/*
 *    GeoTools - The Open Source Java GIS Toolkit
 *    http://geotools.org
 *
 *    (C) 2007-2008, Open Source Geospatial Foundation (OSGeo)
 *
 *    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.geotools.renderer3d.utils.quadtree;

/**
 * Listens to QuadTreeNode events, such as expansion or collapse, and deletion.
 *
 * @author Hans H�ggstr�m
 */
public interface NodeListener<N>
{
    /**
     * Called when a node is collapsed, that is, its child nodes are removed.
     */
    void onCollapsed( QuadTreeNode<N> node );

    /**
     * Called when a node is expanded, that is, child nodes are added.
     */
    void onExpanded( QuadTreeNode<N> node );
}