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  * <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"</code>.
  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</code>
  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</code>
  70  * or <code>KeyAdapter</code> object which registered to receive such
  71  * events using the component's <code>addKeyListener</code> method.
  72  * (<code>KeyAdapter</code> objects implement the
  73  * <code>KeyListener</code> interface.)
  74  * <p>
  75  * It is also possible to fire an <code>ActionEvent</code>.
  76  * If action events are enabled for the text field, they may
  77  * be fired by pressing the <code>Return</code> key.
  78  * <p>
  79  * The <code>TextField</code> class's <code>processEvent</code>
  80  * method examines the action event and passes it along to
  81  * <code>processActionEvent</code>. The latter method redirects the
  82  * event to any <code>ActionListener</code> 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</code>.
 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</code> is <code>null</code>, the empty
 161      *             string <code>""</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</code> is less than <code>0</code>,
 176      *             <code>columns</code> is set to <code>0</code>.
 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</code> is <code>null</code>, the empty
 192      *             string <code>""</code> will be displayed.
 193      * @param      columns     the number of columns.  If
 194      *             <code>columns</code> is less than <code>0</code>,
 195      *             <code>columns</code> is set to <code>0</code>.
 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(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> = <code>0</code>, 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> = <code>0</code> 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)</code>.
 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(t);
 301 
 302         // This could change the preferred size of the Component.
 303         invalidateIfValid();
 304     }
 305 
 306     /**
 307      * Indicates whether or not this text field has a
 308      * character set for echoing.
 309      * <p>
 310      * An echo character is useful for text fields where
 311      * user input should not be echoed to the screen, as in
 312      * the case of a text field for entering a password.
 313      * @return     <code>true</code> if this text field has
 314      *                 a character set for echoing;
 315      *                 <code>false</code> otherwise.
 316      * @see        java.awt.TextField#setEchoChar
 317      * @see        java.awt.TextField#getEchoChar
 318      */
 319     public boolean echoCharIsSet() {
 320         return echoChar != 0;
 321     }
 322 
 323     /**
 324      * Gets the number of columns in this text field. A column is an
 325      * approximate average character width that is platform-dependent.
 326      * @return     the number of columns.
 327      * @see        java.awt.TextField#setColumns
 328      * @since      1.1
 329      */
 330     public int getColumns() {
 331         return columns;
 332     }
 333 
 334     /**
 335      * Sets the number of columns in this text field. A column is an
 336      * approximate average character width that is platform-dependent.
 337      * @param      columns   the number of columns.
 338      * @see        java.awt.TextField#getColumns
 339      * @exception  IllegalArgumentException   if the value
 340      *                 supplied for <code>columns</code>
 341      *                 is less than <code>0</code>.
 342      * @since      1.1
 343      */
 344     public void setColumns(int columns) {
 345         int oldVal;
 346         synchronized (this) {
 347             oldVal = this.columns;
 348             if (columns < 0) {
 349                 throw new IllegalArgumentException("columns less than zero.");
 350             }
 351             if (columns != oldVal) {
 352                 this.columns = columns;
 353             }
 354         }
 355 
 356         if (columns != oldVal) {
 357             invalidate();
 358         }
 359     }
 360 
 361     /**
 362      * Gets the preferred size of this text field
 363      * with the specified number of columns.
 364      * @param     columns the number of columns
 365      *                 in this text field.
 366      * @return    the preferred dimensions for
 367      *                 displaying this text field.
 368      * @since     1.1
 369      */
 370     public Dimension getPreferredSize(int columns) {
 371         return preferredSize(columns);
 372     }
 373 
 374     /**
 375      * Returns the preferred size for this text field
 376      * with the specified number of columns.
 377      *
 378      * @param  columns the number of columns
 379      * @return the preferred size for the text field
 380      *
 381      * @deprecated As of JDK version 1.1,
 382      * replaced by <code>getPreferredSize(int)</code>.
 383      */
 384     @Deprecated
 385     public Dimension preferredSize(int columns) {
 386         synchronized (getTreeLock()) {
 387             TextFieldPeer peer = (TextFieldPeer)this.peer;
 388             return (peer != null) ?
 389                        peer.getPreferredSize(columns) :
 390                        super.preferredSize();
 391         }
 392     }
 393 
 394     /**
 395      * Gets the preferred size of this text field.
 396      * @return     the preferred dimensions for
 397      *                         displaying this text field.
 398      * @since      1.1
 399      */
 400     public Dimension getPreferredSize() {
 401         return preferredSize();
 402     }
 403 
 404     /**
 405      * @deprecated As of JDK version 1.1,
 406      * replaced by <code>getPreferredSize()</code>.
 407      */
 408     @Deprecated
 409     public Dimension preferredSize() {
 410         synchronized (getTreeLock()) {
 411             return (columns > 0) ?
 412                        preferredSize(columns) :
 413                        super.preferredSize();
 414         }
 415     }
 416 
 417     /**
 418      * Gets the minimum dimensions for a text field with
 419      * the specified number of columns.
 420      * @param  columns the number of columns in
 421      *         this text field.
 422      * @return the minimum size for this text field
 423      * @since    1.1
 424      */
 425     public Dimension getMinimumSize(int columns) {
 426         return minimumSize(columns);
 427     }
 428 
 429     /**
 430      * Returns the minimum dimensions for a text field with
 431      * the specified number of columns.
 432      *
 433      * @param  columns the number of columns
 434      * @return the minimum size for this text field
 435      * @deprecated As of JDK version 1.1,
 436      * replaced by <code>getMinimumSize(int)</code>.
 437      */
 438     @Deprecated
 439     public Dimension minimumSize(int columns) {
 440         synchronized (getTreeLock()) {
 441             TextFieldPeer peer = (TextFieldPeer)this.peer;
 442             return (peer != null) ?
 443                        peer.getMinimumSize(columns) :
 444                        super.minimumSize();
 445         }
 446     }
 447 
 448     /**
 449      * Gets the minimum dimensions for this text field.
 450      * @return     the minimum dimensions for
 451      *                  displaying this text field.
 452      * @since      1.1
 453      */
 454     public Dimension getMinimumSize() {
 455         return minimumSize();
 456     }
 457 
 458     /**
 459      * @deprecated As of JDK version 1.1,
 460      * replaced by <code>getMinimumSize()</code>.
 461      */
 462     @Deprecated
 463     public Dimension minimumSize() {
 464         synchronized (getTreeLock()) {
 465             return (columns > 0) ?
 466                        minimumSize(columns) :
 467                        super.minimumSize();
 468         }
 469     }
 470 
 471     /**
 472      * Adds the specified action listener to receive
 473      * action events from this text field.
 474      * If l is null, no exception is thrown and no action is performed.
 475      * <p>Refer to <a href="doc-files/AWTThreadIssues.html#ListenersThreads"
 476      * >AWT Threading Issues</a> for details on AWT's threading model.
 477      *
 478      * @param      l the action listener.
 479      * @see        #removeActionListener
 480      * @see        #getActionListeners
 481      * @see        java.awt.event.ActionListener
 482      * @since      1.1
 483      */
 484     public synchronized void addActionListener(ActionListener l) {
 485         if (l == null) {
 486             return;
 487         }
 488         actionListener = AWTEventMulticaster.add(actionListener, l);
 489         newEventsOnly = true;
 490     }
 491 
 492     /**
 493      * Removes the specified action listener so that it no longer
 494      * receives action events from this text field.
 495      * If l is null, no exception is thrown and no action is performed.
 496      * <p>Refer to <a href="doc-files/AWTThreadIssues.html#ListenersThreads"
 497      * >AWT Threading Issues</a> for details on AWT's threading model.
 498      *
 499      * @param           l the action listener.
 500      * @see             #addActionListener
 501      * @see             #getActionListeners
 502      * @see             java.awt.event.ActionListener
 503      * @since           1.1
 504      */
 505     public synchronized void removeActionListener(ActionListener l) {
 506         if (l == null) {
 507             return;
 508         }
 509         actionListener = AWTEventMulticaster.remove(actionListener, l);
 510     }
 511 
 512     /**
 513      * Returns an array of all the action listeners
 514      * registered on this textfield.
 515      *
 516      * @return all of this textfield's <code>ActionListener</code>s
 517      *         or an empty array if no action
 518      *         listeners are currently registered
 519      *
 520      * @see #addActionListener
 521      * @see #removeActionListener
 522      * @see java.awt.event.ActionListener
 523      * @since 1.4
 524      */
 525     public synchronized ActionListener[] getActionListeners() {
 526         return getListeners(ActionListener.class);
 527     }
 528 
 529     /**
 530      * Returns an array of all the objects currently registered
 531      * as <code><em>Foo</em>Listener</code>s
 532      * upon this <code>TextField</code>.
 533      * <code><em>Foo</em>Listener</code>s are registered using the
 534      * <code>add<em>Foo</em>Listener</code> method.
 535      *
 536      * <p>
 537      * You can specify the <code>listenerType</code> argument
 538      * with a class literal, such as
 539      * <code><em>Foo</em>Listener.class</code>.
 540      * For example, you can query a
 541      * <code>TextField</code> <code>t</code>
 542      * for its action listeners with the following code:
 543      *
 544      * <pre>ActionListener[] als = (ActionListener[])(t.getListeners(ActionListener.class));</pre>
 545      *
 546      * If no such listeners exist, this method returns an empty array.
 547      *
 548      * @param listenerType the type of listeners requested; this parameter
 549      *          should specify an interface that descends from
 550      *          <code>java.util.EventListener</code>
 551      * @return an array of all objects registered as
 552      *          <code><em>Foo</em>Listener</code>s on this textfield,
 553      *          or an empty array if no such
 554      *          listeners have been added
 555      * @exception ClassCastException if <code>listenerType</code>
 556      *          doesn't specify a class or interface that implements
 557      *          <code>java.util.EventListener</code>
 558      *
 559      * @see #getActionListeners
 560      * @since 1.3
 561      */
 562     public <T extends EventListener> T[] getListeners(Class<T> listenerType) {
 563         EventListener l = null;
 564         if  (listenerType == ActionListener.class) {
 565             l = actionListener;
 566         } else {
 567             return super.getListeners(listenerType);
 568         }
 569         return AWTEventMulticaster.getListeners(l, listenerType);
 570     }
 571 
 572     // REMIND: remove when filtering is done at lower level
 573     boolean eventEnabled(AWTEvent e) {
 574         if (e.id == ActionEvent.ACTION_PERFORMED) {
 575             if ((eventMask & AWTEvent.ACTION_EVENT_MASK) != 0 ||
 576                 actionListener != null) {
 577                 return true;
 578             }
 579             return false;
 580         }
 581         return super.eventEnabled(e);
 582     }
 583 
 584     /**
 585      * Processes events on this text field. If the event
 586      * is an instance of <code>ActionEvent</code>,
 587      * it invokes the <code>processActionEvent</code>
 588      * method. Otherwise, it invokes <code>processEvent</code>
 589      * on the superclass.
 590      * <p>Note that if the event parameter is <code>null</code>
 591      * the behavior is unspecified and may result in an
 592      * exception.
 593      *
 594      * @param      e the event
 595      * @see        java.awt.event.ActionEvent
 596      * @see        java.awt.TextField#processActionEvent
 597      * @since      1.1
 598      */
 599     protected void processEvent(AWTEvent e) {
 600         if (e instanceof ActionEvent) {
 601             processActionEvent((ActionEvent)e);
 602             return;
 603         }
 604         super.processEvent(e);
 605     }
 606 
 607     /**
 608      * Processes action events occurring on this text field by
 609      * dispatching them to any registered
 610      * <code>ActionListener</code> objects.
 611      * <p>
 612      * This method is not called unless action events are
 613      * enabled for this component. Action events are enabled
 614      * when one of the following occurs:
 615      * <ul>
 616      * <li>An <code>ActionListener</code> object is registered
 617      * via <code>addActionListener</code>.
 618      * <li>Action events are enabled via <code>enableEvents</code>.
 619      * </ul>
 620      * <p>Note that if the event parameter is <code>null</code>
 621      * the behavior is unspecified and may result in an
 622      * exception.
 623      *
 624      * @param       e the action event
 625      * @see         java.awt.event.ActionListener
 626      * @see         java.awt.TextField#addActionListener
 627      * @see         java.awt.Component#enableEvents
 628      * @since       1.1
 629      */
 630     protected void processActionEvent(ActionEvent e) {
 631         ActionListener listener = actionListener;
 632         if (listener != null) {
 633             listener.actionPerformed(e);
 634         }
 635     }
 636 
 637     /**
 638      * Returns a string representing the state of this <code>TextField</code>.
 639      * This method is intended to be used only for debugging purposes, and the
 640      * content and format of the returned string may vary between
 641      * implementations. The returned string may be empty but may not be
 642      * <code>null</code>.
 643      *
 644      * @return      the parameter string of this text field
 645      */
 646     protected String paramString() {
 647         String str = super.paramString();
 648         if (echoChar != 0) {
 649             str += ",echo=" + echoChar;
 650         }
 651         return str;
 652     }
 653 
 654 
 655     /*
 656      * Serialization support.
 657      */
 658     /**
 659      * The textField Serialized Data Version.
 660      *
 661      * @serial
 662      */
 663     private int textFieldSerializedDataVersion = 1;
 664 
 665     /**
 666      * Writes default serializable fields to stream.  Writes
 667      * a list of serializable ActionListener(s) as optional data.
 668      * The non-serializable ActionListener(s) are detected and
 669      * no attempt is made to serialize them.
 670      *
 671      * @serialData Null terminated sequence of zero or more pairs.
 672      *             A pair consists of a String and Object.
 673      *             The String indicates the type of object and
 674      *             is one of the following :
 675      *             ActionListenerK indicating and ActionListener object.
 676      *
 677      * @see AWTEventMulticaster#save(ObjectOutputStream, String, EventListener)
 678      * @see java.awt.Component#actionListenerK
 679      */
 680     private void writeObject(ObjectOutputStream s)
 681       throws IOException
 682     {
 683         s.defaultWriteObject();
 684 
 685         AWTEventMulticaster.save(s, actionListenerK, actionListener);
 686         s.writeObject(null);
 687     }
 688 
 689     /**
 690      * Read the ObjectInputStream and if it isn't null,
 691      * add a listener to receive action events fired by the
 692      * TextField.  Unrecognized keys or values will be
 693      * ignored.
 694      *
 695      * @exception HeadlessException if
 696      * <code>GraphicsEnvironment.isHeadless()</code> returns
 697      * <code>true</code>
 698      * @see #removeActionListener(ActionListener)
 699      * @see #addActionListener(ActionListener)
 700      * @see java.awt.GraphicsEnvironment#isHeadless
 701      */
 702     private void readObject(ObjectInputStream s)
 703       throws ClassNotFoundException, IOException, HeadlessException
 704     {
 705         // HeadlessException will be thrown by TextComponent's readObject
 706         s.defaultReadObject();
 707 
 708         // Make sure the state we just read in for columns has legal values
 709         if (columns < 0) {
 710             columns = 0;
 711         }
 712 
 713         // Read in listeners, if any
 714         Object keyOrNull;
 715         while(null != (keyOrNull = s.readObject())) {
 716             String key = ((String)keyOrNull).intern();
 717 
 718             if (actionListenerK == key) {
 719                 addActionListener((ActionListener)(s.readObject()));
 720             } else {
 721                 // skip value for unrecognized key
 722                 s.readObject();
 723             }
 724         }
 725     }
 726 
 727 
 728 /////////////////
 729 // Accessibility support
 730 ////////////////
 731 
 732 
 733     /**
 734      * Gets the AccessibleContext associated with this TextField.
 735      * For text fields, the AccessibleContext takes the form of an
 736      * AccessibleAWTTextField.
 737      * A new AccessibleAWTTextField instance is created if necessary.
 738      *
 739      * @return an AccessibleAWTTextField that serves as the
 740      *         AccessibleContext of this TextField
 741      * @since 1.3
 742      */
 743     public AccessibleContext getAccessibleContext() {
 744         if (accessibleContext == null) {
 745             accessibleContext = new AccessibleAWTTextField();
 746         }
 747         return accessibleContext;
 748     }
 749 
 750     /**
 751      * This class implements accessibility support for the
 752      * <code>TextField</code> class.  It provides an implementation of the
 753      * Java Accessibility API appropriate to text field user-interface elements.
 754      * @since 1.3
 755      */
 756     protected class AccessibleAWTTextField extends AccessibleAWTTextComponent
 757     {
 758         /*
 759          * JDK 1.3 serialVersionUID
 760          */
 761         private static final long serialVersionUID = 6219164359235943158L;
 762 
 763         /**
 764          * Gets the state set of this object.
 765          *
 766          * @return an instance of AccessibleStateSet describing the states
 767          * of the object
 768          * @see AccessibleState
 769          */
 770         public AccessibleStateSet getAccessibleStateSet() {
 771             AccessibleStateSet states = super.getAccessibleStateSet();
 772             states.add(AccessibleState.SINGLE_LINE);
 773             return states;
 774         }
 775     }
 776 
 777 }
--- EOF ---