001 /* DragGestureRecognizer.java -- 002 Copyright (C) 2002, 2005, 2006 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.awt.Component; 042 import java.awt.Point; 043 import java.awt.event.InputEvent; 044 import java.io.IOException; 045 import java.io.ObjectInputStream; 046 import java.io.ObjectOutputStream; 047 import java.io.Serializable; 048 import java.util.ArrayList; 049 import java.util.TooManyListenersException; 050 051 /** 052 * STUBBED 053 * @author Michael Koch (konqueror@gmx.de) 054 * @author Andrew John Hughes (gnu_andrew@member.fsf.org) 055 * @since 1.2 056 */ 057 public abstract class DragGestureRecognizer implements Serializable 058 { 059 /** 060 * Compatible with JDK 1.2+. 061 */ 062 private static final long serialVersionUID = 8996673345831063337L; 063 064 protected DragSource dragSource; 065 protected Component component; 066 protected transient DragGestureListener dragGestureListener; 067 protected int sourceActions; 068 protected ArrayList<InputEvent> events = new ArrayList<InputEvent>(); 069 070 protected DragGestureRecognizer(DragSource ds, Component c, int sa, 071 DragGestureListener dgl) 072 { 073 if (ds == null) 074 throw new IllegalArgumentException(); 075 dragSource = ds; 076 component = c; 077 sourceActions = sa; 078 dragGestureListener = dgl; 079 } 080 081 protected DragGestureRecognizer(DragSource ds, Component c, int sa) 082 { 083 this(ds, c, sa, null); 084 } 085 086 protected DragGestureRecognizer(DragSource ds, Component c) 087 { 088 this(ds, c, 0, null); 089 } 090 091 protected DragGestureRecognizer(DragSource ds) 092 { 093 this(ds, null, 0, null); 094 } 095 096 protected abstract void registerListeners(); 097 098 protected abstract void unregisterListeners(); 099 100 public DragSource getDragSource() 101 { 102 return dragSource; 103 } 104 105 public Component getComponent() 106 { 107 return component; 108 } 109 110 public void setComponent(Component c) 111 { 112 component = c; 113 } 114 115 public int getSourceActions() 116 { 117 return sourceActions; 118 } 119 120 public void setSourceActions(int sa) 121 { 122 sourceActions = sa; 123 } 124 125 public InputEvent getTriggerEvent() 126 { 127 return events.size() > 0 ? events.get(0) : null; 128 } 129 130 /** 131 * Resets the recognizer. If a gesture is currently recognize, discard it. 132 */ 133 public void resetRecognizer() 134 { 135 events.clear(); 136 } 137 138 /** 139 * Register a new DragGestureListener. 140 * 141 * @exception TooManyListenersException If a DragGestureListener has already 142 * been added. 143 */ 144 public void addDragGestureListener(DragGestureListener dgl) 145 throws TooManyListenersException 146 { 147 if (dragGestureListener != null) 148 throw new TooManyListenersException(); 149 dragGestureListener = dgl; 150 } 151 152 public void removeDragGestureListener(DragGestureListener dgl) 153 { 154 if (dragGestureListener != dgl) 155 throw new IllegalArgumentException(); 156 dragGestureListener = null; 157 } 158 159 /** 160 * Fires a <code>DragGestureEvent</code> to the DragGestureListener 161 * associated with this object, if there is one. 162 */ 163 protected void fireDragGestureRecognized(int dragAction, Point p) 164 { 165 if(dragGestureListener != null) 166 dragGestureListener.dragGestureRecognized 167 (new DragGestureEvent(this, dragAction, p, events)); 168 resetRecognizer(); 169 } 170 171 protected void appendEvent(InputEvent e) 172 { 173 if (e == null) 174 return; 175 events.add(e); 176 } 177 178 private void readObject(ObjectInputStream s) 179 throws ClassNotFoundException, IOException 180 { 181 s.defaultReadObject(); 182 dragGestureListener = (DragGestureListener) s.readObject(); 183 } 184 185 private void writeObject(ObjectOutputStream s) throws IOException 186 { 187 s.defaultWriteObject(); 188 s.writeObject(dragGestureListener instanceof Serializable 189 ? dragGestureListener : null); 190 } 191 } // class DragGestureRecognizer