Mercurial > projects > dwt-addons
annotate dwtx/jface/util/DelegatingDropAdapter.d @ 104:04b47443bb01
Reworked the collection uses to make use of a wrapper collection that is compatible to the Java Collections.
These new wrappers now use the tango.util.containers instead of the tango.util.collections.
| author | Frank Benoit <benoit@tionex.de> |
|---|---|
| date | Thu, 07 Aug 2008 15:01:33 +0200 |
| parents | 644f1334b451 |
| children |
| rev | line source |
|---|---|
| 30 | 1 /******************************************************************************* |
| 2 * Copyright (c) 2000, 2007 IBM Corporation and others. | |
| 3 * All rights reserved. This program and the accompanying materials | |
| 4 * are made available under the terms of the Eclipse Public License v1.0 | |
| 5 * which accompanies this distribution, and is available at | |
| 6 * http://www.eclipse.org/legal/epl-v10.html | |
| 7 * | |
| 8 * Contributors: | |
| 9 * IBM Corporation - initial API and implementation | |
| 10 * Port to the D programming language: | |
| 11 * Frank Benoit <benoit@tionex.de> | |
| 12 *******************************************************************************/ | |
| 13 module dwtx.jface.util.DelegatingDropAdapter; | |
| 14 | |
| 15 import dwtx.jface.util.TransferDropTargetListener; | |
| 16 import dwtx.jface.util.SafeRunnable; | |
| 17 | |
| 18 | |
| 19 import dwt.dnd.DND; | |
| 20 import dwt.dnd.DropTargetEvent; | |
| 21 import dwt.dnd.DropTargetListener; | |
| 22 import dwt.dnd.Transfer; | |
| 23 import dwt.dnd.TransferData; | |
| 24 | |
| 25 import dwt.dwthelper.utils; | |
|
104
04b47443bb01
Reworked the collection uses to make use of a wrapper collection that is compatible to the Java Collections.
Frank Benoit <benoit@tionex.de>
parents:
39
diff
changeset
|
26 import dwtx.dwtxhelper.Collection; |
| 30 | 27 |
| 28 /** | |
| 29 * A <code>DelegatingDropAdapter</code> is a <code>DropTargetListener</code> that | |
| 30 * maintains and delegates to a set of {@link TransferDropTargetListener}s. Each | |
| 31 * <code>TransferDropTargetListener</code> can then be implemented as if it were | |
| 32 * the DropTarget's only <code>DropTargetListener</code>. | |
| 33 * <p> | |
| 34 * On <code>dragEnter</code>, <code>dragOperationChanged</code>, <code>dragOver</code> | |
| 35 * and <code>drop</code>, a <i>current</i> listener is obtained from the set of all | |
| 36 * <code>TransferDropTargetListeners</code>. The current listener is the first listener | |
| 37 * to return <code>true</code> for | |
| 38 * {@link TransferDropTargetListener#isEnabled(DropTargetEvent)}. | |
| 39 * The current listener is forwarded all <code>DropTargetEvents</code> until some other | |
| 40 * listener becomes the current listener, or the drop terminates. | |
| 41 * </p> | |
| 42 * <p> | |
| 43 * After adding all <code>TransferDropTargetListeners</code> to the | |
| 44 * <code>DelegatingDropAdapter</code> the combined set of <code>Transfers</code> should | |
| 45 * be set in the DWT <code>DropTarget</code>. <code>#getTransfers()</code> provides the | |
| 46 * set of <code>Transfer</code> types of all <code>TransferDropTargetListeners</code>. | |
| 47 * </p> | |
| 48 * <p> | |
| 49 * The following example snippet shows a <code>DelegatingDropAdapter</code> with two | |
| 50 * <code>TransferDropTargetListeners</code>. One supports dropping resources and | |
| 51 * demonstrates how a listener can be disabled in the isEnabled method. | |
| 52 * The other listener supports text transfer. | |
| 53 * </p> | |
| 54 * <code><pre> | |
| 55 * final TreeViewer viewer = new TreeViewer(shell, DWT.NONE); | |
| 56 * DelegatingDropAdapter dropAdapter = new DelegatingDropAdapter(); | |
| 57 * dropAdapter.addDropTargetListener(new TransferDropTargetListener() { | |
| 58 * public Transfer getTransfer() { | |
| 59 * return ResourceTransfer.getInstance(); | |
| 60 * } | |
| 61 * public bool isEnabled(DropTargetEvent event) { | |
| 62 * // disable drop listener if there is no viewer selection | |
| 63 * if (viewer.getSelection().isEmpty()) | |
| 64 * return false; | |
| 65 * return true; | |
| 66 * } | |
| 67 * public void dragEnter(DropTargetEvent event) {} | |
| 68 * public void dragLeave(DropTargetEvent event) {} | |
| 69 * public void dragOperationChanged(DropTargetEvent event) {} | |
| 70 * public void dragOver(DropTargetEvent event) {} | |
| 71 * public void drop(DropTargetEvent event) { | |
| 72 * if (event.data is null) | |
| 73 * return; | |
| 74 * IResource[] resources = (IResource[]) event.data; | |
| 75 * if (event.detail is DND.DROP_COPY) { | |
| 76 * // copy resources | |
| 77 * } else { | |
| 78 * // move resources | |
| 79 * } | |
| 80 * | |
| 81 * } | |
| 82 * public void dropAccept(DropTargetEvent event) {} | |
| 83 * }); | |
| 84 * dropAdapter.addDropTargetListener(new TransferDropTargetListener() { | |
| 85 * public Transfer getTransfer() { | |
| 86 * return TextTransfer.getInstance(); | |
| 87 * } | |
| 88 * public bool isEnabled(DropTargetEvent event) { | |
| 89 * return true; | |
| 90 * } | |
| 91 * public void dragEnter(DropTargetEvent event) {} | |
| 92 * public void dragLeave(DropTargetEvent event) {} | |
| 93 * public void dragOperationChanged(DropTargetEvent event) {} | |
| 94 * public void dragOver(DropTargetEvent event) {} | |
| 95 * public void drop(DropTargetEvent event) { | |
| 96 * if (event.data is null) | |
| 97 * return; | |
| 98 * System.out.println(event.data); | |
| 99 * } | |
| 100 * public void dropAccept(DropTargetEvent event) {} | |
| 101 * }); | |
| 102 * viewer.addDropSupport(DND.DROP_COPY | DND.DROP_MOVE, dropAdapter.getTransfers(), dropAdapter); | |
| 103 * </pre></code> | |
| 104 * @since 3.0 | |
| 105 */ | |
| 106 public class DelegatingDropAdapter : DropTargetListener { | |
|
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Reworked the collection uses to make use of a wrapper collection that is compatible to the Java Collections.
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parents:
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diff
changeset
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107 private List listeners; |
| 30 | 108 |
| 109 private TransferDropTargetListener currentListener; | |
| 110 | |
| 111 private int originalDropType; | |
| 112 | |
| 113 this(){ | |
|
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04b47443bb01
Reworked the collection uses to make use of a wrapper collection that is compatible to the Java Collections.
Frank Benoit <benoit@tionex.de>
parents:
39
diff
changeset
|
114 listeners = new ArrayList(); |
| 30 | 115 } |
| 116 | |
| 117 /** | |
| 118 * Adds the given <code>TransferDropTargetListener</code>. | |
| 119 * | |
| 120 * @param listener the new listener | |
| 121 */ | |
| 122 public void addDropTargetListener(TransferDropTargetListener listener) { | |
|
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04b47443bb01
Reworked the collection uses to make use of a wrapper collection that is compatible to the Java Collections.
Frank Benoit <benoit@tionex.de>
parents:
39
diff
changeset
|
123 listeners.add(cast(Object)listener); |
| 30 | 124 } |
| 125 | |
| 126 /** | |
| 127 * The cursor has entered the drop target boundaries. The current listener is | |
| 128 * updated, and <code>#dragEnter()</code> is forwarded to the current listener. | |
| 129 * | |
| 130 * @param event the drop target event | |
| 131 * @see DropTargetListener#dragEnter(DropTargetEvent) | |
| 132 */ | |
| 133 public void dragEnter(DropTargetEvent event) { | |
| 134 // if (Policy.DEBUG_DRAG_DROP) | |
| 135 // System.out.println("Drag Enter: " + toString()); //$NON-NLS-1$ | |
| 136 originalDropType = event.detail; | |
| 137 updateCurrentListener(event); | |
| 138 } | |
| 139 | |
| 140 /** | |
| 141 * The cursor has left the drop target boundaries. The event is forwarded to the | |
| 142 * current listener. | |
| 143 * | |
| 144 * @param event the drop target event | |
| 145 * @see DropTargetListener#dragLeave(DropTargetEvent) | |
| 146 */ | |
| 147 public void dragLeave(DropTargetEvent event) { | |
| 148 // if (Policy.DEBUG_DRAG_DROP) | |
| 149 // System.out.println("Drag Leave: " + toString()); //$NON-NLS-1$ | |
| 150 setCurrentListener(null, event); | |
| 151 } | |
| 152 | |
| 153 /** | |
| 154 * The operation being performed has changed (usually due to the user changing | |
| 155 * a drag modifier key while dragging). Updates the current listener and forwards | |
| 156 * this event to that listener. | |
| 157 * | |
| 158 * @param event the drop target event | |
| 159 * @see DropTargetListener#dragOperationChanged(DropTargetEvent) | |
| 160 */ | |
| 161 public void dragOperationChanged(DropTargetEvent event) { | |
| 162 // if (Policy.DEBUG_DRAG_DROP) | |
| 163 // System.out.println("Drag Operation Changed to: " + event.detail); //$NON-NLS-1$ | |
| 164 originalDropType = event.detail; | |
| 165 TransferDropTargetListener oldListener = getCurrentListener(); | |
| 166 updateCurrentListener(event); | |
| 167 TransferDropTargetListener newListener = getCurrentListener(); | |
| 168 // only notify the current listener if it hasn't changed based on the | |
| 169 // operation change. otherwise the new listener would get a dragEnter | |
| 170 // followed by a dragOperationChanged with the exact same event. | |
| 171 if (newListener !is null && newListener is oldListener) { | |
| 39 | 172 SafeRunnable.run(new class(event,newListener) SafeRunnable { |
| 30 | 173 DropTargetEvent event_; |
| 174 TransferDropTargetListener newListener_; | |
| 39 | 175 this(DropTargetEvent a,TransferDropTargetListener b){ |
| 176 event_=a; | |
| 177 newListener_=b; | |
| 30 | 178 } |
| 179 public void run() { | |
| 180 newListener_.dragOperationChanged(event_); | |
| 181 } | |
| 182 }); | |
| 183 } | |
| 184 } | |
| 185 | |
| 186 /** | |
| 187 * The cursor is moving over the drop target. Updates the current listener and | |
| 188 * forwards this event to that listener. If no listener can handle the drag | |
| 189 * operation the <code>event.detail</code> field is set to <code>DND.DROP_NONE</code> | |
| 190 * to indicate an invalid drop. | |
| 191 * | |
| 192 * @param event the drop target event | |
| 193 * @see DropTargetListener#dragOver(DropTargetEvent) | |
| 194 */ | |
| 195 public void dragOver(DropTargetEvent event) { | |
| 196 TransferDropTargetListener oldListener = getCurrentListener(); | |
| 197 updateCurrentListener(event); | |
| 198 TransferDropTargetListener newListener = getCurrentListener(); | |
| 199 | |
| 200 // only notify the current listener if it hasn't changed based on the | |
| 201 // drag over. otherwise the new listener would get a dragEnter | |
| 202 // followed by a dragOver with the exact same event. | |
| 203 if (newListener !is null && newListener is oldListener) { | |
| 39 | 204 SafeRunnable.run(new class(event,newListener) SafeRunnable { |
| 30 | 205 DropTargetEvent event_; |
| 206 TransferDropTargetListener newListener_; | |
| 39 | 207 this(DropTargetEvent a,TransferDropTargetListener b){ |
| 208 event_=a; | |
| 209 newListener_=b; | |
| 30 | 210 } |
| 211 public void run() { | |
| 212 newListener_.dragOver(event_); | |
| 213 } | |
| 214 }); | |
| 215 } | |
| 216 } | |
| 217 | |
| 218 /** | |
| 219 * Forwards this event to the current listener, if there is one. Sets the | |
| 220 * current listener to <code>null</code> afterwards. | |
| 221 * | |
| 222 * @param event the drop target event | |
| 223 * @see DropTargetListener#drop(DropTargetEvent) | |
| 224 */ | |
| 225 public void drop(DropTargetEvent event) { | |
| 226 // if (Policy.DEBUG_DRAG_DROP) | |
| 227 // System.out.println("Drop: " + toString()); //$NON-NLS-1$ | |
| 228 updateCurrentListener(event); | |
| 229 if (getCurrentListener() !is null) { | |
| 39 | 230 SafeRunnable.run(new class(event) SafeRunnable { |
| 30 | 231 DropTargetEvent event_; |
| 39 | 232 this(DropTargetEvent a){ event_=a;} |
| 30 | 233 public void run() { |
| 234 getCurrentListener().drop(event_); | |
| 235 } | |
| 236 }); | |
| 237 } | |
| 238 setCurrentListener(null, event); | |
| 239 } | |
| 240 | |
| 241 /** | |
| 242 * Forwards this event to the current listener if there is one. | |
| 243 * | |
| 244 * @param event the drop target event | |
| 245 * @see DropTargetListener#dropAccept(DropTargetEvent) | |
| 246 */ | |
| 247 public void dropAccept(DropTargetEvent event) { | |
| 248 // if (Policy.DEBUG_DRAG_DROP) | |
| 249 // System.out.println("Drop Accept: " + toString()); //$NON-NLS-1$ | |
| 250 if (getCurrentListener() !is null) { | |
| 39 | 251 SafeRunnable.run(new class(event) SafeRunnable { |
| 30 | 252 DropTargetEvent event_; |
| 39 | 253 this(DropTargetEvent a){ event_=a;} |
| 30 | 254 public void run() { |
| 255 getCurrentListener().dropAccept(event_); | |
| 256 } | |
| 257 }); | |
| 258 } | |
| 259 } | |
| 260 | |
| 261 /** | |
| 262 * Returns the listener which currently handles drop events. | |
| 263 * | |
| 264 * @return the <code>TransferDropTargetListener</code> which currently | |
| 265 * handles drop events. | |
| 266 */ | |
| 267 private TransferDropTargetListener getCurrentListener() { | |
| 268 return currentListener; | |
| 269 } | |
| 270 | |
| 271 /** | |
| 272 * Returns the transfer data type supported by the given listener. | |
| 273 * Returns <code>null</code> if the listener does not support any of the | |
| 274 * specified data types. | |
| 275 * | |
| 276 * @param dataTypes available data types | |
| 277 * @param listener <code>TransferDropTargetListener</code> to use for testing | |
| 278 * supported data types. | |
| 279 * @return the transfer data type supported by the given listener or | |
| 280 * <code>null</code>. | |
| 281 */ | |
| 282 private TransferData getSupportedTransferType(TransferData[] dataTypes, | |
| 283 TransferDropTargetListener listener) { | |
| 284 for (int i = 0; i < dataTypes.length; i++) { | |
| 285 if (listener.getTransfer().isSupportedType(dataTypes[i])) { | |
| 286 return dataTypes[i]; | |
| 287 } | |
| 288 } | |
| 289 return null; | |
| 290 } | |
| 291 | |
| 292 /** | |
| 293 * Returns the combined set of <code>Transfer</code> types of all | |
| 294 * <code>TransferDropTargetListeners</code>. | |
| 295 * | |
| 296 * @return the combined set of <code>Transfer</code> types | |
| 297 */ | |
| 298 public Transfer[] getTransfers() { | |
| 299 Transfer[] types = new Transfer[listeners.size()]; | |
| 300 for (int i = 0; i < listeners.size(); i++) { | |
| 301 TransferDropTargetListener listener = cast(TransferDropTargetListener) listeners | |
| 302 .get(i); | |
| 303 types[i] = listener.getTransfer(); | |
| 304 } | |
| 305 return types; | |
| 306 } | |
| 307 | |
| 308 /** | |
| 309 * Returns <code>true</code> if there are no listeners to delegate events to. | |
| 310 * | |
| 311 * @return <code>true</code> if there are no <code>TransferDropTargetListeners</code> | |
| 312 * <code>false</code> otherwise | |
| 313 */ | |
| 314 public bool isEmpty() { | |
|
104
04b47443bb01
Reworked the collection uses to make use of a wrapper collection that is compatible to the Java Collections.
Frank Benoit <benoit@tionex.de>
parents:
39
diff
changeset
|
315 return listeners.isEmpty(); |
| 30 | 316 } |
| 317 | |
| 318 /** | |
| 319 * Removes the given <code>TransferDropTargetListener</code>. | |
| 320 * Listeners should not be removed while a drag and drop operation is in progress. | |
| 321 * | |
| 322 * @param listener the listener to remove | |
| 323 */ | |
| 324 public void removeDropTargetListener(TransferDropTargetListener listener) { | |
| 325 if (currentListener is listener) { | |
| 326 currentListener = null; | |
| 327 } | |
| 328 listeners.remove(cast(Object)listener); | |
| 329 } | |
| 330 | |
| 331 /** | |
| 332 * Sets the current listener to <code>listener</code>. Sends the given | |
| 333 * <code>DropTargetEvent</code> if the current listener changes. | |
| 334 * | |
| 335 * @return <code>true</code> if the new listener is different than the previous | |
| 336 * <code>false</code> otherwise | |
| 337 */ | |
| 338 private bool setCurrentListener(TransferDropTargetListener listener, | |
| 339 DropTargetEvent event) { | |
| 340 if (currentListener is listener) { | |
| 341 return false; | |
| 342 } | |
| 343 if (currentListener !is null) { | |
| 39 | 344 SafeRunnable.run(new class(event) SafeRunnable { |
| 30 | 345 DropTargetEvent event_; |
| 39 | 346 this(DropTargetEvent a){ event_=a;} |
| 30 | 347 public void run() { |
| 348 currentListener.dragLeave(event_); | |
| 349 } | |
| 350 }); | |
| 351 } | |
| 352 currentListener = listener; | |
| 353 // if (Policy.DEBUG_DRAG_DROP) | |
| 354 // System.out.println("Current drop listener: " + listener); //$NON-NLS-1$ | |
| 355 if (currentListener !is null) { | |
| 39 | 356 SafeRunnable.run(new class(event) SafeRunnable { |
| 30 | 357 DropTargetEvent event_; |
| 39 | 358 this(DropTargetEvent a){ event_=a;} |
| 30 | 359 public void run() { |
| 360 currentListener.dragEnter(event_); | |
| 361 } | |
| 362 }); | |
| 363 } | |
| 364 return true; | |
| 365 } | |
| 366 | |
| 367 /** | |
| 368 * Updates the current listener to one that can handle the drop. There can be many | |
| 369 * listeners and each listener may be able to handle many <code>TransferData</code> | |
| 370 * types. The first listener found that can handle a drop of one of the given | |
| 371 * <code>TransferData</code> types will be selected. | |
| 372 * If no listener can handle the drag operation the <code>event.detail</code> field | |
| 373 * is set to <code>DND.DROP_NONE</code> to indicate an invalid drop. | |
| 374 * | |
| 375 * @param event the drop target event | |
| 376 */ | |
| 377 private void updateCurrentListener(DropTargetEvent event) { | |
| 378 int originalDetail = event.detail; | |
| 379 // revert the detail to the "original" drop type that the User indicated. | |
| 380 // this is necessary because the previous listener may have changed the detail | |
| 381 // to something other than what the user indicated. | |
| 382 event.detail = originalDropType; | |
| 383 | |
|
104
04b47443bb01
Reworked the collection uses to make use of a wrapper collection that is compatible to the Java Collections.
Frank Benoit <benoit@tionex.de>
parents:
39
diff
changeset
|
384 Iterator iter = listeners.iterator(); |
|
04b47443bb01
Reworked the collection uses to make use of a wrapper collection that is compatible to the Java Collections.
Frank Benoit <benoit@tionex.de>
parents:
39
diff
changeset
|
385 while (iter.hasNext()) { |
|
04b47443bb01
Reworked the collection uses to make use of a wrapper collection that is compatible to the Java Collections.
Frank Benoit <benoit@tionex.de>
parents:
39
diff
changeset
|
386 TransferDropTargetListener listener = cast(TransferDropTargetListener) iter |
|
04b47443bb01
Reworked the collection uses to make use of a wrapper collection that is compatible to the Java Collections.
Frank Benoit <benoit@tionex.de>
parents:
39
diff
changeset
|
387 .next(); |
| 30 | 388 TransferData dataType = getSupportedTransferType(event.dataTypes, |
| 389 listener); | |
| 390 if (dataType !is null) { | |
| 391 TransferData originalDataType = event.currentDataType; | |
| 392 // set the data type supported by the drop listener | |
| 393 event.currentDataType = dataType; | |
| 394 if (listener.isEnabled(event)) { | |
| 395 // if the listener stays the same, set its previously determined | |
| 396 // event detail | |
| 397 if (!setCurrentListener(listener, event)) { | |
| 398 event.detail = originalDetail; | |
| 399 } | |
| 400 return; | |
| 401 } | |
| 402 event.currentDataType = originalDataType; | |
| 403 } | |
| 404 } | |
| 405 setCurrentListener(null, event); | |
| 406 event.detail = DND.DROP_NONE; | |
| 407 | |
| 408 // -always- ensure that expand/scroll are on...otherwise | |
| 409 // if a valid drop target is a child of an invalid one | |
| 410 // you can't get there... | |
| 411 event.feedback = DND.FEEDBACK_EXPAND | DND.FEEDBACK_SCROLL; | |
| 412 } | |
| 413 } |