org.eclipse.sirius.ext.emf.EClassQuery.java Source code

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/*******************************************************************************
 * Copyright (c) 2011 THALES GLOBAL SERVICES.
 * 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.sirius.ext.emf;

import java.util.Collection;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Set;

import org.eclipse.emf.ecore.EClass;
import org.eclipse.emf.ecore.EReference;
import org.eclipse.emf.ecore.EStructuralFeature;

import com.google.common.base.Function;
import com.google.common.base.Predicate;
import com.google.common.base.Predicates;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.Iterables;

/**
 * Queries on {@link EClass}.
 * 
 * @author pierre-charles.david@obeo.fr
 */
public class EClassQuery {
    /**
     * The predicate used to identify containment features.
     * 
     * @author pierre-charles.david@obeo.fr
     */
    private static final class IsContaintmentFeature implements Predicate<EStructuralFeature> {
        public boolean apply(EStructuralFeature input) {
            return new EStructuralFeatureQuery(input).isContainment();
        }
    }

    private final EClass eClass;

    /**
     * Constructor.
     * 
     * @param eClass
     *            the EClass to query.
     */
    public EClassQuery(EClass eClass) {
        this.eClass = eClass;
    }

    /**
     * Returns all the containment features of the queried {@link EClass}.
     * 
     * @return all the containment features of the {@link EClass}.
     */
    public Collection<EStructuralFeature> getAllContainmentFeatures() {
        return ImmutableList
                .copyOf(Iterables.filter(eClass.getEAllStructuralFeatures(), new IsContaintmentFeature()));
    }

    /**
     * Returns all the non-containment features of the queried {@link EClass}.
     * 
     * @return all the non-containment features of the {@link EClass}.
     */
    public Collection<EStructuralFeature> getAllNonContainmentFeatures() {
        return ImmutableList.copyOf(
                Iterables.filter(eClass.getEAllStructuralFeatures(), Predicates.not(new IsContaintmentFeature())));
    }

    /**
     * Search structural features in <code>eClazz</code> and also in its
     * children. For example GaugeSectionDescription is not a StyleDescription
     * but we should searched in its references (also for EdgeStyleDescription
     * with Begin, Center and EndLabelStyleDescription).
     * 
     * @param featureName
     *            The name of the searched EStructuralFeature
     * @param knownEClasses
     *            Already treated EClass (to avoid infinite loop)
     * @return All structural features that have the <code>featureName</code> as
     *         name.
     */
    public Set<EStructuralFeature> getEStructuralFeatures(String featureName, List<EClass> knownEClasses) {
        knownEClasses.add(eClass);
        Set<EStructuralFeature> result = new LinkedHashSet<EStructuralFeature>();
        // Search reference in this EClass,
        EStructuralFeature eStructuralFeature = eClass.getEStructuralFeature(featureName);
        if (eStructuralFeature instanceof EReference) {
            result.add(eStructuralFeature);
        }
        // and in all contents
        Function<EReference, EClass> toEType = new Function<EReference, EClass>() {
            public EClass apply(EReference reference) {
                if (reference.getEType() instanceof EClass) {
                    return (EClass) reference.getEType();
                } else {
                    return null;
                }
            }
        };
        for (EClass subPartMetaModelEClass : Iterables.transform(eClass.getEAllContainments(), toEType)) {
            if (subPartMetaModelEClass != null) {
                if (!knownEClasses.contains(subPartMetaModelEClass)) {
                    result.addAll(new EClassQuery(subPartMetaModelEClass).getEStructuralFeatures(featureName,
                            knownEClasses));
                }
            }
        }
        return result;
    }
}