2 Copyright (C) 2002 Free Software Foundation, Inc.
4 This file is part of GNU Classpath.
6 GNU Classpath is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
11 GNU Classpath is distributed in the hope that it will be useful, but
12 WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with GNU Classpath; see the file COPYING. If not, write to the
18 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
21 Linking this library statically or dynamically with other modules is
22 making a combined work based on this library. Thus, the terms and
23 conditions of the GNU General Public License cover the whole
26 As a special exception, the copyright holders of this library give you
27 permission to link this library with independent modules to produce an
28 executable, regardless of the license terms of these independent
29 modules, and to copy and distribute the resulting executable under
30 terms of your choice, provided that you also meet, for each linked
31 independent module, the terms and conditions of the license of that
32 module. An independent module is a module which is not derived from
33 or based on this library. If you modify this library, you may extend
34 this exception to your version of the library, but you are not
35 obligated to do so. If you do not wish to do so, delete this
36 exception statement from your version. */
40 import java
.io
.Serializable
;
41 import java
.util
.Enumeration
;
42 import java
.util
.Vector
;
46 * Logically groups a set of buttons, so that only one of the buttons in
47 * a <code>ButtonGroup</code> can be selected at the same time. If one
48 * button in a <code>ButtonGroup</code> is selected, all other buttons
49 * are automatically deselected.
51 * While <code>ButtonGroup</code> can be used for all buttons that are derived
52 * from {@link AbstractButton}, it is normally only used for
53 * {@link JRadioButton}s, {@link JRadioButtonMenuItem}s and
54 * {@link JToggleButton}s.
56 * You could use it for {@link JCheckBox}es, but for the sake of usability
57 * this is strongly discouraged because the common expectation of checkboxes
58 * is that the user is allowed to make multiple selections.
60 * It makes no sense to put {@link JButton}s or {@link JMenuItem}s in
61 * a <code>ButtonGroup</code> because they don't implement the
62 * <code>selected</code> semantics.
64 * @author original author unknown
66 public class ButtonGroup
implements Serializable
69 private static final long serialVersionUID
= 4259076101881721375L;
71 /** The buttons added to this button group. */
72 protected Vector buttons
= new Vector();
74 /** The currently selected button model. */
78 * Creates a new button group.
82 // Nothing to do here.
86 * Adds a button to this group.
88 * @param b the button to add
90 public void add(AbstractButton b
)
92 b
.getModel().setGroup(this);
95 buttons
.addElement(b
);
99 * Removed a given button from this group.
101 * @param b the button to remove
103 public void remove(AbstractButton b
)
105 b
.getModel().setGroup(null);
106 buttons
.removeElement(b
);
110 * Returns the currently added buttons.
112 * @return <code>Enumeration</code> over all added buttons
114 public Enumeration
getElements()
116 return buttons
.elements();
120 * Returns the currently selected button model.
122 * @return the currently selected button model, null if none was selected
125 public ButtonModel
getSelection()
133 * @param m DOCUMENT ME!
135 * @return DOCUMENT ME!
137 AbstractButton
FindButton(ButtonModel m
)
139 for (int i
= 0; i
< buttons
.size(); i
++)
141 AbstractButton a
= (AbstractButton
) buttons
.get(i
);
142 if (a
.getModel() == m
)
149 * Sets the currently selected button model. Only one button of a group can
150 * be selected at a time.
152 * @param m the model to select
153 * @param b true if this button is to be selected, false otherwise
155 public void setSelected(ButtonModel m
, boolean b
)
157 if ((sel
!= m
|| b
) && (! b
|| sel
== m
))
162 ButtonModel old
= sel
;
166 old
.setSelected(false);
167 AbstractButton button
= FindButton(old
);
171 else if (!b
&& sel
== m
)
176 * Checks if the given <code>ButtonModel</code> is selected in this button
179 * @param m DOCUMENT ME!
181 * @return true of given <code>ButtonModel</code> is selected, false
184 public boolean isSelected(ButtonModel m
)
190 * Return the number of buttons in this button group.
192 * @return the number of buttons
196 public int getButtonCount()
198 return buttons
.size();