org.eclipse.emf.compare.ide.ui.internal.logical.resolver.ResourceDependencyFoundEvent.java Source code

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Here is the source code for org.eclipse.emf.compare.ide.ui.internal.logical.resolver.ResourceDependencyFoundEvent.java

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/*******************************************************************************
 * Copyright (c) 2015 EclipseSource Munich and others.
 * 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:
 *     Philip Langer - initial API and implementation
 *******************************************************************************/
package org.eclipse.emf.compare.ide.ui.internal.logical.resolver;

import static com.google.common.base.Preconditions.checkNotNull;

import com.google.common.base.Optional;

import org.eclipse.emf.common.util.URI;
import org.eclipse.emf.ecore.EObject;
import org.eclipse.emf.ecore.EReference;
import org.eclipse.emf.ecore.EStructuralFeature;
import org.eclipse.emf.ecore.util.EcoreUtil;

/**
 * An event indicating that a resource dependency is found.
 * 
 * @author Philip Langer <planger@eclipsesource.com>
 */
public class ResourceDependencyFoundEvent extends DependencyFoundEvent<URI> {

    /**
     * Constructor.
     * 
     * @param from
     *            The source of the dependency
     * @param to
     *            The target of the dependency
     * @param parent
     *            The object in the source causing the dependency
     * @param feature
     *            The feature through which the parent causes the dependency
     */
    public ResourceDependencyFoundEvent(URI from, URI to, EObject parent, EStructuralFeature feature) {
        super(from, to, getParentUriIfContainmentReference(checkNotNull(parent), feature));
    }

    /**
     * Returns the URI of the {@code parent} object causing this dependency, if it is the actual owner of the
     * dependency.
     * <p>
     * The {@code parent} object is the actual owner if the {@code feature} through which the {@code parent}
     * object refers to the dependency is a {@link EReference#isContainment() containment reference}.
     * </p>
     * 
     * @param parent
     *            The object in the source causing the dependency
     * @param feature
     *            The feature through which the parent causes the dependency
     * @return the URI of the parent if it is the owner of the dependency, otherwise {@link Optional#absent()}
     */
    private static Optional<URI> getParentUriIfContainmentReference(EObject parent, EStructuralFeature feature) {
        if (feature instanceof EReference && ((EReference) feature).isContainment()) {
            return Optional.of(getUri(parent));
        }
        return Optional.absent();
    }

    /**
     * Returns the URI of the given {@code eObject}.
     * 
     * @param eObject
     *            The object to get the URI of
     * @return The URI of the given {@code eObject}
     */
    public static URI getUri(EObject eObject) {
        return EcoreUtil.getURI(eObject);
    }

}