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      * An accessor for the sun.swing.JLightweightFrame class
  76      */
  77     public interface JLightweightFrameAccessor {
  78 
  79         /*
  80          * Returns the content LightweightContent for the frame
  81          */
  82         LightweightContent getLightweightContent(JLightweightFrame frame);
  83     }
  84 
  85     /**
  86      * The javax.swing.text.JTextComponent class accessor object.
  87      */
  88     private static JTextComponentAccessor jtextComponentAccessor;
  89     /**
  90      * The sun.swing.JLightweightFrame class accessor object
  91      */
  92     private static JLightweightFrameAccessor jLightweightFrameAccessor;
  93 
  94     /**
  95      * Set an accessor object for the javax.swing.text.JTextComponent class.
  96      */
  97     public static void setJTextComponentAccessor(JTextComponentAccessor jtca) {
  98          jtextComponentAccessor = jtca;
  99     }
 100 
 101     /**
 102      * Retrieve the accessor object for the javax.swing.text.JTextComponent class.
 103      */
 104     public static JTextComponentAccessor getJTextComponentAccessor() {
 105         if (jtextComponentAccessor == null) {
 106             unsafe.ensureClassInitialized(JTextComponent.class);
 107         }
 108 
 109         return jtextComponentAccessor;
 110     }
 111 
 112     /**
 113      * Set an accessor object for sun.swing.JLightweightFrame class
 114      */
 115     public static void setJLightweightFrameAccessor(JLightweightFrameAccessor accessor) {
 116         jLightweightFrameAccessor = accessor;
 117     }
 118 
 119     /**
 120      * Retrieve an accessor object for sun.swing.JLightweightFrame class
 121      */
 122     public static JLightweightFrameAccessor getJLightweightFrameAccessor() {
 123         return jLightweightFrameAccessor;
 124     }
 125 }