001/* 002 * $Id: MapComboBoxModel.java 3751 2010-08-08 04:07:44Z 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.util.ArrayList; 025import java.util.LinkedHashMap; 026import java.util.List; 027import java.util.Map; 028import java.util.Set; 029 030/** 031 * A {@code ComboBoxModel} for {@code Map}s. The model will always present a {@code Map} 032 * consistently, once it is instantiated. However, unless the {@code Map} is ordered, as a 033 * {@code java.util.TreeMap} is, the model is not guaranteed to present the maps in a consistent 034 * order between instantiations. 035 * 036 * @author jm158417 037 * @author Karl George Schaefer 038 * 039 * @param <K> 040 * the type of keys maintained by the map backing this model 041 * @param <V> 042 * the type of mapped values 043 */ 044public class MapComboBoxModel<K, V> extends ListComboBoxModel<K> { 045 046 /** 047 * The map backing this model. 048 */ 049 protected Map<K, V> map_data; 050 051 /** 052 * Creates an empty model. 053 */ 054 public MapComboBoxModel() { 055 this(new LinkedHashMap<K, V>()); 056 } 057 058 /** 059 * Creates a model backed by the specified map. 060 * 061 * @param map 062 * the map backing this model 063 */ 064 public MapComboBoxModel(Map<K, V> map) { 065 super(buildIndex(map)); 066 067 this.map_data = map; 068 } 069 070 /** 071 * Builds an index for this model. This method ensures that the map is always presented in a 072 * consistent order. 073 * <p> 074 * This method is called by the constructor and the {@code List} is passed to {@code super}. 075 * 076 * @param <E> 077 * the type of keys for the map 078 * @param map 079 * the map to build an index for 080 * @return a list containing the map keys 081 */ 082 private static <E> List<E> buildIndex(Map<E, ?> map) { 083 return new ArrayList<E>(map.keySet()); 084 } 085 086 /** 087 * {@inheritDoc} 088 */ 089 @Override 090 public int getSize() { 091 return map_data.size(); 092 } 093 094 /** 095 * {@inheritDoc} 096 */ 097 @Override 098 public void actionPerformed(ActionEvent evt) { 099 //kgs - this code might not be performant with large maps 100 if(evt.getActionCommand().equals(UPDATE)) { 101 //add new keys 102 Set<K> keys = map_data.keySet(); 103 keys.removeAll(data); 104 data.addAll(keys); 105 106 //remove dead keys 107 List<K> copy = new ArrayList<K>(data); 108 keys = map_data.keySet(); 109 copy.removeAll(keys); 110 data.removeAll(copy); 111 112 fireContentsChanged(this, 0, getSize() - 1); 113 } 114 } 115 116 /** 117 * Selects an item from the model and returns that map value. 118 * 119 * @param selectedItem 120 * the item to select 121 * @return the value for the selected item 122 */ 123 public V getValue(Object selectedItem) { 124 return map_data.get(selectedItem); 125 } 126 127 /** 128 * Selects an item from the model and returns that map value. 129 * 130 * @param selectedItem 131 * selects the item at the specified index in this model 132 * @return the value for the item at the selected index 133 */ 134 public V getValue(int selectedItem) { 135 return getValue(getElementAt(selectedItem)); 136 } 137}