libjava/java/awt/dnd/DropTarget.java

   1 /* DropTarget.java --
   2    Copyright (C) 2002, 2003, 2004  Free Software Foundation, Inc.
   3
   4 This file is part of GNU Classpath.
   5
   6 GNU Classpath is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2, or (at your option)
   9 any later version.
  10
  11 GNU Classpath is distributed in the hope that it will be useful, but
  12 WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU Classpath; see the file COPYING.  If not, write to the
  18 Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19 02111-1307 USA.
  20
  21 Linking this library statically or dynamically with other modules is
  22 making a combined work based on this library.  Thus, the terms and
  23 conditions of the GNU General Public License cover the whole
  24 combination.
  25
  26 As a special exception, the copyright holders of this library give you
  27 permission to link this library with independent modules to produce an
  28 executable, regardless of the license terms of these independent
  29 modules, and to copy and distribute the resulting executable under
  30 terms of your choice, provided that you also meet, for each linked
  31 independent module, the terms and conditions of the license of that
  32 module.  An independent module is a module which is not derived from
  33 or based on this library.  If you modify this library, you may extend
  34 this exception to your version of the library, but you are not
  35 obligated to do so.  If you do not wish to do so, delete this
  36 exception statement from your version. */
  37
  38
  39 package java.awt.dnd;
  40
  41 import java.awt.Component;
  42 import java.awt.GraphicsEnvironment;
  43 import java.awt.HeadlessException;
  44 import java.awt.Point;
  45 import java.awt.datatransfer.FlavorMap;
  46 import java.awt.event.ActionEvent;
  47 import java.awt.event.ActionListener;
  48 import java.io.Serializable;
  49 import java.util.EventListener;
  50 import java.util.TooManyListenersException;
  51
  52 /**
  53  * @author Michael Koch
  54  * @since 1.2
  55  */
  56 public class DropTarget
  57   implements DropTargetListener, EventListener, Serializable
  58 {
  59   /**
  60    * Compatible with JDK 1.2+
  61    */
  62   private static final long serialVersionUID = -6283860791671019047L;
  63
  64   /** @specnote According to the online documentation, this is
  65    * protected, but in reality it is public.  */
  66   public static class DropTargetAutoScroller
  67     implements ActionListener
  68   {
  69     private Component component;
  70     private Point point;
  71
  72     protected DropTargetAutoScroller (Component c, Point p)
  73     {
  74       component = c;
  75       point = p;
  76     }
  77
  78     protected void updateLocation (Point newLocn)
  79     {
  80       point = newLocn;
  81     }
  82
  83     protected void stop ()
  84     {
  85     }
  86
  87     public void actionPerformed (ActionEvent e)
  88     {
  89     }
  90   }
  91
  92   private Component component;
  93   private FlavorMap flavorMap;
  94   private int actions;
  95   private DropTargetContext dropTargetContext;
  96   private DropTargetListener dropTargetListener;
  97   private boolean active = true;
  98
  99   /**
 100    * Creates a <code>DropTarget</code> object.
 101    *
 102    * @exception HeadlessException If GraphicsEnvironment.isHeadless()
 103    * returns true.
 104    */
 105   public DropTarget ()
 106   {
 107     this (null, 0, null, true, null);
 108   }
 109
 110   /**
 111    * Creates a <code>DropTarget</code> object.
 112    *
 113    * @exception HeadlessException If GraphicsEnvironment.isHeadless()
 114    * returns true.
 115    */
 116   public DropTarget (Component c, DropTargetListener dtl)
 117   {
 118     this (c, 0, dtl, true, null);
 119   }
 120
 121   /**
 122    * Creates a <code>DropTarget</code> object.
 123    *
 124    * @exception HeadlessException If GraphicsEnvironment.isHeadless()
 125    * returns true.
 126    */
 127   public DropTarget (Component c, int i, DropTargetListener dtl)
 128   {
 129     this (c, i, dtl, true, null);
 130   }
 131
 132   /**
 133    * Creates a <code>DropTarget</code> object.
 134    *
 135    * @exception HeadlessException If GraphicsEnvironment.isHeadless()
 136    * returns true.
 137    */
 138   public DropTarget (Component c, int i, DropTargetListener dtl, boolean b)
 139   {
 140     this (c, i, dtl, b, null);
 141   }
 142
 143   /**
 144    * Creates a <code>DropTarget</code> object.
 145    *
 146    * @exception HeadlessException If GraphicsEnvironment.isHeadless()
 147    * returns true.
 148    */
 149   public DropTarget (Component c, int i, DropTargetListener dtl, boolean b,
 150                      FlavorMap fm)
 151   {
 152     if (GraphicsEnvironment.isHeadless ())
 153       throw new HeadlessException ();
 154
 155     component = c;
 156     actions = i;
 157     dropTargetListener = dtl;
 158     flavorMap = fm;
 159
 160     setActive (b);
 161   }
 162
 163   /**
 164    * Sets the component associated with this drop target object.
 165    */
 166   public void setComponent (Component c)
 167   {
 168     component = c;
 169   }
 170
 171   /**
 172    * Returns the component associated with this drop target object.
 173    */
 174   public Component getComponent ()
 175   {
 176     return component;
 177   }
 178
 179   /**
 180    * Sets the default actions.
 181    */
 182   public void setDefaultActions (int ops)
 183   {
 184     actions = ops;
 185   }
 186
 187   /**
 188    * Returns the default actions.
 189    */
 190   public int getDefaultActions ()
 191   {
 192     return actions;
 193   }
 194
 195   public void setActive (boolean active)
 196   {
 197     this.active = active;
 198   }
 199
 200   public boolean isActive()
 201   {
 202     return active;
 203   }
 204
 205   /**
 206    * Adds a new <code>DropTargetListener</code>.
 207    *
 208    * @exception TooManyListenersException Sun's JDK does not, despite
 209    * documentation, throw this exception here when you install an additional
 210    * <code>DropTargetListener</code>.  So to be compatible, we do the same
 211    * thing.
 212    */
 213   public void addDropTargetListener (DropTargetListener dtl)
 214     throws TooManyListenersException
 215   {
 216     dropTargetListener = dtl;
 217   }
 218
 219   public void removeDropTargetListener(DropTargetListener dtl)
 220   {
 221     // FIXME: Do we need to do something with dtl ?
 222     dropTargetListener = null;
 223   }
 224
 225   public void dragEnter(DropTargetDragEvent dtde)
 226   {
 227   }
 228
 229   public void dragOver(DropTargetDragEvent dtde)
 230   {
 231   }
 232
 233   public void dropActionChanged(DropTargetDragEvent dtde)
 234   {
 235   }
 236
 237   public void dragExit(DropTargetEvent dte)
 238   {
 239   }
 240
 241   public void drop(DropTargetDropEvent dtde)
 242   {
 243   }
 244
 245   public FlavorMap getFlavorMap()
 246   {
 247     return flavorMap;
 248   }
 249
 250   public void setFlavorMap(FlavorMap fm)
 251   {
 252     flavorMap = fm;
 253   }
 254
 255   public void addNotify(java.awt.peer.ComponentPeer peer)
 256   {
 257   }
 258
 259   public void removeNotify(java.awt.peer.ComponentPeer peer)
 260   {
 261   }
 262
 263   public DropTargetContext getDropTargetContext()
 264   {
 265     if (dropTargetContext == null)
 266       dropTargetContext = createDropTargetContext ();
 267
 268     return dropTargetContext;
 269   }
 270
 271   protected DropTargetContext createDropTargetContext()
 272   {
 273     return new DropTargetContext (this);
 274   }
 275
 276   protected DropTarget.DropTargetAutoScroller createDropTargetAutoScroller
 277                                                        (Component c, Point p)
 278   {
 279     return new DropTarget.DropTargetAutoScroller (c, p);
 280   }
 281
 282   protected void initializeAutoscrolling(Point p)
 283   {
 284   }
 285
 286   protected void updateAutoscroll(Point dragCursorLocn)
 287   {
 288   }
 289
 290   protected void clearAutoscroll()
 291   {
 292   }
 293 } // class DropTarget