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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 | +} | |