1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
|
/*******************************************************************************
* Copyright (c) 2000, 2009 IBM Corporation and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package org.eclipse.swt.dnd;
import org.eclipse.swt.*;
import org.eclipse.swt.graphics.*;
import org.eclipse.swt.widgets.*;
import org.eclipse.swt.internal.Callback;
import org.eclipse.swt.internal.carbon.CGPoint;
import org.eclipse.swt.internal.carbon.EventRecord;
import org.eclipse.swt.internal.carbon.OS;
import org.eclipse.swt.internal.carbon.Point;
/**
*
* <code>DragSource</code> defines the source object for a drag and drop transfer.
*
* <p>IMPORTANT: This class is <em>not</em> intended to be subclassed.</p>
*
* <p>A drag source is the object which originates a drag and drop operation. For the specified widget,
* it defines the type of data that is available for dragging and the set of operations that can
* be performed on that data. The operations can be any bit-wise combination of DND.MOVE, DND.COPY or
* DND.LINK. The type of data that can be transferred is specified by subclasses of Transfer such as
* TextTransfer or FileTransfer. The type of data transferred can be a predefined system type or it
* can be a type defined by the application. For instructions on how to define your own transfer type,
* refer to <code>ByteArrayTransfer</code>.</p>
*
* <p>You may have several DragSources in an application but you can only have one DragSource
* per Control. Data dragged from this DragSource can be dropped on a site within this application
* or it can be dropped on another application such as an external Text editor.</p>
*
* <p>The application supplies the content of the data being transferred by implementing the
* <code>DragSourceListener</code> and associating it with the DragSource via DragSource#addDragListener.</p>
*
* <p>When a successful move operation occurs, the application is required to take the appropriate
* action to remove the data from its display and remove any associated operating system resources or
* internal references. Typically in a move operation, the drop target makes a copy of the data
* and the drag source deletes the original. However, sometimes copying the data can take a long
* time (such as copying a large file). Therefore, on some platforms, the drop target may actually
* move the data in the operating system rather than make a copy. This is usually only done in
* file transfers. In this case, the drag source is informed in the DragEnd event that a
* DROP_TARGET_MOVE was performed. It is the responsibility of the drag source at this point to clean
* up its displayed information. No action needs to be taken on the operating system resources.</p>
*
* <p> The following example shows a Label widget that allows text to be dragged from it.</p>
*
* <code><pre>
* // Enable a label as a Drag Source
* Label label = new Label(shell, SWT.NONE);
* // This example will allow text to be dragged
* Transfer[] types = new Transfer[] {TextTransfer.getInstance()};
* // This example will allow the text to be copied or moved to the drop target
* int operations = DND.DROP_MOVE | DND.DROP_COPY;
*
* DragSource source = new DragSource(label, operations);
* source.setTransfer(types);
* source.addDragListener(new DragSourceListener() {
* public void dragStart(DragSourceEvent e) {
* // Only start the drag if there is actually text in the
* // label - this text will be what is dropped on the target.
* if (label.getText().length() == 0) {
* event.doit = false;
* }
* };
* public void dragSetData(DragSourceEvent event) {
* // A drop has been performed, so provide the data of the
* // requested type.
* // (Checking the type of the requested data is only
* // necessary if the drag source supports more than
* // one data type but is shown here as an example).
* if (TextTransfer.getInstance().isSupportedType(event.dataType)){
* event.data = label.getText();
* }
* }
* public void dragFinished(DragSourceEvent event) {
* // A Move operation has been performed so remove the data
* // from the source
* if (event.detail == DND.DROP_MOVE)
* label.setText("");
* }
* });
* </pre></code>
*
*
* <dl>
* <dt><b>Styles</b></dt> <dd>DND.DROP_NONE, DND.DROP_COPY, DND.DROP_MOVE, DND.DROP_LINK</dd>
* <dt><b>Events</b></dt> <dd>DND.DragStart, DND.DragSetData, DND.DragEnd</dd>
* </dl>
*
* @see <a href="http://www.eclipse.org/swt/snippets/#dnd">Drag and Drop snippets</a>
* @see <a href="http://www.eclipse.org/swt/examples.php">SWT Example: DNDExample</a>
* @see <a href="http://www.eclipse.org/swt/">Sample code and further information</a>
* @noextend This class is not intended to be subclassed by clients.
*/
public class DragSource extends Widget {
// info for registering as a drag source
Control control;
Listener controlListener;
Transfer[] transferAgents = new Transfer[0];
DragSourceEffect dragEffect;
static final String DEFAULT_DRAG_SOURCE_EFFECT = "DEFAULT_DRAG_SOURCE_EFFECT"; //$NON-NLS-1$
static Callback DragSendDataProc;
static {
DragSendDataProc = new Callback(DragSource.class, "DragSendDataProc", 4); //$NON-NLS-1$
int dragSendDataProcAddress = DragSendDataProc.getAddress();
if (dragSendDataProcAddress == 0) SWT.error(SWT.ERROR_NO_MORE_CALLBACKS);
}
/**
* Creates a new <code>DragSource</code> to handle dragging from the specified <code>Control</code>.
* Creating an instance of a DragSource may cause system resources to be allocated depending on the platform.
* It is therefore mandatory that the DragSource instance be disposed when no longer required.
*
* @param control the <code>Control</code> that the user clicks on to initiate the drag
* @param style the bitwise OR'ing of allowed operations; this may be a combination of any of
* DND.DROP_NONE, DND.DROP_COPY, DND.DROP_MOVE, DND.DROP_LINK
*
* @exception SWTException <ul>
* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the parent</li>
* <li>ERROR_INVALID_SUBCLASS - if this class is not an allowed subclass</li>
* </ul>
* @exception SWTError <ul>
* <li>ERROR_CANNOT_INIT_DRAG - unable to initiate drag source; this will occur if more than one
* drag source is created for a control or if the operating system will not allow the creation
* of the drag source</li>
* </ul>
*
* <p>NOTE: ERROR_CANNOT_INIT_DRAG should be an SWTException, since it is a
* recoverable error, but can not be changed due to backward compatibility.</p>
*
* @see Widget#dispose
* @see DragSource#checkSubclass
* @see DND#DROP_NONE
* @see DND#DROP_COPY
* @see DND#DROP_MOVE
* @see DND#DROP_LINK
*/
public DragSource(Control control, int style) {
super (control, checkStyle(style));
this.control = control;
if (control.getData(DND.DRAG_SOURCE_KEY) != null) {
DND.error(DND.ERROR_CANNOT_INIT_DRAG);
}
control.setData(DND.DRAG_SOURCE_KEY, this);
controlListener = new Listener () {
public void handleEvent (Event event) {
if (event.type == SWT.Dispose) {
if (!DragSource.this.isDisposed()) {
DragSource.this.dispose();
}
}
if (event.type == SWT.DragDetect) {
if (!DragSource.this.isDisposed()) {
DragSource.this.drag(event);
}
}
}
};
control.addListener (SWT.Dispose, controlListener);
control.addListener (SWT.DragDetect, controlListener);
this.addListener(SWT.Dispose, new Listener() {
public void handleEvent(Event e) {
onDispose();
}
});
Object effect = control.getData(DEFAULT_DRAG_SOURCE_EFFECT);
if (effect instanceof DragSourceEffect) {
dragEffect = (DragSourceEffect) effect;
} else if (control instanceof Tree) {
dragEffect = new TreeDragSourceEffect((Tree) control);
} else if (control instanceof Table) {
dragEffect = new TableDragSourceEffect((Table) control);
}
}
static int checkStyle (int style) {
if (style == SWT.NONE) return DND.DROP_MOVE;
return style;
}
static int DragSendDataProc(int theType, int dragSendRefCon, int theItemRef, int theDrag) {
DragSource source = FindDragSource(dragSendRefCon, theDrag);
if (source == null) return OS.cantGetFlavorErr;
return source.dragSendDataProc(theType, dragSendRefCon, theItemRef, theDrag);
}
static DragSource FindDragSource(int dragSendRefCon, int theDrag) {
if (dragSendRefCon == 0) return null;
Display display = Display.findDisplay(Thread.currentThread());
if (display == null || display.isDisposed()) return null;
Widget widget = display.findWidget(dragSendRefCon);
if (widget == null) return null;
return (DragSource)widget.getData(DND.DRAG_SOURCE_KEY);
}
/**
* Adds the listener to the collection of listeners who will
* be notified when a drag and drop operation is in progress, by sending
* it one of the messages defined in the <code>DragSourceListener</code>
* interface.
*
* <p><ul>
* <li><code>dragStart</code> is called when the user has begun the actions required to drag the widget.
* This event gives the application the chance to decide if a drag should be started.
* <li><code>dragSetData</code> is called when the data is required from the drag source.
* <li><code>dragFinished</code> is called when the drop has successfully completed (mouse up
* over a valid target) or has been terminated (such as hitting the ESC key). Perform cleanup
* such as removing data from the source side on a successful move operation.
* </ul></p>
*
* @param listener the listener which should be notified
*
* @exception IllegalArgumentException <ul>
* <li>ERROR_NULL_ARGUMENT - if the listener is null</li>
* </ul>
* @exception SWTException <ul>
* <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
* </ul>
*
* @see DragSourceListener
* @see #getDragListeners
* @see #removeDragListener
* @see DragSourceEvent
*/
public void addDragListener(DragSourceListener listener) {
if (listener == null) DND.error (SWT.ERROR_NULL_ARGUMENT);
DNDListener typedListener = new DNDListener (listener);
typedListener.dndWidget = this;
addListener (DND.DragStart, typedListener);
addListener (DND.DragSetData, typedListener);
addListener (DND.DragEnd, typedListener);
}
protected void checkSubclass () {
String name = getClass().getName ();
String validName = DragSource.class.getName();
if (!validName.equals(name)) {
DND.error (SWT.ERROR_INVALID_SUBCLASS);
}
}
void drag(Event dragEvent) {
DNDEvent event = new DNDEvent();
event.widget = this;
event.x = dragEvent.x;
event.y = dragEvent.y;
event.time = dragEvent.time;
event.doit = true;
notifyListeners(DND.DragStart, event);
if (!event.doit || transferAgents == null || transferAgents.length == 0) return;
int[] theDrag = new int[1];
if (OS.NewDrag(theDrag) != OS.noErr) {
event = new DNDEvent();
event.widget = this;
event.time = (int)System.currentTimeMillis();
event.doit = false;
event.detail = DND.DROP_NONE;
notifyListeners(DND.DragEnd, event);
return;
}
Point pt = new Point();
OS.GetGlobalMouse (pt);
for (int i = 0; i < transferAgents.length; i++) {
Transfer transfer = transferAgents[i];
if (transfer != null) {
int[] types = transfer.getTypeIds();
for (int j = 0; j < types.length; j++) {
OS.AddDragItemFlavor(theDrag[0], 1, types[j], null, 0, 0);
}
}
}
OS.SetDragSendProc(theDrag[0], DragSendDataProc.getAddress(), control.handle);
int theRegion = 0;
Image newImage = null;
try {
theRegion = OS.NewRgn();
OS.SetRectRgn(theRegion, (short)(pt.h), (short)(pt.v), (short)(pt.h+20), (short)(pt.v+20));
int operations = opToOsOp(getStyle());
//set operations twice - local and not local
OS.SetDragAllowableActions(theDrag[0], operations, true);
OS.SetDragAllowableActions(theDrag[0], operations, false);
Image image = event.image;
if (image != null) {
CGPoint imageOffsetPt = new CGPoint();
imageOffsetPt.x = 0;
imageOffsetPt.y = 0;
/*
* Bug in the Macintosh. For some reason, it seems that SetDragImageWithCGImage()
* expects an image with the alpha, otherwise the image does not draw. The fix is
* to make sure that the image has an alpha by creating a new image with alpha
* when necessary.
*/
if (OS.CGImageGetAlphaInfo(image.handle) == OS.kCGImageAlphaNoneSkipFirst) {
ImageData data = image.getImageData();
data.alpha = 0xFF;
newImage = new Image(image.getDevice(), data);
image = newImage;
}
OS.SetDragImageWithCGImage(theDrag[0], image.handle, imageOffsetPt, 0);
}
EventRecord theEvent = new EventRecord();
theEvent.message = OS.kEventMouseMoved;
theEvent.modifiers = (short)OS.GetCurrentEventKeyModifiers();
theEvent.what = (short)OS.osEvt;
theEvent.where_h = pt.h;
theEvent.where_v = pt.v;
int result = OS.TrackDrag(theDrag[0], theEvent, theRegion);
int operation = DND.DROP_NONE;
if (result == OS.noErr) {
int[] outAction = new int[1];
OS.GetDragDropAction(theDrag[0], outAction);
operation = osOpToOp(outAction[0]);
}
event = new DNDEvent();
event.widget = this;
event.time = (int)System.currentTimeMillis();
event.doit = result == OS.noErr;
event.detail = operation;
notifyListeners(DND.DragEnd, event);
} finally {
if (theRegion != 0) OS.DisposeRgn(theRegion);
if (newImage != null) newImage.dispose();
}
OS.DisposeDrag(theDrag[0]);
}
int dragSendDataProc(int theType, int dragSendRefCon, int theItemRef, int theDrag) {
if (theType == 0) return OS.badDragFlavorErr;
TransferData transferData = new TransferData();
transferData.type = theType;
DNDEvent event = new DNDEvent();
event.widget = this;
event.time = (int)System.currentTimeMillis();
event.dataType = transferData;
notifyListeners(DND.DragSetData, event);
if (!event.doit) return OS.dragNotAcceptedErr;
Transfer transfer = null;
for (int i = 0; i < transferAgents.length; i++) {
Transfer transferAgent = transferAgents[i];
if (transferAgent != null && transferAgent.isSupportedType(transferData)) {
transfer = transferAgent;
break;
}
}
if (transfer == null) return OS.badDragFlavorErr;
transfer.javaToNative(event.data, transferData);
if (transferData.result != OS.noErr) return transferData.result;
byte[] datum = transferData.data[0];
if (datum == null) return OS.cantGetFlavorErr;
int rc = OS.SetDragItemFlavorData(theDrag, theItemRef, theType, datum, datum.length, 0);
if (rc == OS.noErr && transfer instanceof FileTransfer) {
for (int i = 1; i < transferData.data.length; i++) {
datum = transferData.data[i];
if (datum == null) return OS.cantGetFlavorErr;
rc = OS.AddDragItemFlavor(theDrag, 1 + i, theType, datum, datum.length, 0);
if (rc != OS.noErr) break;
}
}
return rc;
}
/**
* Returns the Control which is registered for this DragSource. This is the control that the
* user clicks in to initiate dragging.
*
* @return the Control which is registered for this DragSource
*/
public Control getControl () {
return control;
}
/**
* Returns an array of listeners who will be notified when a drag and drop
* operation is in progress, by sending it one of the messages defined in
* the <code>DragSourceListener</code> interface.
*
* @return the listeners who will be notified when a drag and drop
* operation is in progress
*
* @exception SWTException <ul>
* <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
* </ul>
*
* @see DragSourceListener
* @see #addDragListener
* @see #removeDragListener
* @see DragSourceEvent
*
* @since 3.4
*/
public DragSourceListener[] getDragListeners() {
Listener[] listeners = getListeners(DND.DragStart);
int length = listeners.length;
DragSourceListener[] dragListeners = new DragSourceListener[length];
int count = 0;
for (int i = 0; i < length; i++) {
Listener listener = listeners[i];
if (listener instanceof DNDListener) {
dragListeners[count] = (DragSourceListener) ((DNDListener) listener).getEventListener();
count++;
}
}
if (count == length) return dragListeners;
DragSourceListener[] result = new DragSourceListener[count];
System.arraycopy(dragListeners, 0, result, 0, count);
return result;
}
/**
* Returns the drag effect that is registered for this DragSource. This drag
* effect will be used during a drag and drop operation.
*
* @return the drag effect that is registered for this DragSource
*
* @since 3.3
*/
public DragSourceEffect getDragSourceEffect() {
return dragEffect;
}
/**
* Returns the list of data types that can be transferred by this DragSource.
*
* @return the list of data types that can be transferred by this DragSource
*/
public Transfer[] getTransfer(){
return transferAgents;
}
void onDispose() {
if (control == null)
return;
if (controlListener != null) {
control.removeListener(SWT.Dispose, controlListener);
control.removeListener(SWT.DragDetect, controlListener);
}
controlListener = null;
control.setData(DND.DRAG_SOURCE_KEY, null);
control = null;
transferAgents = null;
}
int opToOsOp(int operation) {
int osOperation = 0;
if ((operation & DND.DROP_COPY) != 0){
osOperation |= OS.kDragActionCopy;
}
if ((operation & DND.DROP_LINK) != 0) {
osOperation |= OS.kDragActionAlias;
}
if ((operation & DND.DROP_MOVE) != 0) {
osOperation |= OS.kDragActionMove;
}
if ((operation & DND.DROP_TARGET_MOVE) != 0) {
osOperation |= OS.kDragActionDelete;
}
return osOperation;
}
int osOpToOp(int osOperation){
int operation = 0;
if ((osOperation & OS.kDragActionCopy) != 0){
operation |= DND.DROP_COPY;
}
if ((osOperation & OS.kDragActionAlias) != 0) {
operation |= DND.DROP_LINK;
}
if ((osOperation & OS.kDragActionDelete) != 0) {
operation |= DND.DROP_TARGET_MOVE;
}
if ((osOperation & OS.kDragActionMove) != 0) {
operation |= DND.DROP_MOVE;
}
if (osOperation == OS.kDragActionAll) {
operation = DND.DROP_COPY | DND.DROP_MOVE | DND.DROP_LINK;
}
return operation;
}
/**
* Removes the listener from the collection of listeners who will
* be notified when a drag and drop operation is in progress.
*
* @param listener the listener which should no longer be notified
*
* @exception IllegalArgumentException <ul>
* <li>ERROR_NULL_ARGUMENT - if the listener is null</li>
* </ul>
* @exception SWTException <ul>
* <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
* </ul>
*
* @see DragSourceListener
* @see #addDragListener
* @see #getDragListeners
*/
public void removeDragListener(DragSourceListener listener) {
if (listener == null) DND.error (SWT.ERROR_NULL_ARGUMENT);
removeListener (DND.DragStart, listener);
removeListener (DND.DragSetData, listener);
removeListener (DND.DragEnd, listener);
}
/**
* Specifies the drag effect for this DragSource. This drag effect will be
* used during a drag and drop operation.
*
* @param effect the drag effect that is registered for this DragSource
*
* @since 3.3
*/
public void setDragSourceEffect(DragSourceEffect effect) {
dragEffect = effect;
}
/**
* Specifies the list of data types that can be transferred by this DragSource.
* The application must be able to provide data to match each of these types when
* a successful drop has occurred.
*
* @param transferAgents a list of Transfer objects which define the types of data that can be
* dragged from this source
*/
public void setTransfer(Transfer[] transferAgents){
this.transferAgents = transferAgents;
}
}
|