001/* 002 * $Id: ListComboBoxModel.java 3935 2011-03-02 19:06:41Z kschaefe $ 003 * 004 * Copyright 2004 Sun Microsystems, Inc., 4150 Network Circle, 005 * Santa Clara, California 95054, U.S.A. All rights reserved. 006 * 007 * This library is free software; you can redistribute it and/or 008 * modify it under the terms of the GNU Lesser General Public 009 * License as published by the Free Software Foundation; either 010 * version 2.1 of the License, or (at your option) any later version. 011 * 012 * This library is distributed in the hope that it will be useful, 013 * but WITHOUT ANY WARRANTY; without even the implied warranty of 014 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 015 * Lesser General Public License for more details. 016 * 017 * You should have received a copy of the GNU Lesser General Public 018 * License along with this library; if not, write to the Free Software 019 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA 020 */ 021package org.jdesktop.swingx.combobox; 022 023import java.awt.event.ActionEvent; 024import java.awt.event.ActionListener; 025import java.util.List; 026 027import javax.swing.AbstractListModel; 028import javax.swing.ComboBoxModel; 029 030/** 031 * A {@code ComboBoxModel} for {@code List}s. 032 * 033 * @param <E> the type of elements maintained by the list backing this model 034 * 035 * @author jm158417 036 * @author Karl George Schaefer 037 */ 038public class ListComboBoxModel<E> extends AbstractListModel implements ComboBoxModel, ActionListener { 039 /** 040 * A key used to notify the model that the backing {@code List} has changed. 041 */ 042 public static final String UPDATE = "update"; 043 044 /** 045 * A reference to the list backing this model. 046 * <p> 047 * This model does <b>not</b> make a copy of the list, so any changes in 048 * the list without synchronizing the model may have drastic effects. 049 */ 050 protected final List<E> data; 051 052 /** 053 * The currently selected item. 054 */ 055 protected E selected; 056 057 /** 058 * Creates a {@code ListComboBoxModel} backed by the supplied {@code list}. 059 * 060 * @param list 061 * the list backing this model 062 * @throws NullPointerException 063 * if {@code list} is {@code null} 064 */ 065 public ListComboBoxModel(List<E> list) { 066 this.data = list; 067 068 if(list.size() > 0) { 069 selected = list.get(0); 070 } 071 } 072 073 /** 074 * Set the selected item. The implementation of this method should notify 075 * all registered {@code ListDataListener}s that the contents have changed. 076 * 077 * @param item 078 * the list object to select or {@code null} to clear the 079 * selection 080 * @throws ClassCastException 081 * if {@code item} is not of type {@code E} 082 */ 083 @Override 084 @SuppressWarnings("unchecked") 085 public void setSelectedItem(Object item) { 086 if ((selected != null && !selected.equals(item)) 087 || selected == null && item != null) { 088 selected = (E) item; 089 fireContentsChanged(this, -1, -1); 090 } 091 } 092 093 /** 094 * {@inheritDoc} 095 */ 096 @Override 097 public E getSelectedItem() { 098 return this.selected; 099 } 100 101 /** 102 * {@inheritDoc} 103 */ 104 @Override 105 public E getElementAt(int index) { 106 return data.get(index); 107 } 108 109 /** 110 * {@inheritDoc} 111 */ 112 @Override 113 public int getSize() { 114 return data.size(); 115 } 116 117 /** 118 * {@inheritDoc} 119 */ 120 @Override 121 public void actionPerformed(ActionEvent evt) { 122 if(evt.getActionCommand().equals(UPDATE)) { 123 this.fireContentsChanged(this, 0, getSize() - 1); 124 } 125 } 126}