1 /*
2 * Copyright (c) 1995, 2006, 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.event.InputEvent;
28 import java.awt.event.KeyEvent;
29 import java.awt.peer.TextAreaPeer;
30 import java.io.ObjectOutputStream;
31 import java.io.ObjectInputStream;
32 import java.io.IOException;
33 import java.util.HashSet;
34 import java.util.Set;
35 import javax.accessibility.*;
36
37 /**
38 * A <code>TextArea</code> object is a multi-line region
39 * that displays text. It can be set to allow editing or
40 * to be read-only.
41 * <p>
42 * The following image shows the appearance of a text area:
43 * <p>
44 * <img src="doc-files/TextArea-1.gif" alt="A TextArea showing the word 'Hello!'"
45 * ALIGN=center HSPACE=10 VSPACE=7>
46 * <p>
47 * This text area could be created by the following line of code:
48 * <p>
49 * <hr><blockquote><pre>
50 * new TextArea("Hello", 5, 40);
51 * </pre></blockquote><hr>
52 * <p>
53 * @author Sami Shaio
54 * @since JDK1.0
55 */
56 public class TextArea extends TextComponent {
57
58 /**
59 * The number of rows in the <code>TextArea</code>.
60 * This parameter will determine the text area's height.
61 * Guaranteed to be non-negative.
62 *
63 * @serial
64 * @see #getRows()
65 * @see #setRows(int)
66 */
67 int rows;
68
69 /**
70 * The number of columns in the <code>TextArea</code>.
71 * A column is an approximate average character
72 * width that is platform-dependent.
73 * This parameter will determine the text area's width.
74 * Guaranteed to be non-negative.
75 *
76 * @serial
77 * @see #setColumns(int)
78 * @see #getColumns()
79 */
80 int columns;
81
82 private static final String base = "text";
83 private static int nameCounter = 0;
84
85 /**
86 * Create and display both vertical and horizontal scrollbars.
87 * @since JDK1.1
88 */
89 public static final int SCROLLBARS_BOTH = 0;
90
91 /**
92 * Create and display vertical scrollbar only.
93 * @since JDK1.1
94 */
95 public static final int SCROLLBARS_VERTICAL_ONLY = 1;
96
97 /**
98 * Create and display horizontal scrollbar only.
99 * @since JDK1.1
100 */
101 public static final int SCROLLBARS_HORIZONTAL_ONLY = 2;
102
103 /**
104 * Do not create or display any scrollbars for the text area.
105 * @since JDK1.1
106 */
107 public static final int SCROLLBARS_NONE = 3;
108
109 /**
110 * Determines which scrollbars are created for the
111 * text area. It can be one of four values :
112 * <code>SCROLLBARS_BOTH</code> = both scrollbars.<BR>
113 * <code>SCROLLBARS_HORIZONTAL_ONLY</code> = Horizontal bar only.<BR>
114 * <code>SCROLLBARS_VERTICAL_ONLY</code> = Vertical bar only.<BR>
115 * <code>SCROLLBARS_NONE</code> = No scrollbars.<BR>
116 *
117 * @serial
118 * @see #getScrollbarVisibility()
119 */
120 private int scrollbarVisibility;
121
122 /**
123 * Cache the Sets of forward and backward traversal keys so we need not
124 * look them up each time.
125 */
126 private static Set forwardTraversalKeys, backwardTraversalKeys;
127
128 /*
129 * JDK 1.1 serialVersionUID
130 */
131 private static final long serialVersionUID = 3692302836626095722L;
132
133 /**
134 * Initialize JNI field and method ids
135 */
136 private static native void initIDs();
137
138 static {
139 /* ensure that the necessary native libraries are loaded */
140 Toolkit.loadLibraries();
141 if (!GraphicsEnvironment.isHeadless()) {
142 initIDs();
143 }
144 forwardTraversalKeys = KeyboardFocusManager.initFocusTraversalKeysSet(
145 "ctrl TAB",
146 new HashSet());
147 backwardTraversalKeys = KeyboardFocusManager.initFocusTraversalKeysSet(
148 "ctrl shift TAB",
149 new HashSet());
150 }
151
152 /**
153 * Constructs a new text area with the empty string as text.
154 * This text area is created with scrollbar visibility equal to
155 * {@link #SCROLLBARS_BOTH}, so both vertical and horizontal
156 * scrollbars will be visible for this text area.
157 * @exception HeadlessException if
158 * <code>GraphicsEnvironment.isHeadless</code> returns true
159 * @see java.awt.GraphicsEnvironment#isHeadless()
160 */
161 public TextArea() throws HeadlessException {
162 this("", 0, 0, SCROLLBARS_BOTH);
163 }
164
165 /**
166 * Constructs a new text area with the specified text.
167 * This text area is created with scrollbar visibility equal to
168 * {@link #SCROLLBARS_BOTH}, so both vertical and horizontal
169 * scrollbars will be visible for this text area.
170 * @param text the text to be displayed; if
171 * <code>text</code> is <code>null</code>, the empty
172 * string <code>""</code> will be displayed
173 * @exception HeadlessException if
174 * <code>GraphicsEnvironment.isHeadless</code> returns true
175 * @see java.awt.GraphicsEnvironment#isHeadless()
176 */
177 public TextArea(String text) throws HeadlessException {
178 this(text, 0, 0, SCROLLBARS_BOTH);
179 }
180
181 /**
182 * Constructs a new text area with the specified number of
183 * rows and columns and the empty string as text.
184 * A column is an approximate average character
185 * width that is platform-dependent. The text area is created with
186 * scrollbar visibility equal to {@link #SCROLLBARS_BOTH}, so both
187 * vertical and horizontal scrollbars will be visible for this
188 * text area.
189 * @param rows the number of rows
190 * @param columns the number of columns
191 * @exception HeadlessException if
192 * <code>GraphicsEnvironment.isHeadless</code> returns true
193 * @see java.awt.GraphicsEnvironment#isHeadless()
194 */
195 public TextArea(int rows, int columns) throws HeadlessException {
196 this("", rows, columns, SCROLLBARS_BOTH);
197 }
198
199 /**
200 * Constructs a new text area with the specified text,
201 * and with the specified number of rows and columns.
202 * A column is an approximate average character
203 * width that is platform-dependent. The text area is created with
204 * scrollbar visibility equal to {@link #SCROLLBARS_BOTH}, so both
205 * vertical and horizontal scrollbars will be visible for this
206 * text area.
207 * @param text the text to be displayed; if
208 * <code>text</code> is <code>null</code>, the empty
209 * string <code>""</code> will be displayed
210 * @param rows the number of rows
211 * @param columns the number of columns
212 * @exception HeadlessException if
213 * <code>GraphicsEnvironment.isHeadless</code> returns true
214 * @see java.awt.GraphicsEnvironment#isHeadless()
215 */
216 public TextArea(String text, int rows, int columns)
217 throws HeadlessException {
218 this(text, rows, columns, SCROLLBARS_BOTH);
219 }
220
221 /**
222 * Constructs a new text area with the specified text,
223 * and with the rows, columns, and scroll bar visibility
224 * as specified. All <code>TextArea</code> constructors defer to
225 * this one.
226 * <p>
227 * The <code>TextArea</code> class defines several constants
228 * that can be supplied as values for the
229 * <code>scrollbars</code> argument:
230 * <ul>
231 * <li><code>SCROLLBARS_BOTH</code>,
232 * <li><code>SCROLLBARS_VERTICAL_ONLY</code>,
233 * <li><code>SCROLLBARS_HORIZONTAL_ONLY</code>,
234 * <li><code>SCROLLBARS_NONE</code>.
235 * </ul>
236 * Any other value for the
237 * <code>scrollbars</code> argument is invalid and will result in
238 * this text area being created with scrollbar visibility equal to
239 * the default value of {@link #SCROLLBARS_BOTH}.
240 * @param text the text to be displayed; if
241 * <code>text</code> is <code>null</code>, the empty
242 * string <code>""</code> will be displayed
243 * @param rows the number of rows; if
244 * <code>rows</code> is less than <code>0</code>,
245 * <code>rows</code> is set to <code>0</code>
246 * @param columns the number of columns; if
247 * <code>columns</code> is less than <code>0</code>,
248 * <code>columns</code> is set to <code>0</code>
249 * @param scrollbars a constant that determines what
250 * scrollbars are created to view the text area
251 * @since JDK1.1
252 * @exception HeadlessException if
253 * <code>GraphicsEnvironment.isHeadless</code> returns true
254 * @see java.awt.GraphicsEnvironment#isHeadless()
255 */
256 public TextArea(String text, int rows, int columns, int scrollbars)
257 throws HeadlessException {
258 super(text);
259
260 this.rows = (rows >= 0) ? rows : 0;
261 this.columns = (columns >= 0) ? columns : 0;
262
263 if (scrollbars >= SCROLLBARS_BOTH && scrollbars <= SCROLLBARS_NONE) {
264 this.scrollbarVisibility = scrollbars;
265 } else {
266 this.scrollbarVisibility = SCROLLBARS_BOTH;
267 }
268
269 setFocusTraversalKeys(KeyboardFocusManager.FORWARD_TRAVERSAL_KEYS,
270 forwardTraversalKeys);
271 setFocusTraversalKeys(KeyboardFocusManager.BACKWARD_TRAVERSAL_KEYS,
272 backwardTraversalKeys);
273 }
274
275 /**
276 * Construct a name for this component. Called by <code>getName</code>
277 * when the name is <code>null</code>.
278 */
279 String constructComponentName() {
280 synchronized (TextArea.class) {
281 return base + nameCounter++;
282 }
283 }
284
285 /**
286 * Creates the <code>TextArea</code>'s peer. The peer allows us to modify
287 * the appearance of the <code>TextArea</code> without changing any of its
288 * functionality.
289 */
290 public void addNotify() {
291 synchronized (getTreeLock()) {
292 if (peer == null)
293 peer = getToolkit().createTextArea(this);
294 super.addNotify();
295 }
296 }
297
298 /**
299 * Inserts the specified text at the specified position
300 * in this text area.
301 * <p>Note that passing <code>null</code> or inconsistent
302 * parameters is invalid and will result in unspecified
303 * behavior.
304 *
305 * @param str the non-<code>null</code> text to insert
306 * @param pos the position at which to insert
307 * @see java.awt.TextComponent#setText
308 * @see java.awt.TextArea#replaceRange
309 * @see java.awt.TextArea#append
310 * @since JDK1.1
311 */
312 public void insert(String str, int pos) {
313 insertText(str, pos);
314 }
315
316 /**
317 * @deprecated As of JDK version 1.1,
318 * replaced by <code>insert(String, int)</code>.
319 */
320 @Deprecated
321 public synchronized void insertText(String str, int pos) {
322 TextAreaPeer peer = (TextAreaPeer)this.peer;
323 if (peer != null) {
324 peer.insert(str, pos);
325 } else {
326 text = text.substring(0, pos) + str + text.substring(pos);
327 }
328 }
329
330 /**
331 * Appends the given text to the text area's current text.
332 * <p>Note that passing <code>null</code> or inconsistent
333 * parameters is invalid and will result in unspecified
334 * behavior.
335 *
336 * @param str the non-<code>null</code> text to append
337 * @see java.awt.TextArea#insert
338 * @since JDK1.1
339 */
340 public void append(String str) {
341 appendText(str);
342 }
343
344 /**
345 * @deprecated As of JDK version 1.1,
346 * replaced by <code>append(String)</code>.
347 */
348 @Deprecated
349 public synchronized void appendText(String str) {
350 if (peer != null) {
351 insertText(str, getText().length());
352 } else {
353 text = text + str;
354 }
355 }
356
357 /**
358 * Replaces text between the indicated start and end positions
359 * with the specified replacement text. The text at the end
360 * position will not be replaced. The text at the start
361 * position will be replaced (unless the start position is the
362 * same as the end position).
363 * The text position is zero-based. The inserted substring may be
364 * of a different length than the text it replaces.
365 * <p>Note that passing <code>null</code> or inconsistent
366 * parameters is invalid and will result in unspecified
367 * behavior.
368 *
369 * @param str the non-<code>null</code> text to use as
370 * the replacement
371 * @param start the start position
372 * @param end the end position
373 * @see java.awt.TextArea#insert
374 * @since JDK1.1
375 */
376 public void replaceRange(String str, int start, int end) {
377 replaceText(str, start, end);
378 }
379
380 /**
381 * @deprecated As of JDK version 1.1,
382 * replaced by <code>replaceRange(String, int, int)</code>.
383 */
384 @Deprecated
385 public synchronized void replaceText(String str, int start, int end) {
386 TextAreaPeer peer = (TextAreaPeer)this.peer;
387 if (peer != null) {
388 peer.replaceRange(str, start, end);
389 } else {
390 text = text.substring(0, start) + str + text.substring(end);
391 }
392 }
393
394 /**
395 * Returns the number of rows in the text area.
396 * @return the number of rows in the text area
397 * @see #setRows(int)
398 * @see #getColumns()
399 * @since JDK1
400 */
401 public int getRows() {
402 return rows;
403 }
404
405 /**
406 * Sets the number of rows for this text area.
407 * @param rows the number of rows
408 * @see #getRows()
409 * @see #setColumns(int)
410 * @exception IllegalArgumentException if the value
411 * supplied for <code>rows</code>
412 * is less than <code>0</code>
413 * @since JDK1.1
414 */
415 public void setRows(int rows) {
416 int oldVal = this.rows;
417 if (rows < 0) {
418 throw new IllegalArgumentException("rows less than zero.");
419 }
420 if (rows != oldVal) {
421 this.rows = rows;
422 invalidate();
423 }
424 }
425
426 /**
427 * Returns the number of columns in this text area.
428 * @return the number of columns in the text area
429 * @see #setColumns(int)
430 * @see #getRows()
431 */
432 public int getColumns() {
433 return columns;
434 }
435
436 /**
437 * Sets the number of columns for this text area.
438 * @param columns the number of columns
439 * @see #getColumns()
440 * @see #setRows(int)
441 * @exception IllegalArgumentException if the value
442 * supplied for <code>columns</code>
443 * is less than <code>0</code>
444 * @since JDK1.1
445 */
446 public void setColumns(int columns) {
447 int oldVal = this.columns;
448 if (columns < 0) {
449 throw new IllegalArgumentException("columns less than zero.");
450 }
451 if (columns != oldVal) {
452 this.columns = columns;
453 invalidate();
454 }
455 }
456
457 /**
458 * Returns an enumerated value that indicates which scroll bars
459 * the text area uses.
460 * <p>
461 * The <code>TextArea</code> class defines four integer constants
462 * that are used to specify which scroll bars are available.
463 * <code>TextArea</code> has one constructor that gives the
464 * application discretion over scroll bars.
465 *
466 * @return an integer that indicates which scroll bars are used
467 * @see java.awt.TextArea#SCROLLBARS_BOTH
468 * @see java.awt.TextArea#SCROLLBARS_VERTICAL_ONLY
469 * @see java.awt.TextArea#SCROLLBARS_HORIZONTAL_ONLY
470 * @see java.awt.TextArea#SCROLLBARS_NONE
471 * @see java.awt.TextArea#TextArea(java.lang.String, int, int, int)
472 * @since JDK1.1
473 */
474 public int getScrollbarVisibility() {
475 return scrollbarVisibility;
476 }
477
478
479 /**
480 * Determines the preferred size of a text area with the specified
481 * number of rows and columns.
482 * @param rows the number of rows
483 * @param columns the number of columns
484 * @return the preferred dimensions required to display
485 * the text area with the specified
486 * number of rows and columns
487 * @see java.awt.Component#getPreferredSize
488 * @since JDK1.1
489 */
490 public Dimension getPreferredSize(int rows, int columns) {
491 return preferredSize(rows, columns);
492 }
493
494 /**
495 * @deprecated As of JDK version 1.1,
496 * replaced by <code>getPreferredSize(int, int)</code>.
497 */
498 @Deprecated
499 public Dimension preferredSize(int rows, int columns) {
500 synchronized (getTreeLock()) {
501 TextAreaPeer peer = (TextAreaPeer)this.peer;
502 return (peer != null) ?
503 peer.getPreferredSize(rows, columns) :
504 super.preferredSize();
505 }
506 }
507
508 /**
509 * Determines the preferred size of this text area.
510 * @return the preferred dimensions needed for this text area
511 * @see java.awt.Component#getPreferredSize
512 * @since JDK1.1
513 */
514 public Dimension getPreferredSize() {
515 return preferredSize();
516 }
517
518 /**
519 * @deprecated As of JDK version 1.1,
520 * replaced by <code>getPreferredSize()</code>.
521 */
522 @Deprecated
523 public Dimension preferredSize() {
524 synchronized (getTreeLock()) {
525 return ((rows > 0) && (columns > 0)) ?
526 preferredSize(rows, columns) :
527 super.preferredSize();
528 }
529 }
530
531 /**
532 * Determines the minimum size of a text area with the specified
533 * number of rows and columns.
534 * @param rows the number of rows
535 * @param columns the number of columns
536 * @return the minimum dimensions required to display
537 * the text area with the specified
538 * number of rows and columns
539 * @see java.awt.Component#getMinimumSize
540 * @since JDK1.1
541 */
542 public Dimension getMinimumSize(int rows, int columns) {
543 return minimumSize(rows, columns);
544 }
545
546 /**
547 * @deprecated As of JDK version 1.1,
548 * replaced by <code>getMinimumSize(int, int)</code>.
549 */
550 @Deprecated
551 public Dimension minimumSize(int rows, int columns) {
552 synchronized (getTreeLock()) {
553 TextAreaPeer peer = (TextAreaPeer)this.peer;
554 return (peer != null) ?
555 peer.getMinimumSize(rows, columns) :
556 super.minimumSize();
557 }
558 }
559
560 /**
561 * Determines the minimum size of this text area.
562 * @return the preferred dimensions needed for this text area
563 * @see java.awt.Component#getPreferredSize
564 * @since JDK1.1
565 */
566 public Dimension getMinimumSize() {
567 return minimumSize();
568 }
569
570 /**
571 * @deprecated As of JDK version 1.1,
572 * replaced by <code>getMinimumSize()</code>.
573 */
574 @Deprecated
575 public Dimension minimumSize() {
576 synchronized (getTreeLock()) {
577 return ((rows > 0) && (columns > 0)) ?
578 minimumSize(rows, columns) :
579 super.minimumSize();
580 }
581 }
582
583 /**
584 * Returns a string representing the state of this <code>TextArea</code>.
585 * This method is intended to be used only for debugging purposes, and the
586 * content and format of the returned string may vary between
587 * implementations. The returned string may be empty but may not be
588 * <code>null</code>.
589 *
590 * @return the parameter string of this text area
591 */
592 protected String paramString() {
593 String sbVisStr;
594 switch (scrollbarVisibility) {
595 case SCROLLBARS_BOTH:
596 sbVisStr = "both";
597 break;
598 case SCROLLBARS_VERTICAL_ONLY:
599 sbVisStr = "vertical-only";
600 break;
601 case SCROLLBARS_HORIZONTAL_ONLY:
602 sbVisStr = "horizontal-only";
603 break;
604 case SCROLLBARS_NONE:
605 sbVisStr = "none";
606 break;
607 default:
608 sbVisStr = "invalid display policy";
609 }
610
611 return super.paramString() + ",rows=" + rows +
612 ",columns=" + columns +
613 ",scrollbarVisibility=" + sbVisStr;
614 }
615
616
617 /*
618 * Serialization support.
619 */
620 /**
621 * The textArea Serialized Data Version.
622 *
623 * @serial
624 */
625 private int textAreaSerializedDataVersion = 2;
626
627 /**
628 * Read the ObjectInputStream.
629 * @exception HeadlessException if
630 * <code>GraphicsEnvironment.isHeadless()</code> returns
631 * <code>true</code>
632 * @see java.awt.GraphicsEnvironment#isHeadless
633 */
634 private void readObject(ObjectInputStream s)
635 throws ClassNotFoundException, IOException, HeadlessException
636 {
637 // HeadlessException will be thrown by TextComponent's readObject
638 s.defaultReadObject();
639
640 // Make sure the state we just read in for columns, rows,
641 // and scrollbarVisibility has legal values
642 if (columns < 0) {
643 columns = 0;
644 }
645 if (rows < 0) {
646 rows = 0;
647 }
648
649 if ((scrollbarVisibility < SCROLLBARS_BOTH) ||
650 (scrollbarVisibility > SCROLLBARS_NONE)) {
651 this.scrollbarVisibility = SCROLLBARS_BOTH;
652 }
653
654 if (textAreaSerializedDataVersion < 2) {
655 setFocusTraversalKeys(KeyboardFocusManager.FORWARD_TRAVERSAL_KEYS,
656 forwardTraversalKeys);
657 setFocusTraversalKeys(KeyboardFocusManager.BACKWARD_TRAVERSAL_KEYS,
658 backwardTraversalKeys);
659 }
660 }
661
662
663 /////////////////
664 // Accessibility support
665 ////////////////
666
667
668 /**
669 * Returns the <code>AccessibleContext</code> associated with
670 * this <code>TextArea</code>. For text areas, the
671 * <code>AccessibleContext</code> takes the form of an
672 * <code>AccessibleAWTTextArea</code>.
673 * A new <code>AccessibleAWTTextArea</code> instance is created if necessary.
674 *
675 * @return an <code>AccessibleAWTTextArea</code> that serves as the
676 * <code>AccessibleContext</code> of this <code>TextArea</code>
677 * @since 1.3
678 */
679 public AccessibleContext getAccessibleContext() {
680 if (accessibleContext == null) {
681 accessibleContext = new AccessibleAWTTextArea();
682 }
683 return accessibleContext;
684 }
685
686 /**
687 * This class implements accessibility support for the
688 * <code>TextArea</code> class. It provides an implementation of the
689 * Java Accessibility API appropriate to text area user-interface elements.
690 * @since 1.3
691 */
692 protected class AccessibleAWTTextArea extends AccessibleAWTTextComponent
693 {
694 /*
695 * JDK 1.3 serialVersionUID
696 */
697 private static final long serialVersionUID = 3472827823632144419L;
698
699 /**
700 * Gets the state set of this object.
701 *
702 * @return an instance of AccessibleStateSet describing the states
703 * of the object
704 * @see AccessibleStateSet
705 */
706 public AccessibleStateSet getAccessibleStateSet() {
707 AccessibleStateSet states = super.getAccessibleStateSet();
708 states.add(AccessibleState.MULTI_LINE);
709 return states;
710 }
711 }
712
713
714 }