blob: fac1c86426a8f94a35d396c64cc39fe1649f74ba (
plain)
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
|
/*******************************************************************************
* 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.widgets.*;
/**
* This class provides a default drag under effect (eg. select, insert, scroll and expand)
* when a drag occurs over a <code>Tree</code>.
*
* <p>Classes that wish to provide their own drag under effect for a <code>Tree</code>
* can extend the <code>TreeDropTargetEffect</code> class and override any applicable methods
* in <code>TreeDropTargetEffect</code> to display their own drag under effect.</p>
*
* Subclasses that override any methods of this class must call the corresponding
* <code>super</code> method to get the default drag under effect implementation.
*
* <p>The feedback value is either one of the FEEDBACK constants defined in
* class <code>DND</code> which is applicable to instances of this class,
* or it must be built by <em>bitwise OR</em>'ing together
* (that is, using the <code>int</code> "|" operator) two or more
* of those <code>DND</code> effect constants.
* </p>
* <p>
* <dl>
* <dt><b>Feedback:</b></dt>
* <dd>FEEDBACK_SELECT, FEEDBACK_INSERT_BEFORE, FEEDBACK_INSERT_AFTER, FEEDBACK_EXPAND, FEEDBACK_SCROLL</dd>
* </dl>
* </p><p>
* Note: Only one of the styles FEEDBACK_SELECT, FEEDBACK_INSERT_BEFORE or
* FEEDBACK_INSERT_AFTER may be specified.
* </p>
*
* @see DropTargetAdapter
* @see DropTargetEvent
* @see <a href="http://www.eclipse.org/swt/">Sample code and further information</a>
*
* @since 3.3
*/
public class TreeDropTargetEffect extends DropTargetEffect {
/**
* Creates a new <code>TreeDropTargetEffect</code> to handle the drag under effect on the specified
* <code>Tree</code>.
*
* @param tree the <code>Tree</code> over which the user positions the cursor to drop the data
*/
public TreeDropTargetEffect(Tree tree) {
super(tree);
}
int checkEffect(int effect) {
// Some effects are mutually exclusive. Make sure that only one of the mutually exclusive effects has been specified.
if ((effect & DND.FEEDBACK_SELECT) != 0) effect = effect & ~DND.FEEDBACK_INSERT_AFTER & ~DND.FEEDBACK_INSERT_BEFORE;
if ((effect & DND.FEEDBACK_INSERT_BEFORE) != 0) effect = effect & ~DND.FEEDBACK_INSERT_AFTER;
return effect;
}
/**
* This implementation of <code>dragEnter</code> provides a default drag under effect
* for the feedback specified in <code>event.feedback</code>.
*
* For additional information see <code>DropTargetAdapter.dragEnter</code>.
*
* Subclasses that override this method should call <code>super.dragEnter(event)</code>
* to get the default drag under effect implementation.
*
* @param event the information associated with the drag enter event
*
* @see DropTargetAdapter
* @see DropTargetEvent
*/
public void dragEnter(DropTargetEvent event) {
}
/**
* This implementation of <code>dragLeave</code> provides a default drag under effect
* for the feedback specified in <code>event.feedback</code>.
*
* For additional information see <code>DropTargetAdapter.dragLeave</code>.
*
* Subclasses that override this method should call <code>super.dragLeave(event)</code>
* to get the default drag under effect implementation.
*
* @param event the information associated with the drag leave event
*
* @see DropTargetAdapter
* @see DropTargetEvent
*/
public void dragLeave(DropTargetEvent event) {
}
/**
* This implementation of <code>dragOver</code> provides a default drag under effect
* for the feedback specified in <code>event.feedback</code>.
*
* For additional information see <code>DropTargetAdapter.dragOver</code>.
*
* Subclasses that override this method should call <code>super.dragOver(event)</code>
* to get the default drag under effect implementation.
*
* @param event the information associated with the drag over event
*
* @see DropTargetAdapter
* @see DropTargetEvent
* @see DND#FEEDBACK_SELECT
* @see DND#FEEDBACK_INSERT_BEFORE
* @see DND#FEEDBACK_INSERT_AFTER
* @see DND#FEEDBACK_SCROLL
*/
public void dragOver(DropTargetEvent event) {
int effect = checkEffect(event.feedback);
((DropTarget)event.widget).feedback = effect;
}
}
|
