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| 1 | /* | ||
| 2 | * Copyright (c) 1998, 2008, Oracle and/or its affiliates. All rights reserved. | ||
| 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. | ||
| 4 | * | ||
| 5 | * This code is free software; you can redistribute it and/or modify it | ||
| 6 | * under the terms of the GNU General Public License version 2 only, as | ||
| 7 | * published by the Free Software Foundation. Oracle designates this | ||
| 8 | * particular file as subject to the "Classpath" exception as provided | ||
| 9 | * by Oracle in the LICENSE file that accompanied this code. | ||
| 10 | * | ||
| 11 | * This code is distributed in the hope that it will be useful, but WITHOUT | ||
| 12 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | ||
| 13 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | ||
| 14 | * version 2 for more details (a copy is included in the LICENSE file that | ||
| 15 | * accompanied this code). | ||
| 16 | * | ||
| 17 | * You should have received a copy of the GNU General Public License version | ||
| 18 | * 2 along with this work; if not, write to the Free Software Foundation, | ||
| 19 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. | ||
| 20 | * | ||
| 21 | * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA | ||
| 22 | * or visit www.oracle.com if you need additional information or have any | ||
| 23 | * questions. | ||
| 24 | */ | ||
| 25 | |||
| 26 | |||
| 27 | package java.awt.dnd; | ||
| 28 | |||
| 29 | import java.awt.Component; | ||
| 30 | import java.awt.Cursor; | ||
| 31 | |||
| 32 | import java.awt.Image; | ||
| 33 | import java.awt.Point; | ||
| 34 | |||
| 35 | import java.awt.event.InputEvent; | ||
| 36 | |||
| 37 | import java.awt.datatransfer.Transferable; | ||
| 38 | |||
| 39 | import java.util.EventObject; | ||
| 40 | |||
| 41 | import java.util.Collections; | ||
| 42 | import java.util.List; | ||
| 43 | import java.util.Iterator; | ||
| 44 | |||
| 45 | import java.io.IOException; | ||
| 46 | import java.io.ObjectInputStream; | ||
| 47 | import java.io.ObjectOutputStream; | ||
| 48 | |||
| 49 | |||
| 50 | /** | ||
| 51 | * A <code>DragGestureEvent</code> is passed | ||
| 52 | * to <code>DragGestureListener</code>'s | ||
| 53 | * dragGestureRecognized() method | ||
| 54 | * when a particular <code>DragGestureRecognizer</code> detects that a | ||
| 55 | * platform dependent drag initiating gesture has occurred | ||
| 56 | * on the <code>Component</code> that it is tracking. | ||
| 57 | * | ||
| 58 | * The {@code action} field of any {@code DragGestureEvent} instance should take one of the following | ||
| 59 | * values: | ||
| 60 | * <ul> | ||
| 61 | * <li> {@code DnDConstants.ACTION_COPY} | ||
| 62 | * <li> {@code DnDConstants.ACTION_MOVE} | ||
| 63 | * <li> {@code DnDConstants.ACTION_LINK} | ||
| 64 | * </ul> | ||
| 65 | * Assigning the value different from listed above will cause an unspecified behavior. | ||
| 66 | * | ||
| 67 | * @see java.awt.dnd.DragGestureRecognizer | ||
| 68 | * @see java.awt.dnd.DragGestureListener | ||
| 69 | * @see java.awt.dnd.DragSource | ||
| 70 | * @see java.awt.dnd.DnDConstants | ||
| 71 | */ | ||
| 72 | |||
| 73 | public class DragGestureEvent extends EventObject { | ||
| 74 | |||
| 75 | private static final long serialVersionUID = 9080172649166731306L; | ||
| 76 | |||
| 77 | /** | ||
| 78 | * Constructs a <code>DragGestureEvent</code> object given by the | ||
| 79 | * <code>DragGestureRecognizer</code> instance firing this event, | ||
| 80 | * an {@code act} parameter representing | ||
| 81 | * the user's preferred action, an {@code ori} parameter | ||
| 82 | * indicating the origin of the drag, and a {@code List} of | ||
| 83 | * events that comprise the gesture({@code evs} parameter). | ||
| 84 | * <P> | ||
| 85 | * @param dgr The <code>DragGestureRecognizer</code> firing this event | ||
| 86 | * @param act The user's preferred action. | ||
| 87 | * For information on allowable values, see | ||
| 88 | * the class description for {@link DragGestureEvent} | ||
| 89 | * @param ori The origin of the drag | ||
| 90 | * @param evs The <code>List</code> of events that comprise the gesture | ||
| 91 | * <P> | ||
| 92 | * @throws IllegalArgumentException if any parameter equals {@code null} | ||
| 93 | * @throws IllegalArgumentException if the act parameter does not comply with | ||
| 94 | * the values given in the class | ||
| 95 | * description for {@link DragGestureEvent} | ||
| 96 | * @see java.awt.dnd.DnDConstants | ||
| 97 | */ | ||
| 98 | |||
| 99 | public DragGestureEvent(DragGestureRecognizer dgr, int act, Point ori, | ||
| 100 | List<? extends InputEvent> evs) | ||
| 101 | { | ||
| 102 | super(dgr); | ||
| 103 | |||
| 104 | if ((component = dgr.getComponent()) == null) | ||
| 105 | throw new IllegalArgumentException("null component"); | ||
| 106 | if ((dragSource = dgr.getDragSource()) == null) | ||
| 107 | throw new IllegalArgumentException("null DragSource"); | ||
| 108 | |||
| 109 | if (evs == null || evs.isEmpty()) | ||
| 110 | throw new IllegalArgumentException("null or empty list of events"); | ||
| 111 | |||
| 112 | if (act != DnDConstants.ACTION_COPY && | ||
| 113 | act != DnDConstants.ACTION_MOVE && | ||
| 114 | act != DnDConstants.ACTION_LINK) | ||
| 115 | throw new IllegalArgumentException("bad action"); | ||
| 116 | |||
| 117 | if (ori == null) throw new IllegalArgumentException("null origin"); | ||
| 118 | |||
| 119 | events = evs; | ||
| 120 | action = act; | ||
| 121 | origin = ori; | ||
| 122 | } | ||
| 123 | |||
| 124 | /** | ||
| 125 | * Returns the source as a <code>DragGestureRecognizer</code>. | ||
| 126 | * <P> | ||
| 127 | * @return the source as a <code>DragGestureRecognizer</code> | ||
| 128 | */ | ||
| 129 | |||
| 130 | public DragGestureRecognizer getSourceAsDragGestureRecognizer() { | ||
| 131 | return (DragGestureRecognizer)getSource(); | ||
| 132 | } | ||
| 133 | |||
| 134 | /** | ||
| 135 | * Returns the <code>Component</code> associated | ||
| 136 | * with this <code>DragGestureEvent</code>. | ||
| 137 | * <P> | ||
| 138 | * @return the Component | ||
| 139 | */ | ||
| 140 | |||
| 141 | public Component getComponent() { return component; } | ||
| 142 | |||
| 143 | /** | ||
| 144 | * Returns the <code>DragSource</code>. | ||
| 145 | * <P> | ||
| 146 | * @return the <code>DragSource</code> | ||
| 147 | */ | ||
| 148 | |||
| 149 | public DragSource getDragSource() { return dragSource; } | ||
| 150 | |||
| 151 | /** | ||
| 152 | * Returns a <code>Point</code> in the coordinates | ||
| 153 | * of the <code>Component</code> over which the drag originated. | ||
| 154 | * <P> | ||
| 155 | * @return the Point where the drag originated in Component coords. | ||
| 156 | */ | ||
| 157 | |||
| 158 | public Point getDragOrigin() { | ||
| 159 | return origin; | ||
| 160 | } | ||
| 161 | |||
| 162 | /** | ||
| 163 | * Returns an <code>Iterator</code> for the events | ||
| 164 | * comprising the gesture. | ||
| 165 | * <P> | ||
| 166 | * @return an Iterator for the events comprising the gesture | ||
| 167 | */ | ||
| 168 | |||
| 169 | public Iterator<InputEvent> iterator() { return events.iterator(); } | ||
| 170 | |||
| 171 | /** | ||
| 172 | * Returns an <code>Object</code> array of the | ||
| 173 | * events comprising the drag gesture. | ||
| 174 | * <P> | ||
| 175 | * @return an array of the events comprising the gesture | ||
| 176 | */ | ||
| 177 | |||
| 178 | public Object[] toArray() { return events.toArray(); } | ||
| 179 | |||
| 180 | /** | ||
| 181 | * Returns an array of the events comprising the drag gesture. | ||
| 182 | * <P> | ||
| 183 | * @param array the array of <code>EventObject</code> sub(types) | ||
| 184 | * <P> | ||
| 185 | * @return an array of the events comprising the gesture | ||
| 186 | */ | ||
| 187 | |||
| 188 | public Object[] toArray(Object[] array) { return events.toArray(array); } | ||
| 189 | |||
| 190 | /** | ||
| 191 | * Returns an <code>int</code> representing the | ||
| 192 | * action selected by the user. | ||
| 193 | * <P> | ||
| 194 | * @return the action selected by the user | ||
| 195 | */ | ||
| 196 | |||
| 197 | public int getDragAction() { return action; } | ||
| 198 | |||
| 199 | /** | ||
| 200 | * Returns the initial event that triggered the gesture. | ||
| 201 | * <P> | ||
| 202 | * @return the first "triggering" event in the sequence of the gesture | ||
| 203 | */ | ||
| 204 | |||
| 205 | public InputEvent getTriggerEvent() { | ||
| 206 | return getSourceAsDragGestureRecognizer().getTriggerEvent(); | ||
| 207 | } | ||
| 208 | |||
| 209 | /** | ||
| 210 | * Starts the drag operation given the <code>Cursor</code> for this drag | ||
| 211 | * operation and the <code>Transferable</code> representing the source data | ||
| 212 | * for this drag operation. | ||
| 213 | * <br> | ||
| 214 | * If a <code>null</code> <code>Cursor</code> is specified no exception will | ||
| 215 | * be thrown and default drag cursors will be used instead. | ||
| 216 | * <br> | ||
| 217 | * If a <code>null</code> <code>Transferable</code> is specified | ||
| 218 | * <code>NullPointerException</code> will be thrown. | ||
| 219 | * @param dragCursor The initial {@code Cursor} for this drag operation | ||
| 220 | * or {@code null} for the default cursor handling; | ||
| 221 | * see | ||
| 222 | * <a href="DragSourceContext.html#defaultCursor">DragSourceContext</a> | ||
| 223 | * for more details on the cursor handling mechanism | ||
| 224 | * during drag and drop | ||
| 225 | * @param transferable The <code>Transferable</code> representing the source | ||
| 226 | * data for this drag operation. | ||
| 227 | * | ||
| 228 | * @throws InvalidDnDOperationException if the Drag and Drop | ||
| 229 | * system is unable to initiate a drag operation, or if the user | ||
| 230 | * attempts to start a drag while an existing drag operation is | ||
| 231 | * still executing. | ||
| 232 | * @throws NullPointerException if the {@code Transferable} is {@code null} | ||
| 233 | * @since 1.4 | ||
| 234 | */ | ||
| 235 | public void startDrag(Cursor dragCursor, Transferable transferable) | ||
| 236 | throws InvalidDnDOperationException { | ||
| 237 | dragSource.startDrag(this, dragCursor, transferable, null); | ||
| 238 | } | ||
| 239 | |||
| 240 | /** | ||
| 241 | * Starts the drag given the initial <code>Cursor</code> to display, | ||
| 242 | * the <code>Transferable</code> object, | ||
| 243 | * and the <code>DragSourceListener</code> to use. | ||
| 244 | * <P> | ||
| 245 | * @param dragCursor The initial {@code Cursor} for this drag operation | ||
| 246 | * or {@code null} for the default cursor handling; | ||
| 247 | * see | ||
| 248 | * <a href="DragSourceContext.html#defaultCursor">DragSourceContext</a> | ||
| 249 | * for more details on the cursor handling mechanism | ||
| 250 | * during drag and drop | ||
| 251 | * @param transferable The source's Transferable | ||
| 252 | * @param dsl The source's DragSourceListener | ||
| 253 | * <P> | ||
| 254 | * @throws InvalidDnDOperationException if | ||
| 255 | * the Drag and Drop system is unable to | ||
| 256 | * initiate a drag operation, or if the user | ||
| 257 | * attempts to start a drag while an existing | ||
| 258 | * drag operation is still executing. | ||
| 259 | */ | ||
| 260 | |||
| 261 | public void startDrag(Cursor dragCursor, Transferable transferable, DragSourceListener dsl) throws InvalidDnDOperationException { | ||
| 262 | dragSource.startDrag(this, dragCursor, transferable, dsl); | ||
| 263 | } | ||
| 264 | |||
| 265 | /** | ||
| 266 | * Start the drag given the initial <code>Cursor</code> to display, | ||
| 267 | * a drag <code>Image</code>, the offset of | ||
| 268 | * the <code>Image</code>, | ||
| 269 | * the <code>Transferable</code> object, and | ||
| 270 | * the <code>DragSourceListener</code> to use. | ||
| 271 | * <P> | ||
| 272 | * @param dragCursor The initial {@code Cursor} for this drag operation | ||
| 273 | * or {@code null} for the default cursor handling; | ||
| 274 | * see | ||
| 275 | * <a href="DragSourceContext.html#defaultCursor">DragSourceContext</a> | ||
| 276 | * for more details on the cursor handling mechanism | ||
| 277 | * during drag and drop | ||
| 278 | * @param dragImage The source's dragImage | ||
| 279 | * @param imageOffset The dragImage's offset | ||
| 280 | * @param transferable The source's Transferable | ||
| 281 | * @param dsl The source's DragSourceListener | ||
| 282 | * <P> | ||
| 283 | * @throws InvalidDnDOperationException if | ||
| 284 | * the Drag and Drop system is unable to | ||
| 285 | * initiate a drag operation, or if the user | ||
| 286 | * attempts to start a drag while an existing | ||
| 287 | * drag operation is still executing. | ||
| 288 | */ | ||
| 289 | |||
| 290 | public void startDrag(Cursor dragCursor, Image dragImage, Point imageOffset, Transferable transferable, DragSourceListener dsl) throws InvalidDnDOperationException { | ||
| 291 | dragSource.startDrag(this, dragCursor, dragImage, imageOffset, transferable, dsl); | ||
| 292 | } | ||
| 293 | |||
| 294 | /** | ||
| 295 | * Serializes this <code>DragGestureEvent</code>. Performs default | ||
| 296 | * serialization and then writes out this object's <code>List</code> of | ||
| 297 | * gesture events if and only if the <code>List</code> can be serialized. | ||
| 298 | * If not, <code>null</code> is written instead. In this case, a | ||
| 299 | * <code>DragGestureEvent</code> created from the resulting deserialized | ||
| 300 | * stream will contain an empty <code>List</code> of gesture events. | ||
| 301 | * | ||
| 302 | * @serialData The default serializable fields, in alphabetical order, | ||
| 303 | * followed by either a <code>List</code> instance, or | ||
| 304 | * <code>null</code>. | ||
| 305 | * @since 1.4 | ||
| 306 | */ | ||
| 307 | private void writeObject(ObjectOutputStream s) throws IOException { | ||
| 308 | s.defaultWriteObject(); | ||
| 309 | |||
| 310 | s.writeObject(SerializationTester.test(events) ? events : null); | ||
| 311 | } | ||
| 312 | |||
| 313 | /** | ||
| 314 | * Deserializes this <code>DragGestureEvent</code>. This method first | ||
| 315 | * performs default deserialization for all non-<code>transient</code> | ||
| 316 | * fields. An attempt is then made to deserialize this object's | ||
| 317 | * <code>List</code> of gesture events as well. This is first attempted | ||
| 318 | * by deserializing the field <code>events</code>, because, in releases | ||
| 319 | * prior to 1.4, a non-<code>transient</code> field of this name stored the | ||
| 320 | * <code>List</code> of gesture events. If this fails, the next object in | ||
| 321 | * the stream is used instead. If the resulting <code>List</code> is | ||
| 322 | * <code>null</code>, this object's <code>List</code> of gesture events | ||
| 323 | * is set to an empty <code>List</code>. | ||
| 324 | * | ||
| 325 | * @since 1.4 | ||
| 326 | */ | ||
| 327 | private void readObject(ObjectInputStream s) | ||
| 328 | throws ClassNotFoundException, IOException | ||
| 329 | { | ||
| 330 | ObjectInputStream.GetField f = s.readFields(); | ||
| 331 | |||
| 332 | dragSource = (DragSource)f.get("dragSource", null); | ||
| 333 | component = (Component)f.get("component", null); | ||
| 334 | origin = (Point)f.get("origin", null); | ||
| 335 | action = f.get("action", 0); | ||
| 336 | |||
| 337 | // Pre-1.4 support. 'events' was previously non-transient | ||
| 338 | try { | ||
| 339 | events = (List)f.get("events", null); | ||
| 340 | } catch (IllegalArgumentException e) { | ||
| 341 | // 1.4-compatible byte stream. 'events' was written explicitly | ||
| 342 | events = (List)s.readObject(); | ||
| 343 | } | ||
| 344 | |||
| 345 | // Implementation assumes 'events' is never null. | ||
| 346 | if (events == null) { | ||
| 347 | events = Collections.EMPTY_LIST; | ||
| 348 | } | ||
| 349 | } | ||
| 350 | |||
| 351 | /* | ||
| 352 | * fields | ||
| 353 | */ | ||
| 354 | |||
| 355 | private transient List events; | ||
| 356 | |||
| 357 | /** | ||
| 358 | * The DragSource associated with this DragGestureEvent. | ||
| 359 | * | ||
| 360 | * @serial | ||
| 361 | */ | ||
| 362 | private DragSource dragSource; | ||
| 363 | |||
| 364 | /** | ||
| 365 | * The Component associated with this DragGestureEvent. | ||
| 366 | * | ||
| 367 | * @serial | ||
| 368 | */ | ||
| 369 | private Component component; | ||
| 370 | |||
| 371 | /** | ||
| 372 | * The origin of the drag. | ||
| 373 | * | ||
| 374 | * @serial | ||
| 375 | */ | ||
| 376 | private Point origin; | ||
| 377 | |||
| 378 | /** | ||
| 379 | * The user's preferred action. | ||
| 380 | * | ||
| 381 | * @serial | ||
| 382 | */ | ||
| 383 | private int action; | ||
| 384 | } | ||