1 /*
   2  * Copyright (c) 1997, 2011, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 package javax.swing;
  26 
  27 /**
  28  * A data model for a combo box. This interface extends <code>ListDataModel</code>
  29  * and adds the concept of a <i>selected item</i>. The selected item is generally
  30  * the item which is visible in the combo box display area.
  31  * <p>
  32  * The selected item may not necessarily be managed by the underlying
  33  * <code>ListModel</code>. This disjoint behavior allows for the temporary
  34  * storage and retrieval of a selected item in the model.
  35  *
  36  * @param <E> the type of the elements of this model
  37  *
  38  * @author Arnaud Weber
  39  */
  40 public interface ComboBoxModel<E> extends ListModel<E> {
  41 
  42   /**
  43    * Set the selected item. The implementation of this  method should notify
  44    * all registered <code>ListDataListener</code>s that the contents
  45    * have changed.
  46    *
  47    * @param anItem the list object to select or <code>null</code>
  48    *        to clear the selection
  49    */
  50   void setSelectedItem(Object anItem);
  51 
  52   /**
  53    * Returns the selected item
  54    * @return The selected item or <code>null</code> if there is no selection
  55    */
  56   Object getSelectedItem();
  57 }