org.graphstream.ui.layout.Layouts Maven / Gradle / Ivy

/*
 * This file is part of GraphStream .
 * 
 * GraphStream is a library whose purpose is to handle static or dynamic
 * graph, create them from scratch, file or any source and display them.
 * 
 * This program is free software distributed under the terms of two licenses, the
 * CeCILL-C license that fits European law, and the GNU Lesser General Public
 * License. You can  use, modify and/ or redistribute the software under the terms
 * of the CeCILL-C license as circulated by CEA, CNRS and INRIA at the following
 * URL  or under the terms of the GNU LGPL as published by
 * the Free Software Foundation, either version 3 of the License, or (at your
 * option) any later version.
 * 
 * This program 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 program.  If not, see .
 * 
 * The fact that you are presently reading this means that you have had
 * knowledge of the CeCILL-C and LGPL licenses and that you accept their terms.
 */

/**
 * @since 2010-03-05
 * 
 * @author Antoine Dutot 
 * @author Guilhelm Savin 
 * @author Alex Bowen 
 * @author Hicham Brahimi 
 */
package org.graphstream.ui.layout;

import java.security.AccessControlException;
import java.util.logging.Level;
import java.util.logging.Logger;

/**
 * A factory in charge or creating various layout implementations.
 * 
 * This class is mainly used to create the default layout for the graph viewer.
 * You can also use layouts directly on your graphs, but in this case you do not
 * need this factory.
 * 
 * This class looks at the "gs.ui.layout" system property to create a layout
 * class. You can change this property using
 * System.setProperty("gs.ui.layout", you_layout_class_name).
 */
public class Layouts {

	/**
	 * class level logger
	 */
	private static final Logger logger = Logger.getLogger(Layouts.class.getSimpleName());

	/**
	 * Creates a layout according to the "org.graphstream.ui.layout" system
	 * property.
	 * 
	 * @return The new layout or the default GraphStream "Spring-Box" layout if the
	 *         "gs.ui.layout" system property is either not set or contains a class
	 *         that cannot be found.
	 */
	public static Layout newLayoutAlgorithm() {
		String layoutClassName;

		try {
			layoutClassName = System.getProperty("gs.ui.layout");
			if (layoutClassName != null) {
				logger.log(Level.WARNING, "\"gs.ui.layout\" is deprecated, use \"org.graphstream.ui.layout\" instead.");
			} else {
				layoutClassName = System.getProperty("org.graphstream.ui.layout");
			}
		} catch (AccessControlException e) {
			layoutClassName = null;
		}

		if (layoutClassName != null) {
			try {
				Class c = Class.forName(layoutClassName);
				Object object = c.newInstance();

				if (object instanceof Layout) {
					return (Layout) object;
				} else {
					logger.warning(String.format("class '%s' is not a 'GraphRenderer'%n", object));
				}
			} catch (Exception e) {
				logger.log(Level.WARNING, "Cannot create layout.", e);
			}
		}

		return new org.graphstream.ui.layout.springbox.implementations.SpringBox(false);
	}
}