1 /*
2 * Copyright (c) 1995, 2014, 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 java.awt;
26
27 import java.awt.peer.TextComponentPeer;
28 import java.awt.event.*;
29 import java.util.EventListener;
30 import java.io.ObjectOutputStream;
31 import java.io.ObjectInputStream;
32 import java.io.IOException;
33 import java.text.BreakIterator;
34 import javax.swing.text.AttributeSet;
35 import javax.accessibility.*;
36 import java.awt.im.InputMethodRequests;
37 import sun.awt.AWTPermissions;
38 import sun.awt.InputMethodSupport;
39
40 /**
41 * The <code>TextComponent</code> class is the superclass of
42 * any component that allows the editing of some text.
43 * <p>
44 * A text component embodies a string of text. The
45 * <code>TextComponent</code> class defines a set of methods
46 * that determine whether or not this text is editable. If the
47 * component is editable, it defines another set of methods
48 * that supports a text insertion caret.
49 * <p>
50 * In addition, the class defines methods that are used
51 * to maintain a current <em>selection</em> from the text.
52 * The text selection, a substring of the component's text,
53 * is the target of editing operations. It is also referred
54 * to as the <em>selected text</em>.
55 *
56 * @author Sami Shaio
57 * @author Arthur van Hoff
58 * @since 1.0
59 */
60 public class TextComponent extends Component implements Accessible {
61
62 /**
63 * The value of the text.
64 * A <code>null</code> value is the same as "".
65 *
66 * @serial
67 * @see #setText(String)
68 * @see #getText()
69 */
70 String text;
71
72 /**
73 * A boolean indicating whether or not this
74 * <code>TextComponent</code> is editable.
75 * It will be <code>true</code> if the text component
76 * is editable and <code>false</code> if not.
77 *
78 * @serial
79 * @see #isEditable()
80 */
81 boolean editable = true;
82
83 /**
84 * The selection refers to the selected text, and the
85 * <code>selectionStart</code> is the start position
86 * of the selected text.
87 *
88 * @serial
89 * @see #getSelectionStart()
90 * @see #setSelectionStart(int)
91 */
92 int selectionStart;
93
94 /**
95 * The selection refers to the selected text, and the
96 * <code>selectionEnd</code>
97 * is the end position of the selected text.
98 *
99 * @serial
100 * @see #getSelectionEnd()
101 * @see #setSelectionEnd(int)
102 */
103 int selectionEnd;
104
105 // A flag used to tell whether the background has been set by
106 // developer code (as opposed to AWT code). Used to determine
107 // the background color of non-editable TextComponents.
108 boolean backgroundSetByClientCode = false;
109
110 /**
111 * A list of listeners that will receive events from this object.
112 */
113 transient protected TextListener textListener;
114
115 /*
116 * JDK 1.1 serialVersionUID
117 */
118 private static final long serialVersionUID = -2214773872412987419L;
119
120 /**
121 * Constructs a new text component initialized with the
122 * specified text. Sets the value of the cursor to
123 * <code>Cursor.TEXT_CURSOR</code>.
124 * @param text the text to be displayed; if
125 * <code>text</code> is <code>null</code>, the empty
126 * string <code>""</code> will be displayed
127 * @exception HeadlessException if
128 * <code>GraphicsEnvironment.isHeadless</code>
129 * returns true
130 * @see java.awt.GraphicsEnvironment#isHeadless
131 * @see java.awt.Cursor
132 */
133 TextComponent(String text) throws HeadlessException {
134 GraphicsEnvironment.checkHeadless();
135 this.text = (text != null) ? text : "";
136 setCursor(Cursor.getPredefinedCursor(Cursor.TEXT_CURSOR));
137 }
138
139 private void enableInputMethodsIfNecessary() {
140 if (checkForEnableIM) {
141 checkForEnableIM = false;
142 try {
143 Toolkit toolkit = Toolkit.getDefaultToolkit();
144 boolean shouldEnable = false;
145 if (toolkit instanceof InputMethodSupport) {
146 shouldEnable = ((InputMethodSupport)toolkit)
147 .enableInputMethodsForTextComponent();
148 }
149 enableInputMethods(shouldEnable);
150 } catch (Exception e) {
151 // if something bad happens, just don't enable input methods
152 }
153 }
154 }
155
156 /**
157 * Enables or disables input method support for this text component. If input
158 * method support is enabled and the text component also processes key events,
159 * incoming events are offered to the current input method and will only be
160 * processed by the component or dispatched to its listeners if the input method
161 * does not consume them. Whether and how input method support for this text
162 * component is enabled or disabled by default is implementation dependent.
163 *
164 * @param enable true to enable, false to disable
165 * @see #processKeyEvent
166 * @since 1.2
167 */
168 public void enableInputMethods(boolean enable) {
169 checkForEnableIM = false;
170 super.enableInputMethods(enable);
171 }
172
173 boolean areInputMethodsEnabled() {
174 // moved from the constructor above to here and addNotify below,
175 // this call will initialize the toolkit if not already initialized.
176 if (checkForEnableIM) {
177 enableInputMethodsIfNecessary();
178 }
179
180 // TextComponent handles key events without touching the eventMask or
181 // having a key listener, so just check whether the flag is set
182 return (eventMask & AWTEvent.INPUT_METHODS_ENABLED_MASK) != 0;
183 }
184
185 public InputMethodRequests getInputMethodRequests() {
186 TextComponentPeer peer = (TextComponentPeer)this.peer;
187 if (peer != null) return peer.getInputMethodRequests();
188 else return null;
189 }
190
191
192
193 /**
194 * Makes this Component displayable by connecting it to a
195 * native screen resource.
196 * This method is called internally by the toolkit and should
197 * not be called directly by programs.
198 * @see java.awt.TextComponent#removeNotify
199 */
200 public void addNotify() {
201 super.addNotify();
202 enableInputMethodsIfNecessary();
203 }
204
205 /**
206 * Removes the <code>TextComponent</code>'s peer.
207 * The peer allows us to modify the appearance of the
208 * <code>TextComponent</code> without changing its
209 * functionality.
210 */
211 public void removeNotify() {
212 synchronized (getTreeLock()) {
213 TextComponentPeer peer = (TextComponentPeer)this.peer;
214 if (peer != null) {
215 text = peer.getText();
216 selectionStart = peer.getSelectionStart();
217 selectionEnd = peer.getSelectionEnd();
218 }
219 super.removeNotify();
220 }
221 }
222
223 /**
224 * Sets the text that is presented by this
225 * text component to be the specified text.
226 * @param t the new text;
227 * if this parameter is <code>null</code> then
228 * the text is set to the empty string ""
229 * @see java.awt.TextComponent#getText
230 */
231 public synchronized void setText(String t) {
232 boolean skipTextEvent = (text == null || text.isEmpty())
233 && (t == null || t.isEmpty());
234 text = (t != null) ? t : "";
235 TextComponentPeer peer = (TextComponentPeer)this.peer;
236 // Please note that we do not want to post an event
237 // if TextArea.setText() or TextField.setText() replaces an empty text
238 // by an empty text, that is, if component's text remains unchanged.
239 if (peer != null && !skipTextEvent) {
240 peer.setText(text);
241 }
242 }
243
244 /**
245 * Returns the text that is presented by this text component.
246 * By default, this is an empty string.
247 *
248 * @return the value of this <code>TextComponent</code>
249 * @see java.awt.TextComponent#setText
250 */
251 public synchronized String getText() {
252 TextComponentPeer peer = (TextComponentPeer)this.peer;
253 if (peer != null) {
254 text = peer.getText();
255 }
256 return text;
257 }
258
259 /**
260 * Returns the selected text from the text that is
261 * presented by this text component.
262 * @return the selected text of this text component
263 * @see java.awt.TextComponent#select
264 */
265 public synchronized String getSelectedText() {
266 return getText().substring(getSelectionStart(), getSelectionEnd());
267 }
268
269 /**
270 * Indicates whether or not this text component is editable.
271 * @return <code>true</code> if this text component is
272 * editable; <code>false</code> otherwise.
273 * @see java.awt.TextComponent#setEditable
274 * @since 1.0
275 */
276 public boolean isEditable() {
277 return editable;
278 }
279
280 /**
281 * Sets the flag that determines whether or not this
282 * text component is editable.
283 * <p>
284 * If the flag is set to <code>true</code>, this text component
285 * becomes user editable. If the flag is set to <code>false</code>,
286 * the user cannot change the text of this text component.
287 * By default, non-editable text components have a background color
288 * of SystemColor.control. This default can be overridden by
289 * calling setBackground.
290 *
291 * @param b a flag indicating whether this text component
292 * is user editable.
293 * @see java.awt.TextComponent#isEditable
294 * @since 1.0
295 */
296 public synchronized void setEditable(boolean b) {
297 if (editable == b) {
298 return;
299 }
300
301 editable = b;
302 TextComponentPeer peer = (TextComponentPeer)this.peer;
303 if (peer != null) {
304 peer.setEditable(b);
305 }
306 }
307
308 /**
309 * Gets the background color of this text component.
310 *
311 * By default, non-editable text components have a background color
312 * of SystemColor.control. This default can be overridden by
313 * calling setBackground.
314 *
315 * @return This text component's background color.
316 * If this text component does not have a background color,
317 * the background color of its parent is returned.
318 * @see #setBackground(Color)
319 * @since 1.0
320 */
321 public Color getBackground() {
322 if (!editable && !backgroundSetByClientCode) {
323 return SystemColor.control;
324 }
325
326 return super.getBackground();
327 }
328
329 /**
330 * Sets the background color of this text component.
331 *
332 * @param c The color to become this text component's color.
333 * If this parameter is null then this text component
334 * will inherit the background color of its parent.
335 * @see #getBackground()
336 * @since 1.0
337 */
338 public void setBackground(Color c) {
339 backgroundSetByClientCode = true;
340 super.setBackground(c);
341 }
342
343 /**
344 * Gets the start position of the selected text in
345 * this text component.
346 * @return the start position of the selected text
347 * @see java.awt.TextComponent#setSelectionStart
348 * @see java.awt.TextComponent#getSelectionEnd
349 */
350 public synchronized int getSelectionStart() {
351 TextComponentPeer peer = (TextComponentPeer)this.peer;
352 if (peer != null) {
353 selectionStart = peer.getSelectionStart();
354 }
355 return selectionStart;
356 }
357
358 /**
359 * Sets the selection start for this text component to
360 * the specified position. The new start point is constrained
361 * to be at or before the current selection end. It also
362 * cannot be set to less than zero, the beginning of the
363 * component's text.
364 * If the caller supplies a value for <code>selectionStart</code>
365 * that is out of bounds, the method enforces these constraints
366 * silently, and without failure.
367 * @param selectionStart the start position of the
368 * selected text
369 * @see java.awt.TextComponent#getSelectionStart
370 * @see java.awt.TextComponent#setSelectionEnd
371 * @since 1.1
372 */
373 public synchronized void setSelectionStart(int selectionStart) {
374 /* Route through select method to enforce consistent policy
375 * between selectionStart and selectionEnd.
376 */
377 select(selectionStart, getSelectionEnd());
378 }
379
380 /**
381 * Gets the end position of the selected text in
382 * this text component.
383 * @return the end position of the selected text
384 * @see java.awt.TextComponent#setSelectionEnd
385 * @see java.awt.TextComponent#getSelectionStart
386 */
387 public synchronized int getSelectionEnd() {
388 TextComponentPeer peer = (TextComponentPeer)this.peer;
389 if (peer != null) {
390 selectionEnd = peer.getSelectionEnd();
391 }
392 return selectionEnd;
393 }
394
395 /**
396 * Sets the selection end for this text component to
397 * the specified position. The new end point is constrained
398 * to be at or after the current selection start. It also
399 * cannot be set beyond the end of the component's text.
400 * If the caller supplies a value for <code>selectionEnd</code>
401 * that is out of bounds, the method enforces these constraints
402 * silently, and without failure.
403 * @param selectionEnd the end position of the
404 * selected text
405 * @see java.awt.TextComponent#getSelectionEnd
406 * @see java.awt.TextComponent#setSelectionStart
407 * @since 1.1
408 */
409 public synchronized void setSelectionEnd(int selectionEnd) {
410 /* Route through select method to enforce consistent policy
411 * between selectionStart and selectionEnd.
412 */
413 select(getSelectionStart(), selectionEnd);
414 }
415
416 /**
417 * Selects the text between the specified start and end positions.
418 * <p>
419 * This method sets the start and end positions of the
420 * selected text, enforcing the restriction that the start position
421 * must be greater than or equal to zero. The end position must be
422 * greater than or equal to the start position, and less than or
423 * equal to the length of the text component's text. The
424 * character positions are indexed starting with zero.
425 * The length of the selection is
426 * <code>endPosition</code> - <code>startPosition</code>, so the
427 * character at <code>endPosition</code> is not selected.
428 * If the start and end positions of the selected text are equal,
429 * all text is deselected.
430 * <p>
431 * If the caller supplies values that are inconsistent or out of
432 * bounds, the method enforces these constraints silently, and
433 * without failure. Specifically, if the start position or end
434 * position is greater than the length of the text, it is reset to
435 * equal the text length. If the start position is less than zero,
436 * it is reset to zero, and if the end position is less than the
437 * start position, it is reset to the start position.
438 *
439 * @param selectionStart the zero-based index of the first
440 character (<code>char</code> value) to be selected
441 * @param selectionEnd the zero-based end position of the
442 text to be selected; the character (<code>char</code> value) at
443 <code>selectionEnd</code> is not selected
444 * @see java.awt.TextComponent#setSelectionStart
445 * @see java.awt.TextComponent#setSelectionEnd
446 * @see java.awt.TextComponent#selectAll
447 */
448 public synchronized void select(int selectionStart, int selectionEnd) {
449 String text = getText();
450 if (selectionStart < 0) {
451 selectionStart = 0;
452 }
453 if (selectionStart > text.length()) {
454 selectionStart = text.length();
455 }
456 if (selectionEnd > text.length()) {
457 selectionEnd = text.length();
458 }
459 if (selectionEnd < selectionStart) {
460 selectionEnd = selectionStart;
461 }
462
463 this.selectionStart = selectionStart;
464 this.selectionEnd = selectionEnd;
465
466 TextComponentPeer peer = (TextComponentPeer)this.peer;
467 if (peer != null) {
468 peer.select(selectionStart, selectionEnd);
469 }
470 }
471
472 /**
473 * Selects all the text in this text component.
474 * @see java.awt.TextComponent#select
475 */
476 public synchronized void selectAll() {
477 this.selectionStart = 0;
478 this.selectionEnd = getText().length();
479
480 TextComponentPeer peer = (TextComponentPeer)this.peer;
481 if (peer != null) {
482 peer.select(selectionStart, selectionEnd);
483 }
484 }
485
486 /**
487 * Sets the position of the text insertion caret.
488 * The caret position is constrained to be between 0
489 * and the last character of the text, inclusive.
490 * If the passed-in value is greater than this range,
491 * the value is set to the last character (or 0 if
492 * the <code>TextComponent</code> contains no text)
493 * and no error is returned. If the passed-in value is
494 * less than 0, an <code>IllegalArgumentException</code>
495 * is thrown.
496 *
497 * @param position the position of the text insertion caret
498 * @exception IllegalArgumentException if <code>position</code>
499 * is less than zero
500 * @since 1.1
501 */
502 public synchronized void setCaretPosition(int position) {
503 if (position < 0) {
504 throw new IllegalArgumentException("position less than zero.");
505 }
506
507 int maxposition = getText().length();
508 if (position > maxposition) {
509 position = maxposition;
510 }
511
512 TextComponentPeer peer = (TextComponentPeer)this.peer;
513 if (peer != null) {
514 peer.setCaretPosition(position);
515 } else {
516 select(position, position);
517 }
518 }
519
520 /**
521 * Returns the position of the text insertion caret.
522 * The caret position is constrained to be between 0
523 * and the last character of the text, inclusive.
524 * If the text or caret have not been set, the default
525 * caret position is 0.
526 *
527 * @return the position of the text insertion caret
528 * @see #setCaretPosition(int)
529 * @since 1.1
530 */
531 public synchronized int getCaretPosition() {
532 TextComponentPeer peer = (TextComponentPeer)this.peer;
533 int position = 0;
534
535 if (peer != null) {
536 position = peer.getCaretPosition();
537 } else {
538 position = selectionStart;
539 }
540 int maxposition = getText().length();
541 if (position > maxposition) {
542 position = maxposition;
543 }
544 return position;
545 }
546
547 /**
548 * Adds the specified text event listener to receive text events
549 * from this text component.
550 * If <code>l</code> is <code>null</code>, no exception is
551 * thrown and no action is performed.
552 * <p>Refer to <a href="doc-files/AWTThreadIssues.html#ListenersThreads"
553 * >AWT Threading Issues</a> for details on AWT's threading model.
554 *
555 * @param l the text event listener
556 * @see #removeTextListener
557 * @see #getTextListeners
558 * @see java.awt.event.TextListener
559 */
560 public synchronized void addTextListener(TextListener l) {
561 if (l == null) {
562 return;
563 }
564 textListener = AWTEventMulticaster.add(textListener, l);
565 newEventsOnly = true;
566 }
567
568 /**
569 * Removes the specified text event listener so that it no longer
570 * receives text events from this text component
571 * If <code>l</code> is <code>null</code>, no exception is
572 * thrown and no action is performed.
573 * <p>Refer to <a href="doc-files/AWTThreadIssues.html#ListenersThreads"
574 * >AWT Threading Issues</a> for details on AWT's threading model.
575 *
576 * @param l the text listener
577 * @see #addTextListener
578 * @see #getTextListeners
579 * @see java.awt.event.TextListener
580 * @since 1.1
581 */
582 public synchronized void removeTextListener(TextListener l) {
583 if (l == null) {
584 return;
585 }
586 textListener = AWTEventMulticaster.remove(textListener, l);
587 }
588
589 /**
590 * Returns an array of all the text listeners
591 * registered on this text component.
592 *
593 * @return all of this text component's <code>TextListener</code>s
594 * or an empty array if no text
595 * listeners are currently registered
596 *
597 *
598 * @see #addTextListener
599 * @see #removeTextListener
600 * @since 1.4
601 */
602 public synchronized TextListener[] getTextListeners() {
603 return getListeners(TextListener.class);
604 }
605
606 /**
607 * Returns an array of all the objects currently registered
608 * as <code><em>Foo</em>Listener</code>s
609 * upon this <code>TextComponent</code>.
610 * <code><em>Foo</em>Listener</code>s are registered using the
611 * <code>add<em>Foo</em>Listener</code> method.
612 *
613 * <p>
614 * You can specify the <code>listenerType</code> argument
615 * with a class literal, such as
616 * <code><em>Foo</em>Listener.class</code>.
617 * For example, you can query a
618 * <code>TextComponent</code> <code>t</code>
619 * for its text listeners with the following code:
620 *
621 * <pre>TextListener[] tls = (TextListener[])(t.getListeners(TextListener.class));</pre>
622 *
623 * If no such listeners exist, this method returns an empty array.
624 *
625 * @param listenerType the type of listeners requested; this parameter
626 * should specify an interface that descends from
627 * <code>java.util.EventListener</code>
628 * @return an array of all objects registered as
629 * <code><em>Foo</em>Listener</code>s on this text component,
630 * or an empty array if no such
631 * listeners have been added
632 * @exception ClassCastException if <code>listenerType</code>
633 * doesn't specify a class or interface that implements
634 * <code>java.util.EventListener</code>
635 *
636 * @see #getTextListeners
637 * @since 1.3
638 */
639 public <T extends EventListener> T[] getListeners(Class<T> listenerType) {
640 EventListener l = null;
641 if (listenerType == TextListener.class) {
642 l = textListener;
643 } else {
644 return super.getListeners(listenerType);
645 }
646 return AWTEventMulticaster.getListeners(l, listenerType);
647 }
648
649 // REMIND: remove when filtering is done at lower level
650 boolean eventEnabled(AWTEvent e) {
651 if (e.id == TextEvent.TEXT_VALUE_CHANGED) {
652 if ((eventMask & AWTEvent.TEXT_EVENT_MASK) != 0 ||
653 textListener != null) {
654 return true;
655 }
656 return false;
657 }
658 return super.eventEnabled(e);
659 }
660
661 /**
662 * Processes events on this text component. If the event is a
663 * <code>TextEvent</code>, it invokes the <code>processTextEvent</code>
664 * method else it invokes its superclass's <code>processEvent</code>.
665 * <p>Note that if the event parameter is <code>null</code>
666 * the behavior is unspecified and may result in an
667 * exception.
668 *
669 * @param e the event
670 */
671 protected void processEvent(AWTEvent e) {
672 if (e instanceof TextEvent) {
673 processTextEvent((TextEvent)e);
674 return;
675 }
676 super.processEvent(e);
677 }
678
679 /**
680 * Processes text events occurring on this text component by
681 * dispatching them to any registered <code>TextListener</code> objects.
682 * <p>
683 * NOTE: This method will not be called unless text events
684 * are enabled for this component. This happens when one of the
685 * following occurs:
686 * <ul>
687 * <li>A <code>TextListener</code> object is registered
688 * via <code>addTextListener</code>
689 * <li>Text events are enabled via <code>enableEvents</code>
690 * </ul>
691 * <p>Note that if the event parameter is <code>null</code>
692 * the behavior is unspecified and may result in an
693 * exception.
694 *
695 * @param e the text event
696 * @see Component#enableEvents
697 */
698 protected void processTextEvent(TextEvent e) {
699 TextListener listener = textListener;
700 if (listener != null) {
701 int id = e.getID();
702 switch (id) {
703 case TextEvent.TEXT_VALUE_CHANGED:
704 listener.textValueChanged(e);
705 break;
706 }
707 }
708 }
709
710 /**
711 * Returns a string representing the state of this
712 * <code>TextComponent</code>. This
713 * method is intended to be used only for debugging purposes, and the
714 * content and format of the returned string may vary between
715 * implementations. The returned string may be empty but may not be
716 * <code>null</code>.
717 *
718 * @return the parameter string of this text component
719 */
720 protected String paramString() {
721 String str = super.paramString() + ",text=" + getText();
722 if (editable) {
723 str += ",editable";
724 }
725 return str + ",selection=" + getSelectionStart() + "-" + getSelectionEnd();
726 }
727
728 /**
729 * Assigns a valid value to the canAccessClipboard instance variable.
730 */
731 private boolean canAccessClipboard() {
732 SecurityManager sm = System.getSecurityManager();
733 if (sm == null) return true;
734 try {
735 sm.checkPermission(AWTPermissions.ACCESS_CLIPBOARD_PERMISSION);
736 return true;
737 } catch (SecurityException e) {}
738 return false;
739 }
740
741 /*
742 * Serialization support.
743 */
744 /**
745 * The textComponent SerializedDataVersion.
746 *
747 * @serial
748 */
749 private int textComponentSerializedDataVersion = 1;
750
751 /**
752 * Writes default serializable fields to stream. Writes
753 * a list of serializable TextListener(s) as optional data.
754 * The non-serializable TextListener(s) are detected and
755 * no attempt is made to serialize them.
756 *
757 * @serialData Null terminated sequence of zero or more pairs.
758 * A pair consists of a String and Object.
759 * The String indicates the type of object and
760 * is one of the following :
761 * textListenerK indicating and TextListener object.
762 *
763 * @see AWTEventMulticaster#save(ObjectOutputStream, String, EventListener)
764 * @see java.awt.Component#textListenerK
765 */
766 private void writeObject(java.io.ObjectOutputStream s)
767 throws IOException
768 {
769 // Serialization support. Since the value of the fields
770 // selectionStart, selectionEnd, and text aren't necessarily
771 // up to date, we sync them up with the peer before serializing.
772 TextComponentPeer peer = (TextComponentPeer)this.peer;
773 if (peer != null) {
774 text = peer.getText();
775 selectionStart = peer.getSelectionStart();
776 selectionEnd = peer.getSelectionEnd();
777 }
778
779 s.defaultWriteObject();
780
781 AWTEventMulticaster.save(s, textListenerK, textListener);
782 s.writeObject(null);
783 }
784
785 /**
786 * Read the ObjectInputStream, and if it isn't null,
787 * add a listener to receive text events fired by the
788 * TextComponent. Unrecognized keys or values will be
789 * ignored.
790 *
791 * @exception HeadlessException if
792 * <code>GraphicsEnvironment.isHeadless()</code> returns
793 * <code>true</code>
794 * @see #removeTextListener
795 * @see #addTextListener
796 * @see java.awt.GraphicsEnvironment#isHeadless
797 */
798 private void readObject(ObjectInputStream s)
799 throws ClassNotFoundException, IOException, HeadlessException
800 {
801 GraphicsEnvironment.checkHeadless();
802 s.defaultReadObject();
803
804 // Make sure the state we just read in for text,
805 // selectionStart and selectionEnd has legal values
806 this.text = (text != null) ? text : "";
807 select(selectionStart, selectionEnd);
808
809 Object keyOrNull;
810 while(null != (keyOrNull = s.readObject())) {
811 String key = ((String)keyOrNull).intern();
812
813 if (textListenerK == key) {
814 addTextListener((TextListener)(s.readObject()));
815 } else {
816 // skip value for unrecognized key
817 s.readObject();
818 }
819 }
820 enableInputMethodsIfNecessary();
821 }
822
823
824 /////////////////
825 // Accessibility support
826 ////////////////
827
828 /**
829 * Gets the AccessibleContext associated with this TextComponent.
830 * For text components, the AccessibleContext takes the form of an
831 * AccessibleAWTTextComponent.
832 * A new AccessibleAWTTextComponent instance is created if necessary.
833 *
834 * @return an AccessibleAWTTextComponent that serves as the
835 * AccessibleContext of this TextComponent
836 * @since 1.3
837 */
838 public AccessibleContext getAccessibleContext() {
839 if (accessibleContext == null) {
840 accessibleContext = new AccessibleAWTTextComponent();
841 }
842 return accessibleContext;
843 }
844
845 /**
846 * This class implements accessibility support for the
847 * <code>TextComponent</code> class. It provides an implementation of the
848 * Java Accessibility API appropriate to text component user-interface
849 * elements.
850 * @since 1.3
851 */
852 protected class AccessibleAWTTextComponent extends AccessibleAWTComponent
853 implements AccessibleText, TextListener
854 {
855 /*
856 * JDK 1.3 serialVersionUID
857 */
858 private static final long serialVersionUID = 3631432373506317811L;
859
860 /**
861 * Constructs an AccessibleAWTTextComponent. Adds a listener to track
862 * caret change.
863 */
864 public AccessibleAWTTextComponent() {
865 TextComponent.this.addTextListener(this);
866 }
867
868 /**
869 * TextListener notification of a text value change.
870 */
871 public void textValueChanged(TextEvent textEvent) {
872 Integer cpos = Integer.valueOf(TextComponent.this.getCaretPosition());
873 firePropertyChange(ACCESSIBLE_TEXT_PROPERTY, null, cpos);
874 }
875
876 /**
877 * Gets the state set of the TextComponent.
878 * The AccessibleStateSet of an object is composed of a set of
879 * unique AccessibleStates. A change in the AccessibleStateSet
880 * of an object will cause a PropertyChangeEvent to be fired
881 * for the AccessibleContext.ACCESSIBLE_STATE_PROPERTY property.
882 *
883 * @return an instance of AccessibleStateSet containing the
884 * current state set of the object
885 * @see AccessibleStateSet
886 * @see AccessibleState
887 * @see #addPropertyChangeListener
888 */
889 public AccessibleStateSet getAccessibleStateSet() {
890 AccessibleStateSet states = super.getAccessibleStateSet();
891 if (TextComponent.this.isEditable()) {
892 states.add(AccessibleState.EDITABLE);
893 }
894 return states;
895 }
896
897
898 /**
899 * Gets the role of this object.
900 *
901 * @return an instance of AccessibleRole describing the role of the
902 * object (AccessibleRole.TEXT)
903 * @see AccessibleRole
904 */
905 public AccessibleRole getAccessibleRole() {
906 return AccessibleRole.TEXT;
907 }
908
909 /**
910 * Get the AccessibleText associated with this object. In the
911 * implementation of the Java Accessibility API for this class,
912 * return this object, which is responsible for implementing the
913 * AccessibleText interface on behalf of itself.
914 *
915 * @return this object
916 */
917 public AccessibleText getAccessibleText() {
918 return this;
919 }
920
921
922 // --- interface AccessibleText methods ------------------------
923
924 /**
925 * Many of these methods are just convenience methods; they
926 * just call the equivalent on the parent
927 */
928
929 /**
930 * Given a point in local coordinates, return the zero-based index
931 * of the character under that Point. If the point is invalid,
932 * this method returns -1.
933 *
934 * @param p the Point in local coordinates
935 * @return the zero-based index of the character under Point p.
936 */
937 public int getIndexAtPoint(Point p) {
938 return -1;
939 }
940
941 /**
942 * Determines the bounding box of the character at the given
943 * index into the string. The bounds are returned in local
944 * coordinates. If the index is invalid a null rectangle
945 * is returned.
946 *
947 * @param i the index into the String >= 0
948 * @return the screen coordinates of the character's bounding box
949 */
950 public Rectangle getCharacterBounds(int i) {
951 return null;
952 }
953
954 /**
955 * Returns the number of characters (valid indicies)
956 *
957 * @return the number of characters >= 0
958 */
959 public int getCharCount() {
960 return TextComponent.this.getText().length();
961 }
962
963 /**
964 * Returns the zero-based offset of the caret.
965 *
966 * Note: The character to the right of the caret will have the
967 * same index value as the offset (the caret is between
968 * two characters).
969 *
970 * @return the zero-based offset of the caret.
971 */
972 public int getCaretPosition() {
973 return TextComponent.this.getCaretPosition();
974 }
975
976 /**
977 * Returns the AttributeSet for a given character (at a given index).
978 *
979 * @param i the zero-based index into the text
980 * @return the AttributeSet of the character
981 */
982 public AttributeSet getCharacterAttribute(int i) {
983 return null; // No attributes in TextComponent
984 }
985
986 /**
987 * Returns the start offset within the selected text.
988 * If there is no selection, but there is
989 * a caret, the start and end offsets will be the same.
990 * Return 0 if the text is empty, or the caret position
991 * if no selection.
992 *
993 * @return the index into the text of the start of the selection >= 0
994 */
995 public int getSelectionStart() {
996 return TextComponent.this.getSelectionStart();
997 }
998
999 /**
1000 * Returns the end offset within the selected text.
1001 * If there is no selection, but there is
1002 * a caret, the start and end offsets will be the same.
1003 * Return 0 if the text is empty, or the caret position
1004 * if no selection.
1005 *
1006 * @return the index into the text of the end of the selection >= 0
1007 */
1008 public int getSelectionEnd() {
1009 return TextComponent.this.getSelectionEnd();
1010 }
1011
1012 /**
1013 * Returns the portion of the text that is selected.
1014 *
1015 * @return the text, null if no selection
1016 */
1017 public String getSelectedText() {
1018 String selText = TextComponent.this.getSelectedText();
1019 // Fix for 4256662
1020 if (selText == null || selText.equals("")) {
1021 return null;
1022 }
1023 return selText;
1024 }
1025
1026 /**
1027 * Returns the String at a given index.
1028 *
1029 * @param part the AccessibleText.CHARACTER, AccessibleText.WORD,
1030 * or AccessibleText.SENTENCE to retrieve
1031 * @param index an index within the text >= 0
1032 * @return the letter, word, or sentence,
1033 * null for an invalid index or part
1034 */
1035 public String getAtIndex(int part, int index) {
1036 if (index < 0 || index >= TextComponent.this.getText().length()) {
1037 return null;
1038 }
1039 switch (part) {
1040 case AccessibleText.CHARACTER:
1041 return TextComponent.this.getText().substring(index, index+1);
1042 case AccessibleText.WORD: {
1043 String s = TextComponent.this.getText();
1044 BreakIterator words = BreakIterator.getWordInstance();
1045 words.setText(s);
1046 int end = words.following(index);
1047 return s.substring(words.previous(), end);
1048 }
1049 case AccessibleText.SENTENCE: {
1050 String s = TextComponent.this.getText();
1051 BreakIterator sentence = BreakIterator.getSentenceInstance();
1052 sentence.setText(s);
1053 int end = sentence.following(index);
1054 return s.substring(sentence.previous(), end);
1055 }
1056 default:
1057 return null;
1058 }
1059 }
1060
1061 private static final boolean NEXT = true;
1062 private static final boolean PREVIOUS = false;
1063
1064 /**
1065 * Needed to unify forward and backward searching.
1066 * The method assumes that s is the text assigned to words.
1067 */
1068 private int findWordLimit(int index, BreakIterator words, boolean direction,
1069 String s) {
1070 // Fix for 4256660 and 4256661.
1071 // Words iterator is different from character and sentence iterators
1072 // in that end of one word is not necessarily start of another word.
1073 // Please see java.text.BreakIterator JavaDoc. The code below is
1074 // based on nextWordStartAfter example from BreakIterator.java.
1075 int last = (direction == NEXT) ? words.following(index)
1076 : words.preceding(index);
1077 int current = (direction == NEXT) ? words.next()
1078 : words.previous();
1079 while (current != BreakIterator.DONE) {
1080 for (int p = Math.min(last, current); p < Math.max(last, current); p++) {
1081 if (Character.isLetter(s.charAt(p))) {
1082 return last;
1083 }
1084 }
1085 last = current;
1086 current = (direction == NEXT) ? words.next()
1087 : words.previous();
1088 }
1089 return BreakIterator.DONE;
1090 }
1091
1092 /**
1093 * Returns the String after a given index.
1094 *
1095 * @param part the AccessibleText.CHARACTER, AccessibleText.WORD,
1096 * or AccessibleText.SENTENCE to retrieve
1097 * @param index an index within the text >= 0
1098 * @return the letter, word, or sentence, null for an invalid
1099 * index or part
1100 */
1101 public String getAfterIndex(int part, int index) {
1102 if (index < 0 || index >= TextComponent.this.getText().length()) {
1103 return null;
1104 }
1105 switch (part) {
1106 case AccessibleText.CHARACTER:
1107 if (index+1 >= TextComponent.this.getText().length()) {
1108 return null;
1109 }
1110 return TextComponent.this.getText().substring(index+1, index+2);
1111 case AccessibleText.WORD: {
1112 String s = TextComponent.this.getText();
1113 BreakIterator words = BreakIterator.getWordInstance();
1114 words.setText(s);
1115 int start = findWordLimit(index, words, NEXT, s);
1116 if (start == BreakIterator.DONE || start >= s.length()) {
1117 return null;
1118 }
1119 int end = words.following(start);
1120 if (end == BreakIterator.DONE || end >= s.length()) {
1121 return null;
1122 }
1123 return s.substring(start, end);
1124 }
1125 case AccessibleText.SENTENCE: {
1126 String s = TextComponent.this.getText();
1127 BreakIterator sentence = BreakIterator.getSentenceInstance();
1128 sentence.setText(s);
1129 int start = sentence.following(index);
1130 if (start == BreakIterator.DONE || start >= s.length()) {
1131 return null;
1132 }
1133 int end = sentence.following(start);
1134 if (end == BreakIterator.DONE || end >= s.length()) {
1135 return null;
1136 }
1137 return s.substring(start, end);
1138 }
1139 default:
1140 return null;
1141 }
1142 }
1143
1144
1145 /**
1146 * Returns the String before a given index.
1147 *
1148 * @param part the AccessibleText.CHARACTER, AccessibleText.WORD,
1149 * or AccessibleText.SENTENCE to retrieve
1150 * @param index an index within the text >= 0
1151 * @return the letter, word, or sentence, null for an invalid index
1152 * or part
1153 */
1154 public String getBeforeIndex(int part, int index) {
1155 if (index < 0 || index > TextComponent.this.getText().length()-1) {
1156 return null;
1157 }
1158 switch (part) {
1159 case AccessibleText.CHARACTER:
1160 if (index == 0) {
1161 return null;
1162 }
1163 return TextComponent.this.getText().substring(index-1, index);
1164 case AccessibleText.WORD: {
1165 String s = TextComponent.this.getText();
1166 BreakIterator words = BreakIterator.getWordInstance();
1167 words.setText(s);
1168 int end = findWordLimit(index, words, PREVIOUS, s);
1169 if (end == BreakIterator.DONE) {
1170 return null;
1171 }
1172 int start = words.preceding(end);
1173 if (start == BreakIterator.DONE) {
1174 return null;
1175 }
1176 return s.substring(start, end);
1177 }
1178 case AccessibleText.SENTENCE: {
1179 String s = TextComponent.this.getText();
1180 BreakIterator sentence = BreakIterator.getSentenceInstance();
1181 sentence.setText(s);
1182 int end = sentence.following(index);
1183 end = sentence.previous();
1184 int start = sentence.previous();
1185 if (start == BreakIterator.DONE) {
1186 return null;
1187 }
1188 return s.substring(start, end);
1189 }
1190 default:
1191 return null;
1192 }
1193 }
1194 } // end of AccessibleAWTTextComponent
1195
1196 private boolean checkForEnableIM = true;
1197 }