664 listenerList.remove(AdjustmentListener.class, l);
665 }
666
667
668 /**
669 * Returns an array of all the <code>AdjustmentListener</code>s added
670 * to this JScrollBar with addAdjustmentListener().
671 *
672 * @return all of the <code>AdjustmentListener</code>s added or an empty
673 * array if no listeners have been added
674 * @since 1.4
675 */
676 @BeanProperty(bound = false)
677 public AdjustmentListener[] getAdjustmentListeners() {
678 return listenerList.getListeners(AdjustmentListener.class);
679 }
680
681
682 /**
683 * Notify listeners that the scrollbar's model has changed.
684 *
685 * @param id an integer indicating the type of event.
686 * @param type an integer indicating the adjustment type.
687 * @param value the current value of the adjustment
688 *
689 * @see #addAdjustmentListener
690 * @see EventListenerList
691 */
692 protected void fireAdjustmentValueChanged(int id, int type, int value) {
693 fireAdjustmentValueChanged(id, type, value, getValueIsAdjusting());
694 }
695
696 /**
697 * Notify listeners that the scrollbar's model has changed.
698 *
699 * @see #addAdjustmentListener
700 * @see EventListenerList
701 */
702 private void fireAdjustmentValueChanged(int id, int type, int value,
703 boolean isAdjusting) {
704 Object[] listeners = listenerList.getListenerList();
705 AdjustmentEvent e = null;
706 for (int i = listeners.length - 2; i >= 0; i -= 2) {
707 if (listeners[i]==AdjustmentListener.class) {
708 if (e == null) {
709 e = new AdjustmentEvent(this, id, type, value, isAdjusting);
710 }
711 ((AdjustmentListener)listeners[i+1]).adjustmentValueChanged(e);
712 }
713 }
714 }
715
716
717 /**
718 * This class listens to ChangeEvents on the model and forwards
719 * AdjustmentEvents for the sake of backwards compatibility.
720 * Unfortunately there's no way to determine the proper
721 * type of the AdjustmentEvent as all updates to the model's
722 * value are considered equivalent.
723 */
724 private class ModelListener implements ChangeListener, Serializable {
725 public void stateChanged(ChangeEvent e) {
726 Object obj = e.getSource();
727 if (obj instanceof BoundedRangeModel) {
728 int id = AdjustmentEvent.ADJUSTMENT_VALUE_CHANGED;
729 int type = AdjustmentEvent.TRACK;
730 BoundedRangeModel model = (BoundedRangeModel)obj;
731 int value = model.getValue();
732 boolean isAdjusting = model.getValueIsAdjusting();
733 fireAdjustmentValueChanged(id, type, value, isAdjusting);
734 }
735 }
736 }
737
738 // PENDING(hmuller) - the next three methods should be removed
739
740 /**
741 * The scrollbar is flexible along it's scrolling axis and
742 * rigid along the other axis.
743 */
744 public Dimension getMinimumSize() {
745 Dimension pref = getPreferredSize();
746 if (orientation == VERTICAL) {
747 return new Dimension(pref.width, 5);
748 } else {
749 return new Dimension(5, pref.height);
750 }
751 }
752
753 /**
754 * The scrollbar is flexible along it's scrolling axis and
755 * rigid along the other axis.
756 */
757 public Dimension getMaximumSize() {
758 Dimension pref = getPreferredSize();
759 if (getOrientation() == VERTICAL) {
760 return new Dimension(pref.width, Short.MAX_VALUE);
761 } else {
762 return new Dimension(Short.MAX_VALUE, pref.height);
763 }
764 }
765
766 /**
767 * Enables the component so that the knob position can be changed.
768 * When the disabled, the knob position cannot be changed.
769 *
770 * @param x a boolean value, where true enables the component and
771 * false disables it
772 */
773 public void setEnabled(boolean x) {
774 super.setEnabled(x);
775 Component[] children = getComponents();
776 for (Component child : children) {
777 child.setEnabled(x);
778 }
779 }
780
781 /**
782 * See readObject() and writeObject() in JComponent for more
783 * information about serialization in Swing.
784 */
785 private void writeObject(ObjectOutputStream s) throws IOException {
786 s.defaultWriteObject();
787 if (getUIClassID().equals(uiClassID)) {
788 byte count = JComponent.getWriteObjCounter(this);
789 JComponent.setWriteObjCounter(this, --count);
790 if (count == 0 && ui != null) {
791 ui.installUI(this);
792 }
793 }
794 }
795
796
797 /**
798 * Returns a string representation of this JScrollBar. This method
799 * is intended to be used only for debugging purposes, and the
800 * content and format of the returned string may vary between
801 * implementations. The returned string may be empty but may not
802 * be <code>null</code>.
803 *
804 * @return a string representation of this JScrollBar.
805 */
806 protected String paramString() {
807 String orientationString = (orientation == HORIZONTAL ?
808 "HORIZONTAL" : "VERTICAL");
809
810 return super.paramString() +
811 ",blockIncrement=" + blockIncrement +
812 ",orientation=" + orientationString +
813 ",unitIncrement=" + unitIncrement;
814 }
815
816 /////////////////
817 // Accessibility support
818 ////////////////
819
820 /**
821 * Gets the AccessibleContext associated with this JScrollBar.
822 * For JScrollBar, the AccessibleContext takes the form of an
823 * AccessibleJScrollBar.
824 * A new AccessibleJScrollBar instance is created if necessary.
825 *
826 * @return an AccessibleJScrollBar that serves as the
827 * AccessibleContext of this JScrollBar
828 */
829 @BeanProperty(bound = false)
830 public AccessibleContext getAccessibleContext() {
831 if (accessibleContext == null) {
832 accessibleContext = new AccessibleJScrollBar();
833 }
834 return accessibleContext;
835 }
836
837 /**
838 * This class implements accessibility support for the
839 * <code>JScrollBar</code> class. It provides an implementation of the
840 * Java Accessibility API appropriate to scroll bar user-interface
841 * elements.
842 * <p>
843 * <strong>Warning:</strong>
844 * Serialized objects of this class will not be compatible with
845 * future Swing releases. The current serialization support is
846 * appropriate for short term storage or RMI between applications running
847 * the same version of Swing. As of 1.4, support for long term storage
848 * of all JavaBeans™
849 * has been added to the <code>java.beans</code> package.
850 * Please see {@link java.beans.XMLEncoder}.
851 */
852 @SuppressWarnings("serial") // Same-version serialization only
853 protected class AccessibleJScrollBar extends AccessibleJComponent
854 implements AccessibleValue {
855
856 /**
857 * Get the state set of this object.
858 *
859 * @return an instance of AccessibleState containing the current state
860 * of the object
861 * @see AccessibleState
862 */
863 public AccessibleStateSet getAccessibleStateSet() {
864 AccessibleStateSet states = super.getAccessibleStateSet();
865 if (getValueIsAdjusting()) {
866 states.add(AccessibleState.BUSY);
867 }
868 if (getOrientation() == VERTICAL) {
869 states.add(AccessibleState.VERTICAL);
870 } else {
871 states.add(AccessibleState.HORIZONTAL);
872 }
873 return states;
874 }
875
876 /**
877 * Get the role of this object.
878 *
879 * @return an instance of AccessibleRole describing the role of the
880 * object
881 */
882 public AccessibleRole getAccessibleRole() {
883 return AccessibleRole.SCROLL_BAR;
884 }
885
886 /**
887 * Get the AccessibleValue associated with this object. In the
888 * implementation of the Java Accessibility API for this class,
889 * return this object, which is responsible for implementing the
890 * AccessibleValue interface on behalf of itself.
891 *
892 * @return this object
893 */
894 public AccessibleValue getAccessibleValue() {
895 return this;
896 }
897
898 /**
899 * Get the accessible value of this object.
900 *
901 * @return The current value of this object.
902 */
903 public Number getCurrentAccessibleValue() {
904 return Integer.valueOf(getValue());
905 }
906
907 /**
908 * Set the value of this object as a Number.
909 *
910 * @return True if the value was set.
911 */
912 public boolean setCurrentAccessibleValue(Number n) {
913 // TIGER - 4422535
914 if (n == null) {
915 return false;
916 }
917 setValue(n.intValue());
918 return true;
919 }
920
921 /**
922 * Get the minimum accessible value of this object.
923 *
924 * @return The minimum value of this object.
925 */
926 public Number getMinimumAccessibleValue() {
927 return Integer.valueOf(getMinimum());
928 }
929
930 /**
931 * Get the maximum accessible value of this object.
932 *
933 * @return The maximum value of this object.
934 */
935 public Number getMaximumAccessibleValue() {
936 // TIGER - 4422362
937 return model.getMaximum() - model.getExtent();
938 }
939
940 } // AccessibleJScrollBar
941 }