org.yakindu.base.expressions.scoping.AbstractLibraryGlobalScopeProvider.java Source code

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Here is the source code for org.yakindu.base.expressions.scoping.AbstractLibraryGlobalScopeProvider.java

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/** 
 * Copyright (c) 2017 committers of YAKINDU 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:
 * committers of YAKINDU - initial API and implementation
 *
*/
package org.yakindu.base.expressions.scoping;

import java.util.Collections;
import java.util.List;
import java.util.Set;
import java.util.concurrent.Callable;

import org.eclipse.emf.common.util.URI;
import org.eclipse.emf.ecore.EReference;
import org.eclipse.emf.ecore.resource.Resource;
import org.eclipse.emf.ecore.resource.ResourceSet;
import org.eclipse.emf.ecore.resource.URIConverter;
import org.eclipse.emf.ecore.resource.impl.ResourceSetImpl;
import org.eclipse.xtext.resource.IEObjectDescription;
import org.eclipse.xtext.resource.IResourceDescription;
import org.eclipse.xtext.resource.IResourceServiceProvider;
import org.eclipse.xtext.resource.impl.EObjectDescriptionLookUp;
import org.eclipse.xtext.scoping.IGlobalScopeProvider;
import org.eclipse.xtext.scoping.IScope;
import org.eclipse.xtext.scoping.Scopes;
import org.eclipse.xtext.scoping.impl.AbstractGlobalScopeProvider;
import org.eclipse.xtext.scoping.impl.SelectableBasedScope;

import com.google.common.base.Predicate;
import com.google.common.cache.Cache;
import com.google.common.cache.CacheBuilder;
import com.google.common.collect.Iterables;
import com.google.common.collect.Lists;
import com.google.inject.Inject;

/**
 * 
 * @author andreas muelder - Initial contribution and API
 * 
 */
public abstract class AbstractLibraryGlobalScopeProvider extends AbstractGlobalScopeProvider
        implements IGlobalScopeProvider {

    @Inject
    private IResourceServiceProvider.Registry serviceProviderRegistry;

    protected abstract Set<URI> getLibraries(Resource context);

    protected Iterable<URI> getValidLibraries(Resource context) {
        return Iterables.filter(getLibraries(context), new Predicate<URI>() {
            @Override
            public boolean apply(URI input) {
                return URIConverter.INSTANCE.exists(input, Collections.EMPTY_MAP);
            }
        });
    }

    private Cache<URI, Iterable<IEObjectDescription>> libraryCache;

    public AbstractLibraryGlobalScopeProvider() {
        libraryCache = CacheBuilder.newBuilder().<URI, Iterable<IEObjectDescription>>build();
    }

    @Override
    public IScope getScope(Resource context, EReference reference, Predicate<IEObjectDescription> filter) {
        List<IEObjectDescription> descriptions = Lists.newArrayList();
        for (URI uri : getValidLibraries(context)) {
            try {
                Iterables.addAll(descriptions, libraryCache.get(uri, new Callable<Iterable<IEObjectDescription>>() {

                    @Override
                    public Iterable<IEObjectDescription> call() throws Exception {
                        return getDescriptions(context, uri);
                    }
                }));
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        return SelectableBasedScope.createScope(IScope.NULLSCOPE, new EObjectDescriptionLookUp(descriptions),
                reference.getEReferenceType(), isIgnoreCase(reference));
    }

    protected Iterable<IEObjectDescription> getDescriptions(Resource context, URI uri) {
        List<IEObjectDescription> result = Lists.newArrayList();
        ResourceSet set = new ResourceSetImpl();
        Resource resource = set.getResource(uri, true);
        IResourceServiceProvider resourceServiceProvider = serviceProviderRegistry.getResourceServiceProvider(uri);
        if (resourceServiceProvider == null) {
            Iterables.addAll(result, Scopes.scopedElementsFor(Lists.newArrayList(resource.getAllContents())));
        } else {
            IResourceDescription resourceDescription = resourceServiceProvider.getResourceDescriptionManager()
                    .getResourceDescription(resource);
            Iterables.addAll(result, resourceDescription.getExportedObjects());
        }
        resource.unload();
        return result;
    }

}