/*
 * grEMF
 *
 * Copyright (C) 2006-2012 Institute for Software Technology
 *                         University of Koblenz-Landau, Germany
 *                         ist@uni-koblenz.de
 *
 * For bug reports, documentation and further information, visit
 *
 *                         https://github.com/jgralab/gremf
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License 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 General
 * Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, see <http://www.gnu.org/licenses>.
 *
 * Additional permission under GNU GPL version 3 section 7
 *
 * If you modify this Program, or any covered work, by linking or combining
 * it with Eclipse (or a modified version of that program or an Eclipse
 * plugin), containing parts covered by the terms of the Eclipse Public
 * License (EPL), the licensors of this Program grant you additional
 * permission to convey the resulting work.  Corresponding Source for a
 * non-source form of such a combination shall include the source code for
 * the parts of JGraLab used as well as that of the covered work.
 */
package de.uni_koblenz.gremf.resource;

import java.io.InputStream;
import java.io.OutputStream;
import java.util.Map;

import org.eclipse.emf.ecore.EObject;
import org.eclipse.emf.ecore.xmi.XMLResource;
import org.eclipse.emf.ecore.xmi.impl.BasicResourceHandler;

import de.uni_koblenz.gremf.GrEMFInstanceType;
import de.uni_koblenz.gremf.impl.GrEMFGraphImpl;
import de.uni_koblenz.jgralab.GraphElement;

/**
 * Resource handler for loading EMF instances into grEMF: <br>
 * The graph object is added as first content object to the resource
 * 
 * @see {@link de.uni_koblenz.gremf.resource.GrEMFInstanceResourceImpl
 *      GrEMFInstanceResourceImpl} (grEMF instance resource implementation)
 */
public class GrEMFInstanceResourceHandler extends BasicResourceHandler {

	@Override
	public void postLoad(XMLResource r, InputStream inStream, Map<?, ?> options) {
		if ((r == null) || r.getContents().isEmpty()) {
			return;
		}
		EObject first = r.getContents().get(0);
		if (first instanceof GrEMFInstanceType) {
			r.getContents().add(0,
					(EObject) ((GraphElement<?, ?>) first).getGraph());
		}
	}

	@Override
	public void preSave(XMLResource resource, OutputStream outputStream,
			Map<?, ?> options) {
		EObject first = resource.getContents().get(0);
		if (first instanceof GrEMFGraphImpl) {
			resource.getContents().remove(0);
		}
		super.preSave(resource, outputStream, options);
	}
}