eu.numberfour.n4js.scoping.utils.CompositeScope.java Source code

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Here is the source code for eu.numberfour.n4js.scoping.utils.CompositeScope.java

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/**
 * Copyright (c) 2016 NumberFour AG.
 * 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:
 *   NumberFour AG - Initial API and implementation
 */
package eu.numberfour.n4js.scoping.utils;

import java.util.Arrays;
import java.util.stream.Collectors;

import org.eclipse.emf.ecore.EObject;
import org.eclipse.xtext.naming.QualifiedName;
import org.eclipse.xtext.resource.IEObjectDescription;
import org.eclipse.xtext.scoping.IScope;

import com.google.common.collect.Iterables;

/**
 * A scope that is composed of other scopes.
 * <p>
 * IMPORTANT:<br>
 * Usually, scopes should *not* be composed with this class, instead nesting should be used (one scope being a parent of
 * the other). This class is intended only for some tweaks related to content assist.
 */
public class CompositeScope implements IScope {

    /**
     * The child scopes that together constitute this scope.
     */
    protected final IScope[] childScopes;

    /**
     * @see #create(IScope...)
     */
    protected CompositeScope(IScope... scopes) {
        childScopes = scopes;
    }

    /**
     * Creates a new {@link CompositeScope}.
     */
    public static final CompositeScope create(IScope... scopes) {
        return new CompositeScope(scopes);
    }

    @Override
    public IEObjectDescription getSingleElement(QualifiedName name) {
        for (IScope currScope : childScopes) {
            final IEObjectDescription currResult = currScope.getSingleElement(name);
            if (currResult != null)
                return currResult;
        }
        return null;
    }

    @Override
    public IEObjectDescription getSingleElement(EObject object) {
        for (IScope currScope : childScopes) {
            final IEObjectDescription currResult = currScope.getSingleElement(object);
            if (currResult != null)
                return currResult;
        }
        return null;
    }

    @Override
    public Iterable<IEObjectDescription> getElements(QualifiedName name) {
        return Iterables.concat(Arrays.stream(childScopes).map(currScope -> currScope.getElements(name))
                .collect(Collectors.toList()));
    }

    @Override
    public Iterable<IEObjectDescription> getElements(EObject object) {
        return Iterables.concat(Arrays.stream(childScopes).map(currScope -> currScope.getElements(object))
                .collect(Collectors.toList()));
    }

    @Override
    public Iterable<IEObjectDescription> getAllElements() {
        return Iterables.concat(Arrays.stream(childScopes).map(currScope -> currScope.getAllElements())
                .collect(Collectors.toList()));
    }
}