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| 1 | /* | ||
| 2 | * Copyright (c) 1997, 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 | package java.awt.dnd; | ||
| 27 | |||
| 28 | import java.util.TooManyListenersException; | ||
| 29 | |||
| 30 | import java.io.IOException; | ||
| 31 | import java.io.ObjectInputStream; | ||
| 32 | import java.io.ObjectOutputStream; | ||
| 33 | import java.io.Serializable; | ||
| 34 | |||
| 35 | import java.awt.Component; | ||
| 36 | import java.awt.Dimension; | ||
| 37 | import java.awt.GraphicsEnvironment; | ||
| 38 | import java.awt.HeadlessException; | ||
| 39 | import java.awt.Insets; | ||
| 40 | import java.awt.Point; | ||
| 41 | import java.awt.Rectangle; | ||
| 42 | import java.awt.Toolkit; | ||
| 43 | import java.awt.event.ActionEvent; | ||
| 44 | import java.awt.event.ActionListener; | ||
| 45 | import java.awt.datatransfer.FlavorMap; | ||
| 46 | import java.awt.datatransfer.SystemFlavorMap; | ||
| 47 | import javax.swing.Timer; | ||
| 48 | import java.awt.peer.ComponentPeer; | ||
| 49 | import java.awt.peer.LightweightPeer; | ||
| 50 | import java.awt.dnd.peer.DropTargetPeer; | ||
| 51 | |||
| 52 | |||
| 53 | /** | ||
| 54 | * The <code>DropTarget</code> is associated | ||
| 55 | * with a <code>Component</code> when that <code>Component</code> | ||
| 56 | * wishes | ||
| 57 | * to accept drops during Drag and Drop operations. | ||
| 58 | * <P> | ||
| 59 | * Each | ||
| 60 | * <code>DropTarget</code> is associated with a <code>FlavorMap</code>. | ||
| 61 | * The default <code>FlavorMap</code> hereafter designates the | ||
| 62 | * <code>FlavorMap</code> returned by <code>SystemFlavorMap.getDefaultFlavorMap()</code>. | ||
| 63 | * | ||
| 64 | * @since 1.2 | ||
| 65 | */ | ||
| 66 | |||
| 67 | public class DropTarget implements DropTargetListener, Serializable { | ||
| 68 | |||
| 69 | private static final long serialVersionUID = -6283860791671019047L; | ||
| 70 | |||
| 71 | /** | ||
| 72 | * Creates a new DropTarget given the <code>Component</code> | ||
| 73 | * to associate itself with, an <code>int</code> representing | ||
| 74 | * the default acceptable action(s) to | ||
| 75 | * support, a <code>DropTargetListener</code> | ||
| 76 | * to handle event processing, a <code>boolean</code> indicating | ||
| 77 | * if the <code>DropTarget</code> is currently accepting drops, and | ||
| 78 | * a <code>FlavorMap</code> to use (or null for the default <CODE>FlavorMap</CODE>). | ||
| 79 | * <P> | ||
| 80 | * The Component will receive drops only if it is enabled. | ||
| 81 | * @param c The <code>Component</code> with which this <code>DropTarget</code> is associated | ||
| 82 | * @param ops The default acceptable actions for this <code>DropTarget</code> | ||
| 83 | * @param dtl The <code>DropTargetListener</code> for this <code>DropTarget</code> | ||
| 84 | * @param act Is the <code>DropTarget</code> accepting drops. | ||
| 85 | * @param fm The <code>FlavorMap</code> to use, or null for the default <CODE>FlavorMap</CODE> | ||
| 86 | * @exception HeadlessException if GraphicsEnvironment.isHeadless() | ||
| 87 | * returns true | ||
| 88 | * @see java.awt.GraphicsEnvironment#isHeadless | ||
| 89 | */ | ||
| 90 | public DropTarget(Component c, int ops, DropTargetListener dtl, | ||
| 91 | boolean act, FlavorMap fm) | ||
| 92 | throws HeadlessException | ||
| 93 | { | ||
| 94 | if (GraphicsEnvironment.isHeadless()) { | ||
| 95 | throw new HeadlessException(); | ||
| 96 | } | ||
| 97 | |||
| 98 | component = c; | ||
| 99 | |||
| 100 | setDefaultActions(ops); | ||
| 101 | |||
| 102 | if (dtl != null) try { | ||
| 103 | addDropTargetListener(dtl); | ||
| 104 | } catch (TooManyListenersException tmle) { | ||
| 105 | // do nothing! | ||
| 106 | } | ||
| 107 | |||
| 108 | if (c != null) { | ||
| 109 | c.setDropTarget(this); | ||
| 110 | setActive(act); | ||
| 111 | } | ||
| 112 | |||
| 113 | if (fm != null) { | ||
| 114 | flavorMap = fm; | ||
| 115 | } else { | ||
| 116 | flavorMap = SystemFlavorMap.getDefaultFlavorMap(); | ||
| 117 | } | ||
| 118 | } | ||
| 119 | |||
| 120 | /** | ||
| 121 | * Creates a <code>DropTarget</code> given the <code>Component</code> | ||
| 122 | * to associate itself with, an <code>int</code> representing | ||
| 123 | * the default acceptable action(s) | ||
| 124 | * to support, a <code>DropTargetListener</code> | ||
| 125 | * to handle event processing, and a <code>boolean</code> indicating | ||
| 126 | * if the <code>DropTarget</code> is currently accepting drops. | ||
| 127 | * <P> | ||
| 128 | * The Component will receive drops only if it is enabled. | ||
| 129 | * @param c The <code>Component</code> with which this <code>DropTarget</code> is associated | ||
| 130 | * @param ops The default acceptable actions for this <code>DropTarget</code> | ||
| 131 | * @param dtl The <code>DropTargetListener</code> for this <code>DropTarget</code> | ||
| 132 | * @param act Is the <code>DropTarget</code> accepting drops. | ||
| 133 | * @exception HeadlessException if GraphicsEnvironment.isHeadless() | ||
| 134 | * returns true | ||
| 135 | * @see java.awt.GraphicsEnvironment#isHeadless | ||
| 136 | */ | ||
| 137 | public DropTarget(Component c, int ops, DropTargetListener dtl, | ||
| 138 | boolean act) | ||
| 139 | throws HeadlessException | ||
| 140 | { | ||
| 141 | this(c, ops, dtl, act, null); | ||
| 142 | } | ||
| 143 | |||
| 144 | /** | ||
| 145 | * Creates a <code>DropTarget</code>. | ||
| 146 | * @exception HeadlessException if GraphicsEnvironment.isHeadless() | ||
| 147 | * returns true | ||
| 148 | * @see java.awt.GraphicsEnvironment#isHeadless | ||
| 149 | */ | ||
| 150 | public DropTarget() throws HeadlessException { | ||
| 151 | this(null, DnDConstants.ACTION_COPY_OR_MOVE, null, true, null); | ||
| 152 | } | ||
| 153 | |||
| 154 | /** | ||
| 155 | * Creates a <code>DropTarget</code> given the <code>Component</code> | ||
| 156 | * to associate itself with, and the <code>DropTargetListener</code> | ||
| 157 | * to handle event processing. | ||
| 158 | * <P> | ||
| 159 | * The Component will receive drops only if it is enabled. | ||
| 160 | * @param c The <code>Component</code> with which this <code>DropTarget</code> is associated | ||
| 161 | * @param dtl The <code>DropTargetListener</code> for this <code>DropTarget</code> | ||
| 162 | * @exception HeadlessException if GraphicsEnvironment.isHeadless() | ||
| 163 | * returns true | ||
| 164 | * @see java.awt.GraphicsEnvironment#isHeadless | ||
| 165 | */ | ||
| 166 | public DropTarget(Component c, DropTargetListener dtl) | ||
| 167 | throws HeadlessException | ||
| 168 | { | ||
| 169 | this(c, DnDConstants.ACTION_COPY_OR_MOVE, dtl, true, null); | ||
| 170 | } | ||
| 171 | |||
| 172 | /** | ||
| 173 | * Creates a <code>DropTarget</code> given the <code>Component</code> | ||
| 174 | * to associate itself with, an <code>int</code> representing | ||
| 175 | * the default acceptable action(s) to support, and a | ||
| 176 | * <code>DropTargetListener</code> to handle event processing. | ||
| 177 | * <P> | ||
| 178 | * The Component will receive drops only if it is enabled. | ||
| 179 | * @param c The <code>Component</code> with which this <code>DropTarget</code> is associated | ||
| 180 | * @param ops The default acceptable actions for this <code>DropTarget</code> | ||
| 181 | * @param dtl The <code>DropTargetListener</code> for this <code>DropTarget</code> | ||
| 182 | * @exception HeadlessException if GraphicsEnvironment.isHeadless() | ||
| 183 | * returns true | ||
| 184 | * @see java.awt.GraphicsEnvironment#isHeadless | ||
| 185 | */ | ||
| 186 | public DropTarget(Component c, int ops, DropTargetListener dtl) | ||
| 187 | throws HeadlessException | ||
| 188 | { | ||
| 189 | this(c, ops, dtl, true); | ||
| 190 | } | ||
| 191 | |||
| 192 | /** | ||
| 193 | * Note: this interface is required to permit the safe association | ||
| 194 | * of a DropTarget with a Component in one of two ways, either: | ||
| 195 | * <code> component.setDropTarget(droptarget); </code> | ||
| 196 | * or <code> droptarget.setComponent(component); </code> | ||
| 197 | * <P> | ||
| 198 | * The Component will receive drops only if it is enabled. | ||
| 199 | * @param c The new <code>Component</code> this <code>DropTarget</code> | ||
| 200 | * is to be associated with.<P> | ||
| 201 | */ | ||
| 202 | |||
| 203 | public synchronized void setComponent(Component c) { | ||
| 204 | if (component == c || component != null && component.equals(c)) | ||
| 205 | return; | ||
| 206 | |||
| 207 | Component old; | ||
| 208 | ComponentPeer oldPeer = null; | ||
| 209 | |||
| 210 | if ((old = component) != null) { | ||
| 211 | clearAutoscroll(); | ||
| 212 | |||
| 213 | component = null; | ||
| 214 | |||
| 215 | if (componentPeer != null) { | ||
| 216 | oldPeer = componentPeer; | ||
| 217 | removeNotify(componentPeer); | ||
| 218 | } | ||
| 219 | |||
| 220 | old.setDropTarget(null); | ||
| 221 | |||
| 222 | } | ||
| 223 | |||
| 224 | if ((component = c) != null) try { | ||
| 225 | c.setDropTarget(this); | ||
| 226 | } catch (Exception e) { // undo the change | ||
| 227 | if (old != null) { | ||
| 228 | old.setDropTarget(this); | ||
| 229 | addNotify(oldPeer); | ||
| 230 | } | ||
| 231 | } | ||
| 232 | } | ||
| 233 | |||
| 234 | /** | ||
| 235 | * Gets the <code>Component</code> associated | ||
| 236 | * with this <code>DropTarget</code>. | ||
| 237 | * <P> | ||
| 238 | * @return the current <code>Component</code> | ||
| 239 | */ | ||
| 240 | |||
| 241 | public synchronized Component getComponent() { | ||
| 242 | return component; | ||
| 243 | } | ||
| 244 | |||
| 245 | /** | ||
| 246 | * Sets the default acceptable actions for this <code>DropTarget</code> | ||
| 247 | * <P> | ||
| 248 | * @param ops the default actions | ||
| 249 | * <P> | ||
| 250 | * @see java.awt.dnd.DnDConstants | ||
| 251 | */ | ||
| 252 | |||
| 253 | public void setDefaultActions(int ops) { | ||
| 254 | getDropTargetContext().setTargetActions(ops & (DnDConstants.ACTION_COPY_OR_MOVE | DnDConstants.ACTION_REFERENCE)); | ||
| 255 | } | ||
| 256 | |||
| 257 | /* | ||
| 258 | * Called by DropTargetContext.setTargetActions() | ||
| 259 | * with appropriate synchronization. | ||
| 260 | */ | ||
| 261 | void doSetDefaultActions(int ops) { | ||
| 262 | actions = ops; | ||
| 263 | } | ||
| 264 | |||
| 265 | /** | ||
| 266 | * Gets an <code>int</code> representing the | ||
| 267 | * current action(s) supported by this <code>DropTarget</code>. | ||
| 268 | * <P> | ||
| 269 | * @return the current default actions | ||
| 270 | */ | ||
| 271 | |||
| 272 | public int getDefaultActions() { | ||
| 273 | return actions; | ||
| 274 | } | ||
| 275 | |||
| 276 | /** | ||
| 277 | * Sets the DropTarget active if <code>true</code>, | ||
| 278 | * inactive if <code>false</code>. | ||
| 279 | * <P> | ||
| 280 | * @param isActive sets the <code>DropTarget</code> (in)active. | ||
| 281 | */ | ||
| 282 | |||
| 283 | public synchronized void setActive(boolean isActive) { | ||
| 284 | if (isActive != active) { | ||
| 285 | active = isActive; | ||
| 286 | } | ||
| 287 | |||
| 288 | if (!active) clearAutoscroll(); | ||
| 289 | } | ||
| 290 | |||
| 291 | /** | ||
| 292 | * Reports whether or not | ||
| 293 | * this <code>DropTarget</code> | ||
| 294 | * is currently active (ready to accept drops). | ||
| 295 | * <P> | ||
| 296 | * @return <CODE>true</CODE> if active, <CODE>false</CODE> if not | ||
| 297 | */ | ||
| 298 | |||
| 299 | public boolean isActive() { | ||
| 300 | return active; | ||
| 301 | } | ||
| 302 | |||
| 303 | /** | ||
| 304 | * Adds a new <code>DropTargetListener</code> (UNICAST SOURCE). | ||
| 305 | * <P> | ||
| 306 | * @param dtl The new <code>DropTargetListener</code> | ||
| 307 | * <P> | ||
| 308 | * @throws <code>TooManyListenersException</code> if a | ||
| 309 | * <code>DropTargetListener</code> is already added to this | ||
| 310 | * <code>DropTarget</code>. | ||
| 311 | */ | ||
| 312 | |||
| 313 | public synchronized void addDropTargetListener(DropTargetListener dtl) throws TooManyListenersException { | ||
| 314 | if (dtl == null) return; | ||
| 315 | |||
| 316 | if (equals(dtl)) throw new IllegalArgumentException("DropTarget may not be its own Listener"); | ||
| 317 | |||
| 318 | if (dtListener == null) | ||
| 319 | dtListener = dtl; | ||
| 320 | else | ||
| 321 | throw new TooManyListenersException(); | ||
| 322 | } | ||
| 323 | |||
| 324 | /** | ||
| 325 | * Removes the current <code>DropTargetListener</code> (UNICAST SOURCE). | ||
| 326 | * <P> | ||
| 327 | * @param dtl the DropTargetListener to deregister. | ||
| 328 | */ | ||
| 329 | |||
| 330 | public synchronized void removeDropTargetListener(DropTargetListener dtl) { | ||
| 331 | if (dtl != null && dtListener != null) { | ||
| 332 | if(dtListener.equals(dtl)) | ||
| 333 | dtListener = null; | ||
| 334 | else | ||
| 335 | throw new IllegalArgumentException("listener mismatch"); | ||
| 336 | } | ||
| 337 | } | ||
| 338 | |||
| 339 | /** | ||
| 340 | * Calls <code>dragEnter</code> on the registered | ||
| 341 | * <code>DropTargetListener</code> and passes it | ||
| 342 | * the specified <code>DropTargetDragEvent</code>. | ||
| 343 | * Has no effect if this <code>DropTarget</code> | ||
| 344 | * is not active. | ||
| 345 | * | ||
| 346 | * @param dtde the <code>DropTargetDragEvent</code> | ||
| 347 | * | ||
| 348 | * @throws NullPointerException if this <code>DropTarget</code> | ||
| 349 | * is active and <code>dtde</code> is <code>null</code> | ||
| 350 | * | ||
| 351 | * @see #isActive | ||
| 352 | */ | ||
| 353 | public synchronized void dragEnter(DropTargetDragEvent dtde) { | ||
| 354 | if (!active) return; | ||
| 355 | |||
| 356 | if (dtListener != null) { | ||
| 357 | dtListener.dragEnter(dtde); | ||
| 358 | } else | ||
| 359 | dtde.getDropTargetContext().setTargetActions(DnDConstants.ACTION_NONE); | ||
| 360 | |||
| 361 | initializeAutoscrolling(dtde.getLocation()); | ||
| 362 | } | ||
| 363 | |||
| 364 | /** | ||
| 365 | * Calls <code>dragOver</code> on the registered | ||
| 366 | * <code>DropTargetListener</code> and passes it | ||
| 367 | * the specified <code>DropTargetDragEvent</code>. | ||
| 368 | * Has no effect if this <code>DropTarget</code> | ||
| 369 | * is not active. | ||
| 370 | * | ||
| 371 | * @param dtde the <code>DropTargetDragEvent</code> | ||
| 372 | * | ||
| 373 | * @throws NullPointerException if this <code>DropTarget</code> | ||
| 374 | * is active and <code>dtde</code> is <code>null</code> | ||
| 375 | * | ||
| 376 | * @see #isActive | ||
| 377 | */ | ||
| 378 | public synchronized void dragOver(DropTargetDragEvent dtde) { | ||
| 379 | if (!active) return; | ||
| 380 | |||
| 381 | if (dtListener != null && active) dtListener.dragOver(dtde); | ||
| 382 | |||
| 383 | updateAutoscroll(dtde.getLocation()); | ||
| 384 | } | ||
| 385 | |||
| 386 | /** | ||
| 387 | * Calls <code>dropActionChanged</code> on the registered | ||
| 388 | * <code>DropTargetListener</code> and passes it | ||
| 389 | * the specified <code>DropTargetDragEvent</code>. | ||
| 390 | * Has no effect if this <code>DropTarget</code> | ||
| 391 | * is not active. | ||
| 392 | * | ||
| 393 | * @param dtde the <code>DropTargetDragEvent</code> | ||
| 394 | * | ||
| 395 | * @throws NullPointerException if this <code>DropTarget</code> | ||
| 396 | * is active and <code>dtde</code> is <code>null</code> | ||
| 397 | * | ||
| 398 | * @see #isActive | ||
| 399 | */ | ||
| 400 | public synchronized void dropActionChanged(DropTargetDragEvent dtde) { | ||
| 401 | if (!active) return; | ||
| 402 | |||
| 403 | if (dtListener != null) dtListener.dropActionChanged(dtde); | ||
| 404 | |||
| 405 | updateAutoscroll(dtde.getLocation()); | ||
| 406 | } | ||
| 407 | |||
| 408 | /** | ||
| 409 | * Calls <code>dragExit</code> on the registered | ||
| 410 | * <code>DropTargetListener</code> and passes it | ||
| 411 | * the specified <code>DropTargetEvent</code>. | ||
| 412 | * Has no effect if this <code>DropTarget</code> | ||
| 413 | * is not active. | ||
| 414 | * <p> | ||
| 415 | * This method itself does not throw any exception | ||
| 416 | * for null parameter but for exceptions thrown by | ||
| 417 | * the respective method of the listener. | ||
| 418 | * | ||
| 419 | * @param dte the <code>DropTargetEvent</code> | ||
| 420 | * | ||
| 421 | * @see #isActive | ||
| 422 | */ | ||
| 423 | public synchronized void dragExit(DropTargetEvent dte) { | ||
| 424 | if (!active) return; | ||
| 425 | |||
| 426 | if (dtListener != null && active) dtListener.dragExit(dte); | ||
| 427 | |||
| 428 | clearAutoscroll(); | ||
| 429 | } | ||
| 430 | |||
| 431 | /** | ||
| 432 | * Calls <code>drop</code> on the registered | ||
| 433 | * <code>DropTargetListener</code> and passes it | ||
| 434 | * the specified <code>DropTargetDropEvent</code> | ||
| 435 | * if this <code>DropTarget</code> is active. | ||
| 436 | * | ||
| 437 | * @param dtde the <code>DropTargetDropEvent</code> | ||
| 438 | * | ||
| 439 | * @throws NullPointerException if <code>dtde</code> is null | ||
| 440 | * and at least one of the following is true: this | ||
| 441 | * <code>DropTarget</code> is not active, or there is | ||
| 442 | * no a <code>DropTargetListener</code> registered. | ||
| 443 | * | ||
| 444 | * @see #isActive | ||
| 445 | */ | ||
| 446 | public synchronized void drop(DropTargetDropEvent dtde) { | ||
| 447 | clearAutoscroll(); | ||
| 448 | |||
| 449 | if (dtListener != null && active) | ||
| 450 | dtListener.drop(dtde); | ||
| 451 | else { // we should'nt get here ... | ||
| 452 | dtde.rejectDrop(); | ||
| 453 | } | ||
| 454 | } | ||
| 455 | |||
| 456 | /** | ||
| 457 | * Gets the <code>FlavorMap</code> | ||
| 458 | * associated with this <code>DropTarget</code>. | ||
| 459 | * If no <code>FlavorMap</code> has been set for this | ||
| 460 | * <code>DropTarget</code>, it is associated with the default | ||
| 461 | * <code>FlavorMap</code>. | ||
| 462 | * <P> | ||
| 463 | * @return the FlavorMap for this DropTarget | ||
| 464 | */ | ||
| 465 | |||
| 466 | public FlavorMap getFlavorMap() { return flavorMap; } | ||
| 467 | |||
| 468 | /** | ||
| 469 | * Sets the <code>FlavorMap</code> associated | ||
| 470 | * with this <code>DropTarget</code>. | ||
| 471 | * <P> | ||
| 472 | * @param fm the new <code>FlavorMap</code>, or null to | ||
| 473 | * associate the default FlavorMap with this DropTarget. | ||
| 474 | */ | ||
| 475 | |||
| 476 | public void setFlavorMap(FlavorMap fm) { | ||
| 477 | flavorMap = fm == null ? SystemFlavorMap.getDefaultFlavorMap() : fm; | ||
| 478 | } | ||
| 479 | |||
| 480 | /** | ||
| 481 | * Notify the DropTarget that it has been associated with a Component | ||
| 482 | * | ||
| 483 | ********************************************************************** | ||
| 484 | * This method is usually called from java.awt.Component.addNotify() of | ||
| 485 | * the Component associated with this DropTarget to notify the DropTarget | ||
| 486 | * that a ComponentPeer has been associated with that Component. | ||
| 487 | * | ||
| 488 | * Calling this method, other than to notify this DropTarget of the | ||
| 489 | * association of the ComponentPeer with the Component may result in | ||
| 490 | * a malfunction of the DnD system. | ||
| 491 | ********************************************************************** | ||
| 492 | * <P> | ||
| 493 | * @param peer The Peer of the Component we are associated with! | ||
| 494 | * | ||
| 495 | */ | ||
| 496 | |||
| 497 | public void addNotify(ComponentPeer peer) { | ||
| 498 | if (peer == componentPeer) return; | ||
| 499 | |||
| 500 | componentPeer = peer; | ||
| 501 | |||
| 502 | for (Component c = component; | ||
| 503 | c != null && peer instanceof LightweightPeer; c = c.getParent()) { | ||
| 504 | peer = c.getPeer(); | ||
| 505 | } | ||
| 506 | |||
| 507 | if (peer instanceof DropTargetPeer) { | ||
| 508 | nativePeer = peer; | ||
| 509 | ((DropTargetPeer)peer).addDropTarget(this); | ||
| 510 | } else { | ||
| 511 | nativePeer = null; | ||
| 512 | } | ||
| 513 | } | ||
| 514 | |||
| 515 | /** | ||
| 516 | * Notify the DropTarget that it has been disassociated from a Component | ||
| 517 | * | ||
| 518 | ********************************************************************** | ||
| 519 | * This method is usually called from java.awt.Component.removeNotify() of | ||
| 520 | * the Component associated with this DropTarget to notify the DropTarget | ||
| 521 | * that a ComponentPeer has been disassociated with that Component. | ||
| 522 | * | ||
| 523 | * Calling this method, other than to notify this DropTarget of the | ||
| 524 | * disassociation of the ComponentPeer from the Component may result in | ||
| 525 | * a malfunction of the DnD system. | ||
| 526 | ********************************************************************** | ||
| 527 | * <P> | ||
| 528 | * @param peer The Peer of the Component we are being disassociated from! | ||
| 529 | */ | ||
| 530 | |||
| 531 | public void removeNotify(ComponentPeer peer) { | ||
| 532 | if (nativePeer != null) | ||
| 533 | ((DropTargetPeer)nativePeer).removeDropTarget(this); | ||
| 534 | |||
| 535 | componentPeer = nativePeer = null; | ||
| 536 | } | ||
| 537 | |||
| 538 | /** | ||
| 539 | * Gets the <code>DropTargetContext</code> associated | ||
| 540 | * with this <code>DropTarget</code>. | ||
| 541 | * <P> | ||
| 542 | * @return the <code>DropTargetContext</code> associated with this <code>DropTarget</code>. | ||
| 543 | */ | ||
| 544 | |||
| 545 | public DropTargetContext getDropTargetContext() { | ||
| 546 | return dropTargetContext; | ||
| 547 | } | ||
| 548 | |||
| 549 | /** | ||
| 550 | * Creates the DropTargetContext associated with this DropTarget. | ||
| 551 | * Subclasses may override this method to instantiate their own | ||
| 552 | * DropTargetContext subclass. | ||
| 553 | * | ||
| 554 | * This call is typically *only* called by the platform's | ||
| 555 | * DropTargetContextPeer as a drag operation encounters this | ||
| 556 | * DropTarget. Accessing the Context while no Drag is current | ||
| 557 | * has undefined results. | ||
| 558 | */ | ||
| 559 | |||
| 560 | protected DropTargetContext createDropTargetContext() { | ||
| 561 | return new DropTargetContext(this); | ||
| 562 | } | ||
| 563 | |||
| 564 | /** | ||
| 565 | * Serializes this <code>DropTarget</code>. Performs default serialization, | ||
| 566 | * and then writes out this object's <code>DropTargetListener</code> if and | ||
| 567 | * only if it can be serialized. If not, <code>null</code> is written | ||
| 568 | * instead. | ||
| 569 | * | ||
| 570 | * @serialData The default serializable fields, in alphabetical order, | ||
| 571 | * followed by either a <code>DropTargetListener</code> | ||
| 572 | * instance, or <code>null</code>. | ||
| 573 | * @since 1.4 | ||
| 574 | */ | ||
| 575 | private void writeObject(ObjectOutputStream s) throws IOException { | ||
| 576 | s.defaultWriteObject(); | ||
| 577 | |||
| 578 | s.writeObject(SerializationTester.test(dtListener) | ||
| 579 | ? dtListener : null); | ||
| 580 | } | ||
| 581 | |||
| 582 | /** | ||
| 583 | * Deserializes this <code>DropTarget</code>. This method first performs | ||
| 584 | * default deserialization for all non-<code>transient</code> fields. An | ||
| 585 | * attempt is then made to deserialize this object's | ||
| 586 | * <code>DropTargetListener</code> as well. This is first attempted by | ||
| 587 | * deserializing the field <code>dtListener</code>, because, in releases | ||
| 588 | * prior to 1.4, a non-<code>transient</code> field of this name stored the | ||
| 589 | * <code>DropTargetListener</code>. If this fails, the next object in the | ||
| 590 | * stream is used instead. | ||
| 591 | * | ||
| 592 | * @since 1.4 | ||
| 593 | */ | ||
| 594 | private void readObject(ObjectInputStream s) | ||
| 595 | throws ClassNotFoundException, IOException | ||
| 596 | { | ||
| 597 | ObjectInputStream.GetField f = s.readFields(); | ||
| 598 | |||
| 599 | try { | ||
| 600 | dropTargetContext = | ||
| 601 | (DropTargetContext)f.get("dropTargetContext", null); | ||
| 602 | } catch (IllegalArgumentException e) { | ||
| 603 | // Pre-1.4 support. 'dropTargetContext' was previoulsy transient | ||
| 604 | } | ||
| 605 | if (dropTargetContext == null) { | ||
| 606 | dropTargetContext = createDropTargetContext(); | ||
| 607 | } | ||
| 608 | |||
| 609 | component = (Component)f.get("component", null); | ||
| 610 | actions = f.get("actions", DnDConstants.ACTION_COPY_OR_MOVE); | ||
| 611 | active = f.get("active", true); | ||
| 612 | |||
| 613 | // Pre-1.4 support. 'dtListener' was previously non-transient | ||
| 614 | try { | ||
| 615 | dtListener = (DropTargetListener)f.get("dtListener", null); | ||
| 616 | } catch (IllegalArgumentException e) { | ||
| 617 | // 1.4-compatible byte stream. 'dtListener' was written explicitly | ||
| 618 | dtListener = (DropTargetListener)s.readObject(); | ||
| 619 | } | ||
| 620 | } | ||
| 621 | |||
| 622 | /*********************************************************************/ | ||
| 623 | |||
| 624 | /** | ||
| 625 | * this protected nested class implements autoscrolling | ||
| 626 | */ | ||
| 627 | |||
| 628 | protected static class DropTargetAutoScroller implements ActionListener { | ||
| 629 | |||
| 630 | /** | ||
| 631 | * construct a DropTargetAutoScroller | ||
| 632 | * <P> | ||
| 633 | * @param c the <code>Component</code> | ||
| 634 | * @param p the <code>Point</code> | ||
| 635 | */ | ||
| 636 | |||
| 637 | protected DropTargetAutoScroller(Component c, Point p) { | ||
| 638 | super(); | ||
| 639 | |||
| 640 | component = c; | ||
| 641 | autoScroll = (Autoscroll)component; | ||
| 642 | |||
| 643 | Toolkit t = Toolkit.getDefaultToolkit(); | ||
| 644 | |||
| 645 | Integer initial = Integer.valueOf(100); | ||
| 646 | Integer interval = Integer.valueOf(100); | ||
| 647 | |||
| 648 | try { | ||
| 649 | initial = (Integer)t.getDesktopProperty("DnD.Autoscroll.initialDelay"); | ||
| 650 | } catch (Exception e) { | ||
| 651 | // ignore | ||
| 652 | } | ||
| 653 | |||
| 654 | try { | ||
| 655 | interval = (Integer)t.getDesktopProperty("DnD.Autoscroll.interval"); | ||
| 656 | } catch (Exception e) { | ||
| 657 | // ignore | ||
| 658 | } | ||
| 659 | |||
| 660 | timer = new Timer(interval.intValue(), this); | ||
| 661 | |||
| 662 | timer.setCoalesce(true); | ||
| 663 | timer.setInitialDelay(initial.intValue()); | ||
| 664 | |||
| 665 | locn = p; | ||
| 666 | prev = p; | ||
| 667 | |||
| 668 | try { | ||
| 669 | hysteresis = ((Integer)t.getDesktopProperty("DnD.Autoscroll.cursorHysteresis")).intValue(); | ||
| 670 | } catch (Exception e) { | ||
| 671 | // ignore | ||
| 672 | } | ||
| 673 | |||
| 674 | timer.start(); | ||
| 675 | } | ||
| 676 | |||
| 677 | /** | ||
| 678 | * update the geometry of the autoscroll region | ||
| 679 | */ | ||
| 680 | |||
| 681 | private void updateRegion() { | ||
| 682 | Insets i = autoScroll.getAutoscrollInsets(); | ||
| 683 | Dimension size = component.getSize(); | ||
| 684 | |||
| 685 | if (size.width != outer.width || size.height != outer.height) | ||
| 686 | outer.reshape(0, 0, size.width, size.height); | ||
| 687 | |||
| 688 | if (inner.x != i.left || inner.y != i.top) | ||
| 689 | inner.setLocation(i.left, i.top); | ||
| 690 | |||
| 691 | int newWidth = size.width - (i.left + i.right); | ||
| 692 | int newHeight = size.height - (i.top + i.bottom); | ||
| 693 | |||
| 694 | if (newWidth != inner.width || newHeight != inner.height) | ||
| 695 | inner.setSize(newWidth, newHeight); | ||
| 696 | |||
| 697 | } | ||
| 698 | |||
| 699 | /** | ||
| 700 | * cause autoscroll to occur | ||
| 701 | * <P> | ||
| 702 | * @param newLocn the <code>Point</code> | ||
| 703 | */ | ||
| 704 | |||
| 705 | protected synchronized void updateLocation(Point newLocn) { | ||
| 706 | prev = locn; | ||
| 707 | locn = newLocn; | ||
| 708 | |||
| 709 | if (Math.abs(locn.x - prev.x) > hysteresis || | ||
| 710 | Math.abs(locn.y - prev.y) > hysteresis) { | ||
| 711 | if (timer.isRunning()) timer.stop(); | ||
| 712 | } else { | ||
| 713 | if (!timer.isRunning()) timer.start(); | ||
| 714 | } | ||
| 715 | } | ||
| 716 | |||
| 717 | /** | ||
| 718 | * cause autoscrolling to stop | ||
| 719 | */ | ||
| 720 | |||
| 721 | protected void stop() { timer.stop(); } | ||
| 722 | |||
| 723 | /** | ||
| 724 | * cause autoscroll to occur | ||
| 725 | * <P> | ||
| 726 | * @param e the <code>ActionEvent</code> | ||
| 727 | */ | ||
| 728 | |||
| 729 | public synchronized void actionPerformed(ActionEvent e) { | ||
| 730 | updateRegion(); | ||
| 731 | |||
| 732 | if (outer.contains(locn) && !inner.contains(locn)) | ||
| 733 | autoScroll.autoscroll(locn); | ||
| 734 | } | ||
| 735 | |||
| 736 | /* | ||
| 737 | * fields | ||
| 738 | */ | ||
| 739 | |||
| 740 | private Component component; | ||
| 741 | private Autoscroll autoScroll; | ||
| 742 | |||
| 743 | private Timer timer; | ||
| 744 | |||
| 745 | private Point locn; | ||
| 746 | private Point prev; | ||
| 747 | |||
| 748 | private Rectangle outer = new Rectangle(); | ||
| 749 | private Rectangle inner = new Rectangle(); | ||
| 750 | |||
| 751 | private int hysteresis = 10; | ||
| 752 | } | ||
| 753 | |||
| 754 | /*********************************************************************/ | ||
| 755 | |||
| 756 | /** | ||
| 757 | * create an embedded autoscroller | ||
| 758 | * <P> | ||
| 759 | * @param c the <code>Component</code> | ||
| 760 | * @param p the <code>Point</code> | ||
| 761 | */ | ||
| 762 | |||
| 763 | protected DropTargetAutoScroller createDropTargetAutoScroller(Component c, Point p) { | ||
| 764 | return new DropTargetAutoScroller(c, p); | ||
| 765 | } | ||
| 766 | |||
| 767 | /** | ||
| 768 | * initialize autoscrolling | ||
| 769 | * <P> | ||
| 770 | * @param p the <code>Point</code> | ||
| 771 | */ | ||
| 772 | |||
| 773 | protected void initializeAutoscrolling(Point p) { | ||
| 774 | if (component == null || !(component instanceof Autoscroll)) return; | ||
| 775 | |||
| 776 | autoScroller = createDropTargetAutoScroller(component, p); | ||
| 777 | } | ||
| 778 | |||
| 779 | /** | ||
| 780 | * update autoscrolling with current cursor locn | ||
| 781 | * <P> | ||
| 782 | * @param dragCursorLocn the <code>Point</code> | ||
| 783 | */ | ||
| 784 | |||
| 785 | protected void updateAutoscroll(Point dragCursorLocn) { | ||
| 786 | if (autoScroller != null) autoScroller.updateLocation(dragCursorLocn); | ||
| 787 | } | ||
| 788 | |||
| 789 | /** | ||
| 790 | * clear autoscrolling | ||
| 791 | */ | ||
| 792 | |||
| 793 | protected void clearAutoscroll() { | ||
| 794 | if (autoScroller != null) { | ||
| 795 | autoScroller.stop(); | ||
| 796 | autoScroller = null; | ||
| 797 | } | ||
| 798 | } | ||
| 799 | |||
| 800 | /** | ||
| 801 | * The DropTargetContext associated with this DropTarget. | ||
| 802 | * | ||
| 803 | * @serial | ||
| 804 | */ | ||
| 805 | private DropTargetContext dropTargetContext = createDropTargetContext(); | ||
| 806 | |||
| 807 | /** | ||
| 808 | * The Component associated with this DropTarget. | ||
| 809 | * | ||
| 810 | * @serial | ||
| 811 | */ | ||
| 812 | private Component component; | ||
| 813 | |||
| 814 | /* | ||
| 815 | * That Component's Peer | ||
| 816 | */ | ||
| 817 | private transient ComponentPeer componentPeer; | ||
| 818 | |||
| 819 | /* | ||
| 820 | * That Component's "native" Peer | ||
| 821 | */ | ||
| 822 | private transient ComponentPeer nativePeer; | ||
| 823 | |||
| 824 | |||
| 825 | /** | ||
| 826 | * Default permissible actions supported by this DropTarget. | ||
| 827 | * | ||
| 828 | * @see #setDefaultActions | ||
| 829 | * @see #getDefaultActions | ||
| 830 | * @serial | ||
| 831 | */ | ||
| 832 | int actions = DnDConstants.ACTION_COPY_OR_MOVE; | ||
| 833 | |||
| 834 | /** | ||
| 835 | * <code>true</code> if the DropTarget is accepting Drag & Drop operations. | ||
| 836 | * | ||
| 837 | * @serial | ||
| 838 | */ | ||
| 839 | boolean active = true; | ||
| 840 | |||
| 841 | /* | ||
| 842 | * the auto scrolling object | ||
| 843 | */ | ||
| 844 | |||
| 845 | private transient DropTargetAutoScroller autoScroller; | ||
| 846 | |||
| 847 | /* | ||
| 848 | * The delegate | ||
| 849 | */ | ||
| 850 | |||
| 851 | private transient DropTargetListener dtListener; | ||
| 852 | |||
| 853 | /* | ||
| 854 | * The FlavorMap | ||
| 855 | */ | ||
| 856 | |||
| 857 | private transient FlavorMap flavorMap; | ||
| 858 | } | ||