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