org.eclipse.viatra2.editor/src/org/eclipse/viatra2/treeeditor/commands/RetargetRelationCommand.java

/*******************************************************************************
 * Copyright (c) 2004-2008 Istvan Rath and Daniel Varro
 * 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:
 *    Istvan Rath - initial API and implementation
 *******************************************************************************/

 package org.eclipse.viatra2.treeeditor.commands;

import org.eclipse.viatra2.core.IModelElement;
import org.eclipse.viatra2.core.IRelation;
import org.eclipse.viatra2.errors.VPMCoreException;

public class RetargetRelationCommand extends ViatraEditorCommand {

	private IModelElement newtarget, oldtarget;

	private IRelation relation;

	private String newtarget_name, oldtarget_name, relation_name,
			relation_oldname;

	public void setRelation(IRelation aRel, IModelElement aNewTarget) {
		relation = aRel;
		oldtarget = relation.getTo();
		newtarget = aNewTarget;
		relation_name = relation.getFullyQualifiedName();
		if (oldtarget!=null) {
			oldtarget_name = oldtarget.getFullyQualifiedName();
		}
		else {
			oldtarget_name = ".illegal.";
		}
		if (newtarget!=null) {
			newtarget_name = newtarget.getFullyQualifiedName();
		}
		else {
			newtarget_name = ".illegal.";
		}
	}

	public void execute() throws VPMCoreException {
		newtarget = Lookup(newtarget, newtarget_name);
		oldtarget = Lookup(oldtarget, oldtarget_name);
		relation = (IRelation) Lookup(relation, relation_name);
		if (relation != null && oldtarget != null && newtarget != null) {
			// we're retargeting a relation
			iTransactionID = relation.getModelSpace().getTransactionManager().beginUndoableTransaction();
			//relation.getModelSpace().getUndoManager().nextUndoBlock("vte_retarget");
			relation.getModelSpace().getModelManager().setRelationTo(relation, newtarget);
			relation_oldname = relation_name;
			relation_name = relation.getFullyQualifiedName();
			relation.getModelSpace().getTransactionManager().commitTransaction();
		}
	}

	public void undo() {
		newtarget = Lookup(newtarget, newtarget_name);
		oldtarget = Lookup(oldtarget, oldtarget_name);
		relation = (IRelation) Lookup(relation, relation_name);
		if (relation != null && oldtarget != null && newtarget != null) {
			relation.getModelSpace().getTransactionManager().undoTransaction(iTransactionID);
			//relation.getModelSpace().getUndoManager().undo("vte_retarget");
			relation_name = relation_oldname;
		}
	}

}