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
|
/* SelectionModel.java
* =========================================================================
* This file is part of the GrInvIn project - http://www.grinvin.org
*
* Copyright (C) 2005-2008 Universiteit Gent
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or (at
* your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* A copy of the GNU General Public License can be found in the file
* LICENSE.txt provided with the source distribution of this program (see
* the META-INF directory in the source jar). This license can also be
* found on the GNU website at http://www.gnu.org/licenses/gpl.html.
*
* If you did not receive a copy of the GNU General Public License along
* with this program, contact the lead developer, or write to the Free
* Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*/
package org.grinvin.gui;
import java.util.Collection;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Observable;
/**
* Keeps track of a selection of items of similar type. This model allows
* multiple selections (but no interval selections).<p>
*/
public class SelectionModel<T> extends Observable implements Iterable<T> {
/**
* Tell all observers that the selection has changed.
*/
protected void notifySelectionChanged () {
setChanged();
notifyObservers();
}
// Keeps track of the current selection
protected Collection<T> selection ;
/**
* Clear the selection.
*/
public void clearSelection() {
if (! selection.isEmpty()) {
selection.clear ();
notifySelectionChanged ();
}
}
/**
* Check whether the current selection is empty.
* @return {@code true} if and only if the selection is empty.
*/
public boolean isSelectionEmpty() {
return selection.isEmpty();
}
/**
* Check whether the given element is selected.
* @return whether the given item is currently selected.
*/
public boolean isSelected (T item) {
return selection.contains(item);
}
/**
* Toggles the selection.
* Removes the given item from the selection if it already
* belongs to the selection. Otherwise adds it to the selection.
*/
public void toggleSelection (T item) {
if (!selection.remove(item)) {
selection.add(item);
}
notifySelectionChanged ();
}
/**
* Set the selection to be (only) the given object.
*/
public void setSelection (T v) {
if (selection.size() !=1 || !selection.contains(v)) {
selection.clear ();
selection.add (v);
notifySelectionChanged ();
}
}
/**
* Set the selection to be the given set of objects.
*/
public void setSelection (Collection<T> set) {
selection.clear ();
selection.addAll (set);
notifySelectionChanged ();
}
/**
* Toggle the selection for the given set of objects.
* The resulting selection is the symmetric difference of the current
* selection and the given set of elements.
*/
public void toggleSelection (Collection<T> c) {
if (c.isEmpty())
return ;
for (T el: c)
if (!selection.remove (el))
selection.add (el);
notifySelectionChanged ();
}
/**
* Add the given object to the selection. Does nothing when the object was
* already selected.
*/
public void addSelection (T c) {
if (selection.add(c))
notifySelectionChanged ();
}
/**
* Add the objects in the given set to the selection.
*/
public void addSelection (Collection<T> c) {
if (selection.addAll(c))
notifySelectionChanged ();
}
/**
* Return the number of items that is currently selected.
*/
public int selectionCount () {
return selection.size ();
}
/**
* Return an iterator that iterates over all selected elements.
* Clients should not use the {@code remove}-method of this iterator
* as removals will not be signaled to the observers of this model.
*/
public Iterator<T> iterator () {
return selection.iterator();
}
/** Creates a new selection model with empty selection. Uses a
* {@link HashSet} to keep track of the selected objects. */
public SelectionModel() {
this.selection = new HashSet <T>();
}
/** Creates a new SelectionModel which uses the given
* collection to keep track of the selected objects.
*/
public SelectionModel (Collection<T> c) {
this.selection = c;
}
/**
* Add the current selection to the given collection.
* @param c Collection to which all currently selected elements
* are to be added.
* @return A reference to argument c
*/
public Collection<T> getSelection (Collection<T> c) {
c.addAll (selection);
return c;
}
}
|
