Skip to main content
aboutsummaryrefslogtreecommitdiffstats
blob: 00642a449b7bbe51dccbbd82d2b75013a93d70b6 (plain) (blame)
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
/*******************************************************************************
 * Copyright (c) 2000, 2008 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.graphics.*;
import org.eclipse.swt.internal.gtk.*;
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 {
	static final int SCROLL_HYSTERESIS = 150; // milli seconds
	static final int EXPAND_HYSTERESIS = 1000; // milli seconds

	int scrollIndex = -1;
	long scrollBeginTime;

	int expandIndex = -1;
	long expandBeginTime;

	/**
	 * 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) {
		expandBeginTime = 0;
		expandIndex = -1;	
		scrollBeginTime = 0;
		scrollIndex = -1;
	}
	
	/**
	 * 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) {
		Tree tree = (Tree) control;
		int /*long*/ handle = tree.handle;
		OS.gtk_tree_view_set_drag_dest_row(handle, 0, OS.GTK_TREE_VIEW_DROP_BEFORE);

		scrollBeginTime = 0;
		scrollIndex = -1;
		expandBeginTime = 0;
		expandIndex = -1;
	}

	/**
	 * 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) {
		Tree tree = (Tree) control;
		int effect = checkEffect(event.feedback);

		int /*long*/ handle = tree.handle;
		Point coordinates = new Point(event.x, event.y);
		coordinates = tree.toControl(coordinates);
		int /*long*/ [] path = new int /*long*/ [1];
		OS.gtk_tree_view_get_path_at_pos (handle, coordinates.x, coordinates.y, path, null, null, null);
		int index = -1;
		if (path[0] != 0) {
			int /*long*/ indices = OS.gtk_tree_path_get_indices(path[0]);
			if (indices != 0) {	
				int depth = OS.gtk_tree_path_get_depth(path[0]);
				int[] temp = new int[depth];
				OS.memmove (temp, indices, temp.length * 4);
				index = temp[temp.length - 1];
			}
		}
		if ((effect & DND.FEEDBACK_SCROLL) == 0) {
			scrollBeginTime = 0;
			scrollIndex = -1;
		} else {
			if (index != -1 && scrollIndex == index && scrollBeginTime != 0) {
				if (System.currentTimeMillis() >= scrollBeginTime) {
					GdkRectangle cellRect = new GdkRectangle ();
					OS.gtk_tree_view_get_cell_area (handle, path[0], 0, cellRect);
					if (cellRect.y < cellRect.height) {
						int[] tx = new int[1], ty = new int[1];
						if (OS.GTK_VERSION >= OS.VERSION(2, 12, 0)) {
							OS.gtk_tree_view_widget_to_tree_coords(handle, cellRect.x, cellRect.y - cellRect.height, tx, ty);
						} else {
							OS.gtk_tree_view_convert_widget_to_bin_window_coords(handle, cellRect.x, cellRect.y - cellRect.height, tx, ty);
						}
						OS.gtk_tree_view_scroll_to_point (handle, -1, ty[0]);
					} else {
						//scroll down
						OS.gtk_tree_view_get_path_at_pos (handle, coordinates.x, coordinates.y + cellRect.height, path, null, null, null);
						if (path[0] != 0) {
							OS.gtk_tree_view_scroll_to_cell(handle, path[0], 0, false, 0, 0);
							OS.gtk_tree_path_free(path[0]);
							path[0] = 0;
						}
						OS.gtk_tree_view_get_path_at_pos (handle, coordinates.x, coordinates.y, path, null, null, null);	
					}
					scrollBeginTime = 0;
					scrollIndex = -1;
				}
			} else {
				scrollBeginTime = System.currentTimeMillis() + SCROLL_HYSTERESIS;
				scrollIndex = index;
			}
		}
		if ((effect & DND.FEEDBACK_EXPAND) == 0) {
			expandBeginTime = 0;
			expandIndex = -1;
		} else {
			if (index != -1 && expandIndex == index && expandBeginTime != 0) {
				if (System.currentTimeMillis() >= expandBeginTime) {
					OS.gtk_tree_view_expand_row (handle, path[0], false);
					expandBeginTime = 0;
					expandIndex = -1;
				}
			} else {
				expandBeginTime = System.currentTimeMillis() + EXPAND_HYSTERESIS;
				expandIndex = index;
			}
		}
		if (path[0] != 0) {
			int position = -1;
			if ((effect & DND.FEEDBACK_SELECT) != 0) position = OS.GTK_TREE_VIEW_DROP_INTO_OR_BEFORE;
			if ((effect & DND.FEEDBACK_INSERT_BEFORE) != 0) position = OS.GTK_TREE_VIEW_DROP_BEFORE;
			if ((effect & DND.FEEDBACK_INSERT_AFTER) != 0) position = OS.GTK_TREE_VIEW_DROP_AFTER;		
			if (position != -1) {
				OS.gtk_tree_view_set_drag_dest_row(handle, path[0], position);
			} else {
				OS.gtk_tree_view_set_drag_dest_row(handle, 0, OS.GTK_TREE_VIEW_DROP_BEFORE);
			}
		} else {
			OS.gtk_tree_view_set_drag_dest_row(handle, 0, OS.GTK_TREE_VIEW_DROP_BEFORE);
		}
		
		if (path[0] != 0) OS.gtk_tree_path_free (path [0]);
	}

}

Back to the top