1 /*
2 * Copyright (c) 1995, 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 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 JDK1.0
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 transient protected TextListener textListener;
111
112 /*
113 * JDK 1.1 serialVersionUID
114 */
115 private static final long serialVersionUID = -2214773872412987419L;
116
117 /**
118 * Constructs a new text component initialized with the
119 * specified text. Sets the value of the cursor to
120 * <code>Cursor.TEXT_CURSOR</code>.
121 * @param text the text to be displayed; if
122 * <code>text</code> is <code>null</code>, the empty
123 * string <code>""</code> will be displayed
124 * @exception HeadlessException if
125 * <code>GraphicsEnvironment.isHeadless</code>
126 * returns true
127 * @see java.awt.GraphicsEnvironment#isHeadless
128 * @see java.awt.Cursor
129 */
130 TextComponent(String text) throws HeadlessException {
131 GraphicsEnvironment.checkHeadless();
132 this.text = (text != null) ? text : "";
133 setCursor(Cursor.getPredefinedCursor(Cursor.TEXT_CURSOR));
134 }
135
136 private void enableInputMethodsIfNecessary() {
137 if (checkForEnableIM) {
138 checkForEnableIM = false;
139 try {
140 Toolkit toolkit = Toolkit.getDefaultToolkit();
141 boolean shouldEnable = false;
142 if (toolkit instanceof InputMethodSupport) {
143 shouldEnable = ((InputMethodSupport)toolkit)
144 .enableInputMethodsForTextComponent();
145 }
146 enableInputMethods(shouldEnable);
147 } catch (Exception e) {
148 // if something bad happens, just don't enable input methods
149 }
150 }
151 }
152
153 /**
154 * Enables or disables input method support for this text component. If input
155 * method support is enabled and the text component also processes key events,
156 * incoming events are offered to the current input method and will only be
157 * processed by the component or dispatched to its listeners if the input method
158 * does not consume them. Whether and how input method support for this text
159 * component is enabled or disabled by default is implementation dependent.
160 *
161 * @param enable true to enable, false to disable
162 * @see #processKeyEvent
163 * @since 1.2
164 */
165 public void enableInputMethods(boolean enable) {
166 checkForEnableIM = false;
167 super.enableInputMethods(enable);
168 }
169
170 boolean areInputMethodsEnabled() {
171 // moved from the constructor above to here and addNotify below,
172 // this call will initialize the toolkit if not already initialized.
173 if (checkForEnableIM) {
174 enableInputMethodsIfNecessary();
175 }
176
177 // TextComponent handles key events without touching the eventMask or
178 // having a key listener, so just check whether the flag is set
179 return (eventMask & AWTEvent.INPUT_METHODS_ENABLED_MASK) != 0;
180 }
181
182 public InputMethodRequests getInputMethodRequests() {
183 TextComponentPeer peer = (TextComponentPeer)this.peer;
184 if (peer != null) return peer.getInputMethodRequests();
185 else return null;
186 }
187
188
189
190 /**
191 * Makes this Component displayable by connecting it to a
192 * native screen resource.
193 * This method is called internally by the toolkit and should
194 * not be called directly by programs.
195 * @see java.awt.TextComponent#removeNotify
196 */
197 public void addNotify() {
198 super.addNotify();
199 enableInputMethodsIfNecessary();
200 }
201
202 /**
203 * Removes the <code>TextComponent</code>'s peer.
204 * The peer allows us to modify the appearance of the
205 * <code>TextComponent</code> without changing its
206 * functionality.
207 */
208 public void removeNotify() {
209 synchronized (getTreeLock()) {
210 TextComponentPeer peer = (TextComponentPeer)this.peer;
211 if (peer != null) {
212 text = peer.getText();
213 selectionStart = peer.getSelectionStart();
214 selectionEnd = peer.getSelectionEnd();
215 }
216 super.removeNotify();
217 }
218 }
219
220 /**
221 * Sets the text that is presented by this
222 * text component to be the specified text.
223 * @param t the new text;
224 * if this parameter is <code>null</code> then
225 * the text is set to the empty string ""
226 * @see java.awt.TextComponent#getText
227 */
228 public synchronized void setText(String t) {
229 boolean skipTextEvent = (text == null || text.isEmpty())
230 && (t == null || t.isEmpty());
231 text = (t != null) ? t : "";
232 TextComponentPeer peer = (TextComponentPeer)this.peer;
233 // Please note that we do not want to post an event
234 // if TextArea.setText() or TextField.setText() replaces an empty text
235 // by an empty text, that is, if component's text remains unchanged.
236 if (peer != null && !skipTextEvent) {
237 peer.setText(text);
238 }
239 }
240
241 /**
242 * Returns the text that is presented by this text component.
243 * By default, this is an empty string.
244 *
245 * @return the value of this <code>TextComponent</code>
246 * @see java.awt.TextComponent#setText
247 */
248 public synchronized String getText() {
249 TextComponentPeer peer = (TextComponentPeer)this.peer;
250 if (peer != null) {
251 text = peer.getText();
252 }
253 return text;
254 }
255
256 /**
257 * Returns the selected text from the text that is
258 * presented by this text component.
259 * @return the selected text of this text component
260 * @see java.awt.TextComponent#select
261 */
262 public synchronized String getSelectedText() {
263 return getText().substring(getSelectionStart(), getSelectionEnd());
264 }
265
266 /**
267 * Indicates whether or not this text component is editable.
268 * @return <code>true</code> if this text component is
269 * editable; <code>false</code> otherwise.
270 * @see java.awt.TextComponent#setEditable
271 * @since JDK1.0
272 */
273 public boolean isEditable() {
274 return editable;
275 }
276
277 /**
278 * Sets the flag that determines whether or not this
279 * text component is editable.
280 * <p>
281 * If the flag is set to <code>true</code>, this text component
282 * becomes user editable. If the flag is set to <code>false</code>,
283 * the user cannot change the text of this text component.
284 * By default, non-editable text components have a background color
285 * of SystemColor.control. This default can be overridden by
286 * calling setBackground.
287 *
288 * @param b a flag indicating whether this text component
289 * is user editable.
290 * @see java.awt.TextComponent#isEditable
291 * @since JDK1.0
292 */
293 public synchronized void setEditable(boolean b) {
294 if (editable == b) {
295 return;
296 }
297
298 editable = b;
299 TextComponentPeer peer = (TextComponentPeer)this.peer;
300 if (peer != null) {
301 peer.setEditable(b);
302 }
303 }
304
305 /**
306 * Gets the background color of this text component.
307 *
308 * By default, non-editable text components have a background color
309 * of SystemColor.control. This default can be overridden by
310 * calling setBackground.
311 *
312 * @return This text component's background color.
313 * If this text component does not have a background color,
314 * the background color of its parent is returned.
315 * @see #setBackground(Color)
316 * @since JDK1.0
317 */
318 public Color getBackground() {
319 if (!editable && !backgroundSetByClientCode) {
320 return SystemColor.control;
321 }
322
323 return super.getBackground();
324 }
325
326 /**
327 * Sets the background color of this text component.
328 *
329 * @param c The color to become this text component's color.
330 * If this parameter is null then this text component
331 * will inherit the background color of its parent.
332 * @see #getBackground()
333 * @since JDK1.0
334 */
335 public void setBackground(Color c) {
336 backgroundSetByClientCode = true;
337 super.setBackground(c);
338 }
339
340 /**
341 * Gets the start position of the selected text in
342 * this text component.
343 * @return the start position of the selected text
344 * @see java.awt.TextComponent#setSelectionStart
345 * @see java.awt.TextComponent#getSelectionEnd
346 */
347 public synchronized int getSelectionStart() {
348 TextComponentPeer peer = (TextComponentPeer)this.peer;
349 if (peer != null) {
350 selectionStart = peer.getSelectionStart();
351 }
352 return selectionStart;
353 }
354
355 /**
356 * Sets the selection start for this text component to
357 * the specified position. The new start point is constrained
358 * to be at or before the current selection end. It also
359 * cannot be set to less than zero, the beginning of the
360 * component's text.
361 * If the caller supplies a value for <code>selectionStart</code>
362 * that is out of bounds, the method enforces these constraints
363 * silently, and without failure.
364 * @param selectionStart the start position of the
365 * selected text
366 * @see java.awt.TextComponent#getSelectionStart
367 * @see java.awt.TextComponent#setSelectionEnd
368 * @since JDK1.1
369 */
370 public synchronized void setSelectionStart(int selectionStart) {
371 /* Route through select method to enforce consistent policy
372 * between selectionStart and selectionEnd.
373 */
374 select(selectionStart, getSelectionEnd());
375 }
376
377 /**
378 * Gets the end position of the selected text in
379 * this text component.
380 * @return the end position of the selected text
381 * @see java.awt.TextComponent#setSelectionEnd
382 * @see java.awt.TextComponent#getSelectionStart
383 */
384 public synchronized int getSelectionEnd() {
385 TextComponentPeer peer = (TextComponentPeer)this.peer;
386 if (peer != null) {
387 selectionEnd = peer.getSelectionEnd();
388 }
389 return selectionEnd;
390 }
391
392 /**
393 * Sets the selection end for this text component to
394 * the specified position. The new end point is constrained
395 * to be at or after the current selection start. It also
396 * cannot be set beyond the end of the component's text.
397 * If the caller supplies a value for <code>selectionEnd</code>
398 * that is out of bounds, the method enforces these constraints
399 * silently, and without failure.
400 * @param selectionEnd the end position of the
401 * selected text
402 * @see java.awt.TextComponent#getSelectionEnd
403 * @see java.awt.TextComponent#setSelectionStart
404 * @since JDK1.1
405 */
406 public synchronized void setSelectionEnd(int selectionEnd) {
407 /* Route through select method to enforce consistent policy
408 * between selectionStart and selectionEnd.
409 */
410 select(getSelectionStart(), selectionEnd);
411 }
412
413 /**
414 * Selects the text between the specified start and end positions.
415 * <p>
416 * This method sets the start and end positions of the
417 * selected text, enforcing the restriction that the start position
418 * must be greater than or equal to zero. The end position must be
419 * greater than or equal to the start position, and less than or
420 * equal to the length of the text component's text. The
421 * character positions are indexed starting with zero.
422 * The length of the selection is
423 * <code>endPosition</code> - <code>startPosition</code>, so the
424 * character at <code>endPosition</code> is not selected.
425 * If the start and end positions of the selected text are equal,
426 * all text is deselected.
427 * <p>
428 * If the caller supplies values that are inconsistent or out of
429 * bounds, the method enforces these constraints silently, and
430 * without failure. Specifically, if the start position or end
431 * position is greater than the length of the text, it is reset to
432 * equal the text length. If the start position is less than zero,
433 * it is reset to zero, and if the end position is less than the
434 * start position, it is reset to the start position.
435 *
436 * @param selectionStart the zero-based index of the first
437 character (<code>char</code> value) to be selected
438 * @param selectionEnd the zero-based end position of the
439 text to be selected; the character (<code>char</code> value) at
440 <code>selectionEnd</code> is not selected
441 * @see java.awt.TextComponent#setSelectionStart
442 * @see java.awt.TextComponent#setSelectionEnd
443 * @see java.awt.TextComponent#selectAll
444 */
445 public synchronized void select(int selectionStart, int selectionEnd) {
446 String text = getText();
447 if (selectionStart < 0) {
448 selectionStart = 0;
449 }
450 if (selectionStart > text.length()) {
451 selectionStart = text.length();
452 }
453 if (selectionEnd > text.length()) {
454 selectionEnd = text.length();
455 }
456 if (selectionEnd < selectionStart) {
457 selectionEnd = selectionStart;
458 }
459
460 this.selectionStart = selectionStart;
461 this.selectionEnd = selectionEnd;
462
463 TextComponentPeer peer = (TextComponentPeer)this.peer;
464 if (peer != null) {
465 peer.select(selectionStart, selectionEnd);
466 }
467 }
468
469 /**
470 * Selects all the text in this text component.
471 * @see java.awt.TextComponent#select
472 */
473 public synchronized void selectAll() {
474 this.selectionStart = 0;
475 this.selectionEnd = getText().length();
476
477 TextComponentPeer peer = (TextComponentPeer)this.peer;
478 if (peer != null) {
479 peer.select(selectionStart, selectionEnd);
480 }
481 }
482
483 /**
484 * Sets the position of the text insertion caret.
485 * The caret position is constrained to be between 0
486 * and the last character of the text, inclusive.
487 * If the passed-in value is greater than this range,
488 * the value is set to the last character (or 0 if
489 * the <code>TextComponent</code> contains no text)
490 * and no error is returned. If the passed-in value is
491 * less than 0, an <code>IllegalArgumentException</code>
492 * is thrown.
493 *
494 * @param position the position of the text insertion caret
495 * @exception IllegalArgumentException if <code>position</code>
496 * is less than zero
497 * @since JDK1.1
498 */
499 public synchronized void setCaretPosition(int position) {
500 if (position < 0) {
501 throw new IllegalArgumentException("position less than zero.");
502 }
503
504 int maxposition = getText().length();
505 if (position > maxposition) {
506 position = maxposition;
507 }
508
509 TextComponentPeer peer = (TextComponentPeer)this.peer;
510 if (peer != null) {
511 peer.setCaretPosition(position);
512 } else {
513 select(position, position);
514 }
515 }
516
517 /**
518 * Returns the position of the text insertion caret.
519 * The caret position is constrained to be between 0
520 * and the last character of the text, inclusive.
521 * If the text or caret have not been set, the default
522 * caret position is 0.
523 *
524 * @return the position of the text insertion caret
525 * @see #setCaretPosition(int)
526 * @since JDK1.1
527 */
528 public synchronized int getCaretPosition() {
529 TextComponentPeer peer = (TextComponentPeer)this.peer;
530 int position = 0;
531
532 if (peer != null) {
533 position = peer.getCaretPosition();
534 } else {
535 position = selectionStart;
536 }
537 int maxposition = getText().length();
538 if (position > maxposition) {
539 position = maxposition;
540 }
541 return position;
542 }
543
544 /**
545 * Adds the specified text event listener to receive text events
546 * from this text component.
547 * If <code>l</code> is <code>null</code>, no exception is
548 * thrown and no action is performed.
549 * <p>Refer to <a href="doc-files/AWTThreadIssues.html#ListenersThreads"
550 * >AWT Threading Issues</a> for details on AWT's threading model.
551 *
552 * @param l the text event listener
553 * @see #removeTextListener
554 * @see #getTextListeners
555 * @see java.awt.event.TextListener
556 */
557 public synchronized void addTextListener(TextListener l) {
558 if (l == null) {
559 return;
560 }
561 textListener = AWTEventMulticaster.add(textListener, l);
562 newEventsOnly = true;
563 }
564
565 /**
566 * Removes the specified text event listener so that it no longer
567 * receives text events from this text component
568 * If <code>l</code> is <code>null</code>, no exception is
569 * thrown and no action is performed.
570 * <p>Refer to <a href="doc-files/AWTThreadIssues.html#ListenersThreads"
571 * >AWT Threading Issues</a> for details on AWT's threading model.
572 *
573 * @param l the text listener
574 * @see #addTextListener
575 * @see #getTextListeners
576 * @see java.awt.event.TextListener
577 * @since JDK1.1
578 */
579 public synchronized void removeTextListener(TextListener l) {
580 if (l == null) {
581 return;
582 }
583 textListener = AWTEventMulticaster.remove(textListener, l);
584 }
585
586 /**
587 * Returns an array of all the text listeners
588 * registered on this text component.
589 *
590 * @return all of this text component's <code>TextListener</code>s
591 * or an empty array if no text
592 * listeners are currently registered
593 *
594 *
595 * @see #addTextListener
596 * @see #removeTextListener
597 * @since 1.4
598 */
599 public synchronized TextListener[] getTextListeners() {
600 return getListeners(TextListener.class);
601 }
602
603 /**
604 * Returns an array of all the objects currently registered
605 * as <code><em>Foo</em>Listener</code>s
606 * upon this <code>TextComponent</code>.
607 * <code><em>Foo</em>Listener</code>s are registered using the
608 * <code>add<em>Foo</em>Listener</code> method.
609 *
610 * <p>
611 * You can specify the <code>listenerType</code> argument
612 * with a class literal, such as
613 * <code><em>Foo</em>Listener.class</code>.
614 * For example, you can query a
615 * <code>TextComponent</code> <code>t</code>
616 * for its text listeners with the following code:
617 *
618 * <pre>TextListener[] tls = (TextListener[])(t.getListeners(TextListener.class));</pre>
619 *
620 * If no such listeners exist, this method returns an empty array.
621 *
622 * @param listenerType the type of listeners requested; this parameter
623 * should specify an interface that descends from
624 * <code>java.util.EventListener</code>
625 * @return an array of all objects registered as
626 * <code><em>Foo</em>Listener</code>s on this text component,
627 * or an empty array if no such
628 * listeners have been added
629 * @exception ClassCastException if <code>listenerType</code>
630 * doesn't specify a class or interface that implements
631 * <code>java.util.EventListener</code>
632 *
633 * @see #getTextListeners
634 * @since 1.3
635 */
636 public <T extends EventListener> T[] getListeners(Class<T> listenerType) {
637 EventListener l = null;
638 if (listenerType == TextListener.class) {
639 l = textListener;
640 } else {
641 return super.getListeners(listenerType);
642 }
643 return AWTEventMulticaster.getListeners(l, listenerType);
644 }
645
646 // REMIND: remove when filtering is done at lower level
647 boolean eventEnabled(AWTEvent e) {
648 if (e.id == TextEvent.TEXT_VALUE_CHANGED) {
649 if ((eventMask & AWTEvent.TEXT_EVENT_MASK) != 0 ||
650 textListener != null) {
651 return true;
652 }
653 return false;
654 }
655 return super.eventEnabled(e);
656 }
657
658 /**
659 * Processes events on this text component. If the event is a
660 * <code>TextEvent</code>, it invokes the <code>processTextEvent</code>
661 * method else it invokes its superclass's <code>processEvent</code>.
662 * <p>Note that if the event parameter is <code>null</code>
663 * the behavior is unspecified and may result in an
664 * exception.
665 *
666 * @param e the event
667 */
668 protected void processEvent(AWTEvent e) {
669 if (e instanceof TextEvent) {
670 processTextEvent((TextEvent)e);
671 return;
672 }
673 super.processEvent(e);
674 }
675
676 /**
677 * Processes text events occurring on this text component by
678 * dispatching them to any registered <code>TextListener</code> objects.
679 * <p>
680 * NOTE: This method will not be called unless text events
681 * are enabled for this component. This happens when one of the
682 * following occurs:
683 * <ul>
684 * <li>A <code>TextListener</code> object is registered
685 * via <code>addTextListener</code>
686 * <li>Text events are enabled via <code>enableEvents</code>
687 * </ul>
688 * <p>Note that if the event parameter is <code>null</code>
689 * the behavior is unspecified and may result in an
690 * exception.
691 *
692 * @param e the text event
693 * @see Component#enableEvents
694 */
695 protected void processTextEvent(TextEvent e) {
696 TextListener listener = textListener;
697 if (listener != null) {
698 int id = e.getID();
699 switch (id) {
700 case TextEvent.TEXT_VALUE_CHANGED:
701 listener.textValueChanged(e);
702 break;
703 }
704 }
705 }
706
707 /**
708 * Returns a string representing the state of this
709 * <code>TextComponent</code>. This
710 * method is intended to be used only for debugging purposes, and the
711 * content and format of the returned string may vary between
712 * implementations. The returned string may be empty but may not be
713 * <code>null</code>.
714 *
715 * @return the parameter string of this text component
716 */
717 protected String paramString() {
718 String str = super.paramString() + ",text=" + getText();
719 if (editable) {
720 str += ",editable";
721 }
722 return str + ",selection=" + getSelectionStart() + "-" + getSelectionEnd();
723 }
724
725 /**
726 * Assigns a valid value to the canAccessClipboard instance variable.
727 */
728 private boolean canAccessClipboard() {
729 SecurityManager sm = System.getSecurityManager();
730 if (sm == null) return true;
731 try {
732 sm.checkPermission(AWTPermissions.ACCESS_CLIPBOARD_PERMISSION);
733 return true;
734 } catch (SecurityException e) {}
735 return false;
736 }
737
738 /*
739 * Serialization support.
740 */
741 /**
742 * The textComponent SerializedDataVersion.
743 *
744 * @serial
745 */
746 private int textComponentSerializedDataVersion = 1;
747
748 /**
749 * Writes default serializable fields to stream. Writes
750 * a list of serializable TextListener(s) as optional data.
751 * The non-serializable TextListener(s) are detected and
752 * no attempt is made to serialize them.
753 *
754 * @serialData Null terminated sequence of zero or more pairs.
755 * A pair consists of a String and Object.
756 * The String indicates the type of object and
757 * is one of the following :
758 * textListenerK indicating and TextListener object.
759 *
760 * @see AWTEventMulticaster#save(ObjectOutputStream, String, EventListener)
761 * @see java.awt.Component#textListenerK
762 */
763 private void writeObject(java.io.ObjectOutputStream s)
764 throws IOException
765 {
766 // Serialization support. Since the value of the fields
767 // selectionStart, selectionEnd, and text aren't necessarily
768 // up to date, we sync them up with the peer before serializing.
769 TextComponentPeer peer = (TextComponentPeer)this.peer;
770 if (peer != null) {
771 text = peer.getText();
772 selectionStart = peer.getSelectionStart();
773 selectionEnd = peer.getSelectionEnd();
774 }
775
776 s.defaultWriteObject();
777
778 AWTEventMulticaster.save(s, textListenerK, textListener);
779 s.writeObject(null);
780 }
781
782 /**
783 * Read the ObjectInputStream, and if it isn't null,
784 * add a listener to receive text events fired by the
785 * TextComponent. Unrecognized keys or values will be
786 * ignored.
787 *
788 * @exception HeadlessException if
789 * <code>GraphicsEnvironment.isHeadless()</code> returns
790 * <code>true</code>
791 * @see #removeTextListener
792 * @see #addTextListener
793 * @see java.awt.GraphicsEnvironment#isHeadless
794 */
795 private void readObject(ObjectInputStream s)
796 throws ClassNotFoundException, IOException, HeadlessException
797 {
798 GraphicsEnvironment.checkHeadless();
799 s.defaultReadObject();
800
801 // Make sure the state we just read in for text,
802 // selectionStart and selectionEnd has legal values
803 this.text = (text != null) ? text : "";
804 select(selectionStart, selectionEnd);
805
806 Object keyOrNull;
807 while(null != (keyOrNull = s.readObject())) {
808 String key = ((String)keyOrNull).intern();
809
810 if (textListenerK == key) {
811 addTextListener((TextListener)(s.readObject()));
812 } else {
813 // skip value for unrecognized key
814 s.readObject();
815 }
816 }
817 enableInputMethodsIfNecessary();
818 }
819
820
821 /////////////////
822 // Accessibility support
823 ////////////////
824
825 /**
826 * Gets the AccessibleContext associated with this TextComponent.
827 * For text components, the AccessibleContext takes the form of an
828 * AccessibleAWTTextComponent.
829 * A new AccessibleAWTTextComponent instance is created if necessary.
830 *
831 * @return an AccessibleAWTTextComponent that serves as the
832 * AccessibleContext of this TextComponent
833 * @since 1.3
834 */
835 public AccessibleContext getAccessibleContext() {
836 if (accessibleContext == null) {
837 accessibleContext = new AccessibleAWTTextComponent();
838 }
839 return accessibleContext;
840 }
841
842 /**
843 * This class implements accessibility support for the
844 * <code>TextComponent</code> class. It provides an implementation of the
845 * Java Accessibility API appropriate to text component user-interface
846 * elements.
847 * @since 1.3
848 */
849 protected class AccessibleAWTTextComponent extends AccessibleAWTComponent
850 implements AccessibleText, TextListener
851 {
852 /*
853 * JDK 1.3 serialVersionUID
854 */
855 private static final long serialVersionUID = 3631432373506317811L;
856
857 /**
858 * Constructs an AccessibleAWTTextComponent. Adds a listener to track
859 * caret change.
860 */
861 public AccessibleAWTTextComponent() {
862 TextComponent.this.addTextListener(this);
863 }
864
865 /**
866 * TextListener notification of a text value change.
867 */
868 public void textValueChanged(TextEvent textEvent) {
869 Integer cpos = Integer.valueOf(TextComponent.this.getCaretPosition());
870 firePropertyChange(ACCESSIBLE_TEXT_PROPERTY, null, cpos);
871 }
872
873 /**
874 * Gets the state set of the TextComponent.
875 * The AccessibleStateSet of an object is composed of a set of
876 * unique AccessibleStates. A change in the AccessibleStateSet
877 * of an object will cause a PropertyChangeEvent to be fired
878 * for the AccessibleContext.ACCESSIBLE_STATE_PROPERTY property.
879 *
880 * @return an instance of AccessibleStateSet containing the
881 * current state set of the object
882 * @see AccessibleStateSet
883 * @see AccessibleState
884 * @see #addPropertyChangeListener
885 */
886 public AccessibleStateSet getAccessibleStateSet() {
887 AccessibleStateSet states = super.getAccessibleStateSet();
888 if (TextComponent.this.isEditable()) {
889 states.add(AccessibleState.EDITABLE);
890 }
891 return states;
892 }
893
894
895 /**
896 * Gets the role of this object.
897 *
898 * @return an instance of AccessibleRole describing the role of the
899 * object (AccessibleRole.TEXT)
900 * @see AccessibleRole
901 */
902 public AccessibleRole getAccessibleRole() {
903 return AccessibleRole.TEXT;
904 }
905
906 /**
907 * Get the AccessibleText associated with this object. In the
908 * implementation of the Java Accessibility API for this class,
909 * return this object, which is responsible for implementing the
910 * AccessibleText interface on behalf of itself.
911 *
912 * @return this object
913 */
914 public AccessibleText getAccessibleText() {
915 return this;
916 }
917
918
919 // --- interface AccessibleText methods ------------------------
920
921 /**
922 * Many of these methods are just convenience methods; they
923 * just call the equivalent on the parent
924 */
925
926 /**
927 * Given a point in local coordinates, return the zero-based index
928 * of the character under that Point. If the point is invalid,
929 * this method returns -1.
930 *
931 * @param p the Point in local coordinates
932 * @return the zero-based index of the character under Point p.
933 */
934 public int getIndexAtPoint(Point p) {
935 return -1;
936 }
937
938 /**
939 * Determines the bounding box of the character at the given
940 * index into the string. The bounds are returned in local
941 * coordinates. If the index is invalid a null rectangle
942 * is returned.
943 *
944 * @param i the index into the String >= 0
945 * @return the screen coordinates of the character's bounding box
946 */
947 public Rectangle getCharacterBounds(int i) {
948 return null;
949 }
950
951 /**
952 * Returns the number of characters (valid indicies)
953 *
954 * @return the number of characters >= 0
955 */
956 public int getCharCount() {
957 return TextComponent.this.getText().length();
958 }
959
960 /**
961 * Returns the zero-based offset of the caret.
962 *
963 * Note: The character to the right of the caret will have the
964 * same index value as the offset (the caret is between
965 * two characters).
966 *
967 * @return the zero-based offset of the caret.
968 */
969 public int getCaretPosition() {
970 return TextComponent.this.getCaretPosition();
971 }
972
973 /**
974 * Returns the AttributeSet for a given character (at a given index).
975 *
976 * @param i the zero-based index into the text
977 * @return the AttributeSet of the character
978 */
979 public AttributeSet getCharacterAttribute(int i) {
980 return null; // No attributes in TextComponent
981 }
982
983 /**
984 * Returns the start offset within the selected text.
985 * If there is no selection, but there is
986 * a caret, the start and end offsets will be the same.
987 * Return 0 if the text is empty, or the caret position
988 * if no selection.
989 *
990 * @return the index into the text of the start of the selection >= 0
991 */
992 public int getSelectionStart() {
993 return TextComponent.this.getSelectionStart();
994 }
995
996 /**
997 * Returns the end offset within the selected text.
998 * If there is no selection, but there is
999 * a caret, the start and end offsets will be the same.
1000 * Return 0 if the text is empty, or the caret position
1001 * if no selection.
1002 *
1003 * @return the index into the text of the end of the selection >= 0
1004 */
1005 public int getSelectionEnd() {
1006 return TextComponent.this.getSelectionEnd();
1007 }
1008
1009 /**
1010 * Returns the portion of the text that is selected.
1011 *
1012 * @return the text, null if no selection
1013 */
1014 public String getSelectedText() {
1015 String selText = TextComponent.this.getSelectedText();
1016 // Fix for 4256662
1017 if (selText == null || selText.equals("")) {
1018 return null;
1019 }
1020 return selText;
1021 }
1022
1023 /**
1024 * Returns the String at a given index.
1025 *
1026 * @param part the AccessibleText.CHARACTER, AccessibleText.WORD,
1027 * or AccessibleText.SENTENCE to retrieve
1028 * @param index an index within the text >= 0
1029 * @return the letter, word, or sentence,
1030 * null for an invalid index or part
1031 */
1032 public String getAtIndex(int part, int index) {
1033 if (index < 0 || index >= TextComponent.this.getText().length()) {
1034 return null;
1035 }
1036 switch (part) {
1037 case AccessibleText.CHARACTER:
1038 return TextComponent.this.getText().substring(index, index+1);
1039 case AccessibleText.WORD: {
1040 String s = TextComponent.this.getText();
1041 BreakIterator words = BreakIterator.getWordInstance();
1042 words.setText(s);
1043 int end = words.following(index);
1044 return s.substring(words.previous(), end);
1045 }
1046 case AccessibleText.SENTENCE: {
1047 String s = TextComponent.this.getText();
1048 BreakIterator sentence = BreakIterator.getSentenceInstance();
1049 sentence.setText(s);
1050 int end = sentence.following(index);
1051 return s.substring(sentence.previous(), end);
1052 }
1053 default:
1054 return null;
1055 }
1056 }
1057
1058 private static final boolean NEXT = true;
1059 private static final boolean PREVIOUS = false;
1060
1061 /**
1062 * Needed to unify forward and backward searching.
1063 * The method assumes that s is the text assigned to words.
1064 */
1065 private int findWordLimit(int index, BreakIterator words, boolean direction,
1066 String s) {
1067 // Fix for 4256660 and 4256661.
1068 // Words iterator is different from character and sentence iterators
1069 // in that end of one word is not necessarily start of another word.
1070 // Please see java.text.BreakIterator JavaDoc. The code below is
1071 // based on nextWordStartAfter example from BreakIterator.java.
1072 int last = (direction == NEXT) ? words.following(index)
1073 : words.preceding(index);
1074 int current = (direction == NEXT) ? words.next()
1075 : words.previous();
1076 while (current != BreakIterator.DONE) {
1077 for (int p = Math.min(last, current); p < Math.max(last, current); p++) {
1078 if (Character.isLetter(s.charAt(p))) {
1079 return last;
1080 }
1081 }
1082 last = current;
1083 current = (direction == NEXT) ? words.next()
1084 : words.previous();
1085 }
1086 return BreakIterator.DONE;
1087 }
1088
1089 /**
1090 * Returns the String after a given index.
1091 *
1092 * @param part the AccessibleText.CHARACTER, AccessibleText.WORD,
1093 * or AccessibleText.SENTENCE to retrieve
1094 * @param index an index within the text >= 0
1095 * @return the letter, word, or sentence, null for an invalid
1096 * index or part
1097 */
1098 public String getAfterIndex(int part, int index) {
1099 if (index < 0 || index >= TextComponent.this.getText().length()) {
1100 return null;
1101 }
1102 switch (part) {
1103 case AccessibleText.CHARACTER:
1104 if (index+1 >= TextComponent.this.getText().length()) {
1105 return null;
1106 }
1107 return TextComponent.this.getText().substring(index+1, index+2);
1108 case AccessibleText.WORD: {
1109 String s = TextComponent.this.getText();
1110 BreakIterator words = BreakIterator.getWordInstance();
1111 words.setText(s);
1112 int start = findWordLimit(index, words, NEXT, s);
1113 if (start == BreakIterator.DONE || start >= s.length()) {
1114 return null;
1115 }
1116 int end = words.following(start);
1117 if (end == BreakIterator.DONE || end >= s.length()) {
1118 return null;
1119 }
1120 return s.substring(start, end);
1121 }
1122 case AccessibleText.SENTENCE: {
1123 String s = TextComponent.this.getText();
1124 BreakIterator sentence = BreakIterator.getSentenceInstance();
1125 sentence.setText(s);
1126 int start = sentence.following(index);
1127 if (start == BreakIterator.DONE || start >= s.length()) {
1128 return null;
1129 }
1130 int end = sentence.following(start);
1131 if (end == BreakIterator.DONE || end >= s.length()) {
1132 return null;
1133 }
1134 return s.substring(start, end);
1135 }
1136 default:
1137 return null;
1138 }
1139 }
1140
1141
1142 /**
1143 * Returns the String before a given index.
1144 *
1145 * @param part the AccessibleText.CHARACTER, AccessibleText.WORD,
1146 * or AccessibleText.SENTENCE to retrieve
1147 * @param index an index within the text >= 0
1148 * @return the letter, word, or sentence, null for an invalid index
1149 * or part
1150 */
1151 public String getBeforeIndex(int part, int index) {
1152 if (index < 0 || index > TextComponent.this.getText().length()-1) {
1153 return null;
1154 }
1155 switch (part) {
1156 case AccessibleText.CHARACTER:
1157 if (index == 0) {
1158 return null;
1159 }
1160 return TextComponent.this.getText().substring(index-1, index);
1161 case AccessibleText.WORD: {
1162 String s = TextComponent.this.getText();
1163 BreakIterator words = BreakIterator.getWordInstance();
1164 words.setText(s);
1165 int end = findWordLimit(index, words, PREVIOUS, s);
1166 if (end == BreakIterator.DONE) {
1167 return null;
1168 }
1169 int start = words.preceding(end);
1170 if (start == BreakIterator.DONE) {
1171 return null;
1172 }
1173 return s.substring(start, end);
1174 }
1175 case AccessibleText.SENTENCE: {
1176 String s = TextComponent.this.getText();
1177 BreakIterator sentence = BreakIterator.getSentenceInstance();
1178 sentence.setText(s);
1179 int end = sentence.following(index);
1180 end = sentence.previous();
1181 int start = sentence.previous();
1182 if (start == BreakIterator.DONE) {
1183 return null;
1184 }
1185 return s.substring(start, end);
1186 }
1187 default:
1188 return null;
1189 }
1190 }
1191 } // end of AccessibleAWTTextComponent
1192
1193 private boolean checkForEnableIM = true;
1194 }