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    1   /*
    2    * Copyright (c) 2009, 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 sun.swing;
   27   
   28   import sun.misc.Unsafe;
   29   
   30   import java.awt.Point;
   31   
   32   import javax.swing.text.JTextComponent;
   33   import javax.swing.TransferHandler;
   34   
   35   /**
   36    * The SwingAccessor utility class.
   37    * The main purpose of this class is to enable accessing
   38    * private and package-private fields of classes from
   39    * different classes/packages. See sun.misc.SharedSecretes
   40    * for another example.
   41    */
   42   public final class SwingAccessor {
   43       private static final Unsafe unsafe = Unsafe.getUnsafe();
   44   
   45       /**
   46        * We don't need any objects of this class.
   47        * It's rather a collection of static methods
   48        * and interfaces.
   49        */
   50       private SwingAccessor() {
   51       }
   52   
   53       /**
   54        * An accessor for the JTextComponent class.
   55        * Note that we intentionally introduce the JTextComponentAccessor,
   56        * and not the JComponentAccessor because the needed methods
   57        * aren't override methods.
   58        */
   59       public interface JTextComponentAccessor {
   60   
   61           /**
   62            * Calculates a custom drop location for the text component,
   63            * representing where a drop at the given point should insert data.
   64            */
   65           TransferHandler.DropLocation dropLocationForPoint(JTextComponent textComp, Point p);
   66   
   67           /**
   68            * Called to set or clear the drop location during a DnD operation.
   69            */
   70           Object setDropLocation(JTextComponent textComp, TransferHandler.DropLocation location,
   71                                  Object state, boolean forDrop);
   72       }
   73   
   74       /**
   75        * The javax.swing.text.JTextComponent class accessor object.
   76        */
   77       private static JTextComponentAccessor jtextComponentAccessor;
   78   
   79       /**
   80        * Set an accessor object for the javax.swing.text.JTextComponent class.
   81        */
   82       public static void setJTextComponentAccessor(JTextComponentAccessor jtca) {
   83            jtextComponentAccessor = jtca;
   84       }
   85   
   86       /**
   87        * Retrieve the accessor object for the javax.swing.text.JTextComponent class.
   88        */
   89       public static JTextComponentAccessor getJTextComponentAccessor() {
   90           if (jtextComponentAccessor == null) {
   91               unsafe.ensureClassInitialized(JTextComponent.class);
   92           }
   93   
   94           return jtextComponentAccessor;
   95       }
   96   }

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