001    /* DragSourceListener.java -- listen to events during the drag
002       Copyright (C) 2002, 2005  Free Software Foundation, Inc.
003    
004    This file is part of GNU Classpath.
005    
006    GNU Classpath is free software; you can redistribute it and/or modify
007    it under the terms of the GNU General Public License as published by
008    the Free Software Foundation; either version 2, or (at your option)
009    any later version.
010    
011    GNU Classpath is distributed in the hope that it will be useful, but
012    WITHOUT ANY WARRANTY; without even the implied warranty of
013    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014    General Public License for more details.
015    
016    You should have received a copy of the GNU General Public License
017    along with GNU Classpath; see the file COPYING.  If not, write to the
018    Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
019    02110-1301 USA.
020    
021    Linking this library statically or dynamically with other modules is
022    making a combined work based on this library.  Thus, the terms and
023    conditions of the GNU General Public License cover the whole
024    combination.
025    
026    As a special exception, the copyright holders of this library give you
027    permission to link this library with independent modules to produce an
028    executable, regardless of the license terms of these independent
029    modules, and to copy and distribute the resulting executable under
030    terms of your choice, provided that you also meet, for each linked
031    independent module, the terms and conditions of the license of that
032    module.  An independent module is a module which is not derived from
033    or based on this library.  If you modify this library, you may extend
034    this exception to your version of the library, but you are not
035    obligated to do so.  If you do not wish to do so, delete this
036    exception statement from your version. */
037    
038    
039    package java.awt.dnd;
040    
041    import java.util.EventListener;
042    
043    /**
044     * This class allows an object to listen for drag and drop events. It can
045     * be used to provide appropriate feedback for "drag over" actions. You can
046     * also use a <code>DragSourceAdapter</code> to filter the events you are
047     * interested in.
048     *
049     * @author Eric Blake (ebb9@email.byu.edu)
050     * @since 1.2
051     * @status updated to 1.4
052     */
053    public interface DragSourceListener extends EventListener
054    {
055      /**
056       * Called when the cursor hotspot enters a drop site which will accept the
057       * drag.
058       *
059       * @param e the drag source drag event
060       */
061      void dragEnter(DragSourceDragEvent e);
062    
063      /**
064       * Called when the cursor hotspot moves inside of a drop site which will
065       * accept the drag.
066       *
067       * @param e the drag source drag event
068       */
069      void dragOver(DragSourceDragEvent e);
070    
071      /**
072       * Called when the user modifies the drop gesture. This is often the case
073       * when additional mouse or key events are received during the drag.
074       *
075       * @param e the drag source drag event
076       */
077      void dropActionChanged(DragSourceDragEvent e);
078    
079      /**
080       * Called when the cursor hotspot moves outside of a drop site which will
081       * accept the drag. This could also happen if the drop site is no longer
082       * active, or no longer accepts the drag.
083       *
084       * @param e the drag source drag event
085       */
086      void dragExit(DragSourceEvent e);
087    
088      /**
089       * Called when the drag and drop operation is complete. After this event,
090       * <code>getDropSuccess</code> of the event is valid, and
091       * <code>getDropAction</code> holds the action requested by the drop site.
092       * Furthermore, the <code>DragSourceContext</code> is invalidated.
093       *
094       * @param e the drag source drag event
095       */
096      void dragDropEnd(DragSourceDropEvent e);
097    } // interface DragSourceListener