1 /*
   2  * Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 package java.awt;
  26 
  27 import java.util.List;
  28 import java.util.ArrayList;
  29 import sun.util.logging.PlatformLogger;
  30 
  31 /**
  32  * A FocusTraversalPolicy that determines traversal order based on the order
  33  * of child Components in a Container. From a particular focus cycle root, the
  34  * policy makes a pre-order traversal of the Component hierarchy, and traverses
  35  * a Container's children according to the ordering of the array returned by
  36  * {@code Container.getComponents()}. Portions of the hierarchy that are
  37  * not visible and displayable will not be searched.
  38  * <p>
  39  * By default, ContainerOrderFocusTraversalPolicy implicitly transfers focus
  40  * down-cycle. That is, during normal forward focus traversal, the Component
  41  * traversed after a focus cycle root will be the focus-cycle-root's default
  42  * Component to focus. This behavior can be disabled using the
  43  * {@code setImplicitDownCycleTraversal} method.
  44  * <p>
  45  * By default, methods of this class will return a Component only if it is
  46  * visible, displayable, enabled, and focusable. Subclasses can modify this
  47  * behavior by overriding the {@code accept} method.
  48  * <p>
  49  * This policy takes into account <a
  50  * href="doc-files/FocusSpec.html#FocusTraversalPolicyProviders">focus traversal
  51  * policy providers</a>.  When searching for first/last/next/previous Component,
  52  * if a focus traversal policy provider is encountered, its focus traversal
  53  * policy is used to perform the search operation.
  54  *
  55  * @author David Mendenhall
  56  *
  57  * @see Container#getComponents
  58  * @since 1.4
  59  */
  60 public class ContainerOrderFocusTraversalPolicy extends FocusTraversalPolicy
  61     implements java.io.Serializable
  62 {
  63     private static final PlatformLogger log = PlatformLogger.getLogger("java.awt.ContainerOrderFocusTraversalPolicy");
  64 
  65     private final int FORWARD_TRAVERSAL = 0;
  66     private final int BACKWARD_TRAVERSAL = 1;
  67 
  68     /*
  69      * JDK 1.4 serialVersionUID
  70      */
  71     private static final long serialVersionUID = 486933713763926351L;
  72 
  73     private boolean implicitDownCycleTraversal = true;
  74 
  75     /**
  76      * Used by getComponentAfter and getComponentBefore for efficiency. In
  77      * order to maintain compliance with the specification of
  78      * FocusTraversalPolicy, if traversal wraps, we should invoke
  79      * getFirstComponent or getLastComponent. These methods may be overriden in
  80      * subclasses to behave in a non-generic way. However, in the generic case,
  81      * these methods will simply return the first or last Components of the
  82      * sorted list, respectively. Since getComponentAfter and
  83      * getComponentBefore have already built the list before determining
  84      * that they need to invoke getFirstComponent or getLastComponent, the
  85      * list should be reused if possible.
  86      */
  87     private transient Container cachedRoot;
  88     private transient List<Component> cachedCycle;
  89 
  90     /*
  91      * We suppose to use getFocusTraversalCycle & getComponentIndex methods in order
  92      * to divide the policy into two parts:
  93      * 1) Making the focus traversal cycle.
  94      * 2) Traversing the cycle.
  95      * The 1st point assumes producing a list of components representing the focus
  96      * traversal cycle. The two methods mentioned above should implement this logic.
  97      * The 2nd point assumes implementing the common concepts of operating on the
  98      * cycle: traversing back and forth, retrieving the initial/default/first/last
  99      * component. These concepts are described in the AWT Focus Spec and they are
 100      * applied to the FocusTraversalPolicy in general.
 101      * Thus, a descendant of this policy may wish to not reimplement the logic of
 102      * the 2nd point but just override the implementation of the 1st one.
 103      * A striking example of such a descendant is the javax.swing.SortingFocusTraversalPolicy.
 104      */
 105     /*protected*/ private List<Component> getFocusTraversalCycle(Container aContainer) {
 106         List<Component> cycle = new ArrayList<Component>();
 107         enumerateCycle(aContainer, cycle);
 108         return cycle;
 109     }
 110     /*protected*/ private int getComponentIndex(List<Component> cycle, Component aComponent) {
 111         return cycle.indexOf(aComponent);
 112     }
 113 
 114     private void enumerateCycle(Container container, List<Component> cycle) {
 115         if (!(container.isVisible() && container.isDisplayable())) {
 116             return;
 117         }
 118 
 119         cycle.add(container);
 120 
 121         Component[] components = container.getComponents();
 122         for (int i = 0; i < components.length; i++) {
 123             Component comp = components[i];
 124             if (comp instanceof Container) {
 125                 Container cont = (Container)comp;
 126 
 127                 if (!cont.isFocusCycleRoot() && !cont.isFocusTraversalPolicyProvider()) {
 128                     enumerateCycle(cont, cycle);
 129                     continue;
 130                 }
 131             }
 132             cycle.add(comp);
 133         }
 134     }
 135 
 136     private Container getTopmostProvider(Container focusCycleRoot, Component aComponent) {
 137         Container aCont = aComponent.getParent();
 138         Container ftp = null;
 139         while (aCont  != focusCycleRoot && aCont != null) {
 140             if (aCont.isFocusTraversalPolicyProvider()) {
 141                 ftp = aCont;
 142             }
 143             aCont = aCont.getParent();
 144         }
 145         if (aCont == null) {
 146             return null;
 147         }
 148         return ftp;
 149     }
 150 
 151     /*
 152      * Checks if a new focus cycle takes place and returns a Component to traverse focus to.
 153      * @param comp a possible focus cycle root or policy provider
 154      * @param traversalDirection the direction of the traversal
 155      * @return a Component to traverse focus to if {@code comp} is a root or provider
 156      *         and implicit down-cycle is set, otherwise {@code null}
 157      */
 158     private Component getComponentDownCycle(Component comp, int traversalDirection) {
 159         Component retComp = null;
 160 
 161         if (comp instanceof Container) {
 162             Container cont = (Container)comp;
 163 
 164             if (cont.isFocusCycleRoot()) {
 165                 if (getImplicitDownCycleTraversal()) {
 166                     retComp = cont.getFocusTraversalPolicy().getDefaultComponent(cont);
 167 
 168                     if (retComp != null && log.isLoggable(PlatformLogger.Level.FINE)) {
 169                         log.fine("### Transferred focus down-cycle to " + retComp +
 170                                  " in the focus cycle root " + cont);
 171                     }
 172                 } else {
 173                     return null;
 174                 }
 175             } else if (cont.isFocusTraversalPolicyProvider()) {
 176                 retComp = (traversalDirection == FORWARD_TRAVERSAL ?
 177                            cont.getFocusTraversalPolicy().getDefaultComponent(cont) :
 178                            cont.getFocusTraversalPolicy().getLastComponent(cont));
 179 
 180                 if (retComp != null && log.isLoggable(PlatformLogger.Level.FINE)) {
 181                     log.fine("### Transferred focus to " + retComp + " in the FTP provider " + cont);
 182                 }
 183             }
 184         }
 185         return retComp;
 186     }
 187 
 188     /**
 189      * Returns the Component that should receive the focus after aComponent.
 190      * aContainer must be a focus cycle root of aComponent or a focus traversal policy provider.
 191      * <p>
 192      * By default, ContainerOrderFocusTraversalPolicy implicitly transfers
 193      * focus down-cycle. That is, during normal forward focus traversal, the
 194      * Component traversed after a focus cycle root will be the focus-cycle-
 195      * root's default Component to focus. This behavior can be disabled using
 196      * the {@code setImplicitDownCycleTraversal} method.
 197      * <p>
 198      * If aContainer is <a href="doc-files/FocusSpec.html#FocusTraversalPolicyProviders">focus
 199      * traversal policy provider</a>, the focus is always transferred down-cycle.
 200      *
 201      * @param aContainer a focus cycle root of aComponent or a focus traversal policy provider
 202      * @param aComponent a (possibly indirect) child of aContainer, or
 203      *        aContainer itself
 204      * @return the Component that should receive the focus after aComponent, or
 205      *         null if no suitable Component can be found
 206      * @throws IllegalArgumentException if aContainer is not a focus cycle
 207      *         root of aComponent or focus traversal policy provider, or if either aContainer or
 208      *         aComponent is null
 209      */
 210     public Component getComponentAfter(Container aContainer, Component aComponent) {
 211         if (log.isLoggable(PlatformLogger.Level.FINE)) {
 212             log.fine("### Searching in " + aContainer + " for component after " + aComponent);
 213         }
 214 
 215         if (aContainer == null || aComponent == null) {
 216             throw new IllegalArgumentException("aContainer and aComponent cannot be null");
 217         }
 218         if (!aContainer.isFocusTraversalPolicyProvider() && !aContainer.isFocusCycleRoot()) {
 219             throw new IllegalArgumentException("aContainer should be focus cycle root or focus traversal policy provider");
 220 
 221         } else if (aContainer.isFocusCycleRoot() && !aComponent.isFocusCycleRoot(aContainer)) {
 222             throw new IllegalArgumentException("aContainer is not a focus cycle root of aComponent");
 223         }
 224 
 225         synchronized(aContainer.getTreeLock()) {
 226 
 227             if (!(aContainer.isVisible() && aContainer.isDisplayable())) {
 228                 return null;
 229             }
 230 
 231             // Before all the checks below we first see if it's an FTP provider or a focus cycle root.
 232             // If it's the case just go down cycle (if it's set to "implicit").
 233             Component comp = getComponentDownCycle(aComponent, FORWARD_TRAVERSAL);
 234             // Check if aComponent is focus-cycle-root's default Component, i.e.
 235             // focus cycle root & focus-cycle-root's default Component is same.
 236             if (comp != null && comp != aComponent) {
 237                 return comp;
 238             }
 239 
 240             // See if the component is inside of policy provider.
 241             Container provider = getTopmostProvider(aContainer, aComponent);
 242             if (provider != null) {
 243                 if (log.isLoggable(PlatformLogger.Level.FINE)) {
 244                     log.fine("### Asking FTP " + provider + " for component after " + aComponent);
 245                 }
 246 
 247                 // FTP knows how to find component after the given. We don't.
 248                 FocusTraversalPolicy policy = provider.getFocusTraversalPolicy();
 249                 Component afterComp = policy.getComponentAfter(provider, aComponent);
 250 
 251                 // Null result means that we overstepped the limit of the FTP's cycle.
 252                 // In that case we must quit the cycle, otherwise return the component found.
 253                 if (afterComp != null) {
 254                     if (log.isLoggable(PlatformLogger.Level.FINE)) {
 255                         log.fine("### FTP returned " + afterComp);
 256                     }
 257                     return afterComp;
 258                 }
 259                 aComponent = provider;
 260             }
 261 
 262             List<Component> cycle = getFocusTraversalCycle(aContainer);
 263 
 264             if (log.isLoggable(PlatformLogger.Level.FINE)) {
 265                 log.fine("### Cycle is " + cycle + ", component is " + aComponent);
 266             }
 267 
 268             int index = getComponentIndex(cycle, aComponent);
 269 
 270             if (index < 0) {
 271                 if (log.isLoggable(PlatformLogger.Level.FINE)) {
 272                     log.fine("### Didn't find component " + aComponent + " in a cycle " + aContainer);
 273                 }
 274                 return getFirstComponent(aContainer);
 275             }
 276 
 277             for (index++; index < cycle.size(); index++) {
 278                 comp = cycle.get(index);
 279                 if (accept(comp)) {
 280                     return comp;
 281                 } else if ((comp = getComponentDownCycle(comp, FORWARD_TRAVERSAL)) != null) {
 282                     return comp;
 283                 }
 284             }
 285 
 286             if (aContainer.isFocusCycleRoot()) {
 287                 this.cachedRoot = aContainer;
 288                 this.cachedCycle = cycle;
 289 
 290                 comp = getFirstComponent(aContainer);
 291 
 292                 this.cachedRoot = null;
 293                 this.cachedCycle = null;
 294 
 295                 return comp;
 296             }
 297         }
 298         return null;
 299     }
 300 
 301     /**
 302      * Returns the Component that should receive the focus before aComponent.
 303      * aContainer must be a focus cycle root of aComponent or a <a
 304      * href="doc-files/FocusSpec.html#FocusTraversalPolicyProviders">focus traversal policy
 305      * provider</a>.
 306      *
 307      * @param aContainer a focus cycle root of aComponent or focus traversal policy provider
 308      * @param aComponent a (possibly indirect) child of aContainer, or
 309      *        aContainer itself
 310      * @return the Component that should receive the focus before aComponent,
 311      *         or null if no suitable Component can be found
 312      * @throws IllegalArgumentException if aContainer is not a focus cycle
 313      *         root of aComponent or focus traversal policy provider, or if either aContainer or
 314      *         aComponent is null
 315      */
 316     public Component getComponentBefore(Container aContainer, Component aComponent) {
 317         if (aContainer == null || aComponent == null) {
 318             throw new IllegalArgumentException("aContainer and aComponent cannot be null");
 319         }
 320         if (!aContainer.isFocusTraversalPolicyProvider() && !aContainer.isFocusCycleRoot()) {
 321             throw new IllegalArgumentException("aContainer should be focus cycle root or focus traversal policy provider");
 322 
 323         } else if (aContainer.isFocusCycleRoot() && !aComponent.isFocusCycleRoot(aContainer)) {
 324             throw new IllegalArgumentException("aContainer is not a focus cycle root of aComponent");
 325         }
 326 
 327         synchronized(aContainer.getTreeLock()) {
 328 
 329             if (!(aContainer.isVisible() && aContainer.isDisplayable())) {
 330                 return null;
 331             }
 332 
 333             // See if the component is inside of policy provider.
 334             Container provider = getTopmostProvider(aContainer, aComponent);
 335             if (provider != null) {
 336                 if (log.isLoggable(PlatformLogger.Level.FINE)) {
 337                     log.fine("### Asking FTP " + provider + " for component after " + aComponent);
 338                 }
 339 
 340                 // FTP knows how to find component after the given. We don't.
 341                 FocusTraversalPolicy policy = provider.getFocusTraversalPolicy();
 342                 Component beforeComp = policy.getComponentBefore(provider, aComponent);
 343 
 344                 // Null result means that we overstepped the limit of the FTP's cycle.
 345                 // In that case we must quit the cycle, otherwise return the component found.
 346                 if (beforeComp != null) {
 347                     if (log.isLoggable(PlatformLogger.Level.FINE)) {
 348                         log.fine("### FTP returned " + beforeComp);
 349                     }
 350                     return beforeComp;
 351                 }
 352                 aComponent = provider;
 353 
 354                 // If the provider is traversable it's returned.
 355                 if (accept(aComponent)) {
 356                     return aComponent;
 357                 }
 358             }
 359 
 360             List<Component> cycle = getFocusTraversalCycle(aContainer);
 361 
 362             if (log.isLoggable(PlatformLogger.Level.FINE)) {
 363                 log.fine("### Cycle is " + cycle + ", component is " + aComponent);
 364             }
 365 
 366             int index = getComponentIndex(cycle, aComponent);
 367 
 368             if (index < 0) {
 369                 if (log.isLoggable(PlatformLogger.Level.FINE)) {
 370                     log.fine("### Didn't find component " + aComponent + " in a cycle " + aContainer);
 371                 }
 372                 return getLastComponent(aContainer);
 373             }
 374 
 375             Component comp = null;
 376             Component tryComp = null;
 377 
 378             for (index--; index>=0; index--) {
 379                 comp = cycle.get(index);
 380                 if (comp != aContainer && (tryComp = getComponentDownCycle(comp, BACKWARD_TRAVERSAL)) != null) {
 381                     return tryComp;
 382                 } else if (accept(comp)) {
 383                     return comp;
 384                 }
 385             }
 386 
 387             if (aContainer.isFocusCycleRoot()) {
 388                 this.cachedRoot = aContainer;
 389                 this.cachedCycle = cycle;
 390 
 391                 comp = getLastComponent(aContainer);
 392 
 393                 this.cachedRoot = null;
 394                 this.cachedCycle = null;
 395 
 396                 return comp;
 397             }
 398         }
 399         return null;
 400     }
 401 
 402     /**
 403      * Returns the first Component in the traversal cycle. This method is used
 404      * to determine the next Component to focus when traversal wraps in the
 405      * forward direction.
 406      *
 407      * @param aContainer the focus cycle root or focus traversal policy provider whose first
 408      *        Component is to be returned
 409      * @return the first Component in the traversal cycle of aContainer,
 410      *         or null if no suitable Component can be found
 411      * @throws IllegalArgumentException if aContainer is null
 412      */
 413     public Component getFirstComponent(Container aContainer) {
 414         List<Component> cycle;
 415 
 416         if (log.isLoggable(PlatformLogger.Level.FINE)) {
 417             log.fine("### Getting first component in " + aContainer);
 418         }
 419         if (aContainer == null) {
 420             throw new IllegalArgumentException("aContainer cannot be null");
 421 
 422         }
 423 
 424         synchronized(aContainer.getTreeLock()) {
 425 
 426             if (!(aContainer.isVisible() && aContainer.isDisplayable())) {
 427                 return null;
 428             }
 429 
 430             if (this.cachedRoot == aContainer) {
 431                 cycle = this.cachedCycle;
 432             } else {
 433                 cycle = getFocusTraversalCycle(aContainer);
 434             }
 435 
 436             if (cycle.size() == 0) {
 437                 if (log.isLoggable(PlatformLogger.Level.FINE)) {
 438                     log.fine("### Cycle is empty");
 439                 }
 440                 return null;
 441             }
 442             if (log.isLoggable(PlatformLogger.Level.FINE)) {
 443                 log.fine("### Cycle is " + cycle);
 444             }
 445 
 446             for (Component comp : cycle) {
 447                 if (accept(comp)) {
 448                     return comp;
 449                 } else if (comp != aContainer &&
 450                            (comp = getComponentDownCycle(comp, FORWARD_TRAVERSAL)) != null)
 451                 {
 452                     return comp;
 453                 }
 454             }
 455         }
 456         return null;
 457     }
 458 
 459     /**
 460      * Returns the last Component in the traversal cycle. This method is used
 461      * to determine the next Component to focus when traversal wraps in the
 462      * reverse direction.
 463      *
 464      * @param aContainer the focus cycle root or focus traversal policy provider whose last
 465      *        Component is to be returned
 466      * @return the last Component in the traversal cycle of aContainer,
 467      *         or null if no suitable Component can be found
 468      * @throws IllegalArgumentException if aContainer is null
 469      */
 470     public Component getLastComponent(Container aContainer) {
 471         List<Component> cycle;
 472         if (log.isLoggable(PlatformLogger.Level.FINE)) {
 473             log.fine("### Getting last component in " + aContainer);
 474         }
 475 
 476         if (aContainer == null) {
 477             throw new IllegalArgumentException("aContainer cannot be null");
 478         }
 479 
 480         synchronized(aContainer.getTreeLock()) {
 481 
 482             if (!(aContainer.isVisible() && aContainer.isDisplayable())) {
 483                 return null;
 484             }
 485 
 486             if (this.cachedRoot == aContainer) {
 487                 cycle = this.cachedCycle;
 488             } else {
 489                 cycle = getFocusTraversalCycle(aContainer);
 490             }
 491 
 492             if (cycle.size() == 0) {
 493                 if (log.isLoggable(PlatformLogger.Level.FINE)) {
 494                     log.fine("### Cycle is empty");
 495                 }
 496                 return null;
 497             }
 498             if (log.isLoggable(PlatformLogger.Level.FINE)) {
 499                 log.fine("### Cycle is " + cycle);
 500             }
 501 
 502             for (int i= cycle.size() - 1; i >= 0; i--) {
 503                 Component comp = cycle.get(i);
 504                 if (accept(comp)) {
 505                     return comp;
 506                 } else if (comp instanceof Container && comp != aContainer) {
 507                     Container cont = (Container)comp;
 508                     if (cont.isFocusTraversalPolicyProvider()) {
 509                         Component retComp = cont.getFocusTraversalPolicy().getLastComponent(cont);
 510                         if (retComp != null) {
 511                             return retComp;
 512                         }
 513                     }
 514                 }
 515             }
 516         }
 517         return null;
 518     }
 519 
 520     /**
 521      * Returns the default Component to focus. This Component will be the first
 522      * to receive focus when traversing down into a new focus traversal cycle
 523      * rooted at aContainer. The default implementation of this method
 524      * returns the same Component as {@code getFirstComponent}.
 525      *
 526      * @param aContainer the focus cycle root or focus traversal policy provider whose default
 527      *        Component is to be returned
 528      * @return the default Component in the traversal cycle of aContainer,
 529      *         or null if no suitable Component can be found
 530      * @see #getFirstComponent
 531      * @throws IllegalArgumentException if aContainer is null
 532      */
 533     public Component getDefaultComponent(Container aContainer) {
 534         return getFirstComponent(aContainer);
 535     }
 536 
 537     /**
 538      * Sets whether this ContainerOrderFocusTraversalPolicy transfers focus
 539      * down-cycle implicitly. If {@code true}, during normal forward focus
 540      * traversal, the Component traversed after a focus cycle root will be the
 541      * focus-cycle-root's default Component to focus. If {@code false},
 542      * the next Component in the focus traversal cycle rooted at the specified
 543      * focus cycle root will be traversed instead. The default value for this
 544      * property is {@code true}.
 545      *
 546      * @param implicitDownCycleTraversal whether this
 547      *        ContainerOrderFocusTraversalPolicy transfers focus down-cycle
 548      *        implicitly
 549      * @see #getImplicitDownCycleTraversal
 550      * @see #getFirstComponent
 551      */
 552     public void setImplicitDownCycleTraversal(boolean implicitDownCycleTraversal) {
 553         this.implicitDownCycleTraversal = implicitDownCycleTraversal;
 554     }
 555 
 556     /**
 557      * Returns whether this ContainerOrderFocusTraversalPolicy transfers focus
 558      * down-cycle implicitly. If {@code true}, during normal forward focus
 559      * traversal, the Component traversed after a focus cycle root will be the
 560      * focus-cycle-root's default Component to focus. If {@code false},
 561      * the next Component in the focus traversal cycle rooted at the specified
 562      * focus cycle root will be traversed instead.
 563      *
 564      * @return whether this ContainerOrderFocusTraversalPolicy transfers focus
 565      *         down-cycle implicitly
 566      * @see #setImplicitDownCycleTraversal
 567      * @see #getFirstComponent
 568      */
 569     public boolean getImplicitDownCycleTraversal() {
 570         return implicitDownCycleTraversal;
 571     }
 572 
 573     /**
 574      * Determines whether a Component is an acceptable choice as the new
 575      * focus owner. By default, this method will accept a Component if and
 576      * only if it is visible, displayable, enabled, and focusable.
 577      *
 578      * @param aComponent the Component whose fitness as a focus owner is to
 579      *        be tested
 580      * @return {@code true} if aComponent is visible, displayable,
 581      *         enabled, and focusable; {@code false} otherwise
 582      */
 583     protected boolean accept(Component aComponent) {
 584         if (!aComponent.canBeFocusOwner()) {
 585             return false;
 586         }
 587 
 588         // Verify that the Component is recursively enabled. Disabling a
 589         // heavyweight Container disables its children, whereas disabling
 590         // a lightweight Container does not.
 591         if (!(aComponent instanceof Window)) {
 592             for (Container enableTest = aComponent.getParent();
 593                  enableTest != null;
 594                  enableTest = enableTest.getParent())
 595             {
 596                 if (!(enableTest.isEnabled() || enableTest.isLightweight())) {
 597                     return false;
 598                 }
 599                 if (enableTest instanceof Window) {
 600                     break;
 601                 }
 602             }
 603         }
 604 
 605         return true;
 606     }
 607 }