001/* DragSourceListener.java -- listen to events during the drag
002   Copyright (C) 2002, 2005  Free Software Foundation, Inc.
003
004This file is part of GNU Classpath.
005
006GNU Classpath is free software; you can redistribute it and/or modify
007it under the terms of the GNU General Public License as published by
008the Free Software Foundation; either version 2, or (at your option)
009any later version.
010
011GNU Classpath is distributed in the hope that it will be useful, but
012WITHOUT ANY WARRANTY; without even the implied warranty of
013MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014General Public License for more details.
015
016You should have received a copy of the GNU General Public License
017along with GNU Classpath; see the file COPYING.  If not, write to the
018Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
01902110-1301 USA.
020
021Linking this library statically or dynamically with other modules is
022making a combined work based on this library.  Thus, the terms and
023conditions of the GNU General Public License cover the whole
024combination.
025
026As a special exception, the copyright holders of this library give you
027permission to link this library with independent modules to produce an
028executable, regardless of the license terms of these independent
029modules, and to copy and distribute the resulting executable under
030terms of your choice, provided that you also meet, for each linked
031independent module, the terms and conditions of the license of that
032module.  An independent module is a module which is not derived from
033or based on this library.  If you modify this library, you may extend
034this exception to your version of the library, but you are not
035obligated to do so.  If you do not wish to do so, delete this
036exception statement from your version. */
037
038
039package java.awt.dnd;
040
041import 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 */
053public 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