org.jdesktop.swingx.combobox.MapComboBoxModel Maven / Gradle / Ivy
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/*
* $Id$
*
* Copyright 2004 Sun Microsystems, Inc., 4150 Network Circle,
* Santa Clara, California 95054, U.S.A. All rights reserved.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
package org.jdesktop.swingx.combobox;
import java.awt.event.ActionEvent;
import java.util.ArrayList;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;
/**
* A {@code ComboBoxModel} for {@code Map}s. The model will always present a {@code Map}
* consistently, once it is instantiated. However, unless the {@code Map} is ordered, as a
* {@code java.util.TreeMap} is, the model is not guaranteed to present the maps in a consistent
* order between instantiations.
*
* @author jm158417
* @author Karl George Schaefer
*
* @param
* the type of keys maintained by the map backing this model
* @param
* the type of mapped values
*/
public class MapComboBoxModel extends ListComboBoxModel {
/**
* The map backing this model.
*/
protected Map map_data;
/**
* Creates an empty model.
*/
public MapComboBoxModel() {
this(new LinkedHashMap());
}
/**
* Creates a model backed by the specified map.
*
* @param map
* the map backing this model
*/
public MapComboBoxModel(Map map) {
super(buildIndex(map));
this.map_data = map;
}
/**
* Builds an index for this model. This method ensures that the map is always presented in a
* consistent order.
*
* This method is called by the constructor and the {@code List} is passed to {@code super}.
*
* @param
* the type of keys for the map
* @param map
* the map to build an index for
* @return a list containing the map keys
*/
private static List buildIndex(Map map) {
return new ArrayList(map.keySet());
}
/**
* {@inheritDoc}
*/
@Override
public int getSize() {
return map_data.size();
}
/**
* {@inheritDoc}
*/
@Override
public void actionPerformed(ActionEvent evt) {
//kgs - this code might not be performant with large maps
if(evt.getActionCommand().equals(UPDATE)) {
//add new keys
Set keys = map_data.keySet();
keys.removeAll(data);
data.addAll(keys);
//remove dead keys
List copy = new ArrayList(data);
keys = map_data.keySet();
copy.removeAll(keys);
data.removeAll(copy);
fireContentsChanged(this, 0, getSize() - 1);
}
}
/**
* Selects an item from the model and returns that map value.
*
* @param selectedItem
* the item to select
* @return the value for the selected item
*/
public V getValue(Object selectedItem) {
return map_data.get(selectedItem);
}
/**
* Selects an item from the model and returns that map value.
*
* @param selectedItem
* selects the item at the specified index in this model
* @return the value for the item at the selected index
*/
public V getValue(int selectedItem) {
return getValue(getElementAt(selectedItem));
}
}