001/* ListModel.java --
002   Copyright (C) 2002, 2004 Free Software Foundation, Inc.
003
004This file is part of GNU Classpath.
005
006GNU Classpath is free software; you can redistribute it and/or modify
007it under the terms of the GNU General Public License as published by
008the Free Software Foundation; either version 2, or (at your option)
009any later version.
010
011GNU Classpath is distributed in the hope that it will be useful, but
012WITHOUT ANY WARRANTY; without even the implied warranty of
013MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014General Public License for more details.
015
016You should have received a copy of the GNU General Public License
017along with GNU Classpath; see the file COPYING.  If not, write to the
018Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
01902110-1301 USA.
020
021Linking this library statically or dynamically with other modules is
022making a combined work based on this library.  Thus, the terms and
023conditions of the GNU General Public License cover the whole
024combination.
025
026As a special exception, the copyright holders of this library give you
027permission to link this library with independent modules to produce an
028executable, regardless of the license terms of these independent
029modules, and to copy and distribute the resulting executable under
030terms of your choice, provided that you also meet, for each linked
031independent module, the terms and conditions of the license of that
032module.  An independent module is a module which is not derived from
033or based on this library.  If you modify this library, you may extend
034this exception to your version of the library, but you are not
035obligated to do so.  If you do not wish to do so, delete this
036exception statement from your version. */
037
038package javax.swing;
039
040import javax.swing.event.ListDataListener;
041
042/**
043 * The data model that is typically used in {@link JList}.
044 *
045 * @author Graydon Hoare (graydon@redhat.com)
046 */
047public interface ListModel
048{
049  /**
050   * Return the number of data elements in the list.
051   *
052   * @return The number of data elements in the list
053   */
054  int getSize();
055
056  /**
057   * Retrieves a data element at a specified index.
058   *
059   * @param index The index of the element to retrieve
060   *
061   * @return The data element at the specified index
062   */
063  Object getElementAt(int index);
064
065  /**
066   * Add a listener object to this model. The listener will be called
067   * any time the set of elements in the model is changed.
068   *
069   * @param l The listener to add
070   */
071  void addListDataListener(ListDataListener l);
072
073  /**
074   * Add a listener object to this model. The listener will no longer be
075   * called when the set of elements in the model is changed.
076   *
077   * @param l The listener to remove
078   */
079  void removeListDataListener(ListDataListener l);
080}