/*
* Geotoolkit - An Open Source Java GIS Toolkit
* http://www.geotoolkit.org
*
* (C) 2010, Geomatys
*
* 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;
* version 2.1 of the License.
*
* 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.
*/
package org.geotoolkit.map;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import java.lang.ref.WeakReference;
import java.util.ArrayList;
import java.util.Collection;
import org.geotoolkit.internal.ReferenceQueueConsumer;
import org.apache.sis.util.Disposable;
import org.geotoolkit.util.collection.CollectionChangeEvent;
/**
* Map item listener.<br/>
* Listen to properties and children changes.
*
* @author Johann Sorel (Geomatys)
* @module
*/
public interface ItemListener extends PropertyChangeListener {
/**
* Called when a change occurs in the live item list.
*/
void itemChange(CollectionChangeEvent<MapItem> event);
/**
* Weak map item listener. Use it when you are not
* sure that the listener will be correctly removed by your class.
*/
public static final class Weak extends WeakReference<ItemListener> implements ItemListener,Disposable{
private final Collection<MapItem> sources = new ArrayList<MapItem>(1);
public Weak(final ItemListener ref) {
this(null,ref);
}
public Weak(final MapItem source, final ItemListener ref) {
super(ref, ReferenceQueueConsumer.DEFAULT.queue);
registerSource(source);
}
/**
* Register this listener on the given source.
*/
public synchronized void registerSource(final MapItem source){
if(source != null && !sources.contains(source)){
//register in the new source
source.addItemListener(this);
this.sources.add(source);
}
}
/**
* Unregister this listener on the given source.
*/
public synchronized void unregisterSource(final MapItem source){
sources.remove(source);
source.removeItemListener(this);
}
@Override
public synchronized void dispose() {
for(MapItem source : sources){
source.removeItemListener(this);
}
sources.clear();
}
@Override
public void propertyChange(final PropertyChangeEvent evt) {
final ItemListener listener = get();
if (listener != null) {
listener.propertyChange(evt);
}
//if the listener is null, that means we are in the reference queue and it will be disposed soon.
}
@Override
public void itemChange(final CollectionChangeEvent<MapItem> event) {
final ItemListener listener = get();
if (listener != null) {
listener.itemChange(event);
}
//if the listener is null, that means we are in the reference queue and it will be disposed soon.
}
}
}