Source for java.awt.dnd.DropTarget

   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., 51 Franklin Street, Fifth Floor, Boston, MA
  19: 02110-1301 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:   protected static class DropTargetAutoScroller
  65:     implements ActionListener
  66:   {
  67:     private Component component;
  68:     private Point point;
  69:     
  70:     protected DropTargetAutoScroller (Component c, Point p)
  71:     {
  72:       component = c;
  73:       point = p;
  74:     }
  75: 
  76:     protected void updateLocation (Point newLocn)
  77:     {
  78:       point = newLocn;
  79:     }
  80: 
  81:     protected void stop ()
  82:     {
  83:     }
  84: 
  85:     public void actionPerformed (ActionEvent e)
  86:     {
  87:     }
  88:   }
  89: 
  90:   private Component component;
  91:   private FlavorMap flavorMap;
  92:   private int actions;
  93:   private DropTargetContext dropTargetContext;
  94:   private DropTargetListener dropTargetListener;
  95:   private boolean active = true;
  96:     
  97:   /**
  98:    * Creates a <code>DropTarget</code> object.
  99:    *
 100:    * @exception HeadlessException If GraphicsEnvironment.isHeadless()
 101:    * returns true.
 102:    */
 103:   public DropTarget ()
 104:   {
 105:     this (null, 0, null, true, null);
 106:   }
 107:   
 108:   /**
 109:    * Creates a <code>DropTarget</code> object.
 110:    *
 111:    * @exception HeadlessException If GraphicsEnvironment.isHeadless()
 112:    * returns true.
 113:    */
 114:   public DropTarget (Component c, DropTargetListener dtl)
 115:   {
 116:     this (c, 0, dtl, true, null);
 117:   }
 118:   
 119:   /**
 120:    * Creates a <code>DropTarget</code> object.
 121:    *
 122:    * @exception HeadlessException If GraphicsEnvironment.isHeadless()
 123:    * returns true.
 124:    */
 125:   public DropTarget (Component c, int i, DropTargetListener dtl)
 126:   {
 127:     this (c, i, dtl, true, null);
 128:   }
 129:   
 130:   /**
 131:    * Creates a <code>DropTarget</code> object.
 132:    *
 133:    * @exception HeadlessException If GraphicsEnvironment.isHeadless()
 134:    * returns true.
 135:    */
 136:   public DropTarget (Component c, int i, DropTargetListener dtl, boolean b)
 137:   {
 138:     this (c, i, dtl, b, null);
 139:   }
 140:   
 141:   /**
 142:    * Creates a <code>DropTarget</code> object.
 143:    *
 144:    * @exception HeadlessException If GraphicsEnvironment.isHeadless()
 145:    * returns true.
 146:    */
 147:   public DropTarget (Component c, int i, DropTargetListener dtl, boolean b,
 148:                      FlavorMap fm)
 149:   {
 150:     if (GraphicsEnvironment.isHeadless ())
 151:       throw new HeadlessException ();
 152: 
 153:     component = c;
 154:     actions = i;
 155:     dropTargetListener = dtl;
 156:     flavorMap = fm;
 157:     
 158:     setActive (b);
 159:   }
 160: 
 161:   /**
 162:    * Sets the component associated with this drop target object.
 163:    */
 164:   public void setComponent (Component c)
 165:   {
 166:     component = c;
 167:   }
 168: 
 169:   /**
 170:    * Returns the component associated with this drop target object.
 171:    */
 172:   public Component getComponent ()
 173:   {
 174:     return component;
 175:   }
 176: 
 177:   /**
 178:    * Sets the default actions.
 179:    */
 180:   public void setDefaultActions (int ops)
 181:   {
 182:     actions = ops;
 183:   }
 184: 
 185:   /**
 186:    * Returns the default actions.
 187:    */
 188:   public int getDefaultActions ()
 189:   {
 190:     return actions;
 191:   }
 192: 
 193:   public void setActive (boolean active)
 194:   {
 195:     this.active = active;
 196:   }
 197: 
 198:   public boolean isActive()
 199:   {
 200:     return active;
 201:   }
 202: 
 203:   /**
 204:    * Adds a new <code>DropTargetListener</code>.
 205:    * 
 206:    * @exception TooManyListenersException Sun's JDK does not, despite
 207:    * documentation, throw this exception here when you install an additional
 208:    * <code>DropTargetListener</code>.  So to be compatible, we do the same
 209:    * thing.
 210:    */
 211:   public void addDropTargetListener (DropTargetListener dtl)
 212:     throws TooManyListenersException
 213:   {
 214:     dropTargetListener = dtl;
 215:   }
 216: 
 217:   public void removeDropTargetListener(DropTargetListener dtl)
 218:   {
 219:     // FIXME: Do we need to do something with dtl ?
 220:     dropTargetListener = null;
 221:   }
 222: 
 223:   public void dragEnter(DropTargetDragEvent dtde)
 224:   {
 225:   }
 226: 
 227:   public void dragOver(DropTargetDragEvent dtde)
 228:   {
 229:   }
 230: 
 231:   public void dropActionChanged(DropTargetDragEvent dtde)
 232:   {
 233:   }
 234: 
 235:   public void dragExit(DropTargetEvent dte)
 236:   {
 237:   }
 238: 
 239:   public void drop(DropTargetDropEvent dtde)
 240:   {
 241:   }
 242: 
 243:   public FlavorMap getFlavorMap()
 244:   {
 245:     return flavorMap;
 246:   }
 247: 
 248:   public void setFlavorMap(FlavorMap fm)
 249:   {
 250:     flavorMap = fm;
 251:   }
 252: 
 253:   public void addNotify(java.awt.peer.ComponentPeer peer)
 254:   {
 255:   }
 256: 
 257:   public void removeNotify(java.awt.peer.ComponentPeer peer)
 258:   {
 259:   }
 260: 
 261:   public DropTargetContext getDropTargetContext()
 262:   {
 263:     if (dropTargetContext == null)
 264:       dropTargetContext = createDropTargetContext ();
 265:     
 266:     return dropTargetContext;
 267:   }
 268: 
 269:   protected DropTargetContext createDropTargetContext()
 270:   {
 271:     return new DropTargetContext (this);
 272:   }
 273: 
 274:   protected DropTarget.DropTargetAutoScroller createDropTargetAutoScroller
 275:                                                        (Component c, Point p)
 276:   {
 277:     return new DropTarget.DropTargetAutoScroller (c, p);
 278:   }
 279: 
 280:   protected void initializeAutoscrolling(Point p)
 281:   {
 282:   }
 283: 
 284:   protected void updateAutoscroll(Point dragCursorLocn)
 285:   {
 286:   }
 287: 
 288:   protected void clearAutoscroll()
 289:   {
 290:   }
 291: } // class DropTarget