/*******************************************************************************
* Copyright (c) 2008, 2012 Obeo.
* 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:
* Obeo - initial API and implementation
*******************************************************************************/
package org.eclipse.emf.eef.runtime.query.explicitpath.path;
import org.eclipse.emf.common.util.EList;
import org.eclipse.emf.ecore.EAttribute;
import org.eclipse.emf.ecore.EObject;
import org.eclipse.emf.eef.runtime.query.explicitpath.exception.EvaluationException;
/**
* @author <a href="mailto:goulwen.lefur@obeo.fr">Goulwen Le Fur</a>
*/
public class AttributeModelNavigation implements ModelNavigation {
/**
* the feature to navigate
*/
public EAttribute feature;
/**
* the index for multivalued attributes
*/
public int index;
/**
* @param feature the feature to navigate
*/
public AttributeModelNavigation(EAttribute feature) {
super();
this.feature = feature;
this.index = -1;
}
/**
* @param feature the feature to navigate
* @param index the index of the object in feature to get
*/
public AttributeModelNavigation(EAttribute feature, int index) {
super();
assert feature.isMany():"Index defined for a not multi-valued attribute";
this.feature = feature;
this.index = index;
}
/**
* @param value the EObject to process
* @return the result of ModelNavigation evaluation
* @throws EvaluationException
*/
public Object evaluate(EObject value) throws EvaluationException {
try {
Object eGet = value.eGet(feature);
if (index < 0) {
return eGet;
}
else {
if (eGet instanceof EList) {
return ((EList<EObject>)eGet).get(index);
}
else
throw new EvaluationException("Index used on non many reference.");
}
} catch (Exception e) {
throw new EvaluationException(e);
}
}
}