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.TextFieldPeer;
28 import java.awt.event.*;
29 import java.util.EventListener;
30 import java.io.ObjectOutputStream;
31 import java.io.ObjectInputStream;
32 import java.io.IOException;
33 import javax.accessibility.*;
34
35
36 /**
37 * A {@code TextField} object is a text component
38 * that allows for the editing of a single line of text.
39 * <p>
40 * For example, the following image depicts a frame with four
41 * text fields of varying widths. Two of these text fields
42 * display the predefined text {@code "Hello"}.
43 * <p>
44 * <img src="doc-files/TextField-1.gif" alt="The preceding text describes this image."
45 * style="float:center; margin: 7px 10px;">
46 * <p>
47 * Here is the code that produces these four text fields:
48 *
49 * <hr><blockquote><pre>
50 * TextField tf1, tf2, tf3, tf4;
51 * // a blank text field
52 * tf1 = new TextField();
53 * // blank field of 20 columns
54 * tf2 = new TextField("", 20);
55 * // predefined text displayed
56 * tf3 = new TextField("Hello!");
57 * // predefined text in 30 columns
58 * tf4 = new TextField("Hello", 30);
59 * </pre></blockquote><hr>
60 * <p>
61 * Every time the user types a key in the text field, one or
62 * more key events are sent to the text field. A {@code KeyEvent}
63 * may be one of three types: keyPressed, keyReleased, or keyTyped.
64 * The properties of a key event indicate which of these types
65 * it is, as well as additional information about the event,
66 * such as what modifiers are applied to the key event and the
67 * time at which the event occurred.
68 * <p>
69 * The key event is passed to every {@code KeyListener}
70 * or {@code KeyAdapter} object which registered to receive such
71 * events using the component's {@code addKeyListener} method.
72 * ({@code KeyAdapter} objects implement the
73 * {@code KeyListener} interface.)
74 * <p>
75 * It is also possible to fire an {@code ActionEvent}.
76 * If action events are enabled for the text field, they may
77 * be fired by pressing the {@code Return} key.
78 * <p>
79 * The {@code TextField} class's {@code processEvent}
80 * method examines the action event and passes it along to
81 * {@code processActionEvent}. The latter method redirects the
82 * event to any {@code ActionListener} objects that have
83 * registered to receive action events generated by this
84 * text field.
85 *
86 * @author Sami Shaio
87 * @see java.awt.event.KeyEvent
88 * @see java.awt.event.KeyAdapter
89 * @see java.awt.event.KeyListener
90 * @see java.awt.event.ActionEvent
91 * @see java.awt.Component#addKeyListener
92 * @see java.awt.TextField#processEvent
93 * @see java.awt.TextField#processActionEvent
94 * @see java.awt.TextField#addActionListener
95 * @since 1.0
96 */
97 public class TextField extends TextComponent {
98
99 /**
100 * The number of columns in the text field.
101 * A column is an approximate average character
102 * width that is platform-dependent.
103 * Guaranteed to be non-negative.
104 *
105 * @serial
106 * @see #setColumns(int)
107 * @see #getColumns()
108 */
109 int columns;
110
111 /**
112 * The echo character, which is used when
113 * the user wishes to disguise the characters
114 * typed into the text field.
115 * The disguises are removed if echoChar = {@code 0}.
116 *
117 * @serial
118 * @see #getEchoChar()
119 * @see #setEchoChar(char)
120 * @see #echoCharIsSet()
121 */
122 char echoChar;
123
124 transient ActionListener actionListener;
125
126 private static final String base = "textfield";
127 private static int nameCounter = 0;
128
129 /*
130 * JDK 1.1 serialVersionUID
131 */
132 private static final long serialVersionUID = -2966288784432217853L;
133
134 /**
135 * Initialize JNI field and method ids
136 */
137 private static native void initIDs();
138
139 static {
140 /* ensure that the necessary native libraries are loaded */
141 Toolkit.loadLibraries();
142 if (!GraphicsEnvironment.isHeadless()) {
143 initIDs();
144 }
145 }
146
147 /**
148 * Constructs a new text field.
149 * @exception HeadlessException if GraphicsEnvironment.isHeadless()
150 * returns true.
151 * @see java.awt.GraphicsEnvironment#isHeadless
152 */
153 public TextField() throws HeadlessException {
154 this("", 0);
155 }
156
157 /**
158 * Constructs a new text field initialized with the specified text.
159 * @param text the text to be displayed. If
160 * {@code text} is {@code null}, the empty
161 * string {@code ""} will be displayed.
162 * @exception HeadlessException if GraphicsEnvironment.isHeadless()
163 * returns true.
164 * @see java.awt.GraphicsEnvironment#isHeadless
165 */
166 public TextField(String text) throws HeadlessException {
167 this(text, (text != null) ? text.length() : 0);
168 }
169
170 /**
171 * Constructs a new empty text field with the specified number
172 * of columns. A column is an approximate average character
173 * width that is platform-dependent.
174 * @param columns the number of columns. If
175 * {@code columns} is less than {@code 0},
176 * {@code columns} is set to {@code 0}.
177 * @exception HeadlessException if GraphicsEnvironment.isHeadless()
178 * returns true.
179 * @see java.awt.GraphicsEnvironment#isHeadless
180 */
181 public TextField(int columns) throws HeadlessException {
182 this("", columns);
183 }
184
185 /**
186 * Constructs a new text field initialized with the specified text
187 * to be displayed, and wide enough to hold the specified
188 * number of columns. A column is an approximate average character
189 * width that is platform-dependent.
190 * @param text the text to be displayed. If
191 * {@code text} is {@code null}, the empty
192 * string {@code ""} will be displayed.
193 * @param columns the number of columns. If
194 * {@code columns} is less than {@code 0},
195 * {@code columns} is set to {@code 0}.
196 * @exception HeadlessException if GraphicsEnvironment.isHeadless()
197 * returns true.
198 * @see java.awt.GraphicsEnvironment#isHeadless
199 */
200 public TextField(String text, int columns) throws HeadlessException {
201 super(replaceEOL(text));
202 this.columns = (columns >= 0) ? columns : 0;
203 }
204
205 /**
206 * Construct a name for this component. Called by getName() when the
207 * name is null.
208 */
209 String constructComponentName() {
210 synchronized (TextField.class) {
211 return base + nameCounter++;
212 }
213 }
214
215 /**
216 * Creates the TextField's peer. The peer allows us to modify the
217 * appearance of the TextField without changing its functionality.
218 */
219 public void addNotify() {
220 synchronized (getTreeLock()) {
221 if (peer == null)
222 peer = getComponentFactory().createTextField(this);
223 super.addNotify();
224 }
225 }
226
227 /**
228 * Gets the character that is to be used for echoing.
229 * <p>
230 * An echo character is useful for text fields where
231 * user input should not be echoed to the screen, as in
232 * the case of a text field for entering a password.
233 * If {@code echoChar} = {@code 0}, user
234 * input is echoed to the screen unchanged.
235 * <p>
236 * A Java platform implementation may support only a limited,
237 * non-empty set of echo characters. This function returns the
238 * echo character originally requested via setEchoChar(). The echo
239 * character actually used by the TextField implementation might be
240 * different.
241 * @return the echo character for this text field.
242 * @see java.awt.TextField#echoCharIsSet
243 * @see java.awt.TextField#setEchoChar
244 */
245 public char getEchoChar() {
246 return echoChar;
247 }
248
249 /**
250 * Sets the echo character for this text field.
251 * <p>
252 * An echo character is useful for text fields where
253 * user input should not be echoed to the screen, as in
254 * the case of a text field for entering a password.
255 * Setting {@code echoChar} = {@code 0} allows
256 * user input to be echoed to the screen again.
257 * <p>
258 * A Java platform implementation may support only a limited,
259 * non-empty set of echo characters. Attempts to set an
260 * unsupported echo character will cause the default echo
261 * character to be used instead. Subsequent calls to getEchoChar()
262 * will return the echo character originally requested. This might
263 * or might not be identical to the echo character actually
264 * used by the TextField implementation.
265 * @param c the echo character for this text field.
266 * @see java.awt.TextField#echoCharIsSet
267 * @see java.awt.TextField#getEchoChar
268 * @since 1.1
269 */
270 public void setEchoChar(char c) {
271 setEchoCharacter(c);
272 }
273
274 /**
275 * Sets the character to be echoed when protected input is displayed.
276 *
277 * @param c the echo character for this text field
278 *
279 * @deprecated As of JDK version 1.1,
280 * replaced by {@code setEchoChar(char)}.
281 */
282 @Deprecated
283 public synchronized void setEchoCharacter(char c) {
284 if (echoChar != c) {
285 echoChar = c;
286 TextFieldPeer peer = (TextFieldPeer)this.peer;
287 if (peer != null) {
288 peer.setEchoChar(c);
289 }
290 }
291 }
292
293 /**
294 * Sets the text that is presented by this
295 * text component to be the specified text.
296 * @param t the new text.
297 * @see java.awt.TextComponent#getText
298 */
299 public void setText(String t) {
300 super.setText(replaceEOL(t));
301
302 // This could change the preferred size of the Component.
303 invalidateIfValid();
304 }
305
306 /**
307 * Replaces EOL characters from the text variable with a space character.
308 * @param text the new text.
309 * @return Returns text after replacing EOL characters.
310 */
311 private static String replaceEOL(String text) {
312 if (text == null) {
313 return text;
314 }
315 String[] strEOLs = {System.lineSeparator(), "\n"};
316 for (String eol : strEOLs) {
317 if (text.contains(eol)) {
318 text = text.replace(eol, " ");
319 }
320 }
321 return text;
322 }
323
324
325 /**
326 * Indicates whether or not this text field has a
327 * character set for echoing.
328 * <p>
329 * An echo character is useful for text fields where
330 * user input should not be echoed to the screen, as in
331 * the case of a text field for entering a password.
332 * @return {@code true} if this text field has
333 * a character set for echoing;
334 * {@code false} otherwise.
335 * @see java.awt.TextField#setEchoChar
336 * @see java.awt.TextField#getEchoChar
337 */
338 public boolean echoCharIsSet() {
339 return echoChar != 0;
340 }
341
342 /**
343 * Gets the number of columns in this text field. A column is an
344 * approximate average character width that is platform-dependent.
345 * @return the number of columns.
346 * @see java.awt.TextField#setColumns
347 * @since 1.1
348 */
349 public int getColumns() {
350 return columns;
351 }
352
353 /**
354 * Sets the number of columns in this text field. A column is an
355 * approximate average character width that is platform-dependent.
356 * @param columns the number of columns.
357 * @see java.awt.TextField#getColumns
358 * @exception IllegalArgumentException if the value
359 * supplied for {@code columns}
360 * is less than {@code 0}.
361 * @since 1.1
362 */
363 public void setColumns(int columns) {
364 int oldVal;
365 synchronized (this) {
366 oldVal = this.columns;
367 if (columns < 0) {
368 throw new IllegalArgumentException("columns less than zero.");
369 }
370 if (columns != oldVal) {
371 this.columns = columns;
372 }
373 }
374
375 if (columns != oldVal) {
376 invalidate();
377 }
378 }
379
380 /**
381 * Gets the preferred size of this text field
382 * with the specified number of columns.
383 * @param columns the number of columns
384 * in this text field.
385 * @return the preferred dimensions for
386 * displaying this text field.
387 * @since 1.1
388 */
389 public Dimension getPreferredSize(int columns) {
390 return preferredSize(columns);
391 }
392
393 /**
394 * Returns the preferred size for this text field
395 * with the specified number of columns.
396 *
397 * @param columns the number of columns
398 * @return the preferred size for the text field
399 *
400 * @deprecated As of JDK version 1.1,
401 * replaced by {@code getPreferredSize(int)}.
402 */
403 @Deprecated
404 public Dimension preferredSize(int columns) {
405 synchronized (getTreeLock()) {
406 TextFieldPeer peer = (TextFieldPeer)this.peer;
407 return (peer != null) ?
408 peer.getPreferredSize(columns) :
409 super.preferredSize();
410 }
411 }
412
413 /**
414 * Gets the preferred size of this text field.
415 * @return the preferred dimensions for
416 * displaying this text field.
417 * @since 1.1
418 */
419 public Dimension getPreferredSize() {
420 return preferredSize();
421 }
422
423 /**
424 * @deprecated As of JDK version 1.1,
425 * replaced by {@code getPreferredSize()}.
426 */
427 @Deprecated
428 public Dimension preferredSize() {
429 synchronized (getTreeLock()) {
430 return (columns > 0) ?
431 preferredSize(columns) :
432 super.preferredSize();
433 }
434 }
435
436 /**
437 * Gets the minimum dimensions for a text field with
438 * the specified number of columns.
439 * @param columns the number of columns in
440 * this text field.
441 * @return the minimum size for this text field
442 * @since 1.1
443 */
444 public Dimension getMinimumSize(int columns) {
445 return minimumSize(columns);
446 }
447
448 /**
449 * Returns the minimum dimensions for a text field with
450 * the specified number of columns.
451 *
452 * @param columns the number of columns
453 * @return the minimum size for this text field
454 * @deprecated As of JDK version 1.1,
455 * replaced by {@code getMinimumSize(int)}.
456 */
457 @Deprecated
458 public Dimension minimumSize(int columns) {
459 synchronized (getTreeLock()) {
460 TextFieldPeer peer = (TextFieldPeer)this.peer;
461 return (peer != null) ?
462 peer.getMinimumSize(columns) :
463 super.minimumSize();
464 }
465 }
466
467 /**
468 * Gets the minimum dimensions for this text field.
469 * @return the minimum dimensions for
470 * displaying this text field.
471 * @since 1.1
472 */
473 public Dimension getMinimumSize() {
474 return minimumSize();
475 }
476
477 /**
478 * @deprecated As of JDK version 1.1,
479 * replaced by {@code getMinimumSize()}.
480 */
481 @Deprecated
482 public Dimension minimumSize() {
483 synchronized (getTreeLock()) {
484 return (columns > 0) ?
485 minimumSize(columns) :
486 super.minimumSize();
487 }
488 }
489
490 /**
491 * Adds the specified action listener to receive
492 * action events from this text field.
493 * If l is null, no exception is thrown and no action is performed.
494 * <p>Refer to <a href="doc-files/AWTThreadIssues.html#ListenersThreads"
495 * >AWT Threading Issues</a> for details on AWT's threading model.
496 *
497 * @param l the action listener.
498 * @see #removeActionListener
499 * @see #getActionListeners
500 * @see java.awt.event.ActionListener
501 * @since 1.1
502 */
503 public synchronized void addActionListener(ActionListener l) {
504 if (l == null) {
505 return;
506 }
507 actionListener = AWTEventMulticaster.add(actionListener, l);
508 newEventsOnly = true;
509 }
510
511 /**
512 * Removes the specified action listener so that it no longer
513 * receives action events from this text field.
514 * If l is null, no exception is thrown and no action is performed.
515 * <p>Refer to <a href="doc-files/AWTThreadIssues.html#ListenersThreads"
516 * >AWT Threading Issues</a> for details on AWT's threading model.
517 *
518 * @param l the action listener.
519 * @see #addActionListener
520 * @see #getActionListeners
521 * @see java.awt.event.ActionListener
522 * @since 1.1
523 */
524 public synchronized void removeActionListener(ActionListener l) {
525 if (l == null) {
526 return;
527 }
528 actionListener = AWTEventMulticaster.remove(actionListener, l);
529 }
530
531 /**
532 * Returns an array of all the action listeners
533 * registered on this textfield.
534 *
535 * @return all of this textfield's {@code ActionListener}s
536 * or an empty array if no action
537 * listeners are currently registered
538 *
539 * @see #addActionListener
540 * @see #removeActionListener
541 * @see java.awt.event.ActionListener
542 * @since 1.4
543 */
544 public synchronized ActionListener[] getActionListeners() {
545 return getListeners(ActionListener.class);
546 }
547
548 /**
549 * Returns an array of all the objects currently registered
550 * as <code><em>Foo</em>Listener</code>s
551 * upon this {@code TextField}.
552 * <code><em>Foo</em>Listener</code>s are registered using the
553 * <code>add<em>Foo</em>Listener</code> method.
554 *
555 * <p>
556 * You can specify the {@code listenerType} argument
557 * with a class literal, such as
558 * <code><em>Foo</em>Listener.class</code>.
559 * For example, you can query a
560 * {@code TextField t}
561 * for its action listeners with the following code:
562 *
563 * <pre>ActionListener[] als = (ActionListener[])(t.getListeners(ActionListener.class));</pre>
564 *
565 * If no such listeners exist, this method returns an empty array.
566 *
567 * @param listenerType the type of listeners requested; this parameter
568 * should specify an interface that descends from
569 * {@code java.util.EventListener}
570 * @return an array of all objects registered as
571 * <code><em>Foo</em>Listener</code>s on this textfield,
572 * or an empty array if no such
573 * listeners have been added
574 * @exception ClassCastException if {@code listenerType}
575 * doesn't specify a class or interface that implements
576 * {@code java.util.EventListener}
577 *
578 * @see #getActionListeners
579 * @since 1.3
580 */
581 public <T extends EventListener> T[] getListeners(Class<T> listenerType) {
582 EventListener l = null;
583 if (listenerType == ActionListener.class) {
584 l = actionListener;
585 } else {
586 return super.getListeners(listenerType);
587 }
588 return AWTEventMulticaster.getListeners(l, listenerType);
589 }
590
591 // REMIND: remove when filtering is done at lower level
592 boolean eventEnabled(AWTEvent e) {
593 if (e.id == ActionEvent.ACTION_PERFORMED) {
594 if ((eventMask & AWTEvent.ACTION_EVENT_MASK) != 0 ||
595 actionListener != null) {
596 return true;
597 }
598 return false;
599 }
600 return super.eventEnabled(e);
601 }
602
603 /**
604 * Processes events on this text field. If the event
605 * is an instance of {@code ActionEvent},
606 * it invokes the {@code processActionEvent}
607 * method. Otherwise, it invokes {@code processEvent}
608 * on the superclass.
609 * <p>Note that if the event parameter is {@code null}
610 * the behavior is unspecified and may result in an
611 * exception.
612 *
613 * @param e the event
614 * @see java.awt.event.ActionEvent
615 * @see java.awt.TextField#processActionEvent
616 * @since 1.1
617 */
618 protected void processEvent(AWTEvent e) {
619 if (e instanceof ActionEvent) {
620 processActionEvent((ActionEvent)e);
621 return;
622 }
623 super.processEvent(e);
624 }
625
626 /**
627 * Processes action events occurring on this text field by
628 * dispatching them to any registered
629 * {@code ActionListener} objects.
630 * <p>
631 * This method is not called unless action events are
632 * enabled for this component. Action events are enabled
633 * when one of the following occurs:
634 * <ul>
635 * <li>An {@code ActionListener} object is registered
636 * via {@code addActionListener}.
637 * <li>Action events are enabled via {@code enableEvents}.
638 * </ul>
639 * <p>Note that if the event parameter is {@code null}
640 * the behavior is unspecified and may result in an
641 * exception.
642 *
643 * @param e the action event
644 * @see java.awt.event.ActionListener
645 * @see java.awt.TextField#addActionListener
646 * @see java.awt.Component#enableEvents
647 * @since 1.1
648 */
649 protected void processActionEvent(ActionEvent e) {
650 ActionListener listener = actionListener;
651 if (listener != null) {
652 listener.actionPerformed(e);
653 }
654 }
655
656 /**
657 * Returns a string representing the state of this {@code TextField}.
658 * This method is intended to be used only for debugging purposes, and the
659 * content and format of the returned string may vary between
660 * implementations. The returned string may be empty but may not be
661 * {@code null}.
662 *
663 * @return the parameter string of this text field
664 */
665 protected String paramString() {
666 String str = super.paramString();
667 if (echoChar != 0) {
668 str += ",echo=" + echoChar;
669 }
670 return str;
671 }
672
673
674 /*
675 * Serialization support.
676 */
677 /**
678 * The textField Serialized Data Version.
679 *
680 * @serial
681 */
682 private int textFieldSerializedDataVersion = 1;
683
684 /**
685 * Writes default serializable fields to stream. Writes
686 * a list of serializable ActionListener(s) as optional data.
687 * The non-serializable ActionListener(s) are detected and
688 * no attempt is made to serialize them.
689 *
690 * @serialData Null terminated sequence of zero or more pairs.
691 * A pair consists of a String and Object.
692 * The String indicates the type of object and
693 * is one of the following :
694 * ActionListenerK indicating and ActionListener object.
695 *
696 * @see AWTEventMulticaster#save(ObjectOutputStream, String, EventListener)
697 * @see java.awt.Component#actionListenerK
698 */
699 private void writeObject(ObjectOutputStream s)
700 throws IOException
701 {
702 s.defaultWriteObject();
703
704 AWTEventMulticaster.save(s, actionListenerK, actionListener);
705 s.writeObject(null);
706 }
707
708 /**
709 * Read the ObjectInputStream and if it isn't null,
710 * add a listener to receive action events fired by the
711 * TextField. Unrecognized keys or values will be
712 * ignored.
713 *
714 * @exception HeadlessException if
715 * {@code GraphicsEnvironment.isHeadless()} returns
716 * {@code true}
717 * @see #removeActionListener(ActionListener)
718 * @see #addActionListener(ActionListener)
719 * @see java.awt.GraphicsEnvironment#isHeadless
720 */
721 private void readObject(ObjectInputStream s)
722 throws ClassNotFoundException, IOException, HeadlessException
723 {
724 // HeadlessException will be thrown by TextComponent's readObject
725 s.defaultReadObject();
726 text = replaceEOL(text);
727
728 // Make sure the state we just read in for columns has legal values
729 if (columns < 0) {
730 columns = 0;
731 }
732
733 // Read in listeners, if any
734 Object keyOrNull;
735 while(null != (keyOrNull = s.readObject())) {
736 String key = ((String)keyOrNull).intern();
737
738 if (actionListenerK == key) {
739 addActionListener((ActionListener)(s.readObject()));
740 } else {
741 // skip value for unrecognized key
742 s.readObject();
743 }
744 }
745 }
746
747
748 /////////////////
749 // Accessibility support
750 ////////////////
751
752
753 /**
754 * Gets the AccessibleContext associated with this TextField.
755 * For text fields, the AccessibleContext takes the form of an
756 * AccessibleAWTTextField.
757 * A new AccessibleAWTTextField instance is created if necessary.
758 *
759 * @return an AccessibleAWTTextField that serves as the
760 * AccessibleContext of this TextField
761 * @since 1.3
762 */
763 public AccessibleContext getAccessibleContext() {
764 if (accessibleContext == null) {
765 accessibleContext = new AccessibleAWTTextField();
766 }
767 return accessibleContext;
768 }
769
770 /**
771 * This class implements accessibility support for the
772 * {@code TextField} class. It provides an implementation of the
773 * Java Accessibility API appropriate to text field user-interface elements.
774 * @since 1.3
775 */
776 protected class AccessibleAWTTextField extends AccessibleAWTTextComponent
777 {
778 /*
779 * JDK 1.3 serialVersionUID
780 */
781 private static final long serialVersionUID = 6219164359235943158L;
782
783 /**
784 * Gets the state set of this object.
785 *
786 * @return an instance of AccessibleStateSet describing the states
787 * of the object
788 * @see AccessibleState
789 */
790 public AccessibleStateSet getAccessibleStateSet() {
791 AccessibleStateSet states = super.getAccessibleStateSet();
792 states.add(AccessibleState.SINGLE_LINE);
793 return states;
794 }
795 }
796
797 }