GenerateChangesHandler.java

/**
O * <copyright> Copyright (c) 2008-2009 Jonas Helming, Maximilian Koegel. 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 </copyright>
 */
package org.eclipse.emf.emfstore.modelgenerator.handler;

import org.eclipse.core.commands.AbstractHandler;
import org.eclipse.core.commands.ExecutionEvent;
import org.eclipse.core.commands.ExecutionException;
import org.eclipse.emf.ecore.EObject;
import org.eclipse.emf.emfstore.client.model.ProjectSpace;
import org.eclipse.emf.emfstore.client.model.util.EMFStoreCommand;
import org.eclipse.emf.emfstore.modelgenerator.modelchanger.*;
import org.eclipse.jface.viewers.ISelection;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.ui.handlers.HandlerUtil;


/**
 * Handler for the "Generate Changes" context menu command for the ECP.
 * The command is only available if one single EObject is selected.
 * If the selected EObject is a ProjectSpace, the contained Project 
 * is used as the root, otherwise the EObject itself will be the root.
 */
public class GenerateChangesHandler extends AbstractHandler {
	
	/**
	 * {@inheritDoc}
	 */
	public Object execute(ExecutionEvent event) throws ExecutionException {
		
		ISelection selection = HandlerUtil.getCurrentSelection(event);
		
		final EObject rootObject = validateSelection(selection);
		
		new EMFStoreCommand() {
			
			@Override
			protected void doRun() {
				ModelChanger.generateChanges(rootObject, System.currentTimeMillis(), true);
			}
		}.run(false);

		return null;
	}
	
	/**
	 * Returns the selected EObject, or a project if a ProjectSpace was selected.
	 * If the selected element is no EObject or nothing is selected, this method 
	 * shouldn't be called, and therefore an IllegalArgumentException is thrown.
	 * 
	 * @param selection the current selection made
	 * @return the valid EObject made from the selection
	 * @throws IllegalArgumentException if selection failed or no EObject is selected
	 */
	private EObject validateSelection(ISelection selection) {
		if(selection != null && selection instanceof IStructuredSelection) {
			IStructuredSelection strucSel = (IStructuredSelection) selection;
			Object selectedElement = strucSel.getFirstElement();
			if(selectedElement instanceof ProjectSpace) {
				return ((ProjectSpace) selectedElement).getProject();
			} else if(selectedElement instanceof EObject) {
				return (EObject) selectedElement;
			} else {
				throw new IllegalArgumentException("No EObject selected!");
			}
		} else {
			throw new IllegalArgumentException("Selection Error!");
		}
	}

}