Showing the changes to java/pkg/java/awt/dnd/DragSourceContext.java (1 of 18352 files). Show all
Unified · Split
| @@ -0,0 +1,634 @@ | ||
| 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.awt.Component; | |
| 29 | +import java.awt.Cursor; | |
| 30 | +import java.awt.Image; | |
| 31 | +import java.awt.Point; | |
| 32 | + | |
| 33 | +import java.awt.datatransfer.DataFlavor; | |
| 34 | +import java.awt.datatransfer.Transferable; | |
| 35 | +import java.awt.datatransfer.UnsupportedFlavorException; | |
| 36 | + | |
| 37 | +import java.awt.dnd.peer.DragSourceContextPeer; | |
| 38 | + | |
| 39 | +import java.io.IOException; | |
| 40 | +import java.io.ObjectOutputStream; | |
| 41 | +import java.io.ObjectInputStream; | |
| 42 | +import java.io.Serializable; | |
| 43 | + | |
| 44 | +import java.util.TooManyListenersException; | |
| 45 | + | |
| 46 | +/** | |
| 47 | + * The <code>DragSourceContext</code> class is responsible for managing the | |
| 48 | + * initiator side of the Drag and Drop protocol. In particular, it is responsible | |
| 49 | + * for managing drag event notifications to the | |
| 50 | + * {@linkplain DragSourceListener DragSourceListeners} | |
| 51 | + * and {@linkplain DragSourceMotionListener DragSourceMotionListeners}, and providing the | |
| 52 | + * {@link Transferable} representing the source data for the drag operation. | |
| 53 | + * <p> | |
| 54 | + * Note that the <code>DragSourceContext</code> itself | |
| 55 | + * implements the <code>DragSourceListener</code> and | |
| 56 | + * <code>DragSourceMotionListener</code> interfaces. | |
| 57 | + * This is to allow the platform peer | |
| 58 | + * (the {@link DragSourceContextPeer} instance) | |
| 59 | + * created by the {@link DragSource} to notify | |
| 60 | + * the <code>DragSourceContext</code> of | |
| 61 | + * state changes in the ongoing operation. This allows the | |
| 62 | + * <code>DragSourceContext</code> object to interpose | |
| 63 | + * itself between the platform and the | |
| 64 | + * listeners provided by the initiator of the drag operation. | |
| 65 | + * <p> | |
| 66 | + * <a name="defaultCursor" /> | |
| 67 | + * By default, {@code DragSourceContext} sets the cursor as appropriate | |
| 68 | + * for the current state of the drag and drop operation. For example, if | |
| 69 | + * the user has chosen {@linkplain DnDConstants#ACTION_MOVE the move action}, | |
| 70 | + * and the pointer is over a target that accepts | |
| 71 | + * the move action, the default move cursor is shown. When | |
| 72 | + * the pointer is over an area that does not accept the transfer, | |
| 73 | + * the default "no drop" cursor is shown. | |
| 74 | + * <p> | |
| 75 | + * This default handling mechanism is disabled when a custom cursor is set | |
| 76 | + * by the {@link #setCursor} method. When the default handling is disabled, | |
| 77 | + * it becomes the responsibility | |
| 78 | + * of the developer to keep the cursor up to date, by listening | |
| 79 | + * to the {@code DragSource} events and calling the {@code setCursor()} method. | |
| 80 | + * Alternatively, you can provide custom cursor behavior by providing | |
| 81 | + * custom implementations of the {@code DragSource} | |
| 82 | + * and the {@code DragSourceContext} classes. | |
| 83 | + * | |
| 84 | + * @see DragSourceListener | |
| 85 | + * @see DragSourceMotionListener | |
| 86 | + * @see DnDConstants | |
| 87 | + * @since 1.2 | |
| 88 | + */ | |
| 89 | + | |
| 90 | +public class DragSourceContext | |
| 91 | + implements DragSourceListener, DragSourceMotionListener, Serializable { | |
| 92 | + | |
| 93 | + private static final long serialVersionUID = -115407898692194719L; | |
| 94 | + | |
| 95 | + // used by updateCurrentCursor | |
| 96 | + | |
| 97 | + /** | |
| 98 | + * An <code>int</code> used by updateCurrentCursor() | |
| 99 | + * indicating that the <code>Cursor</code> should change | |
| 100 | + * to the default (no drop) <code>Cursor</code>. | |
| 101 | + */ | |
| 102 | + protected static final int DEFAULT = 0; | |
| 103 | + | |
| 104 | + /** | |
| 105 | + * An <code>int</code> used by updateCurrentCursor() | |
| 106 | + * indicating that the <code>Cursor</code> | |
| 107 | + * has entered a <code>DropTarget</code>. | |
| 108 | + */ | |
| 109 | + protected static final int ENTER = 1; | |
| 110 | + | |
| 111 | + /** | |
| 112 | + * An <code>int</code> used by updateCurrentCursor() | |
| 113 | + * indicating that the <code>Cursor</code> is | |
| 114 | + * over a <code>DropTarget</code>. | |
| 115 | + */ | |
| 116 | + protected static final int OVER = 2; | |
| 117 | + | |
| 118 | + /** | |
| 119 | + * An <code>int</code> used by updateCurrentCursor() | |
| 120 | + * indicating that the user operation has changed. | |
| 121 | + */ | |
| 122 | + | |
| 123 | + protected static final int CHANGED = 3; | |
| 124 | + | |
| 125 | + /** | |
| 126 | + * Called from <code>DragSource</code>, this constructor creates a new | |
| 127 | + * <code>DragSourceContext</code> given the | |
| 128 | + * <code>DragSourceContextPeer</code> for this Drag, the | |
| 129 | + * <code>DragGestureEvent</code> that triggered the Drag, the initial | |
| 130 | + * <code>Cursor</code> to use for the Drag, an (optional) | |
| 131 | + * <code>Image</code> to display while the Drag is taking place, the offset | |
| 132 | + * of the <code>Image</code> origin from the hotspot at the instant of the | |
| 133 | + * triggering event, the <code>Transferable</code> subject data, and the | |
| 134 | + * <code>DragSourceListener</code> to use during the Drag and Drop | |
| 135 | + * operation. | |
| 136 | + * <br> | |
| 137 | + * If <code>DragSourceContextPeer</code> is <code>null</code> | |
| 138 | + * <code>NullPointerException</code> is thrown. | |
| 139 | + * <br> | |
| 140 | + * If <code>DragGestureEvent</code> is <code>null</code> | |
| 141 | + * <code>NullPointerException</code> is thrown. | |
| 142 | + * <br> | |
| 143 | + * If <code>Cursor</code> is <code>null</code> no exception is thrown and | |
| 144 | + * the default drag cursor behavior is activated for this drag operation. | |
| 145 | + * <br> | |
| 146 | + * If <code>Image</code> is <code>null</code> no exception is thrown. | |
| 147 | + * <br> | |
| 148 | + * If <code>Image</code> is not <code>null</code> and the offset is | |
| 149 | + * <code>null</code> <code>NullPointerException</code> is thrown. | |
| 150 | + * <br> | |
| 151 | + * If <code>Transferable</code> is <code>null</code> | |
| 152 | + * <code>NullPointerException</code> is thrown. | |
| 153 | + * <br> | |
| 154 | + * If <code>DragSourceListener</code> is <code>null</code> no exception | |
| 155 | + * is thrown. | |
| 156 | + * | |
| 157 | + * @param dscp the <code>DragSourceContextPeer</code> for this drag | |
| 158 | + * @param trigger the triggering event | |
| 159 | + * @param dragCursor the initial {@code Cursor} for this drag operation | |
| 160 | + * or {@code null} for the default cursor handling; | |
| 161 | + * see <a href="DragSourceContext.html#defaultCursor">class level documentation</a> | |
| 162 | + * for more details on the cursor handling mechanism during drag and drop | |
| 163 | + * @param dragImage the <code>Image</code> to drag (or <code>null</code>) | |
| 164 | + * @param offset the offset of the image origin from the hotspot at the | |
| 165 | + * instant of the triggering event | |
| 166 | + * @param t the <code>Transferable</code> | |
| 167 | + * @param dsl the <code>DragSourceListener</code> | |
| 168 | + * | |
| 169 | + * @throws IllegalArgumentException if the <code>Component</code> associated | |
| 170 | + * with the trigger event is <code>null</code>. | |
| 171 | + * @throws IllegalArgumentException if the <code>DragSource</code> for the | |
| 172 | + * trigger event is <code>null</code>. | |
| 173 | + * @throws IllegalArgumentException if the drag action for the | |
| 174 | + * trigger event is <code>DnDConstants.ACTION_NONE</code>. | |
| 175 | + * @throws IllegalArgumentException if the source actions for the | |
| 176 | + * <code>DragGestureRecognizer</code> associated with the trigger | |
| 177 | + * event are equal to <code>DnDConstants.ACTION_NONE</code>. | |
| 178 | + * @throws NullPointerException if dscp, trigger, or t are null, or | |
| 179 | + * if dragImage is non-null and offset is null | |
| 180 | + */ | |
| 181 | + public DragSourceContext(DragSourceContextPeer dscp, | |
| 182 | + DragGestureEvent trigger, Cursor dragCursor, | |
| 183 | + Image dragImage, Point offset, Transferable t, | |
| 184 | + DragSourceListener dsl) { | |
| 185 | + if (dscp == null) { | |
| 186 | + throw new NullPointerException("DragSourceContextPeer"); | |
| 187 | + } | |
| 188 | + | |
| 189 | + if (trigger == null) { | |
| 190 | + throw new NullPointerException("Trigger"); | |
| 191 | + } | |
| 192 | + | |
| 193 | + if (trigger.getDragSource() == null) { | |
| 194 | + throw new IllegalArgumentException("DragSource"); | |
| 195 | + } | |
| 196 | + | |
| 197 | + if (trigger.getComponent() == null) { | |
| 198 | + throw new IllegalArgumentException("Component"); | |
| 199 | + } | |
| 200 | + | |
| 201 | + if (trigger.getSourceAsDragGestureRecognizer().getSourceActions() == | |
| 202 | + DnDConstants.ACTION_NONE) { | |
| 203 | + throw new IllegalArgumentException("source actions"); | |
| 204 | + } | |
| 205 | + | |
| 206 | + if (trigger.getDragAction() == DnDConstants.ACTION_NONE) { | |
| 207 | + throw new IllegalArgumentException("no drag action"); | |
| 208 | + } | |
| 209 | + | |
| 210 | + if (t == null) { | |
| 211 | + throw new NullPointerException("Transferable"); | |
| 212 | + } | |
| 213 | + | |
| 214 | + if (dragImage != null && offset == null) { | |
| 215 | + throw new NullPointerException("offset"); | |
| 216 | + } | |
| 217 | + | |
| 218 | + peer = dscp; | |
| 219 | + this.trigger = trigger; | |
| 220 | + cursor = dragCursor; | |
| 221 | + transferable = t; | |
| 222 | + listener = dsl; | |
| 223 | + sourceActions = | |
| 224 | + trigger.getSourceAsDragGestureRecognizer().getSourceActions(); | |
| 225 | + | |
| 226 | + useCustomCursor = (dragCursor != null); | |
| 227 | + | |
| 228 | + updateCurrentCursor(trigger.getDragAction(), getSourceActions(), DEFAULT); | |
| 229 | + } | |
| 230 | + | |
| 231 | + /** | |
| 232 | + * Returns the <code>DragSource</code> | |
| 233 | + * that instantiated this <code>DragSourceContext</code>. | |
| 234 | + * | |
| 235 | + * @return the <code>DragSource</code> that | |
| 236 | + * instantiated this <code>DragSourceContext</code> | |
| 237 | + */ | |
| 238 | + | |
| 239 | + public DragSource getDragSource() { return trigger.getDragSource(); } | |
| 240 | + | |
| 241 | + /** | |
| 242 | + * Returns the <code>Component</code> associated with this | |
| 243 | + * <code>DragSourceContext</code>. | |
| 244 | + * | |
| 245 | + * @return the <code>Component</code> that started the drag | |
| 246 | + */ | |
| 247 | + | |
| 248 | + public Component getComponent() { return trigger.getComponent(); } | |
| 249 | + | |
| 250 | + /** | |
| 251 | + * Returns the <code>DragGestureEvent</code> | |
| 252 | + * that initially triggered the drag. | |
| 253 | + * | |
| 254 | + * @return the Event that triggered the drag | |
| 255 | + */ | |
| 256 | + | |
| 257 | + public DragGestureEvent getTrigger() { return trigger; } | |
| 258 | + | |
| 259 | + /** | |
| 260 | + * Returns a bitwise mask of <code>DnDConstants</code> that | |
| 261 | + * represent the set of drop actions supported by the drag source for the | |
| 262 | + * drag operation associated with this <code>DragSourceContext</code>. | |
| 263 | + * | |
| 264 | + * @return the drop actions supported by the drag source | |
| 265 | + */ | |
| 266 | + public int getSourceActions() { | |
| 267 | + return sourceActions; | |
| 268 | + } | |
| 269 | + | |
| 270 | + /** | |
| 271 | + * Sets the cursor for this drag operation to the specified | |
| 272 | + * <code>Cursor</code>. If the specified <code>Cursor</code> | |
| 273 | + * is <code>null</code>, the default drag cursor behavior is | |
| 274 | + * activated for this drag operation, otherwise it is deactivated. | |
| 275 | + * | |
| 276 | + * @param c the initial {@code Cursor} for this drag operation, | |
| 277 | + * or {@code null} for the default cursor handling; | |
| 278 | + * see {@linkplain Cursor class | |
| 279 | + * level documentation} for more details | |
| 280 | + * on the cursor handling during drag and drop | |
| 281 | + * | |
| 282 | + */ | |
| 283 | + | |
| 284 | + public synchronized void setCursor(Cursor c) { | |
| 285 | + useCustomCursor = (c != null); | |
| 286 | + setCursorImpl(c); | |
| 287 | + } | |
| 288 | + | |
| 289 | + /** | |
| 290 | + * Returns the current drag <code>Cursor</code>. | |
| 291 | + * <P> | |
| 292 | + * @return the current drag <code>Cursor</code> | |
| 293 | + */ | |
| 294 | + | |
| 295 | + public Cursor getCursor() { return cursor; } | |
| 296 | + | |
| 297 | + /** | |
| 298 | + * Add a <code>DragSourceListener</code> to this | |
| 299 | + * <code>DragSourceContext</code> if one has not already been added. | |
| 300 | + * If a <code>DragSourceListener</code> already exists, | |
| 301 | + * this method throws a <code>TooManyListenersException</code>. | |
| 302 | + * <P> | |
| 303 | + * @param dsl the <code>DragSourceListener</code> to add. | |
| 304 | + * Note that while <code>null</code> is not prohibited, | |
| 305 | + * it is not acceptable as a parameter. | |
| 306 | + * <P> | |
| 307 | + * @throws TooManyListenersException if | |
| 308 | + * a <code>DragSourceListener</code> has already been added | |
| 309 | + */ | |
| 310 | + | |
| 311 | + public synchronized void addDragSourceListener(DragSourceListener dsl) throws TooManyListenersException { | |
| 312 | + if (dsl == null) return; | |
| 313 | + | |
| 314 | + if (equals(dsl)) throw new IllegalArgumentException("DragSourceContext may not be its own listener"); | |
| 315 | + | |
| 316 | + if (listener != null) | |
| 317 | + throw new TooManyListenersException(); | |
| 318 | + else | |
| 319 | + listener = dsl; | |
| 320 | + } | |
| 321 | + | |
| 322 | + /** | |
| 323 | + * Removes the specified <code>DragSourceListener</code> | |
| 324 | + * from this <code>DragSourceContext</code>. | |
| 325 | + * | |
| 326 | + * @param dsl the <code>DragSourceListener</code> to remove; | |
| 327 | + * note that while <code>null</code> is not prohibited, | |
| 328 | + * it is not acceptable as a parameter | |
| 329 | + */ | |
| 330 | + | |
| 331 | + public synchronized void removeDragSourceListener(DragSourceListener dsl) { | |
| 332 | + if (listener != null && listener.equals(dsl)) { | |
| 333 | + listener = null; | |
| 334 | + } else | |
| 335 | + throw new IllegalArgumentException(); | |
| 336 | + } | |
| 337 | + | |
| 338 | + /** | |
| 339 | + * Notifies the peer that the <code>Transferable</code>'s | |
| 340 | + * <code>DataFlavor</code>s have changed. | |
| 341 | + */ | |
| 342 | + | |
| 343 | + public void transferablesFlavorsChanged() { | |
| 344 | + if (peer != null) peer.transferablesFlavorsChanged(); | |
| 345 | + } | |
| 346 | + | |
| 347 | + /** | |
| 348 | + * Calls <code>dragEnter</code> on the | |
| 349 | + * <code>DragSourceListener</code>s registered with this | |
| 350 | + * <code>DragSourceContext</code> and with the associated | |
| 351 | + * <code>DragSource</code>, and passes them the specified | |
| 352 | + * <code>DragSourceDragEvent</code>. | |
| 353 | + * | |
| 354 | + * @param dsde the <code>DragSourceDragEvent</code> | |
| 355 | + */ | |
| 356 | + public void dragEnter(DragSourceDragEvent dsde) { | |
| 357 | + DragSourceListener dsl = listener; | |
| 358 | + if (dsl != null) { | |
| 359 | + dsl.dragEnter(dsde); | |
| 360 | + } | |
| 361 | + getDragSource().processDragEnter(dsde); | |
| 362 | + | |
| 363 | + updateCurrentCursor(getSourceActions(), dsde.getTargetActions(), ENTER); | |
| 364 | + } | |
| 365 | + | |
| 366 | + /** | |
| 367 | + * Calls <code>dragOver</code> on the | |
| 368 | + * <code>DragSourceListener</code>s registered with this | |
| 369 | + * <code>DragSourceContext</code> and with the associated | |
| 370 | + * <code>DragSource</code>, and passes them the specified | |
| 371 | + * <code>DragSourceDragEvent</code>. | |
| 372 | + * | |
| 373 | + * @param dsde the <code>DragSourceDragEvent</code> | |
| 374 | + */ | |
| 375 | + public void dragOver(DragSourceDragEvent dsde) { | |
| 376 | + DragSourceListener dsl = listener; | |
| 377 | + if (dsl != null) { | |
| 378 | + dsl.dragOver(dsde); | |
| 379 | + } | |
| 380 | + getDragSource().processDragOver(dsde); | |
| 381 | + | |
| 382 | + updateCurrentCursor(getSourceActions(), dsde.getTargetActions(), OVER); | |
| 383 | + } | |
| 384 | + | |
| 385 | + /** | |
| 386 | + * Calls <code>dragExit</code> on the | |
| 387 | + * <code>DragSourceListener</code>s registered with this | |
| 388 | + * <code>DragSourceContext</code> and with the associated | |
| 389 | + * <code>DragSource</code>, and passes them the specified | |
| 390 | + * <code>DragSourceEvent</code>. | |
| 391 | + * | |
| 392 | + * @param dse the <code>DragSourceEvent</code> | |
| 393 | + */ | |
| 394 | + public void dragExit(DragSourceEvent dse) { | |
| 395 | + DragSourceListener dsl = listener; | |
| 396 | + if (dsl != null) { | |
| 397 | + dsl.dragExit(dse); | |
| 398 | + } | |
| 399 | + getDragSource().processDragExit(dse); | |
| 400 | + | |
| 401 | + updateCurrentCursor(DnDConstants.ACTION_NONE, DnDConstants.ACTION_NONE, DEFAULT); | |
| 402 | + } | |
| 403 | + | |
| 404 | + /** | |
| 405 | + * Calls <code>dropActionChanged</code> on the | |
| 406 | + * <code>DragSourceListener</code>s registered with this | |
| 407 | + * <code>DragSourceContext</code> and with the associated | |
| 408 | + * <code>DragSource</code>, and passes them the specified | |
| 409 | + * <code>DragSourceDragEvent</code>. | |
| 410 | + * | |
| 411 | + * @param dsde the <code>DragSourceDragEvent</code> | |
| 412 | + */ | |
| 413 | + public void dropActionChanged(DragSourceDragEvent dsde) { | |
| 414 | + DragSourceListener dsl = listener; | |
| 415 | + if (dsl != null) { | |
| 416 | + dsl.dropActionChanged(dsde); | |
| 417 | + } | |
| 418 | + getDragSource().processDropActionChanged(dsde); | |
| 419 | + | |
| 420 | + updateCurrentCursor(getSourceActions(), dsde.getTargetActions(), CHANGED); | |
| 421 | + } | |
| 422 | + | |
| 423 | + /** | |
| 424 | + * Calls <code>dragDropEnd</code> on the | |
| 425 | + * <code>DragSourceListener</code>s registered with this | |
| 426 | + * <code>DragSourceContext</code> and with the associated | |
| 427 | + * <code>DragSource</code>, and passes them the specified | |
| 428 | + * <code>DragSourceDropEvent</code>. | |
| 429 | + * | |
| 430 | + * @param dsde the <code>DragSourceDropEvent</code> | |
| 431 | + */ | |
| 432 | + public void dragDropEnd(DragSourceDropEvent dsde) { | |
| 433 | + DragSourceListener dsl = listener; | |
| 434 | + if (dsl != null) { | |
| 435 | + dsl.dragDropEnd(dsde); | |
| 436 | + } | |
| 437 | + getDragSource().processDragDropEnd(dsde); | |
| 438 | + } | |
| 439 | + | |
| 440 | + /** | |
| 441 | + * Calls <code>dragMouseMoved</code> on the | |
| 442 | + * <code>DragSourceMotionListener</code>s registered with the | |
| 443 | + * <code>DragSource</code> associated with this | |
| 444 | + * <code>DragSourceContext</code>, and them passes the specified | |
| 445 | + * <code>DragSourceDragEvent</code>. | |
| 446 | + * | |
| 447 | + * @param dsde the <code>DragSourceDragEvent</code> | |
| 448 | + * @since 1.4 | |
| 449 | + */ | |
| 450 | + public void dragMouseMoved(DragSourceDragEvent dsde) { | |
| 451 | + getDragSource().processDragMouseMoved(dsde); | |
| 452 | + } | |
| 453 | + | |
| 454 | + /** | |
| 455 | + * Returns the <code>Transferable</code> associated with | |
| 456 | + * this <code>DragSourceContext</code>. | |
| 457 | + * | |
| 458 | + * @return the <code>Transferable</code> | |
| 459 | + */ | |
| 460 | + public Transferable getTransferable() { return transferable; } | |
| 461 | + | |
| 462 | + /** | |
| 463 | + * If the default drag cursor behavior is active, this method | |
| 464 | + * sets the default drag cursor for the specified actions | |
| 465 | + * supported by the drag source, the drop target action, | |
| 466 | + * and status, otherwise this method does nothing. | |
| 467 | + * | |
| 468 | + * @param sourceAct the actions supported by the drag source | |
| 469 | + * @param targetAct the drop target action | |
| 470 | + * @param status one of the fields <code>DEFAULT</code>, | |
| 471 | + * <code>ENTER</code>, <code>OVER</code>, | |
| 472 | + * <code>CHANGED</code> | |
| 473 | + */ | |
| 474 | + | |
| 475 | + protected synchronized void updateCurrentCursor(int sourceAct, int targetAct, int status) { | |
| 476 | + | |
| 477 | + // if the cursor has been previously set then dont do any defaults | |
| 478 | + // processing. | |
| 479 | + | |
| 480 | + if (useCustomCursor) { | |
| 481 | + return; | |
| 482 | + } | |
| 483 | + | |
| 484 | + // do defaults processing | |
| 485 | + | |
| 486 | + Cursor c = null; | |
| 487 | + | |
| 488 | + switch (status) { | |
| 489 | + default: | |
| 490 | + targetAct = DnDConstants.ACTION_NONE; | |
| 491 | + case ENTER: | |
| 492 | + case OVER: | |
| 493 | + case CHANGED: | |
| 494 | + int ra = sourceAct & targetAct; | |
| 495 | + | |
| 496 | + if (ra == DnDConstants.ACTION_NONE) { // no drop possible | |
| 497 | + if ((sourceAct & DnDConstants.ACTION_LINK) == DnDConstants.ACTION_LINK) | |
| 498 | + c = DragSource.DefaultLinkNoDrop; | |
| 499 | + else if ((sourceAct & DnDConstants.ACTION_MOVE) == DnDConstants.ACTION_MOVE) | |
| 500 | + c = DragSource.DefaultMoveNoDrop; | |
| 501 | + else | |
| 502 | + c = DragSource.DefaultCopyNoDrop; | |
| 503 | + } else { // drop possible | |
| 504 | + if ((ra & DnDConstants.ACTION_LINK) == DnDConstants.ACTION_LINK) | |
| 505 | + c = DragSource.DefaultLinkDrop; | |
| 506 | + else if ((ra & DnDConstants.ACTION_MOVE) == DnDConstants.ACTION_MOVE) | |
| 507 | + c = DragSource.DefaultMoveDrop; | |
| 508 | + else | |
| 509 | + c = DragSource.DefaultCopyDrop; | |
| 510 | + } | |
| 511 | + } | |
| 512 | + | |
| 513 | + setCursorImpl(c); | |
| 514 | + } | |
| 515 | + | |
| 516 | + private void setCursorImpl(Cursor c) { | |
| 517 | + if (cursor == null || !cursor.equals(c)) { | |
| 518 | + cursor = c; | |
| 519 | + if (peer != null) peer.setCursor(cursor); | |
| 520 | + } | |
| 521 | + } | |
| 522 | + | |
| 523 | + /** | |
| 524 | + * Serializes this <code>DragSourceContext</code>. This method first | |
| 525 | + * performs default serialization. Next, this object's | |
| 526 | + * <code>Transferable</code> is written out if and only if it can be | |
| 527 | + * serialized. If not, <code>null</code> is written instead. In this case, | |
| 528 | + * a <code>DragSourceContext</code> created from the resulting deserialized | |
| 529 | + * stream will contain a dummy <code>Transferable</code> which supports no | |
| 530 | + * <code>DataFlavor</code>s. Finally, this object's | |
| 531 | + * <code>DragSourceListener</code> is written out if and only if it can be | |
| 532 | + * serialized. If not, <code>null</code> is written instead. | |
| 533 | + * | |
| 534 | + * @serialData The default serializable fields, in alphabetical order, | |
| 535 | + * followed by either a <code>Transferable</code> instance, or | |
| 536 | + * <code>null</code>, followed by either a | |
| 537 | + * <code>DragSourceListener</code> instance, or | |
| 538 | + * <code>null</code>. | |
| 539 | + * @since 1.4 | |
| 540 | + */ | |
| 541 | + private void writeObject(ObjectOutputStream s) throws IOException { | |
| 542 | + s.defaultWriteObject(); | |
| 543 | + | |
| 544 | + s.writeObject(SerializationTester.test(transferable) | |
| 545 | + ? transferable : null); | |
| 546 | + s.writeObject(SerializationTester.test(listener) | |
| 547 | + ? listener : null); | |
| 548 | + } | |
| 549 | + | |
| 550 | + /** | |
| 551 | + * Deserializes this <code>DragSourceContext</code>. This method first | |
| 552 | + * performs default deserialization for all non-<code>transient</code> | |
| 553 | + * fields. This object's <code>Transferable</code> and | |
| 554 | + * <code>DragSourceListener</code> are then deserialized as well by using | |
| 555 | + * the next two objects in the stream. If the resulting | |
| 556 | + * <code>Transferable</code> is <code>null</code>, this object's | |
| 557 | + * <code>Transferable</code> is set to a dummy <code>Transferable</code> | |
| 558 | + * which supports no <code>DataFlavor</code>s. | |
| 559 | + * | |
| 560 | + * @since 1.4 | |
| 561 | + */ | |
| 562 | + private void readObject(ObjectInputStream s) | |
| 563 | + throws ClassNotFoundException, IOException | |
| 564 | + { | |
| 565 | + s.defaultReadObject(); | |
| 566 | + | |
| 567 | + transferable = (Transferable)s.readObject(); | |
| 568 | + listener = (DragSourceListener)s.readObject(); | |
| 569 | + | |
| 570 | + // Implementation assumes 'transferable' is never null. | |
| 571 | + if (transferable == null) { | |
| 572 | + if (emptyTransferable == null) { | |
| 573 | + emptyTransferable = new Transferable() { | |
| 574 | + public DataFlavor[] getTransferDataFlavors() { | |
| 575 | + return new DataFlavor[0]; | |
| 576 | + } | |
| 577 | + public boolean isDataFlavorSupported(DataFlavor flavor) | |
| 578 | + { | |
| 579 | + return false; | |
| 580 | + } | |
| 581 | + public Object getTransferData(DataFlavor flavor) | |
| 582 | + throws UnsupportedFlavorException | |
| 583 | + { | |
| 584 | + throw new UnsupportedFlavorException(flavor); | |
| 585 | + } | |
| 586 | + }; | |
| 587 | + } | |
| 588 | + transferable = emptyTransferable; | |
| 589 | + } | |
| 590 | + } | |
| 591 | + | |
| 592 | + private static Transferable emptyTransferable; | |
| 593 | + | |
| 594 | + /* | |
| 595 | + * fields | |
| 596 | + */ | |
| 597 | + | |
| 598 | + private transient DragSourceContextPeer peer; | |
| 599 | + | |
| 600 | + /** | |
| 601 | + * The event which triggered the start of the drag. | |
| 602 | + * | |
| 603 | + * @serial | |
| 604 | + */ | |
| 605 | + private DragGestureEvent trigger; | |
| 606 | + | |
| 607 | + /** | |
| 608 | + * The current drag cursor. | |
| 609 | + * | |
| 610 | + * @serial | |
| 611 | + */ | |
| 612 | + private Cursor cursor; | |
| 613 | + | |
| 614 | + private transient Transferable transferable; | |
| 615 | + | |
| 616 | + private transient DragSourceListener listener; | |
| 617 | + | |
| 618 | + /** | |
| 619 | + * <code>true</code> if the custom drag cursor is used instead of the | |
| 620 | + * default one. | |
| 621 | + * | |
| 622 | + * @serial | |
| 623 | + */ | |
| 624 | + private boolean useCustomCursor; | |
| 625 | + | |
| 626 | + /** | |
| 627 | + * A bitwise mask of <code>DnDConstants</code> that represents the set of | |
| 628 | + * drop actions supported by the drag source for the drag operation associated | |
| 629 | + * with this <code>DragSourceContext.</code> | |
| 630 | + * | |
| 631 | + * @serial | |
| 632 | + */ | |
| 633 | + private final int sourceActions; | |
| 634 | +} | |