J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 1997-2006 Sun Microsystems, Inc. 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. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any questions. |
| 24 | */ |
| 25 | |
| 26 | package java.awt.dnd; |
| 27 | |
| 28 | import java.awt.Component; |
| 29 | import java.awt.Cursor; |
| 30 | import java.awt.GraphicsEnvironment; |
| 31 | import java.awt.HeadlessException; |
| 32 | import java.awt.Image; |
| 33 | import java.awt.Point; |
| 34 | import java.awt.Toolkit; |
| 35 | import java.awt.datatransfer.FlavorMap; |
| 36 | import java.awt.datatransfer.SystemFlavorMap; |
| 37 | import java.awt.datatransfer.Transferable; |
| 38 | import java.awt.dnd.peer.DragSourceContextPeer; |
| 39 | import java.io.IOException; |
| 40 | import java.io.ObjectInputStream; |
| 41 | import java.io.ObjectOutputStream; |
| 42 | import java.io.Serializable; |
| 43 | import java.security.AccessController; |
| 44 | import java.util.EventListener; |
| 45 | import sun.awt.dnd.SunDragSourceContextPeer; |
| 46 | import sun.security.action.GetIntegerAction; |
| 47 | |
| 48 | |
| 49 | /** |
| 50 | * The <code>DragSource</code> is the entity responsible |
| 51 | * for the initiation of the Drag |
| 52 | * and Drop operation, and may be used in a number of scenarios: |
| 53 | * <UL> |
| 54 | * <LI>1 default instance per JVM for the lifetime of that JVM. |
| 55 | * <LI>1 instance per class of potential Drag Initiator object (e.g |
| 56 | * TextField). [implementation dependent] |
| 57 | * <LI>1 per instance of a particular |
| 58 | * <code>Component</code>, or application specific |
| 59 | * object associated with a <code>Component</code> |
| 60 | * instance in the GUI. [implementation dependent] |
| 61 | * <LI>Some other arbitrary association. [implementation dependent] |
| 62 | *</UL> |
| 63 | * |
| 64 | * Once the <code>DragSource</code> is |
| 65 | * obtained, a <code>DragGestureRecognizer</code> should |
| 66 | * also be obtained to associate the <code>DragSource</code> |
| 67 | * with a particular |
| 68 | * <code>Component</code>. |
| 69 | * <P> |
| 70 | * The initial interpretation of the user's gesture, |
| 71 | * and the subsequent starting of the drag operation |
| 72 | * are the responsibility of the implementing |
| 73 | * <code>Component</code>, which is usually |
| 74 | * implemented by a <code>DragGestureRecognizer</code>. |
| 75 | *<P> |
| 76 | * When a drag gesture occurs, the |
| 77 | * <code>DragSource</code>'s |
| 78 | * startDrag() method shall be |
| 79 | * invoked in order to cause processing |
| 80 | * of the user's navigational |
| 81 | * gestures and delivery of Drag and Drop |
| 82 | * protocol notifications. A |
| 83 | * <code>DragSource</code> shall only |
| 84 | * permit a single Drag and Drop operation to be |
| 85 | * current at any one time, and shall |
| 86 | * reject any further startDrag() requests |
| 87 | * by throwing an <code>IllegalDnDOperationException</code> |
| 88 | * until such time as the extant operation is complete. |
| 89 | * <P> |
| 90 | * The startDrag() method invokes the |
| 91 | * createDragSourceContext() method to |
| 92 | * instantiate an appropriate |
| 93 | * <code>DragSourceContext</code> |
| 94 | * and associate the <code>DragSourceContextPeer</code> |
| 95 | * with that. |
| 96 | * <P> |
| 97 | * If the Drag and Drop System is |
| 98 | * unable to initiate a drag operation for |
| 99 | * some reason, the startDrag() method throws |
| 100 | * a <code>java.awt.dnd.InvalidDnDOperationException</code> |
| 101 | * to signal such a condition. Typically this |
| 102 | * exception is thrown when the underlying platform |
| 103 | * system is either not in a state to |
| 104 | * initiate a drag, or the parameters specified are invalid. |
| 105 | * <P> |
| 106 | * Note that during the drag, the |
| 107 | * set of operations exposed by the source |
| 108 | * at the start of the drag operation may not change |
| 109 | * until the operation is complete. |
| 110 | * The operation(s) are constant for the |
| 111 | * duration of the operation with respect to the |
| 112 | * <code>DragSource</code>. |
| 113 | * |
| 114 | * @since 1.2 |
| 115 | */ |
| 116 | |
| 117 | public class DragSource implements Serializable { |
| 118 | |
| 119 | private static final long serialVersionUID = 6236096958971414066L; |
| 120 | |
| 121 | /* |
| 122 | * load a system default cursor |
| 123 | */ |
| 124 | |
| 125 | private static Cursor load(String name) { |
| 126 | if (GraphicsEnvironment.isHeadless()) { |
| 127 | return null; |
| 128 | } |
| 129 | |
| 130 | try { |
| 131 | return (Cursor)Toolkit.getDefaultToolkit().getDesktopProperty(name); |
| 132 | } catch (Exception e) { |
| 133 | e.printStackTrace(); |
| 134 | |
| 135 | throw new RuntimeException("failed to load system cursor: " + name + " : " + e.getMessage()); |
| 136 | } |
| 137 | } |
| 138 | |
| 139 | |
| 140 | /** |
| 141 | * The default <code>Cursor</code> to use with a copy operation indicating |
| 142 | * that a drop is currently allowed. <code>null</code> if |
| 143 | * <code>GraphicsEnvironment.isHeadless()</code> returns <code>true</code>. |
| 144 | * |
| 145 | * @see java.awt.GraphicsEnvironment#isHeadless |
| 146 | */ |
| 147 | public static final Cursor DefaultCopyDrop = |
| 148 | load("DnD.Cursor.CopyDrop"); |
| 149 | |
| 150 | /** |
| 151 | * The default <code>Cursor</code> to use with a move operation indicating |
| 152 | * that a drop is currently allowed. <code>null</code> if |
| 153 | * <code>GraphicsEnvironment.isHeadless()</code> returns <code>true</code>. |
| 154 | * |
| 155 | * @see java.awt.GraphicsEnvironment#isHeadless |
| 156 | */ |
| 157 | public static final Cursor DefaultMoveDrop = |
| 158 | load("DnD.Cursor.MoveDrop"); |
| 159 | |
| 160 | /** |
| 161 | * The default <code>Cursor</code> to use with a link operation indicating |
| 162 | * that a drop is currently allowed. <code>null</code> if |
| 163 | * <code>GraphicsEnvironment.isHeadless()</code> returns <code>true</code>. |
| 164 | * |
| 165 | * @see java.awt.GraphicsEnvironment#isHeadless |
| 166 | */ |
| 167 | public static final Cursor DefaultLinkDrop = |
| 168 | load("DnD.Cursor.LinkDrop"); |
| 169 | |
| 170 | /** |
| 171 | * The default <code>Cursor</code> to use with a copy operation indicating |
| 172 | * that a drop is currently not allowed. <code>null</code> if |
| 173 | * <code>GraphicsEnvironment.isHeadless()</code> returns <code>true</code>. |
| 174 | * |
| 175 | * @see java.awt.GraphicsEnvironment#isHeadless |
| 176 | */ |
| 177 | public static final Cursor DefaultCopyNoDrop = |
| 178 | load("DnD.Cursor.CopyNoDrop"); |
| 179 | |
| 180 | /** |
| 181 | * The default <code>Cursor</code> to use with a move operation indicating |
| 182 | * that a drop is currently not allowed. <code>null</code> if |
| 183 | * <code>GraphicsEnvironment.isHeadless()</code> returns <code>true</code>. |
| 184 | * |
| 185 | * @see java.awt.GraphicsEnvironment#isHeadless |
| 186 | */ |
| 187 | public static final Cursor DefaultMoveNoDrop = |
| 188 | load("DnD.Cursor.MoveNoDrop"); |
| 189 | |
| 190 | /** |
| 191 | * The default <code>Cursor</code> to use with a link operation indicating |
| 192 | * that a drop is currently not allowed. <code>null</code> if |
| 193 | * <code>GraphicsEnvironment.isHeadless()</code> returns <code>true</code>. |
| 194 | * |
| 195 | * @see java.awt.GraphicsEnvironment#isHeadless |
| 196 | */ |
| 197 | public static final Cursor DefaultLinkNoDrop = |
| 198 | load("DnD.Cursor.LinkNoDrop"); |
| 199 | |
| 200 | private static final DragSource dflt = |
| 201 | (GraphicsEnvironment.isHeadless()) ? null : new DragSource(); |
| 202 | |
| 203 | /** |
| 204 | * Internal constants for serialization. |
| 205 | */ |
| 206 | static final String dragSourceListenerK = "dragSourceL"; |
| 207 | static final String dragSourceMotionListenerK = "dragSourceMotionL"; |
| 208 | |
| 209 | /** |
| 210 | * Gets the <code>DragSource</code> object associated with |
| 211 | * the underlying platform. |
| 212 | * |
| 213 | * @return the platform DragSource |
| 214 | * @exception HeadlessException if GraphicsEnvironment.isHeadless() |
| 215 | * returns true |
| 216 | * @see java.awt.GraphicsEnvironment#isHeadless |
| 217 | */ |
| 218 | public static DragSource getDefaultDragSource() { |
| 219 | if (GraphicsEnvironment.isHeadless()) { |
| 220 | throw new HeadlessException(); |
| 221 | } else { |
| 222 | return dflt; |
| 223 | } |
| 224 | } |
| 225 | |
| 226 | /** |
| 227 | * Reports |
| 228 | * whether or not drag |
| 229 | * <code>Image</code> support |
| 230 | * is available on the underlying platform. |
| 231 | * <P> |
| 232 | * @return if the Drag Image support is available on this platform |
| 233 | */ |
| 234 | |
| 235 | public static boolean isDragImageSupported() { |
| 236 | Toolkit t = Toolkit.getDefaultToolkit(); |
| 237 | |
| 238 | Boolean supported; |
| 239 | |
| 240 | try { |
| 241 | supported = (Boolean)Toolkit.getDefaultToolkit().getDesktopProperty("DnD.isDragImageSupported"); |
| 242 | |
| 243 | return supported.booleanValue(); |
| 244 | } catch (Exception e) { |
| 245 | return false; |
| 246 | } |
| 247 | } |
| 248 | |
| 249 | /** |
| 250 | * Creates a new <code>DragSource</code>. |
| 251 | * |
| 252 | * @exception HeadlessException if GraphicsEnvironment.isHeadless() |
| 253 | * returns true |
| 254 | * @see java.awt.GraphicsEnvironment#isHeadless |
| 255 | */ |
| 256 | public DragSource() throws HeadlessException { |
| 257 | if (GraphicsEnvironment.isHeadless()) { |
| 258 | throw new HeadlessException(); |
| 259 | } |
| 260 | } |
| 261 | |
| 262 | /** |
| 263 | * Start a drag, given the <code>DragGestureEvent</code> |
| 264 | * that initiated the drag, the initial |
| 265 | * <code>Cursor</code> to use, |
| 266 | * the <code>Image</code> to drag, |
| 267 | * the offset of the <code>Image</code> origin |
| 268 | * from the hotspot of the <code>Cursor</code> at |
| 269 | * the instant of the trigger, |
| 270 | * the <code>Transferable</code> subject data |
| 271 | * of the drag, the <code>DragSourceListener</code>, |
| 272 | * and the <code>FlavorMap</code>. |
| 273 | * <P> |
| 274 | * @param trigger the <code>DragGestureEvent</code> that initiated the drag |
| 275 | * @param dragCursor the initial {@code Cursor} for this drag operation |
| 276 | * or {@code null} for the default cursor handling; |
| 277 | * see <a href="DragSourceContext.html#defaultCursor">DragSourceContext</a> |
| 278 | * for more details on the cursor handling mechanism during drag and drop |
| 279 | * @param dragImage the image to drag or {@code null} |
| 280 | * @param imageOffset the offset of the <code>Image</code> origin from the hotspot |
| 281 | * of the <code>Cursor</code> at the instant of the trigger |
| 282 | * @param transferable the subject data of the drag |
| 283 | * @param dsl the <code>DragSourceListener</code> |
| 284 | * @param flavorMap the <code>FlavorMap</code> to use, or <code>null</code> |
| 285 | * <P> |
| 286 | * @throws java.awt.dnd.InvalidDnDOperationException |
| 287 | * if the Drag and Drop |
| 288 | * system is unable to initiate a drag operation, or if the user |
| 289 | * attempts to start a drag while an existing drag operation |
| 290 | * is still executing |
| 291 | */ |
| 292 | |
| 293 | public void startDrag(DragGestureEvent trigger, |
| 294 | Cursor dragCursor, |
| 295 | Image dragImage, |
| 296 | Point imageOffset, |
| 297 | Transferable transferable, |
| 298 | DragSourceListener dsl, |
| 299 | FlavorMap flavorMap) throws InvalidDnDOperationException { |
| 300 | |
| 301 | SunDragSourceContextPeer.setDragDropInProgress(true); |
| 302 | |
| 303 | try { |
| 304 | if (flavorMap != null) this.flavorMap = flavorMap; |
| 305 | |
| 306 | DragSourceContextPeer dscp = Toolkit.getDefaultToolkit().createDragSourceContextPeer(trigger); |
| 307 | |
| 308 | DragSourceContext dsc = createDragSourceContext(dscp, |
| 309 | trigger, |
| 310 | dragCursor, |
| 311 | dragImage, |
| 312 | imageOffset, |
| 313 | transferable, |
| 314 | dsl |
| 315 | ); |
| 316 | |
| 317 | if (dsc == null) { |
| 318 | throw new InvalidDnDOperationException(); |
| 319 | } |
| 320 | |
| 321 | dscp.startDrag(dsc, dsc.getCursor(), dragImage, imageOffset); // may throw |
| 322 | } catch (RuntimeException e) { |
| 323 | SunDragSourceContextPeer.setDragDropInProgress(false); |
| 324 | throw e; |
| 325 | } |
| 326 | } |
| 327 | |
| 328 | /** |
| 329 | * Start a drag, given the <code>DragGestureEvent</code> |
| 330 | * that initiated the drag, the initial |
| 331 | * <code>Cursor</code> to use, |
| 332 | * the <code>Transferable</code> subject data |
| 333 | * of the drag, the <code>DragSourceListener</code>, |
| 334 | * and the <code>FlavorMap</code>. |
| 335 | * <P> |
| 336 | * @param trigger the <code>DragGestureEvent</code> that |
| 337 | * initiated the drag |
| 338 | * @param dragCursor the initial {@code Cursor} for this drag operation |
| 339 | * or {@code null} for the default cursor handling; |
| 340 | * see <a href="DragSourceContext.html#defaultCursor">DragSourceContext</a> |
| 341 | * for more details on the cursor handling mechanism during drag and drop |
| 342 | * @param transferable the subject data of the drag |
| 343 | * @param dsl the <code>DragSourceListener</code> |
| 344 | * @param flavorMap the <code>FlavorMap</code> to use or <code>null</code> |
| 345 | * <P> |
| 346 | * @throws java.awt.dnd.InvalidDnDOperationException |
| 347 | * if the Drag and Drop |
| 348 | * system is unable to initiate a drag operation, or if the user |
| 349 | * attempts to start a drag while an existing drag operation |
| 350 | * is still executing |
| 351 | */ |
| 352 | |
| 353 | public void startDrag(DragGestureEvent trigger, |
| 354 | Cursor dragCursor, |
| 355 | Transferable transferable, |
| 356 | DragSourceListener dsl, |
| 357 | FlavorMap flavorMap) throws InvalidDnDOperationException { |
| 358 | startDrag(trigger, dragCursor, null, null, transferable, dsl, flavorMap); |
| 359 | } |
| 360 | |
| 361 | /** |
| 362 | * Start a drag, given the <code>DragGestureEvent</code> |
| 363 | * that initiated the drag, the initial <code>Cursor</code> |
| 364 | * to use, |
| 365 | * the <code>Image</code> to drag, |
| 366 | * the offset of the <code>Image</code> origin |
| 367 | * from the hotspot of the <code>Cursor</code> |
| 368 | * at the instant of the trigger, |
| 369 | * the subject data of the drag, and |
| 370 | * the <code>DragSourceListener</code>. |
| 371 | * <P> |
| 372 | * @param trigger the <code>DragGestureEvent</code> that initiated the drag |
| 373 | * @param dragCursor the initial {@code Cursor} for this drag operation |
| 374 | * or {@code null} for the default cursor handling; |
| 375 | * see <a href="DragSourceContext.html#defaultCursor">DragSourceContext</a> |
| 376 | * for more details on the cursor handling mechanism during drag and drop |
| 377 | * @param dragImage the <code>Image</code> to drag or <code>null</code> |
| 378 | * @param dragOffset the offset of the <code>Image</code> origin from the hotspot |
| 379 | * of the <code>Cursor</code> at the instant of the trigger |
| 380 | * @param transferable the subject data of the drag |
| 381 | * @param dsl the <code>DragSourceListener</code> |
| 382 | * <P> |
| 383 | * @throws java.awt.dnd.InvalidDnDOperationException |
| 384 | * if the Drag and Drop |
| 385 | * system is unable to initiate a drag operation, or if the user |
| 386 | * attempts to start a drag while an existing drag operation |
| 387 | * is still executing |
| 388 | */ |
| 389 | |
| 390 | public void startDrag(DragGestureEvent trigger, |
| 391 | Cursor dragCursor, |
| 392 | Image dragImage, |
| 393 | Point dragOffset, |
| 394 | Transferable transferable, |
| 395 | DragSourceListener dsl) throws InvalidDnDOperationException { |
| 396 | startDrag(trigger, dragCursor, dragImage, dragOffset, transferable, dsl, null); |
| 397 | } |
| 398 | |
| 399 | /** |
| 400 | * Start a drag, given the <code>DragGestureEvent</code> |
| 401 | * that initiated the drag, the initial |
| 402 | * <code>Cursor</code> to |
| 403 | * use, |
| 404 | * the <code>Transferable</code> subject data |
| 405 | * of the drag, and the <code>DragSourceListener</code>. |
| 406 | * <P> |
| 407 | * @param trigger the <code>DragGestureEvent</code> that initiated the drag |
| 408 | * @param dragCursor the initial {@code Cursor} for this drag operation |
| 409 | * or {@code null} for the default cursor handling; |
| 410 | * see <a href="DragSourceContext.html#defaultCursor">DragSourceContext</a> class |
| 411 | * for more details on the cursor handling mechanism during drag and drop |
| 412 | * @param transferable the subject data of the drag |
| 413 | * @param dsl the <code>DragSourceListener</code> |
| 414 | * <P> |
| 415 | * @throws java.awt.dnd.InvalidDnDOperationException |
| 416 | * if the Drag and Drop |
| 417 | * system is unable to initiate a drag operation, or if the user |
| 418 | * attempts to start a drag while an existing drag operation |
| 419 | * is still executing |
| 420 | */ |
| 421 | |
| 422 | public void startDrag(DragGestureEvent trigger, |
| 423 | Cursor dragCursor, |
| 424 | Transferable transferable, |
| 425 | DragSourceListener dsl) throws InvalidDnDOperationException { |
| 426 | startDrag(trigger, dragCursor, null, null, transferable, dsl, null); |
| 427 | } |
| 428 | |
| 429 | /** |
| 430 | * Creates the {@code DragSourceContext} to handle the current drag |
| 431 | * operation. |
| 432 | * <p> |
| 433 | * To incorporate a new <code>DragSourceContext</code> |
| 434 | * subclass, subclass <code>DragSource</code> and |
| 435 | * override this method. |
| 436 | * <p> |
| 437 | * If <code>dragImage</code> is <code>null</code>, no image is used |
| 438 | * to represent the drag over feedback for this drag operation, but |
| 439 | * <code>NullPointerException</code> is not thrown. |
| 440 | * <p> |
| 441 | * If <code>dsl</code> is <code>null</code>, no drag source listener |
| 442 | * is registered with the created <code>DragSourceContext</code>, |
| 443 | * but <code>NullPointerException</code> is not thrown. |
| 444 | * |
| 445 | * @param dscp The <code>DragSourceContextPeer</code> for this drag |
| 446 | * @param dgl The <code>DragGestureEvent</code> that triggered the |
| 447 | * drag |
| 448 | * @param dragCursor The initial {@code Cursor} for this drag operation |
| 449 | * or {@code null} for the default cursor handling; |
| 450 | * see <a href="DragSourceContext.html#defaultCursor">DragSourceContext</a> class |
| 451 | * for more details on the cursor handling mechanism during drag and drop |
| 452 | * @param dragImage The <code>Image</code> to drag or <code>null</code> |
| 453 | * @param imageOffset The offset of the <code>Image</code> origin from the |
| 454 | * hotspot of the cursor at the instant of the trigger |
| 455 | * @param t The subject data of the drag |
| 456 | * @param dsl The <code>DragSourceListener</code> |
| 457 | * |
| 458 | * @return the <code>DragSourceContext</code> |
| 459 | * |
| 460 | * @throws NullPointerException if <code>dscp</code> is <code>null</code> |
| 461 | * @throws NullPointerException if <code>dgl</code> is <code>null</code> |
| 462 | * @throws NullPointerException if <code>dragImage</code> is not |
| 463 | * <code>null</code> and <code>imageOffset</code> is <code>null</code> |
| 464 | * @throws NullPointerException if <code>t</code> is <code>null</code> |
| 465 | * @throws IllegalArgumentException if the <code>Component</code> |
| 466 | * associated with the trigger event is <code>null</code>. |
| 467 | * @throws IllegalArgumentException if the <code>DragSource</code> for the |
| 468 | * trigger event is <code>null</code>. |
| 469 | * @throws IllegalArgumentException if the drag action for the |
| 470 | * trigger event is <code>DnDConstants.ACTION_NONE</code>. |
| 471 | * @throws IllegalArgumentException if the source actions for the |
| 472 | * <code>DragGestureRecognizer</code> associated with the trigger |
| 473 | * event are equal to <code>DnDConstants.ACTION_NONE</code>. |
| 474 | */ |
| 475 | |
| 476 | protected DragSourceContext createDragSourceContext(DragSourceContextPeer dscp, DragGestureEvent dgl, Cursor dragCursor, Image dragImage, Point imageOffset, Transferable t, DragSourceListener dsl) { |
| 477 | return new DragSourceContext(dscp, dgl, dragCursor, dragImage, imageOffset, t, dsl); |
| 478 | } |
| 479 | |
| 480 | /** |
| 481 | * This method returns the |
| 482 | * <code>FlavorMap</code> for this <code>DragSource</code>. |
| 483 | * <P> |
| 484 | * @return the <code>FlavorMap</code> for this <code>DragSource</code> |
| 485 | */ |
| 486 | |
| 487 | public FlavorMap getFlavorMap() { return flavorMap; } |
| 488 | |
| 489 | /** |
| 490 | * Creates a new <code>DragGestureRecognizer</code> |
| 491 | * that implements the specified |
| 492 | * abstract subclass of |
| 493 | * <code>DragGestureRecognizer</code>, and |
| 494 | * sets the specified <code>Component</code> |
| 495 | * and <code>DragGestureListener</code> on |
| 496 | * the newly created object. |
| 497 | * <P> |
| 498 | * @param recognizerAbstractClass the requested abstract type |
| 499 | * @param actions the permitted source drag actions |
| 500 | * @param c the <code>Component</code> target |
| 501 | * @param dgl the <code>DragGestureListener</code> to notify |
| 502 | * <P> |
| 503 | * @return the new <code>DragGestureRecognizer</code> or <code>null</code> |
| 504 | * if the <code>Toolkit.createDragGestureRecognizer</code> method |
| 505 | * has no implementation available for |
| 506 | * the requested <code>DragGestureRecognizer</code> |
| 507 | * subclass and returns <code>null</code> |
| 508 | */ |
| 509 | |
| 510 | public <T extends DragGestureRecognizer> T |
| 511 | createDragGestureRecognizer(Class<T> recognizerAbstractClass, |
| 512 | Component c, int actions, |
| 513 | DragGestureListener dgl) |
| 514 | { |
| 515 | return Toolkit.getDefaultToolkit().createDragGestureRecognizer(recognizerAbstractClass, this, c, actions, dgl); |
| 516 | } |
| 517 | |
| 518 | |
| 519 | /** |
| 520 | * Creates a new <code>DragGestureRecognizer</code> |
| 521 | * that implements the default |
| 522 | * abstract subclass of <code>DragGestureRecognizer</code> |
| 523 | * for this <code>DragSource</code>, |
| 524 | * and sets the specified <code>Component</code> |
| 525 | * and <code>DragGestureListener</code> on the |
| 526 | * newly created object. |
| 527 | * |
| 528 | * For this <code>DragSource</code> |
| 529 | * the default is <code>MouseDragGestureRecognizer</code>. |
| 530 | * <P> |
| 531 | * @param c the <code>Component</code> target for the recognizer |
| 532 | * @param actions the permitted source actions |
| 533 | * @param dgl the <code>DragGestureListener</code> to notify |
| 534 | * <P> |
| 535 | * @return the new <code>DragGestureRecognizer</code> or <code>null</code> |
| 536 | * if the <code>Toolkit.createDragGestureRecognizer</code> method |
| 537 | * has no implementation available for |
| 538 | * the requested <code>DragGestureRecognizer</code> |
| 539 | * subclass and returns <code>null</code> |
| 540 | */ |
| 541 | |
| 542 | public DragGestureRecognizer createDefaultDragGestureRecognizer(Component c, int actions, DragGestureListener dgl) { |
| 543 | return Toolkit.getDefaultToolkit().createDragGestureRecognizer(MouseDragGestureRecognizer.class, this, c, actions, dgl); |
| 544 | } |
| 545 | |
| 546 | /** |
| 547 | * Adds the specified <code>DragSourceListener</code> to this |
| 548 | * <code>DragSource</code> to receive drag source events during drag |
| 549 | * operations intiated with this <code>DragSource</code>. |
| 550 | * If a <code>null</code> listener is specified, no action is taken and no |
| 551 | * exception is thrown. |
| 552 | * |
| 553 | * @param dsl the <code>DragSourceListener</code> to add |
| 554 | * |
| 555 | * @see #removeDragSourceListener |
| 556 | * @see #getDragSourceListeners |
| 557 | * @since 1.4 |
| 558 | */ |
| 559 | public void addDragSourceListener(DragSourceListener dsl) { |
| 560 | if (dsl != null) { |
| 561 | synchronized (this) { |
| 562 | listener = DnDEventMulticaster.add(listener, dsl); |
| 563 | } |
| 564 | } |
| 565 | } |
| 566 | |
| 567 | /** |
| 568 | * Removes the specified <code>DragSourceListener</code> from this |
| 569 | * <code>DragSource</code>. |
| 570 | * If a <code>null</code> listener is specified, no action is taken and no |
| 571 | * exception is thrown. |
| 572 | * If the listener specified by the argument was not previously added to |
| 573 | * this <code>DragSource</code>, no action is taken and no exception |
| 574 | * is thrown. |
| 575 | * |
| 576 | * @param dsl the <code>DragSourceListener</code> to remove |
| 577 | * |
| 578 | * @see #addDragSourceListener |
| 579 | * @see #getDragSourceListeners |
| 580 | * @since 1.4 |
| 581 | */ |
| 582 | public void removeDragSourceListener(DragSourceListener dsl) { |
| 583 | if (dsl != null) { |
| 584 | synchronized (this) { |
| 585 | listener = DnDEventMulticaster.remove(listener, dsl); |
| 586 | } |
| 587 | } |
| 588 | } |
| 589 | |
| 590 | /** |
| 591 | * Gets all the <code>DragSourceListener</code>s |
| 592 | * registered with this <code>DragSource</code>. |
| 593 | * |
| 594 | * @return all of this <code>DragSource</code>'s |
| 595 | * <code>DragSourceListener</code>s or an empty array if no |
| 596 | * such listeners are currently registered |
| 597 | * |
| 598 | * @see #addDragSourceListener |
| 599 | * @see #removeDragSourceListener |
| 600 | * @since 1.4 |
| 601 | */ |
| 602 | public DragSourceListener[] getDragSourceListeners() { |
| 603 | return (DragSourceListener[])getListeners(DragSourceListener.class); |
| 604 | } |
| 605 | |
| 606 | /** |
| 607 | * Adds the specified <code>DragSourceMotionListener</code> to this |
| 608 | * <code>DragSource</code> to receive drag motion events during drag |
| 609 | * operations intiated with this <code>DragSource</code>. |
| 610 | * If a <code>null</code> listener is specified, no action is taken and no |
| 611 | * exception is thrown. |
| 612 | * |
| 613 | * @param dsml the <code>DragSourceMotionListener</code> to add |
| 614 | * |
| 615 | * @see #removeDragSourceMotionListener |
| 616 | * @see #getDragSourceMotionListeners |
| 617 | * @since 1.4 |
| 618 | */ |
| 619 | public void addDragSourceMotionListener(DragSourceMotionListener dsml) { |
| 620 | if (dsml != null) { |
| 621 | synchronized (this) { |
| 622 | motionListener = DnDEventMulticaster.add(motionListener, dsml); |
| 623 | } |
| 624 | } |
| 625 | } |
| 626 | |
| 627 | /** |
| 628 | * Removes the specified <code>DragSourceMotionListener</code> from this |
| 629 | * <code>DragSource</code>. |
| 630 | * If a <code>null</code> listener is specified, no action is taken and no |
| 631 | * exception is thrown. |
| 632 | * If the listener specified by the argument was not previously added to |
| 633 | * this <code>DragSource</code>, no action is taken and no exception |
| 634 | * is thrown. |
| 635 | * |
| 636 | * @param dsml the <code>DragSourceMotionListener</code> to remove |
| 637 | * |
| 638 | * @see #addDragSourceMotionListener |
| 639 | * @see #getDragSourceMotionListeners |
| 640 | * @since 1.4 |
| 641 | */ |
| 642 | public void removeDragSourceMotionListener(DragSourceMotionListener dsml) { |
| 643 | if (dsml != null) { |
| 644 | synchronized (this) { |
| 645 | motionListener = DnDEventMulticaster.remove(motionListener, dsml); |
| 646 | } |
| 647 | } |
| 648 | } |
| 649 | |
| 650 | /** |
| 651 | * Gets all of the <code>DragSourceMotionListener</code>s |
| 652 | * registered with this <code>DragSource</code>. |
| 653 | * |
| 654 | * @return all of this <code>DragSource</code>'s |
| 655 | * <code>DragSourceMotionListener</code>s or an empty array if no |
| 656 | * such listeners are currently registered |
| 657 | * |
| 658 | * @see #addDragSourceMotionListener |
| 659 | * @see #removeDragSourceMotionListener |
| 660 | * @since 1.4 |
| 661 | */ |
| 662 | public DragSourceMotionListener[] getDragSourceMotionListeners() { |
| 663 | return (DragSourceMotionListener[]) |
| 664 | getListeners(DragSourceMotionListener.class); |
| 665 | } |
| 666 | |
| 667 | /** |
| 668 | * Gets all the objects currently registered as |
| 669 | * <code><em>Foo</em>Listener</code>s upon this <code>DragSource</code>. |
| 670 | * <code><em>Foo</em>Listener</code>s are registered using the |
| 671 | * <code>add<em>Foo</em>Listener</code> method. |
| 672 | * |
| 673 | * @param listenerType the type of listeners requested; this parameter |
| 674 | * should specify an interface that descends from |
| 675 | * <code>java.util.EventListener</code> |
| 676 | * @return an array of all objects registered as |
| 677 | * <code><em>Foo</em>Listener</code>s on this |
| 678 | * <code>DragSource</code>, or an empty array if no such listeners |
| 679 | * have been added |
| 680 | * @exception <code>ClassCastException</code> if <code>listenerType</code> |
| 681 | * doesn't specify a class or interface that implements |
| 682 | * <code>java.util.EventListener</code> |
| 683 | * |
| 684 | * @see #getDragSourceListeners |
| 685 | * @see #getDragSourceMotionListeners |
| 686 | * @since 1.4 |
| 687 | */ |
| 688 | public <T extends EventListener> T[] getListeners(Class<T> listenerType) { |
| 689 | EventListener l = null; |
| 690 | if (listenerType == DragSourceListener.class) { |
| 691 | l = listener; |
| 692 | } else if (listenerType == DragSourceMotionListener.class) { |
| 693 | l = motionListener; |
| 694 | } |
| 695 | return DnDEventMulticaster.getListeners(l, listenerType); |
| 696 | } |
| 697 | |
| 698 | /** |
| 699 | * This method calls <code>dragEnter</code> on the |
| 700 | * <code>DragSourceListener</code>s registered with this |
| 701 | * <code>DragSource</code>, and passes them the specified |
| 702 | * <code>DragSourceDragEvent</code>. |
| 703 | * |
| 704 | * @param dsde the <code>DragSourceDragEvent</code> |
| 705 | */ |
| 706 | void processDragEnter(DragSourceDragEvent dsde) { |
| 707 | DragSourceListener dsl = listener; |
| 708 | if (dsl != null) { |
| 709 | dsl.dragEnter(dsde); |
| 710 | } |
| 711 | } |
| 712 | |
| 713 | /** |
| 714 | * This method calls <code>dragOver</code> on the |
| 715 | * <code>DragSourceListener</code>s registered with this |
| 716 | * <code>DragSource</code>, and passes them the specified |
| 717 | * <code>DragSourceDragEvent</code>. |
| 718 | * |
| 719 | * @param dsde the <code>DragSourceDragEvent</code> |
| 720 | */ |
| 721 | void processDragOver(DragSourceDragEvent dsde) { |
| 722 | DragSourceListener dsl = listener; |
| 723 | if (dsl != null) { |
| 724 | dsl.dragOver(dsde); |
| 725 | } |
| 726 | } |
| 727 | |
| 728 | /** |
| 729 | * This method calls <code>dropActionChanged</code> on the |
| 730 | * <code>DragSourceListener</code>s registered with this |
| 731 | * <code>DragSource</code>, and passes them the specified |
| 732 | * <code>DragSourceDragEvent</code>. |
| 733 | * |
| 734 | * @param dsde the <code>DragSourceDragEvent</code> |
| 735 | */ |
| 736 | void processDropActionChanged(DragSourceDragEvent dsde) { |
| 737 | DragSourceListener dsl = listener; |
| 738 | if (dsl != null) { |
| 739 | dsl.dropActionChanged(dsde); |
| 740 | } |
| 741 | } |
| 742 | |
| 743 | /** |
| 744 | * This method calls <code>dragExit</code> on the |
| 745 | * <code>DragSourceListener</code>s registered with this |
| 746 | * <code>DragSource</code>, and passes them the specified |
| 747 | * <code>DragSourceEvent</code>. |
| 748 | * |
| 749 | * @param dse the <code>DragSourceEvent</code> |
| 750 | */ |
| 751 | void processDragExit(DragSourceEvent dse) { |
| 752 | DragSourceListener dsl = listener; |
| 753 | if (dsl != null) { |
| 754 | dsl.dragExit(dse); |
| 755 | } |
| 756 | } |
| 757 | |
| 758 | /** |
| 759 | * This method calls <code>dragDropEnd</code> on the |
| 760 | * <code>DragSourceListener</code>s registered with this |
| 761 | * <code>DragSource</code>, and passes them the specified |
| 762 | * <code>DragSourceDropEvent</code>. |
| 763 | * |
| 764 | * @param dsde the <code>DragSourceEvent</code> |
| 765 | */ |
| 766 | void processDragDropEnd(DragSourceDropEvent dsde) { |
| 767 | DragSourceListener dsl = listener; |
| 768 | if (dsl != null) { |
| 769 | dsl.dragDropEnd(dsde); |
| 770 | } |
| 771 | } |
| 772 | |
| 773 | /** |
| 774 | * This method calls <code>dragMouseMoved</code> on the |
| 775 | * <code>DragSourceMotionListener</code>s registered with this |
| 776 | * <code>DragSource</code>, and passes them the specified |
| 777 | * <code>DragSourceDragEvent</code>. |
| 778 | * |
| 779 | * @param dsde the <code>DragSourceEvent</code> |
| 780 | */ |
| 781 | void processDragMouseMoved(DragSourceDragEvent dsde) { |
| 782 | DragSourceMotionListener dsml = motionListener; |
| 783 | if (dsml != null) { |
| 784 | dsml.dragMouseMoved(dsde); |
| 785 | } |
| 786 | } |
| 787 | |
| 788 | /** |
| 789 | * Serializes this <code>DragSource</code>. This method first performs |
| 790 | * default serialization. Next, it writes out this object's |
| 791 | * <code>FlavorMap</code> if and only if it can be serialized. If not, |
| 792 | * <code>null</code> is written instead. Next, it writes out |
| 793 | * <code>Serializable</code> listeners registered with this |
| 794 | * object. Listeners are written in a <code>null</code>-terminated sequence |
| 795 | * of 0 or more pairs. The pair consists of a <code>String</code> and an |
| 796 | * <code>Object</code>; the <code>String</code> indicates the type of the |
| 797 | * <code>Object</code> and is one of the following: |
| 798 | * <ul> |
| 799 | * <li><code>dragSourceListenerK</code> indicating a |
| 800 | * <code>DragSourceListener</code> object; |
| 801 | * <li><code>dragSourceMotionListenerK</code> indicating a |
| 802 | * <code>DragSourceMotionListener</code> object. |
| 803 | * </ul> |
| 804 | * |
| 805 | * @serialData Either a <code>FlavorMap</code> instance, or |
| 806 | * <code>null</code>, followed by a <code>null</code>-terminated |
| 807 | * sequence of 0 or more pairs; the pair consists of a |
| 808 | * <code>String</code> and an <code>Object</code>; the |
| 809 | * <code>String</code> indicates the type of the <code>Object</code> |
| 810 | * and is one of the following: |
| 811 | * <ul> |
| 812 | * <li><code>dragSourceListenerK</code> indicating a |
| 813 | * <code>DragSourceListener</code> object; |
| 814 | * <li><code>dragSourceMotionListenerK</code> indicating a |
| 815 | * <code>DragSourceMotionListener</code> object. |
| 816 | * </ul>. |
| 817 | * @since 1.4 |
| 818 | */ |
| 819 | private void writeObject(ObjectOutputStream s) throws IOException { |
| 820 | s.defaultWriteObject(); |
| 821 | |
| 822 | s.writeObject(SerializationTester.test(flavorMap) ? flavorMap : null); |
| 823 | |
| 824 | DnDEventMulticaster.save(s, dragSourceListenerK, listener); |
| 825 | DnDEventMulticaster.save(s, dragSourceMotionListenerK, motionListener); |
| 826 | s.writeObject(null); |
| 827 | } |
| 828 | |
| 829 | /** |
| 830 | * Deserializes this <code>DragSource</code>. This method first performs |
| 831 | * default deserialization. Next, this object's <code>FlavorMap</code> is |
| 832 | * deserialized by using the next object in the stream. |
| 833 | * If the resulting <code>FlavorMap</code> is <code>null</code>, this |
| 834 | * object's <code>FlavorMap</code> is set to the default FlavorMap for |
| 835 | * this thread's <code>ClassLoader</code>. |
| 836 | * Next, this object's listeners are deserialized by reading a |
| 837 | * <code>null</code>-terminated sequence of 0 or more key/value pairs |
| 838 | * from the stream: |
| 839 | * <ul> |
| 840 | * <li>If a key object is a <code>String</code> equal to |
| 841 | * <code>dragSourceListenerK</code>, a <code>DragSourceListener</code> is |
| 842 | * deserialized using the corresponding value object and added to this |
| 843 | * <code>DragSource</code>. |
| 844 | * <li>If a key object is a <code>String</code> equal to |
| 845 | * <code>dragSourceMotionListenerK</code>, a |
| 846 | * <code>DragSourceMotionListener</code> is deserialized using the |
| 847 | * corresponding value object and added to this <code>DragSource</code>. |
| 848 | * <li>Otherwise, the key/value pair is skipped. |
| 849 | * </ul> |
| 850 | * |
| 851 | * @see java.awt.datatransfer.SystemFlavorMap#getDefaultFlavorMap |
| 852 | * @since 1.4 |
| 853 | */ |
| 854 | private void readObject(ObjectInputStream s) |
| 855 | throws ClassNotFoundException, IOException { |
| 856 | s.defaultReadObject(); |
| 857 | |
| 858 | // 'flavorMap' was written explicitly |
| 859 | flavorMap = (FlavorMap)s.readObject(); |
| 860 | |
| 861 | // Implementation assumes 'flavorMap' is never null. |
| 862 | if (flavorMap == null) { |
| 863 | flavorMap = SystemFlavorMap.getDefaultFlavorMap(); |
| 864 | } |
| 865 | |
| 866 | Object keyOrNull; |
| 867 | while (null != (keyOrNull = s.readObject())) { |
| 868 | String key = ((String)keyOrNull).intern(); |
| 869 | |
| 870 | if (dragSourceListenerK == key) { |
| 871 | addDragSourceListener((DragSourceListener)(s.readObject())); |
| 872 | } else if (dragSourceMotionListenerK == key) { |
| 873 | addDragSourceMotionListener( |
| 874 | (DragSourceMotionListener)(s.readObject())); |
| 875 | } else { |
| 876 | // skip value for unrecognized key |
| 877 | s.readObject(); |
| 878 | } |
| 879 | } |
| 880 | } |
| 881 | |
| 882 | /** |
| 883 | * Returns the drag gesture motion threshold. The drag gesture motion threshold |
| 884 | * defines the recommended behavior for {@link MouseDragGestureRecognizer}s. |
| 885 | * <p> |
| 886 | * If the system property <code>awt.dnd.drag.threshold</code> is set to |
| 887 | * a positive integer, this method returns the value of the system property; |
| 888 | * otherwise if a pertinent desktop property is available and supported by |
| 889 | * the implementation of the Java platform, this method returns the value of |
| 890 | * that property; otherwise this method returns some default value. |
| 891 | * The pertinent desktop property can be queried using |
| 892 | * <code>java.awt.Toolkit.getDesktopProperty("DnD.gestureMotionThreshold")</code>. |
| 893 | * |
| 894 | * @return the drag gesture motion threshold |
| 895 | * @see MouseDragGestureRecognizer |
| 896 | * @since 1.5 |
| 897 | */ |
| 898 | public static int getDragThreshold() { |
| 899 | int ts = ((Integer)AccessController.doPrivileged( |
| 900 | new GetIntegerAction("awt.dnd.drag.threshold", 0))).intValue(); |
| 901 | if (ts > 0) { |
| 902 | return ts; |
| 903 | } else { |
| 904 | Integer td = (Integer)Toolkit.getDefaultToolkit(). |
| 905 | getDesktopProperty("DnD.gestureMotionThreshold"); |
| 906 | if (td != null) { |
| 907 | return td.intValue(); |
| 908 | } |
| 909 | } |
| 910 | return 5; |
| 911 | } |
| 912 | |
| 913 | /* |
| 914 | * fields |
| 915 | */ |
| 916 | |
| 917 | private transient FlavorMap flavorMap = SystemFlavorMap.getDefaultFlavorMap(); |
| 918 | |
| 919 | private transient DragSourceListener listener; |
| 920 | |
| 921 | private transient DragSourceMotionListener motionListener; |
| 922 | } |