Mercurial > projects > dwt-addons
annotate dwtx/jface/util/DelegatingDragAdapter.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, 2006 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.DelegatingDragAdapter; | |
| 14 | |
| 15 import dwtx.jface.util.TransferDragSourceListener; | |
| 16 import dwtx.jface.util.SafeRunnable; | |
| 17 | |
| 18 | |
| 19 import dwt.dnd.DragSource; | |
| 20 import dwt.dnd.DragSourceEvent; | |
| 21 import dwt.dnd.DragSourceListener; | |
| 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>DelegatingDragAdapter</code> is a <code>DragSourceListener</code> that | |
| 30 * maintains and delegates to a set of {@link TransferDragSourceListener}s. Each | |
| 31 * TransferDragSourceListener can then be implemented as if it were the | |
| 32 * <code>DragSource's</code> only DragSourceListener. | |
| 33 * <p> | |
| 34 * When a drag is started, a subset of all <code>TransferDragSourceListeners</code> | |
| 35 * is generated and stored in a list of <i>active</i> listeners. This subset is | |
| 36 * calculated by forwarding {@link DragSourceListener#dragStart(DragSourceEvent)} to | |
| 37 * every listener, and checking if the {@link DragSourceEvent#doit doit} field is left | |
| 38 * set to <code>true</code>. | |
| 39 * </p> | |
| 40 * The <code>DragSource</code>'s set of supported Transfer types ({@link | |
| 41 * DragSource#setTransfer(Transfer[])}) is updated to reflect the Transfer types | |
| 42 * corresponding to the active listener subset. | |
| 43 * <p> | |
| 44 * If and when {@link #dragSetData(DragSourceEvent)} is called, a single | |
| 45 * <code>TransferDragSourceListener</code> is chosen, and only it is allowed to set the | |
| 46 * drag data. The chosen listener is the first listener in the subset of active listeners | |
| 47 * whose Transfer supports ({@link Transfer#isSupportedType(TransferData)}) the | |
| 48 * <code>dataType</code> in the <code>DragSourceEvent</code>. | |
| 49 * </p> | |
| 50 * <p> | |
| 51 * The following example snippet shows a <code>DelegatingDragAdapter</code> with two | |
| 52 * <code>TransferDragSourceListeners</code>. One implements drag of text strings, | |
| 53 * the other supports file transfer and demonstrates how a listener can be disabled using | |
| 54 * the dragStart method. | |
| 55 * </p> | |
| 56 * <code><pre> | |
| 57 * final TreeViewer viewer = new TreeViewer(shell, DWT.NONE); | |
| 58 * | |
| 59 * DelegatingDragAdapter dragAdapter = new DelegatingDragAdapter(); | |
| 60 * dragAdapter.addDragSourceListener(new TransferDragSourceListener() { | |
| 61 * public Transfer getTransfer() { | |
| 62 * return TextTransfer.getInstance(); | |
| 63 * } | |
| 64 * public void dragStart(DragSourceEvent event) { | |
| 65 * // always enabled, can control enablement based on selection etc. | |
| 66 * } | |
| 67 * public void dragSetData(DragSourceEvent event) { | |
| 68 * event.data = "Transfer data"; | |
| 69 * } | |
| 70 * public void dragFinished(DragSourceEvent event) { | |
| 71 * // no clean-up required | |
| 72 * } | |
| 73 * }); | |
| 74 * dragAdapter.addDragSourceListener(new TransferDragSourceListener() { | |
| 75 * public Transfer getTransfer() { | |
| 76 * return FileTransfer.getInstance(); | |
| 77 * } | |
| 78 * public void dragStart(DragSourceEvent event) { | |
| 79 * // enable drag listener if there is a viewer selection | |
| 80 * event.doit = !viewer.getSelection().isEmpty(); | |
| 81 * } | |
| 82 * public void dragSetData(DragSourceEvent event) { | |
| 83 * File file1 = new File("C:/temp/file1"); | |
| 84 * File file2 = new File("C:/temp/file2"); | |
| 85 * event.data = new String[] {file1.getAbsolutePath(), file2.getAbsolutePath()}; | |
| 86 * } | |
| 87 * public void dragFinished(DragSourceEvent event) { | |
| 88 * // no clean-up required | |
| 89 * } | |
| 90 * }); | |
| 91 * viewer.addDragSupport(DND.DROP_COPY | DND.DROP_MOVE, dragAdapter.getTransfers(), dragAdapter); | |
| 92 * </pre></code> | |
| 93 * @since 3.0 | |
| 94 */ | |
| 95 public class DelegatingDragAdapter : DragSourceListener { | |
|
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
|
96 private List listeners; |
| 30 | 97 |
|
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
|
98 private List activeListeners; |
| 30 | 99 |
| 100 private TransferDragSourceListener currentListener; | |
| 101 | |
| 102 this(){ | |
|
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
|
103 listeners = new ArrayList(); |
|
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
|
104 activeListeners = new ArrayList(); |
| 30 | 105 } |
| 106 | |
| 107 /** | |
| 108 * Adds the given <code>TransferDragSourceListener</code>. | |
| 109 * | |
| 110 * @param listener the new listener | |
| 111 */ | |
| 112 public void addDragSourceListener(TransferDragSourceListener listener) { | |
|
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
|
113 listeners.add(cast(Object)listener); |
| 30 | 114 } |
| 115 | |
| 116 /** | |
| 117 * The drop has successfully completed. This event is forwarded to the current | |
| 118 * drag listener. | |
| 119 * Doesn't update the current listener, since the current listener is already the one | |
| 120 * that completed the drag operation. | |
| 121 * | |
| 122 * @param event the drag source event | |
| 123 * @see DragSourceListener#dragFinished(DragSourceEvent) | |
| 124 */ | |
| 125 public void dragFinished(DragSourceEvent event) { | |
| 126 // if (Policy.DEBUG_DRAG_DROP) | |
| 127 // System.out.println("Drag Finished: " + toString()); //$NON-NLS-1$ | |
| 39 | 128 SafeRunnable.run(new class(event) SafeRunnable { |
| 30 | 129 DragSourceEvent event_; |
| 39 | 130 this(DragSourceEvent a){ |
| 131 event_=a; | |
| 30 | 132 } |
| 133 public void run() { | |
| 134 if (currentListener !is null) { | |
| 135 // there is a listener that can handle the drop, delegate the event | |
| 136 currentListener.dragFinished(event_); | |
| 137 } else { | |
| 138 // The drag was canceled and currentListener was never set, so send the | |
| 139 // dragFinished event to all the active listeners. | |
|
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
|
140 Iterator iterator = activeListeners.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
|
141 while (iterator.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
|
142 (cast(TransferDragSourceListener) iterator.next()) |
| 30 | 143 .dragFinished(event); |
| 144 } | |
| 145 } | |
| 146 } | |
| 147 }); | |
| 148 currentListener = null; | |
| 149 activeListeners.clear(); | |
| 150 } | |
| 151 | |
| 152 /** | |
| 153 * The drop data is requested. | |
| 154 * Updates the current listener and then forwards the event to it. | |
| 155 * | |
| 156 * @param event the drag source event | |
| 157 * @see DragSourceListener#dragSetData(DragSourceEvent) | |
| 158 */ | |
| 159 public void dragSetData(DragSourceEvent event) { | |
| 160 // if (Policy.DEBUG_DRAG_DROP) | |
| 161 // System.out.println("Drag Set Data: " + toString()); //$NON-NLS-1$ | |
| 162 | |
| 163 updateCurrentListener(event); // find a listener that can provide the given data type | |
| 164 if (currentListener !is null) { | |
| 39 | 165 SafeRunnable.run(new class(event) SafeRunnable { |
| 30 | 166 DragSourceEvent event_; |
| 39 | 167 this(DragSourceEvent a){ |
| 168 event_=a; | |
| 30 | 169 } |
| 170 public void run() { | |
| 171 currentListener.dragSetData(event_); | |
| 172 } | |
| 173 }); | |
| 174 } | |
| 175 } | |
| 176 | |
| 177 /** | |
| 178 * A drag operation has started. | |
| 179 * Forwards this event to each listener. A listener must set <code>event.doit</code> | |
| 180 * to <code>false</code> if it cannot handle the drag operation. If a listener can | |
| 181 * handle the drag, it is added to the list of active listeners. | |
| 182 * The drag is aborted if there are no listeners that can handle it. | |
| 183 * | |
| 184 * @param event the drag source event | |
| 185 * @see DragSourceListener#dragStart(DragSourceEvent) | |
| 186 */ | |
| 187 public void dragStart(DragSourceEvent event) { | |
| 188 // if (Policy.DEBUG_DRAG_DROP) | |
| 189 // System.out.println("Drag Start: " + toString()); //$NON-NLS-1$ | |
| 190 bool doit = false; // true if any one of the listeners can handle the drag | |
|
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
|
191 List transfers = new ArrayList(listeners.size()); |
| 30 | 192 |
| 193 activeListeners.clear(); | |
| 194 for (int i = 0; i < listeners.size(); i++) { | |
| 195 TransferDragSourceListener listener = cast(TransferDragSourceListener) listeners | |
| 196 .get(i); | |
| 197 event.doit = true; // restore event.doit | |
| 39 | 198 SafeRunnable.run(new class(event,listener) SafeRunnable { |
| 30 | 199 TransferDragSourceListener listener_; |
| 200 DragSourceEvent event_; | |
| 39 | 201 this(DragSourceEvent a,TransferDragSourceListener b){ |
| 202 event_=a; | |
| 203 listener_=b; | |
| 30 | 204 } |
| 205 public void run() { | |
| 206 listener_.dragStart(event_); | |
| 207 } | |
| 208 }); | |
| 209 if (event.doit) { // the listener can handle this drag | |
|
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
|
210 transfers.add(listener.getTransfer()); |
|
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
|
211 activeListeners.add(cast(Object)listener); |
| 30 | 212 } |
| 213 doit |= event.doit; | |
| 214 } | |
| 215 | |
| 216 if (doit) { | |
| 217 (cast(DragSource) event.widget).setTransfer(arraycast!(Transfer)( transfers | |
| 218 .toArray())); | |
| 219 } | |
| 220 | |
| 221 event.doit = doit; | |
| 222 } | |
| 223 | |
| 224 /** | |
| 225 * Returns the <code>Transfer<code>s from every <code>TransferDragSourceListener</code>. | |
| 226 * | |
| 227 * @return the combined <code>Transfer</code>s | |
| 228 */ | |
| 229 public Transfer[] getTransfers() { | |
| 230 Transfer[] types = new Transfer[listeners.size()]; | |
| 231 for (int i = 0; i < listeners.size(); i++) { | |
| 232 TransferDragSourceListener listener = cast(TransferDragSourceListener) listeners | |
| 233 .get(i); | |
| 234 types[i] = listener.getTransfer(); | |
| 235 } | |
| 236 return types; | |
| 237 } | |
| 238 | |
| 239 /** | |
| 240 * Returns <code>true</code> if there are no listeners to delegate drag events to. | |
| 241 * | |
| 242 * @return <code>true</code> if there are no <code>TransferDragSourceListeners</code> | |
| 243 * <code>false</code> otherwise. | |
| 244 */ | |
| 245 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
|
246 return listeners.isEmpty(); |
| 30 | 247 } |
| 248 | |
| 249 /** | |
| 250 * Removes the given <code>TransferDragSourceListener</code>. | |
| 251 * Listeners should not be removed while a drag and drop operation is in progress. | |
| 252 * | |
| 253 * @param listener the <code>TransferDragSourceListener</code> to remove | |
| 254 */ | |
| 255 public void removeDragSourceListener(TransferDragSourceListener listener) { | |
| 256 listeners.remove(cast(Object)listener); | |
| 257 if (currentListener is listener) { | |
| 258 currentListener = null; | |
| 259 } | |
| 260 if (activeListeners.contains(cast(Object)listener)) { | |
| 261 activeListeners.remove(cast(Object)listener); | |
| 262 } | |
| 263 } | |
| 264 | |
| 265 /** | |
| 266 * Updates the current listener to one that can handle the drag. There can | |
| 267 * be many listeners and each listener may be able to handle many <code>TransferData</code> | |
| 268 * types. The first listener found that supports one of the <code>TransferData</ode> | |
| 269 * types specified in the <code>DragSourceEvent</code> will be selected. | |
| 270 * | |
| 271 * @param event the drag source event | |
| 272 */ | |
| 273 private void updateCurrentListener(DragSourceEvent event) { | |
| 274 currentListener = null; | |
| 275 if (event.dataType is null) { | |
| 276 return; | |
| 277 } | |
|
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
|
278 Iterator iterator = activeListeners.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
|
279 while (iterator.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
|
280 TransferDragSourceListener listener = cast(TransferDragSourceListener) 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
|
281 .next(); |
| 30 | 282 |
| 283 if (listener.getTransfer().isSupportedType(event.dataType)) { | |
| 284 // if (Policy.DEBUG_DRAG_DROP) | |
| 285 // System.out.println("Current drag listener: " + listener); //$NON-NLS-1$ | |
| 286 currentListener = listener; | |
| 287 return; | |
| 288 } | |
| 289 } | |
| 290 } | |
| 291 | |
| 292 } |