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} 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}.
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}.
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} = both scrollbars.<BR>
113 * {@code SCROLLBARS_HORIZONTAL_ONLY} = Horizontal bar only.<BR>
114 * {@code SCROLLBARS_VERTICAL_ONLY} = Vertical bar only.<BR>
115 * {@code SCROLLBARS_NONE} = 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} 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} is {@code null}, the empty
172 * string {@code ""} will be displayed
173 * @exception HeadlessException if
174 * {@code GraphicsEnvironment.isHeadless} 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} 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} is {@code null}, the empty
209 * string {@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} 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} constructors defer to
225 * this one.
226 * <p>
227 * The {@code TextArea} class defines several constants
228 * that can be supplied as values for the
229 * {@code scrollbars} argument:
230 * <ul>
231 * <li>{@code SCROLLBARS_BOTH},
232 * <li>{@code SCROLLBARS_VERTICAL_ONLY},
233 * <li>{@code SCROLLBARS_HORIZONTAL_ONLY},
234 * <li>{@code SCROLLBARS_NONE}.
235 * </ul>
236 * Any other value for the
237 * {@code scrollbars} 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} is {@code null}, the empty
242 * string {@code ""} will be displayed
243 * @param rows the number of rows; if
244 * {@code rows} is less than {@code 0},
245 * {@code rows} is set to {@code 0}
246 * @param columns the number of columns; if
247 * {@code columns} is less than {@code 0},
248 * {@code columns} is set to {@code 0}
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} 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}
277 * when the name is {@code null}.
278 */
279 String constructComponentName() {
280 synchronized (TextArea.class) {
281 return base + nameCounter++;
282 }
283 }
284
285 /**
286 * Creates the {@code TextArea}'s peer. The peer allows us to modify
287 * the appearance of the {@code TextArea} 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} or inconsistent
302 * parameters is invalid and will result in unspecified
303 * behavior.
304 *
305 * @param str the non-{@code null} 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)}.
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.substring(0, pos) + str + text.substring(pos);
332 }
333
334 /**
335 * Appends the given text to the text area's current text.
336 * <p>Note that passing {@code null} or inconsistent
337 * parameters is invalid and will result in unspecified
338 * behavior.
339 *
340 * @param str the non-{@code null} text to append
341 * @see java.awt.TextArea#insert
342 * @since 1.1
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 *
351 * @param str the text to append
352 * @deprecated As of JDK version 1.1,
353 * replaced by {@code append(String)}.
354 */
355 @Deprecated
356 public synchronized void appendText(String str) {
357 insertText(str, getText().length());
358 }
359
360 /**
361 * Replaces text between the indicated start and end positions
362 * with the specified replacement text. The text at the end
363 * position will not be replaced. The text at the start
364 * position will be replaced (unless the start position is the
365 * same as the end position).
366 * The text position is zero-based. The inserted substring may be
367 * of a different length than the text it replaces.
368 * <p>Note that passing {@code null} or inconsistent
369 * parameters is invalid and will result in unspecified
370 * behavior.
371 *
372 * @param str the non-{@code null} text to use as
373 * the replacement
374 * @param start the start position
375 * @param end the end position
376 * @see java.awt.TextArea#insert
377 * @since 1.1
378 */
379 public void replaceRange(String str, int start, int end) {
380 replaceText(str, start, end);
381 }
382
383 /**
384 * Replaces a range of characters between
385 * the indicated start and end positions
386 * with the specified replacement text (the text at the end
387 * position will not be replaced).
388 *
389 * @param str the non-{@code null} text to use as
390 * the replacement
391 * @param start the start position
392 * @param end the end position
393 * @deprecated As of JDK version 1.1,
394 * replaced by {@code replaceRange(String, int, int)}.
395 */
396 @Deprecated
397 public synchronized void replaceText(String str, int start, int end) {
398 TextAreaPeer peer = (TextAreaPeer)this.peer;
399 if (peer != null) {
400 peer.replaceRange(str, start, end);
401 }
402 text = text.substring(0, start) + str + text.substring(end);
403 }
404
405 /**
406 * Returns the number of rows in the text area.
407 * @return the number of rows in the text area
408 * @see #setRows(int)
409 * @see #getColumns()
410 * @since 1.0
411 */
412 public int getRows() {
413 return rows;
414 }
415
416 /**
417 * Sets the number of rows for this text area.
418 * @param rows the number of rows
419 * @see #getRows()
420 * @see #setColumns(int)
421 * @exception IllegalArgumentException if the value
422 * supplied for {@code rows}
423 * is less than {@code 0}
424 * @since 1.1
425 */
426 public void setRows(int rows) {
427 int oldVal = this.rows;
428 if (rows < 0) {
429 throw new IllegalArgumentException("rows less than zero.");
430 }
431 if (rows != oldVal) {
432 this.rows = rows;
433 invalidate();
434 }
435 }
436
437 /**
438 * Returns the number of columns in this text area.
439 * @return the number of columns in the text area
440 * @see #setColumns(int)
441 * @see #getRows()
442 */
443 public int getColumns() {
444 return columns;
445 }
446
447 /**
448 * Sets the number of columns for this text area.
449 * @param columns the number of columns
450 * @see #getColumns()
451 * @see #setRows(int)
452 * @exception IllegalArgumentException if the value
453 * supplied for {@code columns}
454 * is less than {@code 0}
455 * @since 1.1
456 */
457 public void setColumns(int columns) {
458 int oldVal = this.columns;
459 if (columns < 0) {
460 throw new IllegalArgumentException("columns less than zero.");
461 }
462 if (columns != oldVal) {
463 this.columns = columns;
464 invalidate();
465 }
466 }
467
468 /**
469 * Returns an enumerated value that indicates which scroll bars
470 * the text area uses.
471 * <p>
472 * The {@code TextArea} class defines four integer constants
473 * that are used to specify which scroll bars are available.
474 * {@code TextArea} has one constructor that gives the
475 * application discretion over scroll bars.
476 *
477 * @return an integer that indicates which scroll bars are used
478 * @see java.awt.TextArea#SCROLLBARS_BOTH
479 * @see java.awt.TextArea#SCROLLBARS_VERTICAL_ONLY
480 * @see java.awt.TextArea#SCROLLBARS_HORIZONTAL_ONLY
481 * @see java.awt.TextArea#SCROLLBARS_NONE
482 * @see java.awt.TextArea#TextArea(java.lang.String, int, int, int)
483 * @since 1.1
484 */
485 public int getScrollbarVisibility() {
486 return scrollbarVisibility;
487 }
488
489
490 /**
491 * Determines the preferred size of a text area with the specified
492 * number of rows and columns.
493 * @param rows the number of rows
494 * @param columns the number of columns
495 * @return the preferred dimensions required to display
496 * the text area with the specified
497 * number of rows and columns
498 * @see java.awt.Component#getPreferredSize
499 * @since 1.1
500 */
501 public Dimension getPreferredSize(int rows, int columns) {
502 return preferredSize(rows, columns);
503 }
504
505 /**
506 * Determines the preferred size of the text area with the specified
507 * number of rows and columns.
508 *
509 * @param rows the number of rows
510 * @param columns the number of columns
511 * @return the preferred dimensions needed for the text area
512 * @deprecated As of JDK version 1.1,
513 * replaced by {@code getPreferredSize(int, int)}.
514 */
515 @Deprecated
516 public Dimension preferredSize(int rows, int columns) {
517 synchronized (getTreeLock()) {
518 TextAreaPeer peer = (TextAreaPeer)this.peer;
519 return (peer != null) ?
520 peer.getPreferredSize(rows, columns) :
521 super.preferredSize();
522 }
523 }
524
525 /**
526 * Determines the preferred size of this text area.
527 * @return the preferred dimensions needed for this text area
528 * @see java.awt.Component#getPreferredSize
529 * @since 1.1
530 */
531 public Dimension getPreferredSize() {
532 return preferredSize();
533 }
534
535 /**
536 * @deprecated As of JDK version 1.1,
537 * replaced by {@code getPreferredSize()}.
538 */
539 @Deprecated
540 public Dimension preferredSize() {
541 synchronized (getTreeLock()) {
542 return ((rows > 0) && (columns > 0)) ?
543 preferredSize(rows, columns) :
544 super.preferredSize();
545 }
546 }
547
548 /**
549 * Determines the minimum size of a text area with the specified
550 * number of rows and columns.
551 * @param rows the number of rows
552 * @param columns the number of columns
553 * @return the minimum dimensions required to display
554 * the text area with the specified
555 * number of rows and columns
556 * @see java.awt.Component#getMinimumSize
557 * @since 1.1
558 */
559 public Dimension getMinimumSize(int rows, int columns) {
560 return minimumSize(rows, columns);
561 }
562
563 /**
564 * Determines the minimum size of the text area with the specified
565 * number of rows and columns.
566 *
567 * @param rows the number of rows
568 * @param columns the number of columns
569 * @return the minimum size for the text area
570 * @deprecated As of JDK version 1.1,
571 * replaced by {@code getMinimumSize(int, int)}.
572 */
573 @Deprecated
574 public Dimension minimumSize(int rows, int columns) {
575 synchronized (getTreeLock()) {
576 TextAreaPeer peer = (TextAreaPeer)this.peer;
577 return (peer != null) ?
578 peer.getMinimumSize(rows, columns) :
579 super.minimumSize();
580 }
581 }
582
583 /**
584 * Determines the minimum size of this text area.
585 * @return the preferred dimensions needed for this text area
586 * @see java.awt.Component#getPreferredSize
587 * @since 1.1
588 */
589 public Dimension getMinimumSize() {
590 return minimumSize();
591 }
592
593 /**
594 * @deprecated As of JDK version 1.1,
595 * replaced by {@code getMinimumSize()}.
596 */
597 @Deprecated
598 public Dimension minimumSize() {
599 synchronized (getTreeLock()) {
600 return ((rows > 0) && (columns > 0)) ?
601 minimumSize(rows, columns) :
602 super.minimumSize();
603 }
604 }
605
606 /**
607 * Returns a string representing the state of this {@code TextArea}.
608 * This method is intended to be used only for debugging purposes, and the
609 * content and format of the returned string may vary between
610 * implementations. The returned string may be empty but may not be
611 * {@code null}.
612 *
613 * @return the parameter string of this text area
614 */
615 protected String paramString() {
616 String sbVisStr;
617 switch (scrollbarVisibility) {
618 case SCROLLBARS_BOTH:
619 sbVisStr = "both";
620 break;
621 case SCROLLBARS_VERTICAL_ONLY:
622 sbVisStr = "vertical-only";
623 break;
624 case SCROLLBARS_HORIZONTAL_ONLY:
625 sbVisStr = "horizontal-only";
626 break;
627 case SCROLLBARS_NONE:
628 sbVisStr = "none";
629 break;
630 default:
631 sbVisStr = "invalid display policy";
632 }
633
634 return super.paramString() + ",rows=" + rows +
635 ",columns=" + columns +
636 ",scrollbarVisibility=" + sbVisStr;
637 }
638
639
640 /*
641 * Serialization support.
642 */
643 /**
644 * The textArea Serialized Data Version.
645 *
646 * @serial
647 */
648 private int textAreaSerializedDataVersion = 2;
649
650 /**
651 * Read the ObjectInputStream.
652 * @exception HeadlessException if
653 * {@code GraphicsEnvironment.isHeadless()} returns
654 * {@code true}
655 * @see java.awt.GraphicsEnvironment#isHeadless
656 */
657 private void readObject(ObjectInputStream s)
658 throws ClassNotFoundException, IOException, HeadlessException
659 {
660 // HeadlessException will be thrown by TextComponent's readObject
661 s.defaultReadObject();
662
663 // Make sure the state we just read in for columns, rows,
664 // and scrollbarVisibility has legal values
665 if (columns < 0) {
666 columns = 0;
667 }
668 if (rows < 0) {
669 rows = 0;
670 }
671
672 if ((scrollbarVisibility < SCROLLBARS_BOTH) ||
673 (scrollbarVisibility > SCROLLBARS_NONE)) {
674 this.scrollbarVisibility = SCROLLBARS_BOTH;
675 }
676
677 if (textAreaSerializedDataVersion < 2) {
678 setFocusTraversalKeys(KeyboardFocusManager.FORWARD_TRAVERSAL_KEYS,
679 forwardTraversalKeys);
680 setFocusTraversalKeys(KeyboardFocusManager.BACKWARD_TRAVERSAL_KEYS,
681 backwardTraversalKeys);
682 }
683 }
684
685
686 /////////////////
687 // Accessibility support
688 ////////////////
689
690
691 /**
692 * Returns the {@code AccessibleContext} associated with
693 * this {@code TextArea}. For text areas, the
694 * {@code AccessibleContext} takes the form of an
695 * {@code AccessibleAWTTextArea}.
696 * A new {@code AccessibleAWTTextArea} instance is created if necessary.
697 *
698 * @return an {@code AccessibleAWTTextArea} that serves as the
699 * {@code AccessibleContext} of this {@code TextArea}
700 * @since 1.3
701 */
702 public AccessibleContext getAccessibleContext() {
703 if (accessibleContext == null) {
704 accessibleContext = new AccessibleAWTTextArea();
705 }
706 return accessibleContext;
707 }
708
709 /**
710 * This class implements accessibility support for the
711 * {@code TextArea} class. It provides an implementation of the
712 * Java Accessibility API appropriate to text area user-interface elements.
713 * @since 1.3
714 */
715 protected class AccessibleAWTTextArea extends AccessibleAWTTextComponent
716 {
717 /*
718 * JDK 1.3 serialVersionUID
719 */
720 private static final long serialVersionUID = 3472827823632144419L;
721
722 /**
723 * Gets the state set of this object.
724 *
725 * @return an instance of AccessibleStateSet describing the states
726 * of the object
727 * @see AccessibleStateSet
728 */
729 public AccessibleStateSet getAccessibleStateSet() {
730 AccessibleStateSet states = super.getAccessibleStateSet();
731 states.add(AccessibleState.MULTI_LINE);
732 return states;
733 }
734 }
735
736
737 }