1 /*
2 * Copyright (c) 1995, 2015, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25 package java.awt;
26
27 import java.awt.peer.TextAreaPeer;
28 import java.io.IOException;
29 import java.io.ObjectInputStream;
30 import java.util.HashSet;
31 import java.util.Set;
32
33 import javax.accessibility.AccessibleContext;
34 import javax.accessibility.AccessibleState;
35 import javax.accessibility.AccessibleStateSet;
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 1.0
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 1.1
88 */
89 public static final int SCROLLBARS_BOTH = 0;
90
91 /**
92 * Create and display vertical scrollbar only.
93 * @since 1.1
94 */
95 public static final int SCROLLBARS_VERTICAL_ONLY = 1;
96
97 /**
98 * Create and display horizontal scrollbar only.
99 * @since 1.1
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 1.1
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 1.1
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 = getComponentFactory().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 1.1
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 *
320 * @param str the non-{@code null} text to insert
321 * @param pos the position at which to insert
322 * @deprecated As of JDK version 1.1,
323 * replaced by <code>insert(String, int)</code>.
324 */
325 @Deprecated
326 public synchronized void insertText(String str, int pos) {
327 TextAreaPeer peer = (TextAreaPeer)this.peer;
328 if (peer != null) {
329 peer.insert(str, pos);
330 }
331 text = (text != null) ? text.substring(0, pos) + str
332 + text.substring(pos) : str;
333 }
334
335 /**
336 * Appends the given text to the text area's current text.
337 * <p>Note that passing <code>null</code> or inconsistent
338 * parameters is invalid and will result in unspecified
339 * behavior.
340 *
341 * @param str the non-<code>null</code> text to append
342 * @see java.awt.TextArea#insert
343 * @since 1.1
344 */
345 public void append(String str) {
346 insertText(str, getText().length());
347 }
348
349 /**
350 * Appends the given text to the text area's current text.
351 *
352 * @param str the text to append
353 * @deprecated As of JDK version 1.1,
354 * replaced by <code>append(String)</code>.
355 */
356 @Deprecated
357 public synchronized void appendText(String str) {
358 insertText(str, getText().length());
359 }
360
361 /**
362 * Replaces text between the indicated start and end positions
363 * with the specified replacement text. The text at the end
364 * position will not be replaced. The text at the start
365 * position will be replaced (unless the start position is the
366 * same as the end position).
367 * The text position is zero-based. The inserted substring may be
368 * of a different length than the text it replaces.
369 * <p>Note that passing <code>null</code> or inconsistent
370 * parameters is invalid and will result in unspecified
371 * behavior.
372 *
373 * @param str the non-<code>null</code> text to use as
374 * the replacement
375 * @param start the start position
376 * @param end the end position
377 * @see java.awt.TextArea#insert
378 * @since 1.1
379 */
380 public void replaceRange(String str, int start, int end) {
381 replaceText(str, start, end);
382 }
383
384 /**
385 * Replaces a range of characters between
386 * the indicated start and end positions
387 * with the specified replacement text (the text at the end
388 * position will not be replaced).
389 *
390 * @param str the non-{@code null} text to use as
391 * the replacement
392 * @param start the start position
393 * @param end the end position
394 * @deprecated As of JDK version 1.1,
395 * replaced by <code>replaceRange(String, int, int)</code>.
396 */
397 @Deprecated
398 public synchronized void replaceText(String str, int start, int end) {
399 TextAreaPeer peer = (TextAreaPeer)this.peer;
400 if (peer != null) {
401 peer.replaceRange(str, start, end);
402 }
403 text = (text != null) ? text.substring(0, start) + str
404 + text.substring(end) : str;
405 }
406
407 /**
408 * Returns the number of rows in the text area.
409 * @return the number of rows in the text area
410 * @see #setRows(int)
411 * @see #getColumns()
412 * @since 1.0
413 */
414 public int getRows() {
415 return rows;
416 }
417
418 /**
419 * Sets the number of rows for this text area.
420 * @param rows the number of rows
421 * @see #getRows()
422 * @see #setColumns(int)
423 * @exception IllegalArgumentException if the value
424 * supplied for <code>rows</code>
425 * is less than <code>0</code>
426 * @since 1.1
427 */
428 public void setRows(int rows) {
429 int oldVal = this.rows;
430 if (rows < 0) {
431 throw new IllegalArgumentException("rows less than zero.");
432 }
433 if (rows != oldVal) {
434 this.rows = rows;
435 invalidate();
436 }
437 }
438
439 /**
440 * Returns the number of columns in this text area.
441 * @return the number of columns in the text area
442 * @see #setColumns(int)
443 * @see #getRows()
444 */
445 public int getColumns() {
446 return columns;
447 }
448
449 /**
450 * Sets the number of columns for this text area.
451 * @param columns the number of columns
452 * @see #getColumns()
453 * @see #setRows(int)
454 * @exception IllegalArgumentException if the value
455 * supplied for <code>columns</code>
456 * is less than <code>0</code>
457 * @since 1.1
458 */
459 public void setColumns(int columns) {
460 int oldVal = this.columns;
461 if (columns < 0) {
462 throw new IllegalArgumentException("columns less than zero.");
463 }
464 if (columns != oldVal) {
465 this.columns = columns;
466 invalidate();
467 }
468 }
469
470 /**
471 * Returns an enumerated value that indicates which scroll bars
472 * the text area uses.
473 * <p>
474 * The <code>TextArea</code> class defines four integer constants
475 * that are used to specify which scroll bars are available.
476 * <code>TextArea</code> has one constructor that gives the
477 * application discretion over scroll bars.
478 *
479 * @return an integer that indicates which scroll bars are used
480 * @see java.awt.TextArea#SCROLLBARS_BOTH
481 * @see java.awt.TextArea#SCROLLBARS_VERTICAL_ONLY
482 * @see java.awt.TextArea#SCROLLBARS_HORIZONTAL_ONLY
483 * @see java.awt.TextArea#SCROLLBARS_NONE
484 * @see java.awt.TextArea#TextArea(java.lang.String, int, int, int)
485 * @since 1.1
486 */
487 public int getScrollbarVisibility() {
488 return scrollbarVisibility;
489 }
490
491
492 /**
493 * Determines the preferred size of a text area with the specified
494 * number of rows and columns.
495 * @param rows the number of rows
496 * @param columns the number of columns
497 * @return the preferred dimensions required to display
498 * the text area with the specified
499 * number of rows and columns
500 * @see java.awt.Component#getPreferredSize
501 * @since 1.1
502 */
503 public Dimension getPreferredSize(int rows, int columns) {
504 return preferredSize(rows, columns);
505 }
506
507 /**
508 * Determines the preferred size of the text area with the specified
509 * number of rows and columns.
510 *
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 1.1
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 1.1
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 *
569 * @param rows the number of rows
570 * @param columns the number of columns
571 * @return the minimum size for the text area
572 * @deprecated As of JDK version 1.1,
573 * replaced by <code>getMinimumSize(int, int)</code>.
574 */
575 @Deprecated
576 public Dimension minimumSize(int rows, int columns) {
577 synchronized (getTreeLock()) {
578 TextAreaPeer peer = (TextAreaPeer)this.peer;
579 return (peer != null) ?
580 peer.getMinimumSize(rows, columns) :
581 super.minimumSize();
582 }
583 }
584
585 /**
586 * Determines the minimum size of this text area.
587 * @return the preferred dimensions needed for this text area
588 * @see java.awt.Component#getPreferredSize
589 * @since 1.1
590 */
591 public Dimension getMinimumSize() {
592 return minimumSize();
593 }
594
595 /**
596 * @deprecated As of JDK version 1.1,
597 * replaced by <code>getMinimumSize()</code>.
598 */
599 @Deprecated
600 public Dimension minimumSize() {
601 synchronized (getTreeLock()) {
602 return ((rows > 0) && (columns > 0)) ?
603 minimumSize(rows, columns) :
604 super.minimumSize();
605 }
606 }
607
608 /**
609 * Returns a string representing the state of this <code>TextArea</code>.
610 * This method is intended to be used only for debugging purposes, and the
611 * content and format of the returned string may vary between
612 * implementations. The returned string may be empty but may not be
613 * <code>null</code>.
614 *
615 * @return the parameter string of this text area
616 */
617 protected String paramString() {
618 String sbVisStr;
619 switch (scrollbarVisibility) {
620 case SCROLLBARS_BOTH:
621 sbVisStr = "both";
622 break;
623 case SCROLLBARS_VERTICAL_ONLY:
624 sbVisStr = "vertical-only";
625 break;
626 case SCROLLBARS_HORIZONTAL_ONLY:
627 sbVisStr = "horizontal-only";
628 break;
629 case SCROLLBARS_NONE:
630 sbVisStr = "none";
631 break;
632 default:
633 sbVisStr = "invalid display policy";
634 }
635
636 return super.paramString() + ",rows=" + rows +
637 ",columns=" + columns +
638 ",scrollbarVisibility=" + sbVisStr;
639 }
640
641
642 /*
643 * Serialization support.
644 */
645 /**
646 * The textArea Serialized Data Version.
647 *
648 * @serial
649 */
650 private int textAreaSerializedDataVersion = 2;
651
652 /**
653 * Read the ObjectInputStream.
654 * @exception HeadlessException if
655 * <code>GraphicsEnvironment.isHeadless()</code> returns
656 * <code>true</code>
657 * @see java.awt.GraphicsEnvironment#isHeadless
658 */
659 private void readObject(ObjectInputStream s)
660 throws ClassNotFoundException, IOException, HeadlessException
661 {
662 // HeadlessException will be thrown by TextComponent's readObject
663 s.defaultReadObject();
664
665 // Make sure the state we just read in for columns, rows,
666 // and scrollbarVisibility has legal values
667 if (columns < 0) {
668 columns = 0;
669 }
670 if (rows < 0) {
671 rows = 0;
672 }
673
674 if ((scrollbarVisibility < SCROLLBARS_BOTH) ||
675 (scrollbarVisibility > SCROLLBARS_NONE)) {
676 this.scrollbarVisibility = SCROLLBARS_BOTH;
677 }
678
679 if (textAreaSerializedDataVersion < 2) {
680 setFocusTraversalKeys(KeyboardFocusManager.FORWARD_TRAVERSAL_KEYS,
681 forwardTraversalKeys);
682 setFocusTraversalKeys(KeyboardFocusManager.BACKWARD_TRAVERSAL_KEYS,
683 backwardTraversalKeys);
684 }
685 }
686
687
688 /////////////////
689 // Accessibility support
690 ////////////////
691
692
693 /**
694 * Returns the <code>AccessibleContext</code> associated with
695 * this <code>TextArea</code>. For text areas, the
696 * <code>AccessibleContext</code> takes the form of an
697 * <code>AccessibleAWTTextArea</code>.
698 * A new <code>AccessibleAWTTextArea</code> instance is created if necessary.
699 *
700 * @return an <code>AccessibleAWTTextArea</code> that serves as the
701 * <code>AccessibleContext</code> of this <code>TextArea</code>
702 * @since 1.3
703 */
704 public AccessibleContext getAccessibleContext() {
705 if (accessibleContext == null) {
706 accessibleContext = new AccessibleAWTTextArea();
707 }
708 return accessibleContext;
709 }
710
711 /**
712 * This class implements accessibility support for the
713 * <code>TextArea</code> class. It provides an implementation of the
714 * Java Accessibility API appropriate to text area user-interface elements.
715 * @since 1.3
716 */
717 protected class AccessibleAWTTextArea extends AccessibleAWTTextComponent
718 {
719 /*
720 * JDK 1.3 serialVersionUID
721 */
722 private static final long serialVersionUID = 3472827823632144419L;
723
724 /**
725 * Gets the state set of this object.
726 *
727 * @return an instance of AccessibleStateSet describing the states
728 * of the object
729 * @see AccessibleStateSet
730 */
731 public AccessibleStateSet getAccessibleStateSet() {
732 AccessibleStateSet states = super.getAccessibleStateSet();
733 states.add(AccessibleState.MULTI_LINE);
734 return states;
735 }
736 }
737
738
739 }