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 
  26 package java.awt;
  27 
  28 import java.awt.datatransfer.Clipboard;
  29 import java.awt.dnd.DragGestureListener;
  30 import java.awt.dnd.DragGestureRecognizer;
  31 import java.awt.dnd.DragSource;
  32 import java.awt.event.*;
  33 import java.awt.im.InputMethodHighlight;
  34 import java.awt.image.ColorModel;
  35 import java.awt.image.ImageObserver;
  36 import java.awt.image.ImageProducer;
  37 import java.beans.PropertyChangeEvent;
  38 import java.beans.PropertyChangeListener;
  39 import java.beans.PropertyChangeSupport;
  40 import java.io.File;
  41 import java.io.FileInputStream;
  42 import java.net.URL;
  43 import java.util.ArrayList;
  44 import java.util.EventListener;
  45 import java.util.HashMap;
  46 import java.util.Map;
  47 import java.util.MissingResourceException;
  48 import java.util.Properties;
  49 import java.util.ResourceBundle;
  50 import java.util.StringTokenizer;
  51 import java.util.WeakHashMap;
  52 
  53 import sun.awt.AWTAccessor;
  54 import sun.awt.AWTPermissions;
  55 import sun.awt.AppContext;
  56 import sun.awt.HeadlessToolkit;
  57 import sun.awt.PeerEvent;
  58 import sun.awt.SunToolkit;
  59 import sun.util.CoreResourceBundleControl;
  60 
  61 import java.security.AccessController;
  62 import java.security.PrivilegedAction;
  63 import java.util.Arrays;
  64 import java.util.ServiceLoader;
  65 import java.util.Set;
  66 import java.util.stream.Collectors;
  67 import javax.accessibility.AccessibilityProvider;
  68 
  69 /**
  70  * This class is the abstract superclass of all actual
  71  * implementations of the Abstract Window Toolkit. Subclasses of
  72  * the <code>Toolkit</code> class are used to bind the various components
  73  * to particular native toolkit implementations.
  74  * <p>
  75  * Many GUI events may be delivered to user
  76  * asynchronously, if the opposite is not specified explicitly.
  77  * As well as
  78  * many GUI operations may be performed asynchronously.
  79  * This fact means that if the state of a component is set, and then
  80  * the state immediately queried, the returned value may not yet
  81  * reflect the requested change.  This behavior includes, but is not
  82  * limited to:
  83  * <ul>
  84  * <li>Scrolling to a specified position.
  85  * <br>For example, calling <code>ScrollPane.setScrollPosition</code>
  86  *     and then <code>getScrollPosition</code> may return an incorrect
  87  *     value if the original request has not yet been processed.
  88  *
  89  * <li>Moving the focus from one component to another.
  90  * <br>For more information, see
  91  * <a href="http://docs.oracle.com/javase/tutorial/uiswing/misc/focus.html#transferTiming">Timing
  92  * Focus Transfers</a>, a section in
  93  * <a href="http://java.sun.com/docs/books/tutorial/uiswing/">The Swing
  94  * Tutorial</a>.
  95  *
  96  * <li>Making a top-level container visible.
  97  * <br>Calling <code>setVisible(true)</code> on a <code>Window</code>,
  98  *     <code>Frame</code> or <code>Dialog</code> may occur
  99  *     asynchronously.
 100  *
 101  * <li>Setting the size or location of a top-level container.
 102  * <br>Calls to <code>setSize</code>, <code>setBounds</code> or
 103  *     <code>setLocation</code> on a <code>Window</code>,
 104  *     <code>Frame</code> or <code>Dialog</code> are forwarded
 105  *     to the underlying window management system and may be
 106  *     ignored or modified.  See {@link java.awt.Window} for
 107  *     more information.
 108  * </ul>
 109  * <p>
 110  * Most applications should not call any of the methods in this
 111  * class directly. The methods defined by <code>Toolkit</code> are
 112  * the "glue" that joins the platform-independent classes in the
 113  * <code>java.awt</code> package with their counterparts in
 114  * <code>java.awt.peer</code>. Some methods defined by
 115  * <code>Toolkit</code> query the native operating system directly.
 116  *
 117  * @author      Sami Shaio
 118  * @author      Arthur van Hoff
 119  * @author      Fred Ecks
 120  * @since       1.0
 121  */
 122 public abstract class Toolkit {
 123 
 124     // The following method is called by the private method
 125     // <code>updateSystemColors</code> in <code>SystemColor</code>.
 126 
 127     /**
 128      * Fills in the integer array that is supplied as an argument
 129      * with the current system color values.
 130      *
 131      * @param     systemColors an integer array.
 132      * @exception HeadlessException if GraphicsEnvironment.isHeadless()
 133      * returns true
 134      * @see       java.awt.GraphicsEnvironment#isHeadless
 135      * @since     1.1
 136      */
 137     protected void loadSystemColors(int[] systemColors)
 138         throws HeadlessException {
 139         GraphicsEnvironment.checkHeadless();
 140     }
 141 
 142     /**
 143      * Controls whether the layout of Containers is validated dynamically
 144      * during resizing, or statically, after resizing is complete.
 145      * Use {@code isDynamicLayoutActive()} to detect if this feature enabled
 146      * in this program and is supported by this operating system
 147      * and/or window manager.
 148      * Note that this feature is supported not on all platforms, and
 149      * conversely, that this feature cannot be turned off on some platforms.
 150      * On these platforms where dynamic layout during resizing is not supported
 151      * (or is always supported), setting this property has no effect.
 152      * Note that this feature can be set or unset as a property of the
 153      * operating system or window manager on some platforms.  On such
 154      * platforms, the dynamic resize property must be set at the operating
 155      * system or window manager level before this method can take effect.
 156      * This method does not change support or settings of the underlying
 157      * operating system or
 158      * window manager.  The OS/WM support can be
 159      * queried using getDesktopProperty("awt.dynamicLayoutSupported") method.
 160      *
 161      * @param     dynamic  If true, Containers should re-layout their
 162      *            components as the Container is being resized.  If false,
 163      *            the layout will be validated after resizing is completed.
 164      * @exception HeadlessException if GraphicsEnvironment.isHeadless()
 165      *            returns true
 166      * @see       #isDynamicLayoutSet()
 167      * @see       #isDynamicLayoutActive()
 168      * @see       #getDesktopProperty(String propertyName)
 169      * @see       java.awt.GraphicsEnvironment#isHeadless
 170      * @since     1.4
 171      */
 172     public void setDynamicLayout(final boolean dynamic)
 173         throws HeadlessException {
 174         GraphicsEnvironment.checkHeadless();
 175         if (this != getDefaultToolkit()) {
 176             getDefaultToolkit().setDynamicLayout(dynamic);
 177         }
 178     }
 179 
 180     /**
 181      * Returns whether the layout of Containers is validated dynamically
 182      * during resizing, or statically, after resizing is complete.
 183      * Note: this method returns the value that was set programmatically;
 184      * it does not reflect support at the level of the operating system
 185      * or window manager for dynamic layout on resizing, or the current
 186      * operating system or window manager settings.  The OS/WM support can
 187      * be queried using getDesktopProperty("awt.dynamicLayoutSupported").
 188      *
 189      * @return    true if validation of Containers is done dynamically,
 190      *            false if validation is done after resizing is finished.
 191      * @exception HeadlessException if GraphicsEnvironment.isHeadless()
 192      *            returns true
 193      * @see       #setDynamicLayout(boolean dynamic)
 194      * @see       #isDynamicLayoutActive()
 195      * @see       #getDesktopProperty(String propertyName)
 196      * @see       java.awt.GraphicsEnvironment#isHeadless
 197      * @since     1.4
 198      */
 199     protected boolean isDynamicLayoutSet()
 200         throws HeadlessException {
 201         GraphicsEnvironment.checkHeadless();
 202 
 203         if (this != Toolkit.getDefaultToolkit()) {
 204             return Toolkit.getDefaultToolkit().isDynamicLayoutSet();
 205         } else {
 206             return false;
 207         }
 208     }
 209 
 210     /**
 211      * Returns whether dynamic layout of Containers on resize is currently
 212      * active (both set in program ({@code isDynamicLayoutSet()}), and supported
 213      * by the underlying operating system and/or window manager). Note that on
 214      * platforms where dynamic layout during resizing is not supported (or is
 215      * always supported) by the OS/WM, ({@code isDynamicLayoutSet()}) property
 216      * has no effect.
 217      * <p>
 218      * If dynamic layout is currently inactive then Containers
 219      * re-layout their components when resizing is completed. As a result
 220      * the {@code Component.validate()} method will be invoked only
 221      * once per resize.
 222      * If dynamic layout is currently active then Containers
 223      * re-layout their components on every native resize event and
 224      * the {@code validate()} method will be invoked each time.
 225      * The OS/WM support can be queried using
 226      * the getDesktopProperty("awt.dynamicLayoutSupported") method.
 227      *
 228      * @return    true if dynamic layout of Containers on resize is
 229      *            currently active, false otherwise.
 230      * @exception HeadlessException if the GraphicsEnvironment.isHeadless()
 231      *            method returns true
 232      * @see       #setDynamicLayout(boolean dynamic)
 233      * @see       #isDynamicLayoutSet()
 234      * @see       #getDesktopProperty(String propertyName)
 235      * @see       java.awt.GraphicsEnvironment#isHeadless
 236      * @since     1.4
 237      */
 238     public boolean isDynamicLayoutActive()
 239         throws HeadlessException {
 240         GraphicsEnvironment.checkHeadless();
 241 
 242         if (this != Toolkit.getDefaultToolkit()) {
 243             return Toolkit.getDefaultToolkit().isDynamicLayoutActive();
 244         } else {
 245             return false;
 246         }
 247     }
 248 
 249     /**
 250      * Gets the size of the screen.  On systems with multiple displays, the
 251      * primary display is used.  Multi-screen aware display dimensions are
 252      * available from <code>GraphicsConfiguration</code> and
 253      * <code>GraphicsDevice</code>.
 254      * @return    the size of this toolkit's screen, in pixels.
 255      * @exception HeadlessException if GraphicsEnvironment.isHeadless()
 256      * returns true
 257      * @see       java.awt.GraphicsConfiguration#getBounds
 258      * @see       java.awt.GraphicsDevice#getDisplayMode
 259      * @see       java.awt.GraphicsEnvironment#isHeadless
 260      */
 261     public abstract Dimension getScreenSize()
 262         throws HeadlessException;
 263 
 264     /**
 265      * Returns the screen resolution in dots-per-inch.
 266      * @return    this toolkit's screen resolution, in dots-per-inch.
 267      * @exception HeadlessException if GraphicsEnvironment.isHeadless()
 268      * returns true
 269      * @see       java.awt.GraphicsEnvironment#isHeadless
 270      */
 271     public abstract int getScreenResolution()
 272         throws HeadlessException;
 273 
 274     /**
 275      * Gets the insets of the screen.
 276      * @param     gc a <code>GraphicsConfiguration</code>
 277      * @return    the insets of this toolkit's screen, in pixels.
 278      * @exception HeadlessException if GraphicsEnvironment.isHeadless()
 279      * returns true
 280      * @see       java.awt.GraphicsEnvironment#isHeadless
 281      * @since     1.4
 282      */
 283     public Insets getScreenInsets(GraphicsConfiguration gc)
 284         throws HeadlessException {
 285         GraphicsEnvironment.checkHeadless();
 286         if (this != Toolkit.getDefaultToolkit()) {
 287             return Toolkit.getDefaultToolkit().getScreenInsets(gc);
 288         } else {
 289             return new Insets(0, 0, 0, 0);
 290         }
 291     }
 292 
 293     /**
 294      * Determines the color model of this toolkit's screen.
 295      * <p>
 296      * <code>ColorModel</code> is an abstract class that
 297      * encapsulates the ability to translate between the
 298      * pixel values of an image and its red, green, blue,
 299      * and alpha components.
 300      * <p>
 301      * This toolkit method is called by the
 302      * <code>getColorModel</code> method
 303      * of the <code>Component</code> class.
 304      * @return    the color model of this toolkit's screen.
 305      * @exception HeadlessException if GraphicsEnvironment.isHeadless()
 306      * returns true
 307      * @see       java.awt.GraphicsEnvironment#isHeadless
 308      * @see       java.awt.image.ColorModel
 309      * @see       java.awt.Component#getColorModel
 310      */
 311     public abstract ColorModel getColorModel()
 312         throws HeadlessException;
 313 
 314     /**
 315      * Returns the names of the available fonts in this toolkit.<p>
 316      * For 1.1, the following font names are deprecated (the replacement
 317      * name follows):
 318      * <ul>
 319      * <li>TimesRoman (use Serif)
 320      * <li>Helvetica (use SansSerif)
 321      * <li>Courier (use Monospaced)
 322      * </ul><p>
 323      * The ZapfDingbats fontname is also deprecated in 1.1 but the characters
 324      * are defined in Unicode starting at 0x2700, and as of 1.1 Java supports
 325      * those characters.
 326      * @return    the names of the available fonts in this toolkit.
 327      * @deprecated see {@link java.awt.GraphicsEnvironment#getAvailableFontFamilyNames()}
 328      * @see java.awt.GraphicsEnvironment#getAvailableFontFamilyNames()
 329      */
 330     @Deprecated
 331     public abstract String[] getFontList();
 332 
 333     /**
 334      * Gets the screen device metrics for rendering of the font.
 335      * @param     font   a font
 336      * @return    the screen metrics of the specified font in this toolkit
 337      * @deprecated  As of JDK version 1.2, replaced by the <code>Font</code>
 338      *          method <code>getLineMetrics</code>.
 339      * @see java.awt.font.LineMetrics
 340      * @see java.awt.Font#getLineMetrics
 341      * @see java.awt.GraphicsEnvironment#getScreenDevices
 342      */
 343     @Deprecated
 344     public abstract FontMetrics getFontMetrics(Font font);
 345 
 346     /**
 347      * Synchronizes this toolkit's graphics state. Some window systems
 348      * may do buffering of graphics events.
 349      * <p>
 350      * This method ensures that the display is up-to-date. It is useful
 351      * for animation.
 352      */
 353     public abstract void sync();
 354 
 355     /**
 356      * The default toolkit.
 357      */
 358     private static Toolkit toolkit;
 359 
 360     /**
 361      * Used internally by the assistive technologies functions; set at
 362      * init time and used at load time
 363      */
 364     private static String atNames;
 365 
 366     /**
 367      * Initializes properties related to assistive technologies.
 368      * These properties are used both in the loadAssistiveProperties()
 369      * function below, as well as other classes in the jdk that depend
 370      * on the properties (such as the use of the screen_magnifier_present
 371      * property in Java2D hardware acceleration initialization).  The
 372      * initialization of the properties must be done before the platform-
 373      * specific Toolkit class is instantiated so that all necessary
 374      * properties are set up properly before any classes dependent upon them
 375      * are initialized.
 376      */
 377     private static void initAssistiveTechnologies() {
 378 
 379         // Get accessibility properties
 380         final String sep = File.separator;
 381         final Properties properties = new Properties();
 382 
 383 
 384         atNames = java.security.AccessController.doPrivileged(
 385             new java.security.PrivilegedAction<String>() {
 386             public String run() {
 387 
 388                 // Try loading the per-user accessibility properties file.
 389                 try {
 390                     File propsFile = new File(
 391                       System.getProperty("user.home") +
 392                       sep + ".accessibility.properties");
 393                     FileInputStream in =
 394                         new FileInputStream(propsFile);
 395 
 396                     // Inputstream has been buffered in Properties class
 397                     properties.load(in);
 398                     in.close();
 399                 } catch (Exception e) {
 400                     // Per-user accessibility properties file does not exist
 401                 }
 402 
 403                 // Try loading the system-wide accessibility properties
 404                 // file only if a per-user accessibility properties
 405                 // file does not exist or is empty.
 406                 if (properties.size() == 0) {
 407                     try {
 408                         File propsFile = new File(
 409                             System.getProperty("java.home") + sep + "conf" +
 410                             sep + "accessibility.properties");
 411                         FileInputStream in =
 412                             new FileInputStream(propsFile);
 413 
 414                         // Inputstream has been buffered in Properties class
 415                         properties.load(in);
 416                         in.close();
 417                     } catch (Exception e) {
 418                         // System-wide accessibility properties file does
 419                         // not exist;
 420                     }
 421                 }
 422 
 423                 // Get whether a screen magnifier is present.  First check
 424                 // the system property and then check the properties file.
 425                 String magPresent = System.getProperty("javax.accessibility.screen_magnifier_present");
 426                 if (magPresent == null) {
 427                     magPresent = properties.getProperty("screen_magnifier_present", null);
 428                     if (magPresent != null) {
 429                         System.setProperty("javax.accessibility.screen_magnifier_present", magPresent);
 430                     }
 431                 }
 432 
 433                 // Get the names of any assistive technologies to load.  First
 434                 // check the system property and then check the properties
 435                 // file.
 436                 String classNames = System.getProperty("javax.accessibility.assistive_technologies");
 437                 if (classNames == null) {
 438                     classNames = properties.getProperty("assistive_technologies", null);
 439                     if (classNames != null) {
 440                         System.setProperty("javax.accessibility.assistive_technologies", classNames);
 441                     }
 442                 }
 443                 return classNames;
 444             }
 445         });
 446     }
 447 
 448     /**
 449      * Rethrow the AWTError but include the cause.
 450      *
 451      * @param s the error message
 452      * @param e the original exception
 453      * @throws the new AWTError including the cause (the original exception)
 454      */
 455     private static void newAWTError(Throwable e, String s) {
 456         AWTError newAWTError = new AWTError(s);
 457         newAWTError.initCause(e);
 458         throw newAWTError;
 459     }
 460 
 461     /**
 462      * When a service provider for Assistive Technology is not found look for a
 463      * supporting class on the class path and instantiate it.
 464      *
 465      * @param atName the name of the class to be loaded
 466      */
 467     private static void fallbackToLoadClassForAT(String atName) {
 468         try {
 469             Class.forName(atName, false, ClassLoader.getSystemClassLoader()).newInstance();
 470         } catch (ClassNotFoundException e) {
 471             newAWTError(e, "Assistive Technology not found: " + atName);
 472         } catch (InstantiationException e) {
 473             newAWTError(e, "Could not instantiate Assistive Technology: " + atName);
 474         } catch (IllegalAccessException e) {
 475             newAWTError(e, "Could not access Assistive Technology: " + atName);
 476         } catch (Exception e) {
 477             newAWTError(e, "Error trying to install Assistive Technology: " + atName);
 478         }
 479     }
 480 
 481     /**
 482      * Loads accessibility support using the property assistive_technologies.
 483      * The form is assistive_technologies= followed by a comma-separated list of
 484      * assistive technology providers to load.  The order in which providers are
 485      * loaded is determined by the order in which the ServiceLoader discovers
 486      * implementations of the AccessibilityProvider interface, not by the order
 487      * of provider names in the property list.  When a provider is found its
 488      * accessibility implementation will be started by calling the provider's
 489      * activate method.  All errors are handled via an AWTError exception.
 490      */
 491     private static void loadAssistiveTechnologies() {
 492         // Load any assistive technologies
 493         if (atNames != null) {
 494             ClassLoader cl = ClassLoader.getSystemClassLoader();
 495             Set<String> names = Arrays.stream(atNames.split(","))
 496                                       .map(String::trim)
 497                                       .collect(Collectors.toSet());
 498             final Map<String, AccessibilityProvider> providers = new HashMap<>();
 499             AccessController.doPrivileged((PrivilegedAction<Void>) () -> {
 500                 try {
 501                     for (AccessibilityProvider p : ServiceLoader.load(AccessibilityProvider.class, cl)) {
 502                         String name = p.getName();
 503                         if (names.contains(name) && !providers.containsKey(name)) {
 504                             p.activate();
 505                             providers.put(name, p);
 506                         }
 507                     }
 508                 } catch (java.util.ServiceConfigurationError | Exception e) {
 509                     newAWTError(e, "Could not load or activate service provider");
 510                 }
 511                 return null;
 512             });
 513             names.stream()
 514                  .filter(n -> !providers.containsKey(n))
 515                  .forEach(Toolkit::fallbackToLoadClassForAT);
 516         }
 517     }
 518 
 519     /**
 520      * Gets the default toolkit.
 521      * <p>
 522      * If a system property named {@code "java.awt.headless"} is set
 523      * to {@code true} then the headless implementation
 524      * of {@code Toolkit} is used,
 525      * otherwise the default platform-specific implementation of
 526      * {@code Toolkit} is used.
 527      * <p>
 528      * If this Toolkit is not a headless implementation and if they exist, service
 529      * providers of {@link javax.accessibility.AccessibilityProvider} will be loaded
 530      * if specified by the system property
 531      * {@code javax.accessibility.assistive_technologies}.
 532      * <p>
 533      * An example of setting this property is to invoke Java with
 534      * {@code -Djavax.accessibility.assistive_technologies=MyServiceProvider}.
 535      * In addition to MyServiceProvider other service providers can be specified
 536      * using a comma separated list.  Service providers are loaded after the AWT
 537      * toolkit is created. All errors are handled via an AWTError exception.
 538      * <p>
 539      * The names specified in the assistive_technologies property are used to query
 540      * each service provider implementation.  If the requested name matches the
 541      * {@linkplain AccessibilityProvider#getName name} of the service provider, the
 542      * {@link AccessibilityProvider#activate} method will be invoked to activate the
 543      * matching service provider.
 544      *
 545      * @implSpec
 546      * If assistive technology service providers are not specified with a system
 547      * property this implementation will look in a properties file located as follows:
 548      * <ul>
 549      * <li> {@code ${user.home}/.accessibility.properties}
 550      * <li> {@code ${java.home}/conf/accessibility.properties}
 551      * </ul>
 552      * Only the first of these files to be located will be consulted.  The requested
 553      * service providers are specified by setting the {@code assistive_technologies=}
 554      * property.  A single provider or a comma separated list of providers can be
 555      * specified.
 556      *
 557      * @return     the default toolkit.
 558      * @exception  AWTError  if a toolkit could not be found, or
 559      *                 if one could not be accessed or instantiated.
 560      * @see java.util.ServiceLoader
 561      * @see javax.accessibility.AccessibilityProvider
 562      */
 563     public static synchronized Toolkit getDefaultToolkit() {
 564         if (toolkit == null) {
 565             java.security.AccessController.doPrivileged(
 566                     new java.security.PrivilegedAction<Void>() {
 567                 public Void run() {
 568                     Class<?> cls = null;
 569                     String nm = System.getProperty("awt.toolkit");
 570                     try {
 571                         cls = Class.forName(nm);
 572                     } catch (ClassNotFoundException e) {
 573                         ClassLoader cl = ClassLoader.getSystemClassLoader();
 574                         if (cl != null) {
 575                             try {
 576                                 cls = cl.loadClass(nm);
 577                             } catch (final ClassNotFoundException ignored) {
 578                                 throw new AWTError("Toolkit not found: " + nm);
 579                             }
 580                         }
 581                     }
 582                     try {
 583                         if (cls != null) {
 584                             toolkit = (Toolkit)cls.newInstance();
 585                             if (GraphicsEnvironment.isHeadless()) {
 586                                 toolkit = new HeadlessToolkit(toolkit);
 587                             }
 588                         }
 589                     } catch (final InstantiationException ignored) {
 590                         throw new AWTError("Could not instantiate Toolkit: " + nm);
 591                     } catch (final IllegalAccessException ignored) {
 592                         throw new AWTError("Could not access Toolkit: " + nm);
 593                     }
 594                     return null;
 595                 }
 596             });
 597             if (!GraphicsEnvironment.isHeadless()) {
 598                 loadAssistiveTechnologies();
 599             }
 600         }
 601         return toolkit;
 602     }
 603 
 604     /**
 605      * Returns an image which gets pixel data from the specified file,
 606      * whose format can be either GIF, JPEG or PNG.
 607      * The underlying toolkit attempts to resolve multiple requests
 608      * with the same filename to the same returned Image.
 609      * <p>
 610      * Since the mechanism required to facilitate this sharing of
 611      * <code>Image</code> objects may continue to hold onto images
 612      * that are no longer in use for an indefinite period of time,
 613      * developers are encouraged to implement their own caching of
 614      * images by using the {@link #createImage(java.lang.String) createImage}
 615      * variant wherever available.
 616      * If the image data contained in the specified file changes,
 617      * the <code>Image</code> object returned from this method may
 618      * still contain stale information which was loaded from the
 619      * file after a prior call.
 620      * Previously loaded image data can be manually discarded by
 621      * calling the {@link Image#flush flush} method on the
 622      * returned <code>Image</code>.
 623      * <p>
 624      * This method first checks if there is a security manager installed.
 625      * If so, the method calls the security manager's
 626      * <code>checkRead</code> method with the file specified to ensure
 627      * that the access to the image is allowed.
 628      * @param     filename   the name of a file containing pixel data
 629      *                         in a recognized file format.
 630      * @return    an image which gets its pixel data from
 631      *                         the specified file.
 632      * @throws SecurityException  if a security manager exists and its
 633      *                            checkRead method doesn't allow the operation.
 634      * @see #createImage(java.lang.String)
 635      */
 636     public abstract Image getImage(String filename);
 637 
 638     /**
 639      * Returns an image which gets pixel data from the specified URL.
 640      * The pixel data referenced by the specified URL must be in one
 641      * of the following formats: GIF, JPEG or PNG.
 642      * The underlying toolkit attempts to resolve multiple requests
 643      * with the same URL to the same returned Image.
 644      * <p>
 645      * Since the mechanism required to facilitate this sharing of
 646      * <code>Image</code> objects may continue to hold onto images
 647      * that are no longer in use for an indefinite period of time,
 648      * developers are encouraged to implement their own caching of
 649      * images by using the {@link #createImage(java.net.URL) createImage}
 650      * variant wherever available.
 651      * If the image data stored at the specified URL changes,
 652      * the <code>Image</code> object returned from this method may
 653      * still contain stale information which was fetched from the
 654      * URL after a prior call.
 655      * Previously loaded image data can be manually discarded by
 656      * calling the {@link Image#flush flush} method on the
 657      * returned <code>Image</code>.
 658      * <p>
 659      * This method first checks if there is a security manager installed.
 660      * If so, the method calls the security manager's
 661      * <code>checkPermission</code> method with the
 662      * url.openConnection().getPermission() permission to ensure
 663      * that the access to the image is allowed. For compatibility
 664      * with pre-1.2 security managers, if the access is denied with
 665      * <code>FilePermission</code> or <code>SocketPermission</code>,
 666      * the method throws the <code>SecurityException</code>
 667      * if the corresponding 1.1-style SecurityManager.checkXXX method
 668      * also denies permission.
 669      * @param     url   the URL to use in fetching the pixel data.
 670      * @return    an image which gets its pixel data from
 671      *                         the specified URL.
 672      * @throws SecurityException  if a security manager exists and its
 673      *                            checkPermission method doesn't allow
 674      *                            the operation.
 675      * @see #createImage(java.net.URL)
 676      */
 677     public abstract Image getImage(URL url);
 678 
 679     /**
 680      * Returns an image which gets pixel data from the specified file.
 681      * The returned Image is a new object which will not be shared
 682      * with any other caller of this method or its getImage variant.
 683      * <p>
 684      * This method first checks if there is a security manager installed.
 685      * If so, the method calls the security manager's
 686      * <code>checkRead</code> method with the specified file to ensure
 687      * that the image creation is allowed.
 688      * @param     filename   the name of a file containing pixel data
 689      *                         in a recognized file format.
 690      * @return    an image which gets its pixel data from
 691      *                         the specified file.
 692      * @throws SecurityException  if a security manager exists and its
 693      *                            checkRead method doesn't allow the operation.
 694      * @see #getImage(java.lang.String)
 695      */
 696     public abstract Image createImage(String filename);
 697 
 698     /**
 699      * Returns an image which gets pixel data from the specified URL.
 700      * The returned Image is a new object which will not be shared
 701      * with any other caller of this method or its getImage variant.
 702      * <p>
 703      * This method first checks if there is a security manager installed.
 704      * If so, the method calls the security manager's
 705      * <code>checkPermission</code> method with the
 706      * url.openConnection().getPermission() permission to ensure
 707      * that the image creation is allowed. For compatibility
 708      * with pre-1.2 security managers, if the access is denied with
 709      * <code>FilePermission</code> or <code>SocketPermission</code>,
 710      * the method throws <code>SecurityException</code>
 711      * if the corresponding 1.1-style SecurityManager.checkXXX method
 712      * also denies permission.
 713      * @param     url   the URL to use in fetching the pixel data.
 714      * @return    an image which gets its pixel data from
 715      *                         the specified URL.
 716      * @throws SecurityException  if a security manager exists and its
 717      *                            checkPermission method doesn't allow
 718      *                            the operation.
 719      * @see #getImage(java.net.URL)
 720      */
 721     public abstract Image createImage(URL url);
 722 
 723     /**
 724      * Prepares an image for rendering.
 725      * <p>
 726      * If the values of the width and height arguments are both
 727      * <code>-1</code>, this method prepares the image for rendering
 728      * on the default screen; otherwise, this method prepares an image
 729      * for rendering on the default screen at the specified width and height.
 730      * <p>
 731      * The image data is downloaded asynchronously in another thread,
 732      * and an appropriately scaled screen representation of the image is
 733      * generated.
 734      * <p>
 735      * This method is called by components <code>prepareImage</code>
 736      * methods.
 737      * <p>
 738      * Information on the flags returned by this method can be found
 739      * with the definition of the <code>ImageObserver</code> interface.
 740 
 741      * @param     image      the image for which to prepare a
 742      *                           screen representation.
 743      * @param     width      the width of the desired screen
 744      *                           representation, or <code>-1</code>.
 745      * @param     height     the height of the desired screen
 746      *                           representation, or <code>-1</code>.
 747      * @param     observer   the <code>ImageObserver</code>
 748      *                           object to be notified as the
 749      *                           image is being prepared.
 750      * @return    <code>true</code> if the image has already been
 751      *                 fully prepared; <code>false</code> otherwise.
 752      * @see       java.awt.Component#prepareImage(java.awt.Image,
 753      *                 java.awt.image.ImageObserver)
 754      * @see       java.awt.Component#prepareImage(java.awt.Image,
 755      *                 int, int, java.awt.image.ImageObserver)
 756      * @see       java.awt.image.ImageObserver
 757      */
 758     public abstract boolean prepareImage(Image image, int width, int height,
 759                                          ImageObserver observer);
 760 
 761     /**
 762      * Indicates the construction status of a specified image that is
 763      * being prepared for display.
 764      * <p>
 765      * If the values of the width and height arguments are both
 766      * <code>-1</code>, this method returns the construction status of
 767      * a screen representation of the specified image in this toolkit.
 768      * Otherwise, this method returns the construction status of a
 769      * scaled representation of the image at the specified width
 770      * and height.
 771      * <p>
 772      * This method does not cause the image to begin loading.
 773      * An application must call <code>prepareImage</code> to force
 774      * the loading of an image.
 775      * <p>
 776      * This method is called by the component's <code>checkImage</code>
 777      * methods.
 778      * <p>
 779      * Information on the flags returned by this method can be found
 780      * with the definition of the <code>ImageObserver</code> interface.
 781      * @param     image   the image whose status is being checked.
 782      * @param     width   the width of the scaled version whose status is
 783      *                 being checked, or <code>-1</code>.
 784      * @param     height  the height of the scaled version whose status
 785      *                 is being checked, or <code>-1</code>.
 786      * @param     observer   the <code>ImageObserver</code> object to be
 787      *                 notified as the image is being prepared.
 788      * @return    the bitwise inclusive <strong>OR</strong> of the
 789      *                 <code>ImageObserver</code> flags for the
 790      *                 image data that is currently available.
 791      * @see       java.awt.Toolkit#prepareImage(java.awt.Image,
 792      *                 int, int, java.awt.image.ImageObserver)
 793      * @see       java.awt.Component#checkImage(java.awt.Image,
 794      *                 java.awt.image.ImageObserver)
 795      * @see       java.awt.Component#checkImage(java.awt.Image,
 796      *                 int, int, java.awt.image.ImageObserver)
 797      * @see       java.awt.image.ImageObserver
 798      */
 799     public abstract int checkImage(Image image, int width, int height,
 800                                    ImageObserver observer);
 801 
 802     /**
 803      * Creates an image with the specified image producer.
 804      * @param     producer the image producer to be used.
 805      * @return    an image with the specified image producer.
 806      * @see       java.awt.Image
 807      * @see       java.awt.image.ImageProducer
 808      * @see       java.awt.Component#createImage(java.awt.image.ImageProducer)
 809      */
 810     public abstract Image createImage(ImageProducer producer);
 811 
 812     /**
 813      * Creates an image which decodes the image stored in the specified
 814      * byte array.
 815      * <p>
 816      * The data must be in some image format, such as GIF or JPEG,
 817      * that is supported by this toolkit.
 818      * @param     imagedata   an array of bytes, representing
 819      *                         image data in a supported image format.
 820      * @return    an image.
 821      * @since     1.1
 822      */
 823     public Image createImage(byte[] imagedata) {
 824         return createImage(imagedata, 0, imagedata.length);
 825     }
 826 
 827     /**
 828      * Creates an image which decodes the image stored in the specified
 829      * byte array, and at the specified offset and length.
 830      * The data must be in some image format, such as GIF or JPEG,
 831      * that is supported by this toolkit.
 832      * @param     imagedata   an array of bytes, representing
 833      *                         image data in a supported image format.
 834      * @param     imageoffset  the offset of the beginning
 835      *                         of the data in the array.
 836      * @param     imagelength  the length of the data in the array.
 837      * @return    an image.
 838      * @since     1.1
 839      */
 840     public abstract Image createImage(byte[] imagedata,
 841                                       int imageoffset,
 842                                       int imagelength);
 843 
 844     /**
 845      * Gets a <code>PrintJob</code> object which is the result of initiating
 846      * a print operation on the toolkit's platform.
 847      * <p>
 848      * Each actual implementation of this method should first check if there
 849      * is a security manager installed. If there is, the method should call
 850      * the security manager's <code>checkPrintJobAccess</code> method to
 851      * ensure initiation of a print operation is allowed. If the default
 852      * implementation of <code>checkPrintJobAccess</code> is used (that is,
 853      * that method is not overriden), then this results in a call to the
 854      * security manager's <code>checkPermission</code> method with a <code>
 855      * RuntimePermission("queuePrintJob")</code> permission.
 856      *
 857      * @param   frame the parent of the print dialog. May not be null.
 858      * @param   jobtitle the title of the PrintJob. A null title is equivalent
 859      *          to "".
 860      * @param   props a Properties object containing zero or more properties.
 861      *          Properties are not standardized and are not consistent across
 862      *          implementations. Because of this, PrintJobs which require job
 863      *          and page control should use the version of this function which
 864      *          takes JobAttributes and PageAttributes objects. This object
 865      *          may be updated to reflect the user's job choices on exit. May
 866      *          be null.
 867      * @return  a <code>PrintJob</code> object, or <code>null</code> if the
 868      *          user cancelled the print job.
 869      * @throws  NullPointerException if frame is null
 870      * @throws  SecurityException if this thread is not allowed to initiate a
 871      *          print job request
 872      * @see     java.awt.GraphicsEnvironment#isHeadless
 873      * @see     java.awt.PrintJob
 874      * @see     java.lang.RuntimePermission
 875      * @since   1.1
 876      */
 877     public abstract PrintJob getPrintJob(Frame frame, String jobtitle,
 878                                          Properties props);
 879 
 880     /**
 881      * Gets a <code>PrintJob</code> object which is the result of initiating
 882      * a print operation on the toolkit's platform.
 883      * <p>
 884      * Each actual implementation of this method should first check if there
 885      * is a security manager installed. If there is, the method should call
 886      * the security manager's <code>checkPrintJobAccess</code> method to
 887      * ensure initiation of a print operation is allowed. If the default
 888      * implementation of <code>checkPrintJobAccess</code> is used (that is,
 889      * that method is not overriden), then this results in a call to the
 890      * security manager's <code>checkPermission</code> method with a <code>
 891      * RuntimePermission("queuePrintJob")</code> permission.
 892      *
 893      * @param   frame the parent of the print dialog. May not be null.
 894      * @param   jobtitle the title of the PrintJob. A null title is equivalent
 895      *          to "".
 896      * @param   jobAttributes a set of job attributes which will control the
 897      *          PrintJob. The attributes will be updated to reflect the user's
 898      *          choices as outlined in the JobAttributes documentation. May be
 899      *          null.
 900      * @param   pageAttributes a set of page attributes which will control the
 901      *          PrintJob. The attributes will be applied to every page in the
 902      *          job. The attributes will be updated to reflect the user's
 903      *          choices as outlined in the PageAttributes documentation. May be
 904      *          null.
 905      * @return  a <code>PrintJob</code> object, or <code>null</code> if the
 906      *          user cancelled the print job.
 907      * @throws  NullPointerException if frame is null
 908      * @throws  IllegalArgumentException if pageAttributes specifies differing
 909      *          cross feed and feed resolutions. Also if this thread has
 910      *          access to the file system and jobAttributes specifies
 911      *          print to file, and the specified destination file exists but
 912      *          is a directory rather than a regular file, does not exist but
 913      *          cannot be created, or cannot be opened for any other reason.
 914      *          However in the case of print to file, if a dialog is also
 915      *          requested to be displayed then the user will be given an
 916      *          opportunity to select a file and proceed with printing.
 917      *          The dialog will ensure that the selected output file
 918      *          is valid before returning from this method.
 919      * @throws  SecurityException if this thread is not allowed to initiate a
 920      *          print job request, or if jobAttributes specifies print to file,
 921      *          and this thread is not allowed to access the file system
 922      * @see     java.awt.PrintJob
 923      * @see     java.awt.GraphicsEnvironment#isHeadless
 924      * @see     java.lang.RuntimePermission
 925      * @see     java.awt.JobAttributes
 926      * @see     java.awt.PageAttributes
 927      * @since   1.3
 928      */
 929     public PrintJob getPrintJob(Frame frame, String jobtitle,
 930                                 JobAttributes jobAttributes,
 931                                 PageAttributes pageAttributes) {
 932         // Override to add printing support with new job/page control classes
 933 
 934         if (this != Toolkit.getDefaultToolkit()) {
 935             return Toolkit.getDefaultToolkit().getPrintJob(frame, jobtitle,
 936                                                            jobAttributes,
 937                                                            pageAttributes);
 938         } else {
 939             return getPrintJob(frame, jobtitle, null);
 940         }
 941     }
 942 
 943     /**
 944      * Emits an audio beep depending on native system settings and hardware
 945      * capabilities.
 946      * @since     1.1
 947      */
 948     public abstract void beep();
 949 
 950     /**
 951      * Gets the singleton instance of the system Clipboard which interfaces
 952      * with clipboard facilities provided by the native platform. This
 953      * clipboard enables data transfer between Java programs and native
 954      * applications which use native clipboard facilities.
 955      * <p>
 956      * In addition to any and all default formats text returned by the system
 957      * Clipboard's <code>getTransferData()</code> method is available in the
 958      * following flavors:
 959      * <ul>
 960      * <li>DataFlavor.stringFlavor</li>
 961      * <li>DataFlavor.plainTextFlavor (<b>deprecated</b>)</li>
 962      * </ul>
 963      * As with <code>java.awt.datatransfer.StringSelection</code>, if the
 964      * requested flavor is <code>DataFlavor.plainTextFlavor</code>, or an
 965      * equivalent flavor, a Reader is returned. <b>Note:</b> The behavior of
 966      * the system Clipboard's <code>getTransferData()</code> method for <code>
 967      * DataFlavor.plainTextFlavor</code>, and equivalent DataFlavors, is
 968      * inconsistent with the definition of <code>DataFlavor.plainTextFlavor
 969      * </code>. Because of this, support for <code>
 970      * DataFlavor.plainTextFlavor</code>, and equivalent flavors, is
 971      * <b>deprecated</b>.
 972      * <p>
 973      * Each actual implementation of this method should first check if there
 974      * is a security manager installed. If there is, the method should call
 975      * the security manager's {@link SecurityManager#checkPermission
 976      * checkPermission} method to check {@code AWTPermission("accessClipboard")}.
 977      *
 978      * @return    the system Clipboard
 979      * @exception HeadlessException if GraphicsEnvironment.isHeadless()
 980      * returns true
 981      * @see       java.awt.GraphicsEnvironment#isHeadless
 982      * @see       java.awt.datatransfer.Clipboard
 983      * @see       java.awt.datatransfer.StringSelection
 984      * @see       java.awt.datatransfer.DataFlavor#stringFlavor
 985      * @see       java.awt.datatransfer.DataFlavor#plainTextFlavor
 986      * @see       java.io.Reader
 987      * @see       java.awt.AWTPermission
 988      * @since     1.1
 989      */
 990     public abstract Clipboard getSystemClipboard()
 991         throws HeadlessException;
 992 
 993     /**
 994      * Gets the singleton instance of the system selection as a
 995      * <code>Clipboard</code> object. This allows an application to read and
 996      * modify the current, system-wide selection.
 997      * <p>
 998      * An application is responsible for updating the system selection whenever
 999      * the user selects text, using either the mouse or the keyboard.
1000      * Typically, this is implemented by installing a
1001      * <code>FocusListener</code> on all <code>Component</code>s which support
1002      * text selection, and, between <code>FOCUS_GAINED</code> and
1003      * <code>FOCUS_LOST</code> events delivered to that <code>Component</code>,
1004      * updating the system selection <code>Clipboard</code> when the selection
1005      * changes inside the <code>Component</code>. Properly updating the system
1006      * selection ensures that a Java application will interact correctly with
1007      * native applications and other Java applications running simultaneously
1008      * on the system. Note that <code>java.awt.TextComponent</code> and
1009      * <code>javax.swing.text.JTextComponent</code> already adhere to this
1010      * policy. When using these classes, and their subclasses, developers need
1011      * not write any additional code.
1012      * <p>
1013      * Some platforms do not support a system selection <code>Clipboard</code>.
1014      * On those platforms, this method will return <code>null</code>. In such a
1015      * case, an application is absolved from its responsibility to update the
1016      * system selection <code>Clipboard</code> as described above.
1017      * <p>
1018      * Each actual implementation of this method should first check if there
1019      * is a security manager installed. If there is, the method should call
1020      * the security manager's {@link SecurityManager#checkPermission
1021      * checkPermission} method to check {@code AWTPermission("accessClipboard")}.
1022      *
1023      * @return the system selection as a <code>Clipboard</code>, or
1024      *         <code>null</code> if the native platform does not support a
1025      *         system selection <code>Clipboard</code>
1026      * @exception HeadlessException if GraphicsEnvironment.isHeadless()
1027      *            returns true
1028      *
1029      * @see java.awt.datatransfer.Clipboard
1030      * @see java.awt.event.FocusListener
1031      * @see java.awt.event.FocusEvent#FOCUS_GAINED
1032      * @see java.awt.event.FocusEvent#FOCUS_LOST
1033      * @see TextComponent
1034      * @see javax.swing.text.JTextComponent
1035      * @see AWTPermission
1036      * @see GraphicsEnvironment#isHeadless
1037      * @since 1.4
1038      */
1039     public Clipboard getSystemSelection() throws HeadlessException {
1040         GraphicsEnvironment.checkHeadless();
1041 
1042         if (this != Toolkit.getDefaultToolkit()) {
1043             return Toolkit.getDefaultToolkit().getSystemSelection();
1044         } else {
1045             GraphicsEnvironment.checkHeadless();
1046             return null;
1047         }
1048     }
1049 
1050     /**
1051      * Determines which modifier key is the appropriate accelerator
1052      * key for menu shortcuts.
1053      * <p>
1054      * Menu shortcuts, which are embodied in the
1055      * <code>MenuShortcut</code> class, are handled by the
1056      * <code>MenuBar</code> class.
1057      * <p>
1058      * By default, this method returns <code>Event.CTRL_MASK</code>.
1059      * Toolkit implementations should override this method if the
1060      * <b>Control</b> key isn't the correct key for accelerators.
1061      * @return    the modifier mask on the <code>Event</code> class
1062      *                 that is used for menu shortcuts on this toolkit.
1063      * @exception HeadlessException if GraphicsEnvironment.isHeadless()
1064      * returns true
1065      * @see       java.awt.GraphicsEnvironment#isHeadless
1066      * @see       java.awt.MenuBar
1067      * @see       java.awt.MenuShortcut
1068      * @since     1.1
1069      */
1070     public int getMenuShortcutKeyMask() throws HeadlessException {
1071         GraphicsEnvironment.checkHeadless();
1072 
1073         return Event.CTRL_MASK;
1074     }
1075 
1076     /**
1077      * Returns whether the given locking key on the keyboard is currently in
1078      * its "on" state.
1079      * Valid key codes are
1080      * {@link java.awt.event.KeyEvent#VK_CAPS_LOCK VK_CAPS_LOCK},
1081      * {@link java.awt.event.KeyEvent#VK_NUM_LOCK VK_NUM_LOCK},
1082      * {@link java.awt.event.KeyEvent#VK_SCROLL_LOCK VK_SCROLL_LOCK}, and
1083      * {@link java.awt.event.KeyEvent#VK_KANA_LOCK VK_KANA_LOCK}.
1084      *
1085      * @param  keyCode the key code
1086      * @return {@code true} if the given key is currently in its "on" state;
1087      *          otherwise {@code false}
1088      * @exception java.lang.IllegalArgumentException if <code>keyCode</code>
1089      * is not one of the valid key codes
1090      * @exception java.lang.UnsupportedOperationException if the host system doesn't
1091      * allow getting the state of this key programmatically, or if the keyboard
1092      * doesn't have this key
1093      * @exception HeadlessException if GraphicsEnvironment.isHeadless()
1094      * returns true
1095      * @see       java.awt.GraphicsEnvironment#isHeadless
1096      * @since 1.3
1097      */
1098     public boolean getLockingKeyState(int keyCode)
1099         throws UnsupportedOperationException
1100     {
1101         GraphicsEnvironment.checkHeadless();
1102 
1103         if (! (keyCode == KeyEvent.VK_CAPS_LOCK || keyCode == KeyEvent.VK_NUM_LOCK ||
1104                keyCode == KeyEvent.VK_SCROLL_LOCK || keyCode == KeyEvent.VK_KANA_LOCK)) {
1105             throw new IllegalArgumentException("invalid key for Toolkit.getLockingKeyState");
1106         }
1107         throw new UnsupportedOperationException("Toolkit.getLockingKeyState");
1108     }
1109 
1110     /**
1111      * Sets the state of the given locking key on the keyboard.
1112      * Valid key codes are
1113      * {@link java.awt.event.KeyEvent#VK_CAPS_LOCK VK_CAPS_LOCK},
1114      * {@link java.awt.event.KeyEvent#VK_NUM_LOCK VK_NUM_LOCK},
1115      * {@link java.awt.event.KeyEvent#VK_SCROLL_LOCK VK_SCROLL_LOCK}, and
1116      * {@link java.awt.event.KeyEvent#VK_KANA_LOCK VK_KANA_LOCK}.
1117      * <p>
1118      * Depending on the platform, setting the state of a locking key may
1119      * involve event processing and therefore may not be immediately
1120      * observable through getLockingKeyState.
1121      *
1122      * @param  keyCode the key code
1123      * @param  on the state of the key
1124      * @exception java.lang.IllegalArgumentException if <code>keyCode</code>
1125      * is not one of the valid key codes
1126      * @exception java.lang.UnsupportedOperationException if the host system doesn't
1127      * allow setting the state of this key programmatically, or if the keyboard
1128      * doesn't have this key
1129      * @exception HeadlessException if GraphicsEnvironment.isHeadless()
1130      * returns true
1131      * @see       java.awt.GraphicsEnvironment#isHeadless
1132      * @since 1.3
1133      */
1134     public void setLockingKeyState(int keyCode, boolean on)
1135         throws UnsupportedOperationException
1136     {
1137         GraphicsEnvironment.checkHeadless();
1138 
1139         if (! (keyCode == KeyEvent.VK_CAPS_LOCK || keyCode == KeyEvent.VK_NUM_LOCK ||
1140                keyCode == KeyEvent.VK_SCROLL_LOCK || keyCode == KeyEvent.VK_KANA_LOCK)) {
1141             throw new IllegalArgumentException("invalid key for Toolkit.setLockingKeyState");
1142         }
1143         throw new UnsupportedOperationException("Toolkit.setLockingKeyState");
1144     }
1145 
1146     /**
1147      * Give native peers the ability to query the native container
1148      * given a native component (eg the direct parent may be lightweight).
1149      *
1150      * @param  c the component to fetch the container for
1151      * @return the native container object for the component
1152      */
1153     protected static Container getNativeContainer(Component c) {
1154         return c.getNativeContainer();
1155     }
1156 
1157     /**
1158      * Creates a new custom cursor object.
1159      * If the image to display is invalid, the cursor will be hidden (made
1160      * completely transparent), and the hotspot will be set to (0, 0).
1161      *
1162      * <p>Note that multi-frame images are invalid and may cause this
1163      * method to hang.
1164      *
1165      * @param cursor the image to display when the cursor is activated
1166      * @param hotSpot the X and Y of the large cursor's hot spot; the
1167      *   hotSpot values must be less than the Dimension returned by
1168      *   <code>getBestCursorSize</code>
1169      * @param     name a localized description of the cursor, for Java Accessibility use
1170      * @exception IndexOutOfBoundsException if the hotSpot values are outside
1171      *   the bounds of the cursor
1172      * @return the cursor created
1173      * @exception HeadlessException if GraphicsEnvironment.isHeadless()
1174      * returns true
1175      * @see       java.awt.GraphicsEnvironment#isHeadless
1176      * @since     1.2
1177      */
1178     public Cursor createCustomCursor(Image cursor, Point hotSpot, String name)
1179         throws IndexOutOfBoundsException, HeadlessException
1180     {
1181         // Override to implement custom cursor support.
1182         if (this != Toolkit.getDefaultToolkit()) {
1183             return Toolkit.getDefaultToolkit().
1184                 createCustomCursor(cursor, hotSpot, name);
1185         } else {
1186             return new Cursor(Cursor.DEFAULT_CURSOR);
1187         }
1188     }
1189 
1190     /**
1191      * Returns the supported cursor dimension which is closest to the desired
1192      * sizes.  Systems which only support a single cursor size will return that
1193      * size regardless of the desired sizes.  Systems which don't support custom
1194      * cursors will return a dimension of 0, 0. <p>
1195      * Note:  if an image is used whose dimensions don't match a supported size
1196      * (as returned by this method), the Toolkit implementation will attempt to
1197      * resize the image to a supported size.
1198      * Since converting low-resolution images is difficult,
1199      * no guarantees are made as to the quality of a cursor image which isn't a
1200      * supported size.  It is therefore recommended that this method
1201      * be called and an appropriate image used so no image conversion is made.
1202      *
1203      * @param     preferredWidth the preferred cursor width the component would like
1204      * to use.
1205      * @param     preferredHeight the preferred cursor height the component would like
1206      * to use.
1207      * @return    the closest matching supported cursor size, or a dimension of 0,0 if
1208      * the Toolkit implementation doesn't support custom cursors.
1209      * @exception HeadlessException if GraphicsEnvironment.isHeadless()
1210      * returns true
1211      * @see       java.awt.GraphicsEnvironment#isHeadless
1212      * @since     1.2
1213      */
1214     public Dimension getBestCursorSize(int preferredWidth,
1215         int preferredHeight) throws HeadlessException {
1216         GraphicsEnvironment.checkHeadless();
1217 
1218         // Override to implement custom cursor support.
1219         if (this != Toolkit.getDefaultToolkit()) {
1220             return Toolkit.getDefaultToolkit().
1221                 getBestCursorSize(preferredWidth, preferredHeight);
1222         } else {
1223             return new Dimension(0, 0);
1224         }
1225     }
1226 
1227     /**
1228      * Returns the maximum number of colors the Toolkit supports in a custom cursor
1229      * palette.<p>
1230      * Note: if an image is used which has more colors in its palette than
1231      * the supported maximum, the Toolkit implementation will attempt to flatten the
1232      * palette to the maximum.  Since converting low-resolution images is difficult,
1233      * no guarantees are made as to the quality of a cursor image which has more
1234      * colors than the system supports.  It is therefore recommended that this method
1235      * be called and an appropriate image used so no image conversion is made.
1236      *
1237      * @return    the maximum number of colors, or zero if custom cursors are not
1238      * supported by this Toolkit implementation.
1239      * @exception HeadlessException if GraphicsEnvironment.isHeadless()
1240      * returns true
1241      * @see       java.awt.GraphicsEnvironment#isHeadless
1242      * @since     1.2
1243      */
1244     public int getMaximumCursorColors() throws HeadlessException {
1245         GraphicsEnvironment.checkHeadless();
1246 
1247         // Override to implement custom cursor support.
1248         if (this != Toolkit.getDefaultToolkit()) {
1249             return Toolkit.getDefaultToolkit().getMaximumCursorColors();
1250         } else {
1251             return 0;
1252         }
1253     }
1254 
1255     /**
1256      * Returns whether Toolkit supports this state for
1257      * <code>Frame</code>s.  This method tells whether the <em>UI
1258      * concept</em> of, say, maximization or iconification is
1259      * supported.  It will always return false for "compound" states
1260      * like <code>Frame.ICONIFIED|Frame.MAXIMIZED_VERT</code>.
1261      * In other words, the rule of thumb is that only queries with a
1262      * single frame state constant as an argument are meaningful.
1263      * <p>Note that supporting a given concept is a platform-
1264      * dependent feature. Due to native limitations the Toolkit
1265      * object may report a particular state as supported, however at
1266      * the same time the Toolkit object will be unable to apply the
1267      * state to a given frame.  This circumstance has two following
1268      * consequences:
1269      * <ul>
1270      * <li>Only the return value of {@code false} for the present
1271      * method actually indicates that the given state is not
1272      * supported. If the method returns {@code true} the given state
1273      * may still be unsupported and/or unavailable for a particular
1274      * frame.
1275      * <li>The developer should consider examining the value of the
1276      * {@link java.awt.event.WindowEvent#getNewState} method of the
1277      * {@code WindowEvent} received through the {@link
1278      * java.awt.event.WindowStateListener}, rather than assuming
1279      * that the state given to the {@code setExtendedState()} method
1280      * will be definitely applied. For more information see the
1281      * documentation for the {@link Frame#setExtendedState} method.
1282      * </ul>
1283      *
1284      * @param state one of named frame state constants.
1285      * @return <code>true</code> is this frame state is supported by
1286      *     this Toolkit implementation, <code>false</code> otherwise.
1287      * @exception HeadlessException
1288      *     if <code>GraphicsEnvironment.isHeadless()</code>
1289      *     returns <code>true</code>.
1290      * @see java.awt.Window#addWindowStateListener
1291      * @since   1.4
1292      */
1293     public boolean isFrameStateSupported(int state)
1294         throws HeadlessException
1295     {
1296         GraphicsEnvironment.checkHeadless();
1297 
1298         if (this != Toolkit.getDefaultToolkit()) {
1299             return Toolkit.getDefaultToolkit().
1300                 isFrameStateSupported(state);
1301         } else {
1302             return (state == Frame.NORMAL); // others are not guaranteed
1303         }
1304     }
1305 
1306     /**
1307      * Support for I18N: any visible strings should be stored in
1308      * sun.awt.resources.awt.properties.  The ResourceBundle is stored
1309      * here, so that only one copy is maintained.
1310      */
1311     private static ResourceBundle resources;
1312     private static ResourceBundle platformResources;
1313 
1314     // called by platform toolkit
1315     private static void setPlatformResources(ResourceBundle bundle) {
1316         platformResources = bundle;
1317     }
1318 
1319     /**
1320      * Initialize JNI field and method ids
1321      */
1322     private static native void initIDs();
1323 
1324     /**
1325      * WARNING: This is a temporary workaround for a problem in the
1326      * way the AWT loads native libraries. A number of classes in the
1327      * AWT package have a native method, initIDs(), which initializes
1328      * the JNI field and method ids used in the native portion of
1329      * their implementation.
1330      *
1331      * Since the use and storage of these ids is done by the
1332      * implementation libraries, the implementation of these method is
1333      * provided by the particular AWT implementations (for example,
1334      * "Toolkit"s/Peer), such as Motif, Microsoft Windows, or Tiny. The
1335      * problem is that this means that the native libraries must be
1336      * loaded by the java.* classes, which do not necessarily know the
1337      * names of the libraries to load. A better way of doing this
1338      * would be to provide a separate library which defines java.awt.*
1339      * initIDs, and exports the relevant symbols out to the
1340      * implementation libraries.
1341      *
1342      * For now, we know it's done by the implementation, and we assume
1343      * that the name of the library is "awt".  -br.
1344      *
1345      * If you change loadLibraries(), please add the change to
1346      * java.awt.image.ColorModel.loadLibraries(). Unfortunately,
1347      * classes can be loaded in java.awt.image that depend on
1348      * libawt and there is no way to call Toolkit.loadLibraries()
1349      * directly.  -hung
1350      */
1351     private static boolean loaded = false;
1352     static void loadLibraries() {
1353         if (!loaded) {
1354             java.security.AccessController.doPrivileged(
1355                 new java.security.PrivilegedAction<Void>() {
1356                     public Void run() {
1357                         System.loadLibrary("awt");
1358                         return null;
1359                     }
1360                 });
1361             loaded = true;
1362         }
1363     }
1364 
1365     static {
1366         AWTAccessor.setToolkitAccessor(
1367                 new AWTAccessor.ToolkitAccessor() {
1368                     @Override
1369                     public void setPlatformResources(ResourceBundle bundle) {
1370                         Toolkit.setPlatformResources(bundle);
1371                     }
1372                 });
1373 
1374         java.security.AccessController.doPrivileged(
1375                                  new java.security.PrivilegedAction<Void>() {
1376             public Void run() {
1377                 try {
1378                     resources =
1379                         ResourceBundle.getBundle("sun.awt.resources.awt",
1380                                                  CoreResourceBundleControl.getRBControlInstance());
1381                 } catch (MissingResourceException e) {
1382                     // No resource file; defaults will be used.
1383                 }
1384                 return null;
1385             }
1386         });
1387 
1388         // ensure that the proper libraries are loaded
1389         loadLibraries();
1390         initAssistiveTechnologies();
1391         if (!GraphicsEnvironment.isHeadless()) {
1392             initIDs();
1393         }
1394     }
1395 
1396     /**
1397      * Gets a property with the specified key and default.
1398      * This method returns defaultValue if the property is not found.
1399      *
1400      * @param  key the key
1401      * @param  defaultValue the default value
1402      * @return the value of the property or the default value
1403      *         if the property was not found
1404      */
1405     public static String getProperty(String key, String defaultValue) {
1406         // first try platform specific bundle
1407         if (platformResources != null) {
1408             try {
1409                 return platformResources.getString(key);
1410             }
1411             catch (MissingResourceException e) {}
1412         }
1413 
1414         // then shared one
1415         if (resources != null) {
1416             try {
1417                 return resources.getString(key);
1418             }
1419             catch (MissingResourceException e) {}
1420         }
1421 
1422         return defaultValue;
1423     }
1424 
1425     /**
1426      * Get the application's or applet's EventQueue instance.
1427      * Depending on the Toolkit implementation, different EventQueues
1428      * may be returned for different applets.  Applets should
1429      * therefore not assume that the EventQueue instance returned
1430      * by this method will be shared by other applets or the system.
1431      *
1432      * <p> If there is a security manager then its
1433      * {@link SecurityManager#checkPermission checkPermission} method
1434      * is called to check {@code AWTPermission("accessEventQueue")}.
1435      *
1436      * @return    the <code>EventQueue</code> object
1437      * @throws  SecurityException
1438      *          if a security manager is set and it denies access to
1439      *          the {@code EventQueue}
1440      * @see     java.awt.AWTPermission
1441     */
1442     public final EventQueue getSystemEventQueue() {
1443         SecurityManager security = System.getSecurityManager();
1444         if (security != null) {
1445             security.checkPermission(AWTPermissions.CHECK_AWT_EVENTQUEUE_PERMISSION);
1446         }
1447         return getSystemEventQueueImpl();
1448     }
1449 
1450     /**
1451      * Gets the application's or applet's <code>EventQueue</code>
1452      * instance, without checking access.  For security reasons,
1453      * this can only be called from a <code>Toolkit</code> subclass.
1454      * @return the <code>EventQueue</code> object
1455      */
1456     protected abstract EventQueue getSystemEventQueueImpl();
1457 
1458     /* Accessor method for use by AWT package routines. */
1459     static EventQueue getEventQueue() {
1460         return getDefaultToolkit().getSystemEventQueueImpl();
1461     }
1462 
1463     /**
1464      * Creates a concrete, platform dependent, subclass of the abstract
1465      * DragGestureRecognizer class requested, and associates it with the
1466      * DragSource, Component and DragGestureListener specified.
1467      *
1468      * subclasses should override this to provide their own implementation
1469      *
1470      * @param <T> the type of DragGestureRecognizer to create
1471      * @param abstractRecognizerClass The abstract class of the required recognizer
1472      * @param ds                      The DragSource
1473      * @param c                       The Component target for the DragGestureRecognizer
1474      * @param srcActions              The actions permitted for the gesture
1475      * @param dgl                     The DragGestureListener
1476      *
1477      * @return the new object or null.  Always returns null if
1478      * GraphicsEnvironment.isHeadless() returns true.
1479      * @see java.awt.GraphicsEnvironment#isHeadless
1480      */
1481     public <T extends DragGestureRecognizer> T
1482         createDragGestureRecognizer(Class<T> abstractRecognizerClass,
1483                                     DragSource ds, Component c, int srcActions,
1484                                     DragGestureListener dgl)
1485     {
1486         return null;
1487     }
1488 
1489     /**
1490      * Obtains a value for the specified desktop property.
1491      *
1492      * A desktop property is a uniquely named value for a resource that
1493      * is Toolkit global in nature. Usually it also is an abstract
1494      * representation for an underlying platform dependent desktop setting.
1495      * For more information on desktop properties supported by the AWT see
1496      * <a href="doc-files/DesktopProperties.html">AWT Desktop Properties</a>.
1497      *
1498      * @param  propertyName the property name
1499      * @return the value for the specified desktop property
1500      */
1501     public final synchronized Object getDesktopProperty(String propertyName) {
1502         // This is a workaround for headless toolkits.  It would be
1503         // better to override this method but it is declared final.
1504         // "this instanceof" syntax defeats polymorphism.
1505         // --mm, 03/03/00
1506         if (this instanceof HeadlessToolkit) {
1507             return ((HeadlessToolkit)this).getUnderlyingToolkit()
1508                 .getDesktopProperty(propertyName);
1509         }
1510 
1511         if (desktopProperties.isEmpty()) {
1512             initializeDesktopProperties();
1513         }
1514 
1515         Object value;
1516 
1517         // This property should never be cached
1518         if (propertyName.equals("awt.dynamicLayoutSupported")) {
1519             return getDefaultToolkit().lazilyLoadDesktopProperty(propertyName);
1520         }
1521 
1522         value = desktopProperties.get(propertyName);
1523 
1524         if (value == null) {
1525             value = lazilyLoadDesktopProperty(propertyName);
1526 
1527             if (value != null) {
1528                 setDesktopProperty(propertyName, value);
1529             }
1530         }
1531 
1532         /* for property "awt.font.desktophints" */
1533         if (value instanceof RenderingHints) {
1534             value = ((RenderingHints)value).clone();
1535         }
1536 
1537         return value;
1538     }
1539 
1540     /**
1541      * Sets the named desktop property to the specified value and fires a
1542      * property change event to notify any listeners that the value has changed.
1543      *
1544      * @param  name the property name
1545      * @param  newValue the new property value
1546      */
1547     protected final void setDesktopProperty(String name, Object newValue) {
1548         // This is a workaround for headless toolkits.  It would be
1549         // better to override this method but it is declared final.
1550         // "this instanceof" syntax defeats polymorphism.
1551         // --mm, 03/03/00
1552         if (this instanceof HeadlessToolkit) {
1553             ((HeadlessToolkit)this).getUnderlyingToolkit()
1554                 .setDesktopProperty(name, newValue);
1555             return;
1556         }
1557         Object oldValue;
1558 
1559         synchronized (this) {
1560             oldValue = desktopProperties.get(name);
1561             desktopProperties.put(name, newValue);
1562         }
1563 
1564         // Don't fire change event if old and new values are null.
1565         // It helps to avoid recursive resending of WM_THEMECHANGED
1566         if (oldValue != null || newValue != null) {
1567             desktopPropsSupport.firePropertyChange(name, oldValue, newValue);
1568         }
1569     }
1570 
1571     /**
1572      * An opportunity to lazily evaluate desktop property values.
1573      * @return the desktop property or null
1574      * @param name the name
1575      */
1576     protected Object lazilyLoadDesktopProperty(String name) {
1577         return null;
1578     }
1579 
1580     /**
1581      * initializeDesktopProperties
1582      */
1583     protected void initializeDesktopProperties() {
1584     }
1585 
1586     /**
1587      * Adds the specified property change listener for the named desktop
1588      * property. When a {@link java.beans.PropertyChangeListenerProxy} object is added,
1589      * its property name is ignored, and the wrapped listener is added.
1590      * If {@code name} is {@code null} or {@code pcl} is {@code null},
1591      * no exception is thrown and no action is performed.
1592      *
1593      * @param   name The name of the property to listen for
1594      * @param   pcl The property change listener
1595      * @see PropertyChangeSupport#addPropertyChangeListener(String,
1596                 PropertyChangeListener)
1597      * @since   1.2
1598      */
1599     public void addPropertyChangeListener(String name, PropertyChangeListener pcl) {
1600         desktopPropsSupport.addPropertyChangeListener(name, pcl);
1601     }
1602 
1603     /**
1604      * Removes the specified property change listener for the named
1605      * desktop property. When a {@link java.beans.PropertyChangeListenerProxy} object
1606      * is removed, its property name is ignored, and
1607      * the wrapped listener is removed.
1608      * If {@code name} is {@code null} or {@code pcl} is {@code null},
1609      * no exception is thrown and no action is performed.
1610      *
1611      * @param   name The name of the property to remove
1612      * @param   pcl The property change listener
1613      * @see PropertyChangeSupport#removePropertyChangeListener(String,
1614                 PropertyChangeListener)
1615      * @since   1.2
1616      */
1617     public void removePropertyChangeListener(String name, PropertyChangeListener pcl) {
1618         desktopPropsSupport.removePropertyChangeListener(name, pcl);
1619     }
1620 
1621     /**
1622      * Returns an array of all the property change listeners
1623      * registered on this toolkit. The returned array
1624      * contains {@link java.beans.PropertyChangeListenerProxy} objects
1625      * that associate listeners with the names of desktop properties.
1626      *
1627      * @return all of this toolkit's {@link PropertyChangeListener}
1628      *         objects wrapped in {@code java.beans.PropertyChangeListenerProxy} objects
1629      *         or an empty array  if no listeners are added
1630      *
1631      * @see PropertyChangeSupport#getPropertyChangeListeners()
1632      * @since 1.4
1633      */
1634     public PropertyChangeListener[] getPropertyChangeListeners() {
1635         return desktopPropsSupport.getPropertyChangeListeners();
1636     }
1637 
1638     /**
1639      * Returns an array of all property change listeners
1640      * associated with the specified name of a desktop property.
1641      *
1642      * @param  propertyName the named property
1643      * @return all of the {@code PropertyChangeListener} objects
1644      *         associated with the specified name of a desktop property
1645      *         or an empty array if no such listeners are added
1646      *
1647      * @see PropertyChangeSupport#getPropertyChangeListeners(String)
1648      * @since 1.4
1649      */
1650     public PropertyChangeListener[] getPropertyChangeListeners(String propertyName) {
1651         return desktopPropsSupport.getPropertyChangeListeners(propertyName);
1652     }
1653 
1654     /**
1655      * The desktop properties.
1656      */
1657     protected final Map<String,Object> desktopProperties =
1658             new HashMap<String,Object>();
1659     /**
1660      * The desktop properties change support.
1661      */
1662     protected final PropertyChangeSupport desktopPropsSupport =
1663             Toolkit.createPropertyChangeSupport(this);
1664 
1665     /**
1666      * Returns whether the always-on-top mode is supported by this toolkit.
1667      * To detect whether the always-on-top mode is supported for a
1668      * particular Window, use {@link Window#isAlwaysOnTopSupported}.
1669      * @return <code>true</code>, if current toolkit supports the always-on-top mode,
1670      *     otherwise returns <code>false</code>
1671      * @see Window#isAlwaysOnTopSupported
1672      * @see Window#setAlwaysOnTop(boolean)
1673      * @since 1.6
1674      */
1675     public boolean isAlwaysOnTopSupported() {
1676         return true;
1677     }
1678 
1679     /**
1680      * Returns whether the given modality type is supported by this toolkit. If
1681      * a dialog with unsupported modality type is created, then
1682      * <code>Dialog.ModalityType.MODELESS</code> is used instead.
1683      *
1684      * @param modalityType modality type to be checked for support by this toolkit
1685      *
1686      * @return <code>true</code>, if current toolkit supports given modality
1687      *     type, <code>false</code> otherwise
1688      *
1689      * @see java.awt.Dialog.ModalityType
1690      * @see java.awt.Dialog#getModalityType
1691      * @see java.awt.Dialog#setModalityType
1692      *
1693      * @since 1.6
1694      */
1695     public abstract boolean isModalityTypeSupported(Dialog.ModalityType modalityType);
1696 
1697     /**
1698      * Returns whether the given modal exclusion type is supported by this
1699      * toolkit. If an unsupported modal exclusion type property is set on a window,
1700      * then <code>Dialog.ModalExclusionType.NO_EXCLUDE</code> is used instead.
1701      *
1702      * @param modalExclusionType modal exclusion type to be checked for support by this toolkit
1703      *
1704      * @return <code>true</code>, if current toolkit supports given modal exclusion
1705      *     type, <code>false</code> otherwise
1706      *
1707      * @see java.awt.Dialog.ModalExclusionType
1708      * @see java.awt.Window#getModalExclusionType
1709      * @see java.awt.Window#setModalExclusionType
1710      *
1711      * @since 1.6
1712      */
1713     public abstract boolean isModalExclusionTypeSupported(Dialog.ModalExclusionType modalExclusionType);
1714 
1715     // 8014718: logging has been removed from SunToolkit
1716 
1717     private static final int LONG_BITS = 64;
1718     private int[] calls = new int[LONG_BITS];
1719     private static volatile long enabledOnToolkitMask;
1720     private AWTEventListener eventListener = null;
1721     private WeakHashMap<AWTEventListener, SelectiveAWTEventListener> listener2SelectiveListener = new WeakHashMap<>();
1722 
1723     /*
1724      * Extracts a "pure" AWTEventListener from a AWTEventListenerProxy,
1725      * if the listener is proxied.
1726      */
1727     private static AWTEventListener deProxyAWTEventListener(AWTEventListener l)
1728     {
1729         AWTEventListener localL = l;
1730 
1731         if (localL == null) {
1732             return null;
1733         }
1734         // if user passed in a AWTEventListenerProxy object, extract
1735         // the listener
1736         if (l instanceof AWTEventListenerProxy) {
1737             localL = ((AWTEventListenerProxy)l).getListener();
1738         }
1739         return localL;
1740     }
1741 
1742     /**
1743      * Adds an AWTEventListener to receive all AWTEvents dispatched
1744      * system-wide that conform to the given <code>eventMask</code>.
1745      * <p>
1746      * First, if there is a security manager, its <code>checkPermission</code>
1747      * method is called with an
1748      * <code>AWTPermission("listenToAllAWTEvents")</code> permission.
1749      * This may result in a SecurityException.
1750      * <p>
1751      * <code>eventMask</code> is a bitmask of event types to receive.
1752      * It is constructed by bitwise OR-ing together the event masks
1753      * defined in <code>AWTEvent</code>.
1754      * <p>
1755      * Note:  event listener use is not recommended for normal
1756      * application use, but are intended solely to support special
1757      * purpose facilities including support for accessibility,
1758      * event record/playback, and diagnostic tracing.
1759      *
1760      * If listener is null, no exception is thrown and no action is performed.
1761      *
1762      * @param    listener   the event listener.
1763      * @param    eventMask  the bitmask of event types to receive
1764      * @throws SecurityException
1765      *        if a security manager exists and its
1766      *        <code>checkPermission</code> method doesn't allow the operation.
1767      * @see      #removeAWTEventListener
1768      * @see      #getAWTEventListeners
1769      * @see      SecurityManager#checkPermission
1770      * @see      java.awt.AWTEvent
1771      * @see      java.awt.AWTPermission
1772      * @see      java.awt.event.AWTEventListener
1773      * @see      java.awt.event.AWTEventListenerProxy
1774      * @since    1.2
1775      */
1776     public void addAWTEventListener(AWTEventListener listener, long eventMask) {
1777         AWTEventListener localL = deProxyAWTEventListener(listener);
1778 
1779         if (localL == null) {
1780             return;
1781         }
1782         SecurityManager security = System.getSecurityManager();
1783         if (security != null) {
1784           security.checkPermission(AWTPermissions.ALL_AWT_EVENTS_PERMISSION);
1785         }
1786         synchronized (this) {
1787             SelectiveAWTEventListener selectiveListener =
1788                 listener2SelectiveListener.get(localL);
1789 
1790             if (selectiveListener == null) {
1791                 // Create a new selectiveListener.
1792                 selectiveListener = new SelectiveAWTEventListener(localL,
1793                                                                  eventMask);
1794                 listener2SelectiveListener.put(localL, selectiveListener);
1795                 eventListener = ToolkitEventMulticaster.add(eventListener,
1796                                                             selectiveListener);
1797             }
1798             // OR the eventMask into the selectiveListener's event mask.
1799             selectiveListener.orEventMasks(eventMask);
1800 
1801             enabledOnToolkitMask |= eventMask;
1802 
1803             long mask = eventMask;
1804             for (int i=0; i<LONG_BITS; i++) {
1805                 // If no bits are set, break out of loop.
1806                 if (mask == 0) {
1807                     break;
1808                 }
1809                 if ((mask & 1L) != 0) {  // Always test bit 0.
1810                     calls[i]++;
1811                 }
1812                 mask >>>= 1;  // Right shift, fill with zeros on left.
1813             }
1814         }
1815     }
1816 
1817     /**
1818      * Removes an AWTEventListener from receiving dispatched AWTEvents.
1819      * <p>
1820      * First, if there is a security manager, its <code>checkPermission</code>
1821      * method is called with an
1822      * <code>AWTPermission("listenToAllAWTEvents")</code> permission.
1823      * This may result in a SecurityException.
1824      * <p>
1825      * Note:  event listener use is not recommended for normal
1826      * application use, but are intended solely to support special
1827      * purpose facilities including support for accessibility,
1828      * event record/playback, and diagnostic tracing.
1829      *
1830      * If listener is null, no exception is thrown and no action is performed.
1831      *
1832      * @param    listener   the event listener.
1833      * @throws SecurityException
1834      *        if a security manager exists and its
1835      *        <code>checkPermission</code> method doesn't allow the operation.
1836      * @see      #addAWTEventListener
1837      * @see      #getAWTEventListeners
1838      * @see      SecurityManager#checkPermission
1839      * @see      java.awt.AWTEvent
1840      * @see      java.awt.AWTPermission
1841      * @see      java.awt.event.AWTEventListener
1842      * @see      java.awt.event.AWTEventListenerProxy
1843      * @since    1.2
1844      */
1845     public void removeAWTEventListener(AWTEventListener listener) {
1846         AWTEventListener localL = deProxyAWTEventListener(listener);
1847 
1848         if (listener == null) {
1849             return;
1850         }
1851         SecurityManager security = System.getSecurityManager();
1852         if (security != null) {
1853             security.checkPermission(AWTPermissions.ALL_AWT_EVENTS_PERMISSION);
1854         }
1855 
1856         synchronized (this) {
1857             SelectiveAWTEventListener selectiveListener =
1858                 listener2SelectiveListener.get(localL);
1859 
1860             if (selectiveListener != null) {
1861                 listener2SelectiveListener.remove(localL);
1862                 int[] listenerCalls = selectiveListener.getCalls();
1863                 for (int i=0; i<LONG_BITS; i++) {
1864                     calls[i] -= listenerCalls[i];
1865                     assert calls[i] >= 0: "Negative Listeners count";
1866 
1867                     if (calls[i] == 0) {
1868                         enabledOnToolkitMask &= ~(1L<<i);
1869                     }
1870                 }
1871             }
1872             eventListener = ToolkitEventMulticaster.remove(eventListener,
1873             (selectiveListener == null) ? localL : selectiveListener);
1874         }
1875     }
1876 
1877     static boolean enabledOnToolkit(long eventMask) {
1878         return (enabledOnToolkitMask & eventMask) != 0;
1879         }
1880 
1881     synchronized int countAWTEventListeners(long eventMask) {
1882         int ci = 0;
1883         for (; eventMask != 0; eventMask >>>= 1, ci++) {
1884         }
1885         ci--;
1886         return calls[ci];
1887     }
1888     /**
1889      * Returns an array of all the <code>AWTEventListener</code>s
1890      * registered on this toolkit.
1891      * If there is a security manager, its {@code checkPermission}
1892      * method is called with an
1893      * {@code AWTPermission("listenToAllAWTEvents")} permission.
1894      * This may result in a SecurityException.
1895      * Listeners can be returned
1896      * within <code>AWTEventListenerProxy</code> objects, which also contain
1897      * the event mask for the given listener.
1898      * Note that listener objects
1899      * added multiple times appear only once in the returned array.
1900      *
1901      * @return all of the <code>AWTEventListener</code>s or an empty
1902      *         array if no listeners are currently registered
1903      * @throws SecurityException
1904      *        if a security manager exists and its
1905      *        <code>checkPermission</code> method doesn't allow the operation.
1906      * @see      #addAWTEventListener
1907      * @see      #removeAWTEventListener
1908      * @see      SecurityManager#checkPermission
1909      * @see      java.awt.AWTEvent
1910      * @see      java.awt.AWTPermission
1911      * @see      java.awt.event.AWTEventListener
1912      * @see      java.awt.event.AWTEventListenerProxy
1913      * @since 1.4
1914      */
1915     public AWTEventListener[] getAWTEventListeners() {
1916         SecurityManager security = System.getSecurityManager();
1917         if (security != null) {
1918             security.checkPermission(AWTPermissions.ALL_AWT_EVENTS_PERMISSION);
1919         }
1920         synchronized (this) {
1921             EventListener[] la = ToolkitEventMulticaster.getListeners(eventListener,AWTEventListener.class);
1922 
1923             AWTEventListener[] ret = new AWTEventListener[la.length];
1924             for (int i = 0; i < la.length; i++) {
1925                 SelectiveAWTEventListener sael = (SelectiveAWTEventListener)la[i];
1926                 AWTEventListener tempL = sael.getListener();
1927                 //assert tempL is not an AWTEventListenerProxy - we should
1928                 // have weeded them all out
1929                 // don't want to wrap a proxy inside a proxy
1930                 ret[i] = new AWTEventListenerProxy(sael.getEventMask(), tempL);
1931             }
1932             return ret;
1933         }
1934     }
1935 
1936     /**
1937      * Returns an array of all the <code>AWTEventListener</code>s
1938      * registered on this toolkit which listen to all of the event
1939      * types specified in the {@code eventMask} argument.
1940      * If there is a security manager, its {@code checkPermission}
1941      * method is called with an
1942      * {@code AWTPermission("listenToAllAWTEvents")} permission.
1943      * This may result in a SecurityException.
1944      * Listeners can be returned
1945      * within <code>AWTEventListenerProxy</code> objects, which also contain
1946      * the event mask for the given listener.
1947      * Note that listener objects
1948      * added multiple times appear only once in the returned array.
1949      *
1950      * @param  eventMask the bitmask of event types to listen for
1951      * @return all of the <code>AWTEventListener</code>s registered
1952      *         on this toolkit for the specified
1953      *         event types, or an empty array if no such listeners
1954      *         are currently registered
1955      * @throws SecurityException
1956      *        if a security manager exists and its
1957      *        <code>checkPermission</code> method doesn't allow the operation.
1958      * @see      #addAWTEventListener
1959      * @see      #removeAWTEventListener
1960      * @see      SecurityManager#checkPermission
1961      * @see      java.awt.AWTEvent
1962      * @see      java.awt.AWTPermission
1963      * @see      java.awt.event.AWTEventListener
1964      * @see      java.awt.event.AWTEventListenerProxy
1965      * @since 1.4
1966      */
1967     public AWTEventListener[] getAWTEventListeners(long eventMask) {
1968         SecurityManager security = System.getSecurityManager();
1969         if (security != null) {
1970             security.checkPermission(AWTPermissions.ALL_AWT_EVENTS_PERMISSION);
1971         }
1972         synchronized (this) {
1973             EventListener[] la = ToolkitEventMulticaster.getListeners(eventListener,AWTEventListener.class);
1974 
1975             java.util.List<AWTEventListenerProxy> list = new ArrayList<>(la.length);
1976 
1977             for (int i = 0; i < la.length; i++) {
1978                 SelectiveAWTEventListener sael = (SelectiveAWTEventListener)la[i];
1979                 if ((sael.getEventMask() & eventMask) == eventMask) {
1980                     //AWTEventListener tempL = sael.getListener();
1981                     list.add(new AWTEventListenerProxy(sael.getEventMask(),
1982                                                        sael.getListener()));
1983                 }
1984             }
1985             return list.toArray(new AWTEventListener[0]);
1986         }
1987     }
1988 
1989     /*
1990      * This method notifies any AWTEventListeners that an event
1991      * is about to be dispatched.
1992      *
1993      * @param theEvent the event which will be dispatched.
1994      */
1995     void notifyAWTEventListeners(AWTEvent theEvent) {
1996         // This is a workaround for headless toolkits.  It would be
1997         // better to override this method but it is declared package private.
1998         // "this instanceof" syntax defeats polymorphism.
1999         // --mm, 03/03/00
2000         if (this instanceof HeadlessToolkit) {
2001             ((HeadlessToolkit)this).getUnderlyingToolkit()
2002                 .notifyAWTEventListeners(theEvent);
2003             return;
2004         }
2005 
2006         AWTEventListener eventListener = this.eventListener;
2007         if (eventListener != null) {
2008             eventListener.eventDispatched(theEvent);
2009         }
2010     }
2011 
2012     private static class ToolkitEventMulticaster extends AWTEventMulticaster
2013         implements AWTEventListener {
2014         // Implementation cloned from AWTEventMulticaster.
2015 
2016         ToolkitEventMulticaster(AWTEventListener a, AWTEventListener b) {
2017             super(a, b);
2018         }
2019 
2020         @SuppressWarnings("overloads")
2021         static AWTEventListener add(AWTEventListener a,
2022                                     AWTEventListener b) {
2023             if (a == null)  return b;
2024             if (b == null)  return a;
2025             return new ToolkitEventMulticaster(a, b);
2026         }
2027 
2028         @SuppressWarnings("overloads")
2029         static AWTEventListener remove(AWTEventListener l,
2030                                        AWTEventListener oldl) {
2031             return (AWTEventListener) removeInternal(l, oldl);
2032         }
2033 
2034         // #4178589: must overload remove(EventListener) to call our add()
2035         // instead of the static addInternal() so we allocate a
2036         // ToolkitEventMulticaster instead of an AWTEventMulticaster.
2037         // Note: this method is called by AWTEventListener.removeInternal(),
2038         // so its method signature must match AWTEventListener.remove().
2039         protected EventListener remove(EventListener oldl) {
2040             if (oldl == a)  return b;
2041             if (oldl == b)  return a;
2042             AWTEventListener a2 = (AWTEventListener)removeInternal(a, oldl);
2043             AWTEventListener b2 = (AWTEventListener)removeInternal(b, oldl);
2044             if (a2 == a && b2 == b) {
2045                 return this;    // it's not here
2046             }
2047             return add(a2, b2);
2048         }
2049 
2050         public void eventDispatched(AWTEvent event) {
2051             ((AWTEventListener)a).eventDispatched(event);
2052             ((AWTEventListener)b).eventDispatched(event);
2053         }
2054     }
2055 
2056     private class SelectiveAWTEventListener implements AWTEventListener {
2057         AWTEventListener listener;
2058         private long eventMask;
2059         // This array contains the number of times to call the eventlistener
2060         // for each event type.
2061         int[] calls = new int[Toolkit.LONG_BITS];
2062 
2063         public AWTEventListener getListener() {return listener;}
2064         public long getEventMask() {return eventMask;}
2065         public int[] getCalls() {return calls;}
2066 
2067         public void orEventMasks(long mask) {
2068             eventMask |= mask;
2069             // For each event bit set in mask, increment its call count.
2070             for (int i=0; i<Toolkit.LONG_BITS; i++) {
2071                 // If no bits are set, break out of loop.
2072                 if (mask == 0) {
2073                     break;
2074                 }
2075                 if ((mask & 1L) != 0) {  // Always test bit 0.
2076                     calls[i]++;
2077                 }
2078                 mask >>>= 1;  // Right shift, fill with zeros on left.
2079             }
2080         }
2081 
2082         SelectiveAWTEventListener(AWTEventListener l, long mask) {
2083             listener = l;
2084             eventMask = mask;
2085         }
2086 
2087         public void eventDispatched(AWTEvent event) {
2088             long eventBit = 0; // Used to save the bit of the event type.
2089             if (((eventBit = eventMask & AWTEvent.COMPONENT_EVENT_MASK) != 0 &&
2090                  event.id >= ComponentEvent.COMPONENT_FIRST &&
2091                  event.id <= ComponentEvent.COMPONENT_LAST)
2092              || ((eventBit = eventMask & AWTEvent.CONTAINER_EVENT_MASK) != 0 &&
2093                  event.id >= ContainerEvent.CONTAINER_FIRST &&
2094                  event.id <= ContainerEvent.CONTAINER_LAST)
2095              || ((eventBit = eventMask & AWTEvent.FOCUS_EVENT_MASK) != 0 &&
2096                  event.id >= FocusEvent.FOCUS_FIRST &&
2097                  event.id <= FocusEvent.FOCUS_LAST)
2098              || ((eventBit = eventMask & AWTEvent.KEY_EVENT_MASK) != 0 &&
2099                  event.id >= KeyEvent.KEY_FIRST &&
2100                  event.id <= KeyEvent.KEY_LAST)
2101              || ((eventBit = eventMask & AWTEvent.MOUSE_WHEEL_EVENT_MASK) != 0 &&
2102                  event.id == MouseEvent.MOUSE_WHEEL)
2103              || ((eventBit = eventMask & AWTEvent.MOUSE_MOTION_EVENT_MASK) != 0 &&
2104                  (event.id == MouseEvent.MOUSE_MOVED ||
2105                   event.id == MouseEvent.MOUSE_DRAGGED))
2106              || ((eventBit = eventMask & AWTEvent.MOUSE_EVENT_MASK) != 0 &&
2107                  event.id != MouseEvent.MOUSE_MOVED &&
2108                  event.id != MouseEvent.MOUSE_DRAGGED &&
2109                  event.id != MouseEvent.MOUSE_WHEEL &&
2110                  event.id >= MouseEvent.MOUSE_FIRST &&
2111                  event.id <= MouseEvent.MOUSE_LAST)
2112              || ((eventBit = eventMask & AWTEvent.WINDOW_EVENT_MASK) != 0 &&
2113                  (event.id >= WindowEvent.WINDOW_FIRST &&
2114                  event.id <= WindowEvent.WINDOW_LAST))
2115              || ((eventBit = eventMask & AWTEvent.ACTION_EVENT_MASK) != 0 &&
2116                  event.id >= ActionEvent.ACTION_FIRST &&
2117                  event.id <= ActionEvent.ACTION_LAST)
2118              || ((eventBit = eventMask & AWTEvent.ADJUSTMENT_EVENT_MASK) != 0 &&
2119                  event.id >= AdjustmentEvent.ADJUSTMENT_FIRST &&
2120                  event.id <= AdjustmentEvent.ADJUSTMENT_LAST)
2121              || ((eventBit = eventMask & AWTEvent.ITEM_EVENT_MASK) != 0 &&
2122                  event.id >= ItemEvent.ITEM_FIRST &&
2123                  event.id <= ItemEvent.ITEM_LAST)
2124              || ((eventBit = eventMask & AWTEvent.TEXT_EVENT_MASK) != 0 &&
2125                  event.id >= TextEvent.TEXT_FIRST &&
2126                  event.id <= TextEvent.TEXT_LAST)
2127              || ((eventBit = eventMask & AWTEvent.INPUT_METHOD_EVENT_MASK) != 0 &&
2128                  event.id >= InputMethodEvent.INPUT_METHOD_FIRST &&
2129                  event.id <= InputMethodEvent.INPUT_METHOD_LAST)
2130              || ((eventBit = eventMask & AWTEvent.PAINT_EVENT_MASK) != 0 &&
2131                  event.id >= PaintEvent.PAINT_FIRST &&
2132                  event.id <= PaintEvent.PAINT_LAST)
2133              || ((eventBit = eventMask & AWTEvent.INVOCATION_EVENT_MASK) != 0 &&
2134                  event.id >= InvocationEvent.INVOCATION_FIRST &&
2135                  event.id <= InvocationEvent.INVOCATION_LAST)
2136              || ((eventBit = eventMask & AWTEvent.HIERARCHY_EVENT_MASK) != 0 &&
2137                  event.id == HierarchyEvent.HIERARCHY_CHANGED)
2138              || ((eventBit = eventMask & AWTEvent.HIERARCHY_BOUNDS_EVENT_MASK) != 0 &&
2139                  (event.id == HierarchyEvent.ANCESTOR_MOVED ||
2140                   event.id == HierarchyEvent.ANCESTOR_RESIZED))
2141              || ((eventBit = eventMask & AWTEvent.WINDOW_STATE_EVENT_MASK) != 0 &&
2142                  event.id == WindowEvent.WINDOW_STATE_CHANGED)
2143              || ((eventBit = eventMask & AWTEvent.WINDOW_FOCUS_EVENT_MASK) != 0 &&
2144                  (event.id == WindowEvent.WINDOW_GAINED_FOCUS ||
2145                   event.id == WindowEvent.WINDOW_LOST_FOCUS))
2146                 || ((eventBit = eventMask & sun.awt.SunToolkit.GRAB_EVENT_MASK) != 0 &&
2147                     (event instanceof sun.awt.UngrabEvent))) {
2148                 // Get the index of the call count for this event type.
2149                 // Instead of using Math.log(...) we will calculate it with
2150                 // bit shifts. That's what previous implementation looked like:
2151                 //
2152                 // int ci = (int) (Math.log(eventBit)/Math.log(2));
2153                 int ci = 0;
2154                 for (long eMask = eventBit; eMask != 0; eMask >>>= 1, ci++) {
2155                 }
2156                 ci--;
2157                 // Call the listener as many times as it was added for this
2158                 // event type.
2159                 for (int i=0; i<calls[ci]; i++) {
2160                     listener.eventDispatched(event);
2161                 }
2162             }
2163         }
2164     }
2165 
2166     /**
2167      * Returns a map of visual attributes for the abstract level description
2168      * of the given input method highlight, or null if no mapping is found.
2169      * The style field of the input method highlight is ignored. The map
2170      * returned is unmodifiable.
2171      * @param highlight input method highlight
2172      * @return style attribute map, or <code>null</code>
2173      * @exception HeadlessException if
2174      *     <code>GraphicsEnvironment.isHeadless</code> returns true
2175      * @see       java.awt.GraphicsEnvironment#isHeadless
2176      * @since 1.3
2177      */
2178     public abstract Map<java.awt.font.TextAttribute,?>
2179         mapInputMethodHighlight(InputMethodHighlight highlight)
2180         throws HeadlessException;
2181 
2182     private static PropertyChangeSupport createPropertyChangeSupport(Toolkit toolkit) {
2183         if (toolkit instanceof SunToolkit || toolkit instanceof HeadlessToolkit) {
2184             return new DesktopPropertyChangeSupport(toolkit);
2185         } else {
2186             return new PropertyChangeSupport(toolkit);
2187         }
2188     }
2189 
2190     @SuppressWarnings("serial")
2191     private static class DesktopPropertyChangeSupport extends PropertyChangeSupport {
2192 
2193         private static final StringBuilder PROP_CHANGE_SUPPORT_KEY =
2194                 new StringBuilder("desktop property change support key");
2195         private final Object source;
2196 
2197         public DesktopPropertyChangeSupport(Object sourceBean) {
2198             super(sourceBean);
2199             source = sourceBean;
2200         }
2201 
2202         @Override
2203         public synchronized void addPropertyChangeListener(
2204                 String propertyName,
2205                 PropertyChangeListener listener)
2206         {
2207             PropertyChangeSupport pcs = (PropertyChangeSupport)
2208                     AppContext.getAppContext().get(PROP_CHANGE_SUPPORT_KEY);
2209             if (null == pcs) {
2210                 pcs = new PropertyChangeSupport(source);
2211                 AppContext.getAppContext().put(PROP_CHANGE_SUPPORT_KEY, pcs);
2212             }
2213             pcs.addPropertyChangeListener(propertyName, listener);
2214         }
2215 
2216         @Override
2217         public synchronized void removePropertyChangeListener(
2218                 String propertyName,
2219                 PropertyChangeListener listener)
2220         {
2221             PropertyChangeSupport pcs = (PropertyChangeSupport)
2222                     AppContext.getAppContext().get(PROP_CHANGE_SUPPORT_KEY);
2223             if (null != pcs) {
2224                 pcs.removePropertyChangeListener(propertyName, listener);
2225             }
2226         }
2227 
2228         @Override
2229         public synchronized PropertyChangeListener[] getPropertyChangeListeners()
2230         {
2231             PropertyChangeSupport pcs = (PropertyChangeSupport)
2232                     AppContext.getAppContext().get(PROP_CHANGE_SUPPORT_KEY);
2233             if (null != pcs) {
2234                 return pcs.getPropertyChangeListeners();
2235             } else {
2236                 return new PropertyChangeListener[0];
2237             }
2238         }
2239 
2240         @Override
2241         public synchronized PropertyChangeListener[] getPropertyChangeListeners(String propertyName)
2242         {
2243             PropertyChangeSupport pcs = (PropertyChangeSupport)
2244                     AppContext.getAppContext().get(PROP_CHANGE_SUPPORT_KEY);
2245             if (null != pcs) {
2246                 return pcs.getPropertyChangeListeners(propertyName);
2247             } else {
2248                 return new PropertyChangeListener[0];
2249             }
2250         }
2251 
2252         @Override
2253         public synchronized void addPropertyChangeListener(PropertyChangeListener listener) {
2254             PropertyChangeSupport pcs = (PropertyChangeSupport)
2255                     AppContext.getAppContext().get(PROP_CHANGE_SUPPORT_KEY);
2256             if (null == pcs) {
2257                 pcs = new PropertyChangeSupport(source);
2258                 AppContext.getAppContext().put(PROP_CHANGE_SUPPORT_KEY, pcs);
2259             }
2260             pcs.addPropertyChangeListener(listener);
2261         }
2262 
2263         @Override
2264         public synchronized void removePropertyChangeListener(PropertyChangeListener listener) {
2265             PropertyChangeSupport pcs = (PropertyChangeSupport)
2266                     AppContext.getAppContext().get(PROP_CHANGE_SUPPORT_KEY);
2267             if (null != pcs) {
2268                 pcs.removePropertyChangeListener(listener);
2269             }
2270         }
2271 
2272         /*
2273          * we do expect that all other fireXXX() methods of java.beans.PropertyChangeSupport
2274          * use this method.  If this will be changed we will need to change this class.
2275          */
2276         @Override
2277         public void firePropertyChange(final PropertyChangeEvent evt) {
2278             Object oldValue = evt.getOldValue();
2279             Object newValue = evt.getNewValue();
2280             String propertyName = evt.getPropertyName();
2281             if (oldValue != null && newValue != null && oldValue.equals(newValue)) {
2282                 return;
2283             }
2284             Runnable updater = new Runnable() {
2285                 public void run() {
2286                     PropertyChangeSupport pcs = (PropertyChangeSupport)
2287                             AppContext.getAppContext().get(PROP_CHANGE_SUPPORT_KEY);
2288                     if (null != pcs) {
2289                         pcs.firePropertyChange(evt);
2290                     }
2291                 }
2292             };
2293             final AppContext currentAppContext = AppContext.getAppContext();
2294             for (AppContext appContext : AppContext.getAppContexts()) {
2295                 if (null == appContext || appContext.isDisposed()) {
2296                     continue;
2297                 }
2298                 if (currentAppContext == appContext) {
2299                     updater.run();
2300                 } else {
2301                     final PeerEvent e = new PeerEvent(source, updater, PeerEvent.ULTIMATE_PRIORITY_EVENT);
2302                     SunToolkit.postEvent(appContext, e);
2303                 }
2304             }
2305         }
2306     }
2307 
2308     /**
2309     * Reports whether events from extra mouse buttons are allowed to be processed and posted into
2310     * {@code EventQueue}.
2311     * <br>
2312     * To change the returned value it is necessary to set the {@code sun.awt.enableExtraMouseButtons}
2313     * property before the {@code Toolkit} class initialization. This setting could be done on the application
2314     * startup by the following command:
2315     * <pre>
2316     * java -Dsun.awt.enableExtraMouseButtons=false Application
2317     * </pre>
2318     * Alternatively, the property could be set in the application by using the following code:
2319     * <pre>
2320     * System.setProperty("sun.awt.enableExtraMouseButtons", "true");
2321     * </pre>
2322     * before the {@code Toolkit} class initialization.
2323     * If not set by the time of the {@code Toolkit} class initialization, this property will be
2324     * initialized with {@code true}.
2325     * Changing this value after the {@code Toolkit} class initialization will have no effect.
2326     *
2327     * @exception HeadlessException if GraphicsEnvironment.isHeadless() returns true
2328     * @return {@code true} if events from extra mouse buttons are allowed to be processed and posted;
2329     *         {@code false} otherwise
2330     * @see System#getProperty(String propertyName)
2331     * @see System#setProperty(String propertyName, String value)
2332     * @see java.awt.EventQueue
2333     * @since 1.7
2334      */
2335     public boolean areExtraMouseButtonsEnabled() throws HeadlessException {
2336         GraphicsEnvironment.checkHeadless();
2337 
2338         return Toolkit.getDefaultToolkit().areExtraMouseButtonsEnabled();
2339     }
2340 }