/* ========================================================================
* JCommon : a free general purpose class library for the Java(tm) platform
* ========================================================================
*
* (C) Copyright 2000-2005, by Object Refinery Limited and Contributors.
*
* Project Info: http://www.jfree.org/jcommon/index.html
*
* 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 Street, Fifth Floor, Boston, MA 02110-1301,
* USA.
*
* [Java is a trademark or registered trademark of Sun Microsystems, Inc.
* in the United States and other countries.]
*
* ------------------
* KeyedComboBoxModel.java
* ------------------
* (C) Copyright 2004, by Thomas Morgner and Contributors.
*
* Original Author: Thomas Morgner;
* Contributor(s): David Gilbert (for Object Refinery Limited);
*
* $Id: KeyedComboBoxModel.java,v 1.5 2005/10/18 13:18:34 mungady Exp $
*
* Changes
* -------
* 07-Jun-2004 : Added JCommon header (DG);
*
*/
package org.jfree.ui;
import java.util.ArrayList;
import javax.swing.ComboBoxModel;
import javax.swing.event.ListDataEvent;
import javax.swing.event.ListDataListener;
/**
* The KeyedComboBox model allows to define an internal key (the data element) for every
* entry in the model.
* <p/>
* This class is usefull in all cases, where the public text differs from the internal
* view on the data. A separation between presentation data and processing data is a
* prequesite for localizing combobox entries. This model does not allow selected
* elements, which are not in the list of valid elements.
*
* @author Thomas Morgner
*/
public class KeyedComboBoxModel implements ComboBoxModel {
/**
* The internal data carrier to map keys to values and vice versa.
*/
private static class ComboBoxItemPair {
/** The key. */
private Object key;
/** The value for the key. */
private Object value;
/**
* Creates a new item pair for the given key and value. The value
* can be changed later, if needed.
*
* @param key the key
* @param value the value
*/
public ComboBoxItemPair(final Object key, final Object value) {
this.key = key;
this.value = value;
}
/**
* Returns the key.
* @return the key.
*/
public Object getKey() {
return key;
}
/**
* Returns the value.
* @return the value for this key.
*/
public Object getValue() {
return value;
}
/**
* Redefines the value stored for that key.
* @param value the new value.
*/
public void setValue(final Object value) {
this.value = value;
}
}
/** The index of the selected item. */
private int selectedItem;
/** The data (contains ComboBoxItemPairs). */
private ArrayList data;
/** The listeners. */
private ArrayList listdatalistener;
/** The cached listeners as array. */
private transient ListDataListener[] tempListeners;
/**
* Creates a new keyed combobox model.
*/
public KeyedComboBoxModel() {
data = new ArrayList();
listdatalistener = new ArrayList();
}
/**
* Creates a new keyed combobox model for the given keys and values.
* Keys and values must have the same number of items.
*
* @param keys the keys
* @param values the values
*/
public KeyedComboBoxModel(final Object[] keys, final Object[] values) {
this();
setData(keys, values);
}
/**
* Replaces the data in this combobox model. The number of keys must be equals to the
* number of values.
*
* @param keys the keys
* @param values the values
*/
public void setData(final Object[] keys, final Object[] values) {
if (values.length != keys.length) {
throw new IllegalArgumentException("Values and text must have the same length.");
}
data.clear();
data.ensureCapacity(keys.length);
for (int i = 0; i < values.length; i++) {
add(keys[i], values[i]);
}
selectedItem = -1;
final ListDataEvent evt = new ListDataEvent
(this, ListDataEvent.CONTENTS_CHANGED, 0, data.size() - 1);
fireListDataEvent(evt);
}
/**
* Notifies all registered list data listener of the given event.
*
* @param evt the event.
*/
protected synchronized void fireListDataEvent(final ListDataEvent evt) {
if (tempListeners == null) {
tempListeners = (ListDataListener[]) listdatalistener.toArray
(new ListDataListener[listdatalistener.size()]);
}
for (int i = 0; i < tempListeners.length; i++) {
final ListDataListener l = tempListeners[i];
l.contentsChanged(evt);
}
}
/**
* Returns the selected item.
*
* @return The selected item or <code>null</code> if there is no selection
*/
public Object getSelectedItem() {
if (selectedItem >= data.size()) {
return null;
}
if (selectedItem < 0) {
return null;
}
final ComboBoxItemPair item = (ComboBoxItemPair) data.get(selectedItem);
return item.getValue();
}
/**
* Defines the selected key. If the object is not in the list of values, no item
* gets selected.
*
* @param anItem the new selected item.
*/
public void setSelectedKey(final Object anItem) {
if (anItem == null) {
selectedItem = -1;
}
else {
final int newSelectedItem = findDataElementIndex(anItem);
selectedItem = newSelectedItem;
}
fireListDataEvent(new ListDataEvent(this, ListDataEvent.CONTENTS_CHANGED, -1, -1));
}
/**
* Set the selected item. The implementation of this method should notify all
* registered <code>ListDataListener</code>s that the contents have changed.
*
* @param anItem the list object to select or <code>null</code> to clear the selection
*/
public void setSelectedItem(final Object anItem) {
if (anItem == null) {
selectedItem = -1;
}
else {
final int newSelectedItem = findElementIndex(anItem);
selectedItem = newSelectedItem;
}
fireListDataEvent(new ListDataEvent(this, ListDataEvent.CONTENTS_CHANGED, -1, -1));
}
/**
* Adds a listener to the list that's notified each time a change to the data model
* occurs.
*
* @param l the <code>ListDataListener</code> to be added
*/
public synchronized void addListDataListener(final ListDataListener l) {
listdatalistener.add(l);
tempListeners = null;
}
/**
* Returns the value at the specified index.
*
* @param index the requested index
* @return the value at <code>index</code>
*/
public Object getElementAt(final int index) {
if (index >= data.size()) {
return null;
}
final ComboBoxItemPair datacon = (ComboBoxItemPair) data.get(index);
if (datacon == null) {
return null;
}
return datacon.getValue();
}
/**
* Returns the key from the given index.
*
* @param index the index of the key.
* @return the the key at the specified index.
*/
public Object getKeyAt(final int index) {
if (index >= data.size()) {
return null;
}
if (index < 0) {
return null;
}
final ComboBoxItemPair datacon = (ComboBoxItemPair) data.get(index);
if (datacon == null) {
return null;
}
return datacon.getKey();
}
/**
* Returns the selected data element or null if none is set.
*
* @return the selected data element.
*/
public Object getSelectedKey() {
return getKeyAt(selectedItem);
}
/**
* Returns the length of the list.
*
* @return the length of the list
*/
public int getSize() {
return data.size();
}
/**
* Removes a listener from the list that's notified each time a change to the data model
* occurs.
*
* @param l the <code>ListDataListener</code> to be removed
*/
public void removeListDataListener(final ListDataListener l) {
listdatalistener.remove(l);
tempListeners = null;
}
/**
* Searches an element by its data value. This method is called by the setSelectedItem
* method and returns the first occurence of the element.
*
* @param anItem the item
* @return the index of the item or -1 if not found.
*/
private int findDataElementIndex(final Object anItem) {
if (anItem == null) {
throw new NullPointerException("Item to find must not be null");
}
for (int i = 0; i < data.size(); i++) {
final ComboBoxItemPair datacon = (ComboBoxItemPair) data.get(i);
if (anItem.equals(datacon.getKey())) {
return i;
}
}
return -1;
}
/**
* Tries to find the index of element with the given key. The key must not be null.
*
* @param key the key for the element to be searched.
* @return the index of the key, or -1 if not found.
*/
public int findElementIndex(final Object key) {
if (key == null) {
throw new NullPointerException("Item to find must not be null");
}
for (int i = 0; i < data.size(); i++) {
final ComboBoxItemPair datacon = (ComboBoxItemPair) data.get(i);
if (key.equals(datacon.getValue())) {
return i;
}
}
return -1;
}
/**
* Removes an entry from the model.
*
* @param key the key
*/
public void removeDataElement(final Object key) {
final int idx = findDataElementIndex(key);
if (idx == -1) {
return;
}
data.remove(idx);
final ListDataEvent evt = new ListDataEvent
(this, ListDataEvent.INTERVAL_REMOVED, idx, idx);
fireListDataEvent(evt);
}
/**
* Adds a new entry to the model.
*
* @param key the key
* @param cbitem the display value.
*/
public void add(final Object key, final Object cbitem) {
final ComboBoxItemPair con = new ComboBoxItemPair(key, cbitem);
data.add(con);
final ListDataEvent evt = new ListDataEvent
(this, ListDataEvent.INTERVAL_ADDED, data.size() - 2, data.size() - 2);
fireListDataEvent(evt);
}
/**
* Removes all entries from the model.
*/
public void clear() {
final int size = getSize();
data.clear();
final ListDataEvent evt = new ListDataEvent(this, ListDataEvent.INTERVAL_REMOVED, 0, size - 1);
fireListDataEvent(evt);
}
}