001 /* SingleSelectionModel.java --
002 Copyright (C) 2002, 2004 Free Software Foundation, Inc.
003
004 This file is part of GNU Classpath.
005
006 GNU Classpath is free software; you can redistribute it and/or modify
007 it under the terms of the GNU General Public License as published by
008 the Free Software Foundation; either version 2, or (at your option)
009 any later version.
010
011 GNU Classpath is distributed in the hope that it will be useful, but
012 WITHOUT ANY WARRANTY; without even the implied warranty of
013 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
014 General Public License for more details.
015
016 You should have received a copy of the GNU General Public License
017 along with GNU Classpath; see the file COPYING. If not, write to the
018 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
019 02110-1301 USA.
020
021 Linking this library statically or dynamically with other modules is
022 making a combined work based on this library. Thus, the terms and
023 conditions of the GNU General Public License cover the whole
024 combination.
025
026 As a special exception, the copyright holders of this library give you
027 permission to link this library with independent modules to produce an
028 executable, regardless of the license terms of these independent
029 modules, and to copy and distribute the resulting executable under
030 terms of your choice, provided that you also meet, for each linked
031 independent module, the terms and conditions of the license of that
032 module. An independent module is a module which is not derived from
033 or based on this library. If you modify this library, you may extend
034 this exception to your version of the library, but you are not
035 obligated to do so. If you do not wish to do so, delete this
036 exception statement from your version. */
037
038 package javax.swing;
039
040 import javax.swing.event.ChangeEvent;
041 import javax.swing.event.ChangeListener;
042
043 /**
044 * A data model that is used in components that support at most one
045 * selected element, like {@link JTabbedPane}, {@link JMenu} and
046 * {@link JPopupMenu}.
047 *
048 * @author Andrew Selkirk
049 */
050 public interface SingleSelectionModel
051 {
052 /**
053 * Returns the selected index or <code>-1</code> if there is no selection.
054 *
055 * @return The selected index.
056 *
057 * @see #setSelectedIndex(int)
058 */
059 int getSelectedIndex();
060
061 /**
062 * Sets the selected index and, if this is different to the previous
063 * selection, sends a {@link ChangeEvent} to all registered listeners.
064 *
065 * @param index the index (use <code>-1</code> to represent no selection).
066 *
067 * @see #getSelectedIndex()
068 * @see #clearSelection
069 */
070 void setSelectedIndex(int index);
071
072 /**
073 * Clears the selection by setting the selected index to <code>-1</code> and
074 * sends a {@link ChangeEvent} to all registered listeners. If the selected
075 * index is already <code>-1</code>, this method does nothing.
076 */
077 void clearSelection();
078
079 /**
080 * Returns <code>true</code> if there is a selection, and <code>false</code>
081 * otherwise.
082 *
083 * @return A boolean.
084 */
085 boolean isSelected();
086
087 /**
088 * Registers a listener to receive {@link ChangeEvent} notifications from
089 * this model whenever the selected index changes.
090 *
091 * @param listener the listener to add.
092 */
093 void addChangeListener(ChangeListener listener);
094
095 /**
096 * Deregisters a listener so that it no longer receives {@link ChangeEvent}
097 * notifications from this model.
098 *
099 * @param listener the listener to remove.
100 */
101 void removeChangeListener(ChangeListener listener);
102
103 }