/*******************************************************************************
 * Copyright (c) 2008 Conselleria de Infraestructuras y Transporte,
 * Generalitat de la Comunitat Valenciana .
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors: Francisco Javier Cano Muñoz (Prodevelop) - initial API implementation
 *
 ******************************************************************************/
package org.eclipse.papyrus.uml.diagram.common.part;

import org.eclipse.emf.ecore.EClass;
import org.eclipse.emf.ecore.EObject;
import org.eclipse.gef.EditPart;
import org.eclipse.gef.EditPolicy;
import org.eclipse.papyrus.uml.diagram.common.util.MDTUtil;

// TODO: Auto-generated Javadoc
/**
 * Utility methods to "demultiplex" <EClass>es and <EObject>s for different canvas elements.
 * 
 * @author <a href="mailto:fjcano@prodevelop.es">Francisco Javier Cano Muñoz</a>
 */
public class DiagramCanvasSwitch {

	/**
	 * Gets the <Diagram>'s <EObject> given an <EditPolicy>.
	 * 
	 * @param policy
	 *        the policy
	 * 
	 * @return the canvas element
	 */
	public static EObject getCanvasElement(EditPolicy policy) {
		EditPart editPart = policy != null ? policy.getHost() : null;
		return MDTUtil.resolveSemantic(editPart);
	}

	/**
	 * Gets the element to edit in a mutating canvas <Diagram>. By default, it's
	 * the canvas semantic <EObject>.
	 * 
	 * @param editPolicy
	 *        the edit policy
	 * 
	 * @return the element to edit for create command
	 */
	// @unused
	public static EObject getElementToEditForCreateCommand(EditPolicy editPolicy) {
		return getCanvasElement(editPolicy);
	}

	/**
	 * Gets the <EClass> to edit. It's the EClass of the canvas <EObject>
	 * 
	 * @param editPolicy
	 *        the edit policy
	 * 
	 * @return the e class to edit for create command
	 */
	// @unused
	public static EClass getEClassToEditForCreateCommand(EditPolicy editPolicy) {
		EObject element = getCanvasElement(editPolicy);
		return element != null ? element.eClass() : null;
	}

}