org.eclipse.emf.compare.egit.internal.match.EGitMatchEngineFactory.java Source code

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Here is the source code for org.eclipse.emf.compare.egit.internal.match.EGitMatchEngineFactory.java

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/*******************************************************************************
 * Copyright (c) 2015 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.compare.egit.internal.match;

import com.google.common.collect.Sets;

import java.util.Collection;

import org.eclipse.emf.common.notify.Adapter;
import org.eclipse.emf.common.notify.Notifier;
import org.eclipse.emf.compare.ide.internal.utils.StoragePathAdapter;
import org.eclipse.emf.compare.match.DefaultMatchEngine;
import org.eclipse.emf.compare.match.IMatchEngine;
import org.eclipse.emf.compare.match.resource.IResourceMatchingStrategy;
import org.eclipse.emf.compare.match.resource.LocationMatchingStrategy;
import org.eclipse.emf.compare.rcp.EMFCompareRCPPlugin;
import org.eclipse.emf.compare.rcp.internal.match.DefaultRCPMatchEngineFactory;
import org.eclipse.emf.compare.scope.IComparisonScope;
import org.eclipse.emf.compare.utils.UseIdentifiers;
import org.eclipse.emf.ecore.resource.Resource;
import org.eclipse.emf.ecore.resource.ResourceSet;
import org.eclipse.emf.ecore.util.EcoreUtil;

/**
 * Specialization of {@link DefaultRCPMatchEngineFactory} for EGit. When a comparison involves models shared
 * with EGit, the {@link org.eclipse.emf.compare.match.resource.StrategyResourceMatcher} must use the
 * {@link org.eclipse.emf.compare.match.resource.LocationMatchingStrategy} instead of the
 * {@link org.eclipse.emf.compare.match.resource.NameMatchingStrategy}.
 * 
 * @author <a href="mailto:axel.richard@obeo.fr">Axel Richard</a>
 */
@SuppressWarnings("restriction")
public class EGitMatchEngineFactory extends DefaultRCPMatchEngineFactory {

    /**
     * {@inheritDoc}
     */
    @Override
    public boolean isMatchEngineFactoryFor(IComparisonScope scope) {

        final Notifier right = scope.getRight();
        boolean activateEGitMatchEngine = isNotifierContainsSharedResource(right);

        if (!activateEGitMatchEngine) {
            final Notifier left = scope.getLeft();
            activateEGitMatchEngine = isNotifierContainsSharedResource(left);
            if (!activateEGitMatchEngine) {
                final Notifier origin = scope.getOrigin();
                activateEGitMatchEngine = isNotifierContainsSharedResource(origin);
            }
        }

        return activateEGitMatchEngine;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public IMatchEngine getMatchEngine() {
        final UseIdentifiers useUdentifier = getUseIdentifierValue(getConfiguration());
        final Collection<IResourceMatchingStrategy> strategies = Sets.newLinkedHashSet();
        strategies.add(new LocationMatchingStrategy());
        return DefaultMatchEngine.create(useUdentifier,
                EMFCompareRCPPlugin.getDefault().getWeightProviderRegistry(), strategies);
    }

    /**
     * Check if the given {@link Notifier} contains at least on resource shared with git.
     * 
     * @param notifier
     *            the given {@link Notifier}.
     * @return true if the given {@link Notifier} contains at least on resource shared with git, false
     *         otherwise.
     */
    private boolean isNotifierContainsSharedResource(final Notifier notifier) {
        if (notifier instanceof ResourceSet) {
            for (Resource resource : ((ResourceSet) notifier).getResources()) {
                if (isResourceSharedWithGit(resource)) {
                    return true;
                }
            }
        } else if (notifier instanceof Resource && isResourceSharedWithGit((Resource) notifier)) {
            return true;
        }

        return false;
    }

    /**
     * Check if the given {@link Resource} is shared with git.
     * 
     * @param resource
     *            the given {@link Resource}.
     * @return true if the given {@link Resource} is shared with git, false otherwise.
     */
    private boolean isResourceSharedWithGit(Resource resource) {
        Adapter leftAdapter = EcoreUtil.getAdapter(resource.eAdapters(), StoragePathAdapter.class);
        // If the resource is a storage path adapter and this storage path adapter contains a file URI, this
        // means that this is a resource from the Local History, not from a Git repository.
        if (leftAdapter instanceof StoragePathAdapter && !((StoragePathAdapter) leftAdapter).isLocal()
                && !isFileURI(((StoragePathAdapter) leftAdapter).getStoragePath())) {
            return true;
        }
        return false;
    }

    /**
     * Check if the given path is has a file scheme (file:).
     * 
     * @param path
     *            the given path.
     * @return true if the given path is has a file scheme (file:), false otherwise.
     */
    private boolean isFileURI(String path) {
        final boolean isFileURI;
        if (path == null) {
            isFileURI = false;
        } else {
            isFileURI = path.startsWith("file:"); //$NON-NLS-1$
        }
        return isFileURI;
    }
}