bundles/org.eclipse.emf.ecp.workspace.ui/src/org/eclipse/emf/ecp/workspace/internal/ui/UndoLastCommandHandler.java

/*******************************************************************************
 * Copyright (c) 2011-2012 EclipseSource Muenchen GmbH and others.
 * 
 * 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:
 * Eugen Neufeld - initial API and implementation
 * 
 *******************************************************************************/
package org.eclipse.emf.ecp.workspace.internal.ui;

import org.eclipse.emf.ecp.spi.core.InternalProject;

import org.eclipse.core.commands.AbstractHandler;
import org.eclipse.core.commands.ExecutionEvent;
import org.eclipse.core.commands.ExecutionException;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.ui.handlers.HandlerUtil;

/**
 * Undo Last Command Handler.
 * 
 * @author Tobias Verhoeven
 * 
 */
public class UndoLastCommandHandler extends AbstractHandler {

	/** {@inheritDoc} **/
	public Object execute(ExecutionEvent event) throws ExecutionException {
		InternalProject project = (InternalProject) ((IStructuredSelection) HandlerUtil.getActiveMenuSelection(event))
			.getFirstElement();
		if (project == null) {
			return null;
		}
		project.getEditingDomain().getCommandStack().undo();

		return null;
	}
}