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