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.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 * style="float:center; margin: 7px 10px;">
46 * <p>
47 * This text area could be created by the following line of code:
48 *
49 * <hr><blockquote><pre>
50 * new TextArea("Hello", 5, 40);
51 * </pre></blockquote><hr>
52 *
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<AWTKeyStroke> 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<AWTKeyStroke>());
147 backwardTraversalKeys = KeyboardFocusManager.initFocusTraversalKeysSet(
148 "ctrl shift TAB",
149 new HashSet<AWTKeyStroke>());
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 * Inserts the specified text at the specified position
318 * in this text area.
319 * @param str the non-{@code null} text to insert
320 * @param pos the position at which to insert
321 * @deprecated As of JDK version 1.1,
322 * replaced by <code>insert(String, int)</code>.
323 */
324 @Deprecated
325 public synchronized void insertText(String str, int pos) {
326 TextAreaPeer peer = (TextAreaPeer)this.peer;
327 if (peer != null) {
328 peer.insert(str, pos);
329 } else {
330 text = text.substring(0, pos) + str + text.substring(pos);
331 }
332 }
333
334 /**
335 * Appends the given text to the text area's current text.
336 * <p>Note that passing <code>null</code> or inconsistent
337 * parameters is invalid and will result in unspecified
338 * behavior.
339 *
340 * @param str the non-<code>null</code> text to append
341 * @see java.awt.TextArea#insert
342 * @since JDK1.1
343 */
344 public void append(String str) {
345 appendText(str);
346 }
347
348 /**
349 * Appends the given text to the text area's current text.
350 * @param str the text to append
351 * @deprecated As of JDK version 1.1,
352 * replaced by <code>append(String)</code>.
353 */
354 @Deprecated
355 public synchronized void appendText(String str) {
356 if (peer != null) {
357 insertText(str, getText().length());
358 } else {
359 text = text + str;
360 }
361 }
362
363 /**
364 * Replaces text between the indicated start and end positions
365 * with the specified replacement text. The text at the end
366 * position will not be replaced. The text at the start
367 * position will be replaced (unless the start position is the
368 * same as the end position).
369 * The text position is zero-based. The inserted substring may be
370 * of a different length than the text it replaces.
371 * <p>Note that passing <code>null</code> or inconsistent
372 * parameters is invalid and will result in unspecified
373 * behavior.
374 *
375 * @param str the non-<code>null</code> text to use as
376 * the replacement
377 * @param start the start position
378 * @param end the end position
379 * @see java.awt.TextArea#insert
380 * @since JDK1.1
381 */
382 public void replaceRange(String str, int start, int end) {
383 replaceText(str, start, end);
384 }
385
386 /**
387 * Replaces a range of characters between
388 * the indicated start and end positions
389 * with the specified replacement text (the text at the end
390 * position will not be replaced).
391 * @param str the non-{@code null} text to use as
392 * the replacement
393 * @param start the start position
394 * @param end the end position
395 * @deprecated As of JDK version 1.1,
396 * replaced by <code>replaceRange(String, int, int)</code>.
397 */
398 @Deprecated
399 public synchronized void replaceText(String str, int start, int end) {
400 TextAreaPeer peer = (TextAreaPeer)this.peer;
401 if (peer != null) {
402 peer.replaceRange(str, start, end);
403 } else {
404 text = text.substring(0, start) + str + text.substring(end);
405 }
406 }
407
408 /**
409 * Returns the number of rows in the text area.
410 * @return the number of rows in the text area
411 * @see #setRows(int)
412 * @see #getColumns()
413 * @since JDK1
414 */
415 public int getRows() {
416 return rows;
417 }
418
419 /**
420 * Sets the number of rows for this text area.
421 * @param rows the number of rows
422 * @see #getRows()
423 * @see #setColumns(int)
424 * @exception IllegalArgumentException if the value
425 * supplied for <code>rows</code>
426 * is less than <code>0</code>
427 * @since JDK1.1
428 */
429 public void setRows(int rows) {
430 int oldVal = this.rows;
431 if (rows < 0) {
432 throw new IllegalArgumentException("rows less than zero.");
433 }
434 if (rows != oldVal) {
435 this.rows = rows;
436 invalidate();
437 }
438 }
439
440 /**
441 * Returns the number of columns in this text area.
442 * @return the number of columns in the text area
443 * @see #setColumns(int)
444 * @see #getRows()
445 */
446 public int getColumns() {
447 return columns;
448 }
449
450 /**
451 * Sets the number of columns for this text area.
452 * @param columns the number of columns
453 * @see #getColumns()
454 * @see #setRows(int)
455 * @exception IllegalArgumentException if the value
456 * supplied for <code>columns</code>
457 * is less than <code>0</code>
458 * @since JDK1.1
459 */
460 public void setColumns(int columns) {
461 int oldVal = this.columns;
462 if (columns < 0) {
463 throw new IllegalArgumentException("columns less than zero.");
464 }
465 if (columns != oldVal) {
466 this.columns = columns;
467 invalidate();
468 }
469 }
470
471 /**
472 * Returns an enumerated value that indicates which scroll bars
473 * the text area uses.
474 * <p>
475 * The <code>TextArea</code> class defines four integer constants
476 * that are used to specify which scroll bars are available.
477 * <code>TextArea</code> has one constructor that gives the
478 * application discretion over scroll bars.
479 *
480 * @return an integer that indicates which scroll bars are used
481 * @see java.awt.TextArea#SCROLLBARS_BOTH
482 * @see java.awt.TextArea#SCROLLBARS_VERTICAL_ONLY
483 * @see java.awt.TextArea#SCROLLBARS_HORIZONTAL_ONLY
484 * @see java.awt.TextArea#SCROLLBARS_NONE
485 * @see java.awt.TextArea#TextArea(java.lang.String, int, int, int)
486 * @since JDK1.1
487 */
488 public int getScrollbarVisibility() {
489 return scrollbarVisibility;
490 }
491
492
493 /**
494 * Determines the preferred size of a text area with the specified
495 * number of rows and columns.
496 * @param rows the number of rows
497 * @param columns the number of columns
498 * @return the preferred dimensions required to display
499 * the text area with the specified
500 * number of rows and columns
501 * @see java.awt.Component#getPreferredSize
502 * @since JDK1.1
503 */
504 public Dimension getPreferredSize(int rows, int columns) {
505 return preferredSize(rows, columns);
506 }
507
508 /**
509 * Determines the preferred size of the text area with the specified
510 * number of rows and columns.
511 * @param rows the number of rows
512 * @param columns the number of columns
513 * @return the preferred dimensions needed for the text area
514 * @deprecated As of JDK version 1.1,
515 * replaced by <code>getPreferredSize(int, int)</code>.
516 */
517 @Deprecated
518 public Dimension preferredSize(int rows, int columns) {
519 synchronized (getTreeLock()) {
520 TextAreaPeer peer = (TextAreaPeer)this.peer;
521 return (peer != null) ?
522 peer.getPreferredSize(rows, columns) :
523 super.preferredSize();
524 }
525 }
526
527 /**
528 * Determines the preferred size of this text area.
529 * @return the preferred dimensions needed for this text area
530 * @see java.awt.Component#getPreferredSize
531 * @since JDK1.1
532 */
533 public Dimension getPreferredSize() {
534 return preferredSize();
535 }
536
537 /**
538 * @deprecated As of JDK version 1.1,
539 * replaced by <code>getPreferredSize()</code>.
540 */
541 @Deprecated
542 public Dimension preferredSize() {
543 synchronized (getTreeLock()) {
544 return ((rows > 0) && (columns > 0)) ?
545 preferredSize(rows, columns) :
546 super.preferredSize();
547 }
548 }
549
550 /**
551 * Determines the minimum size of a text area with the specified
552 * number of rows and columns.
553 * @param rows the number of rows
554 * @param columns the number of columns
555 * @return the minimum dimensions required to display
556 * the text area with the specified
557 * number of rows and columns
558 * @see java.awt.Component#getMinimumSize
559 * @since JDK1.1
560 */
561 public Dimension getMinimumSize(int rows, int columns) {
562 return minimumSize(rows, columns);
563 }
564
565 /**
566 * Determines the minimum size of the text area with the specified
567 * number of rows and columns.
568 * @param rows the number of rows
569 * @param columns the number of columns
570 * @return the minimum size for the text area
571 * @deprecated As of JDK version 1.1,
572 * replaced by <code>getMinimumSize(int, int)</code>.
573 */
574 @Deprecated
575 public Dimension minimumSize(int rows, int columns) {
576 synchronized (getTreeLock()) {
577 TextAreaPeer peer = (TextAreaPeer)this.peer;
578 return (peer != null) ?
579 peer.getMinimumSize(rows, columns) :
580 super.minimumSize();
581 }
582 }
583
584 /**
585 * Determines the minimum size of this text area.
586 * @return the preferred dimensions needed for this text area
587 * @see java.awt.Component#getPreferredSize
588 * @since JDK1.1
589 */
590 public Dimension getMinimumSize() {
591 return minimumSize();
592 }
593
594 /**
595 * @deprecated As of JDK version 1.1,
596 * replaced by <code>getMinimumSize()</code>.
597 */
598 @Deprecated
599 public Dimension minimumSize() {
600 synchronized (getTreeLock()) {
601 return ((rows > 0) && (columns > 0)) ?
602 minimumSize(rows, columns) :
603 super.minimumSize();
604 }
605 }
606
607 /**
608 * Returns a string representing the state of this <code>TextArea</code>.
609 * This method is intended to be used only for debugging purposes, and the
610 * content and format of the returned string may vary between
611 * implementations. The returned string may be empty but may not be
612 * <code>null</code>.
613 *
614 * @return the parameter string of this text area
615 */
616 protected String paramString() {
617 String sbVisStr;
618 switch (scrollbarVisibility) {
619 case SCROLLBARS_BOTH:
620 sbVisStr = "both";
621 break;
622 case SCROLLBARS_VERTICAL_ONLY:
623 sbVisStr = "vertical-only";
624 break;
625 case SCROLLBARS_HORIZONTAL_ONLY:
626 sbVisStr = "horizontal-only";
627 break;
628 case SCROLLBARS_NONE:
629 sbVisStr = "none";
630 break;
631 default:
632 sbVisStr = "invalid display policy";
633 }
634
635 return super.paramString() + ",rows=" + rows +
636 ",columns=" + columns +
637 ",scrollbarVisibility=" + sbVisStr;
638 }
639
640
641 /*
642 * Serialization support.
643 */
644 /**
645 * The textArea Serialized Data Version.
646 *
647 * @serial
648 */
649 private int textAreaSerializedDataVersion = 2;
650
651 /**
652 * Read the ObjectInputStream.
653 * @exception HeadlessException if
654 * <code>GraphicsEnvironment.isHeadless()</code> returns
655 * <code>true</code>
656 * @see java.awt.GraphicsEnvironment#isHeadless
657 */
658 private void readObject(ObjectInputStream s)
659 throws ClassNotFoundException, IOException, HeadlessException
660 {
661 // HeadlessException will be thrown by TextComponent's readObject
662 s.defaultReadObject();
663
664 // Make sure the state we just read in for columns, rows,
665 // and scrollbarVisibility has legal values
666 if (columns < 0) {
667 columns = 0;
668 }
669 if (rows < 0) {
670 rows = 0;
671 }
672
673 if ((scrollbarVisibility < SCROLLBARS_BOTH) ||
674 (scrollbarVisibility > SCROLLBARS_NONE)) {
675 this.scrollbarVisibility = SCROLLBARS_BOTH;
676 }
677
678 if (textAreaSerializedDataVersion < 2) {
679 setFocusTraversalKeys(KeyboardFocusManager.FORWARD_TRAVERSAL_KEYS,
680 forwardTraversalKeys);
681 setFocusTraversalKeys(KeyboardFocusManager.BACKWARD_TRAVERSAL_KEYS,
682 backwardTraversalKeys);
683 }
684 }
685
686
687 /////////////////
688 // Accessibility support
689 ////////////////
690
691
692 /**
693 * Returns the <code>AccessibleContext</code> associated with
694 * this <code>TextArea</code>. For text areas, the
695 * <code>AccessibleContext</code> takes the form of an
696 * <code>AccessibleAWTTextArea</code>.
697 * A new <code>AccessibleAWTTextArea</code> instance is created if necessary.
698 *
699 * @return an <code>AccessibleAWTTextArea</code> that serves as the
700 * <code>AccessibleContext</code> of this <code>TextArea</code>
701 * @since 1.3
702 */
703 public AccessibleContext getAccessibleContext() {
704 if (accessibleContext == null) {
705 accessibleContext = new AccessibleAWTTextArea();
706 }
707 return accessibleContext;
708 }
709
710 /**
711 * This class implements accessibility support for the
712 * <code>TextArea</code> class. It provides an implementation of the
713 * Java Accessibility API appropriate to text area user-interface elements.
714 * @since 1.3
715 */
716 protected class AccessibleAWTTextArea extends AccessibleAWTTextComponent
717 {
718 /*
719 * JDK 1.3 serialVersionUID
720 */
721 private static final long serialVersionUID = 3472827823632144419L;
722
723 /**
724 * Gets the state set of this object.
725 *
726 * @return an instance of AccessibleStateSet describing the states
727 * of the object
728 * @see AccessibleStateSet
729 */
730 public AccessibleStateSet getAccessibleStateSet() {
731 AccessibleStateSet states = super.getAccessibleStateSet();
732 states.add(AccessibleState.MULTI_LINE);
733 return states;
734 }
735 }
736
737
738 }