plugins/org.eclipse.viatra2.core2/src/org/eclipse/viatra2/core/IRelation.java

/*******************************************************************************
 * Copyright (c) 2004-2008 Andras Schmidt, Andras Balogh, 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:
 *    Andras Schmidt, Andras Balogh, Istvan Rath - initial API and implementation
 *******************************************************************************/

package org.eclipse.viatra2.core;

/**
 * @author Andras Schmidt, Istvan Rath
 * 
 */
public interface IRelation extends IModelElement {

	/**
	 * Gets the source of this relation.
	 * 
	 * @return An Entity
	 */
	public IModelElement getFrom();

	/**
	 * Gets the destination of this relation.
	 * 
	 * @return an Entity
	 */
	public IModelElement getTo();

	/**
	 * Gets the multiplicity of this relation.
	 * 
	 * @return a MultiplicityKind enumeration constant
	 */
	public EMultiplicityKind getMultiplicity();

	/**
	 * Returns a reference to this relation's inverse, or null if it has none.
	 * 
	 * @return a reference to this relation's inverse, or null if it has none
	 */
	public IRelation getInverse();

	/**
	 * Returns whether this relation represents an aggregation.
	 * 
	 * @return true, if this relation represents an aggregation, false otherwise
	 */
	public boolean getIsAggregation();

	/**
	 * Returns whether the type of this relation's source can be omitted
	 * (instances can have source of any type).
	 * 
	 * @return
	 */
	public boolean getIsAnyFrom();

	/**
	 * Returns whether the type of this relation's target can be omitted
	 * (instances can have target of any type).
	 * 
	 * @return
	 */
	public boolean getIsAnyTo();
}