org.eclipse.xtext.resource.containers.StateBasedContainer.java Source code

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Here is the source code for org.eclipse.xtext.resource.containers.StateBasedContainer.java

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/*******************************************************************************
 * Copyright (c) 2010 itemis AG (http://www.itemis.eu) 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
 *******************************************************************************/
package org.eclipse.xtext.resource.containers;

import static java.util.Collections.*;

import java.util.Collection;
import java.util.Collections;
import java.util.Map;

import org.eclipse.emf.common.util.URI;
import org.eclipse.emf.ecore.EClass;
import org.eclipse.emf.ecore.EObject;
import org.eclipse.xtext.naming.QualifiedName;
import org.eclipse.xtext.resource.IEObjectDescription;
import org.eclipse.xtext.resource.IResourceDescription;
import org.eclipse.xtext.resource.IResourceDescriptions;
import org.eclipse.xtext.resource.impl.ResourceDescriptionsBasedContainer;

import com.google.common.base.Predicate;
import com.google.common.collect.Iterables;
import com.google.common.collect.Maps;

/**
 * A specialized container which is based on some long living lightweight state.
 * A {@link IContainerState container state} is used to decide about the actually
 * contained resource descriptions.
 * 
 * @author Sebastian Zarnekow - Initial contribution and API
 */
public class StateBasedContainer extends ResourceDescriptionsBasedContainer {

    private final IContainerState state;

    public StateBasedContainer(IResourceDescriptions descriptions, IContainerState state) {
        super(descriptions);
        this.state = state;
    }

    @Override
    protected Iterable<IEObjectDescription> filterByURI(Iterable<IEObjectDescription> unfiltered) {
        return Iterables.filter(unfiltered, new Predicate<IEObjectDescription>() {
            private Collection<URI> contents = null;

            @Override
            public boolean apply(IEObjectDescription input) {
                if (contents == null) {
                    contents = state.getContents();
                }
                URI resourceURI = input.getEObjectURI().trimFragment();
                final boolean contains = contents.contains(resourceURI);
                return contains;
            }
        });
    }

    @Override
    public boolean hasResourceDescription(URI uri) {
        return state.contains(uri);
    }

    @Override
    public int getResourceDescriptionCount() {
        return state.getContents().size();
    }

    @Override
    public boolean isEmpty() {
        return state.isEmpty();
    }

    @Override
    public IResourceDescription getResourceDescription(URI uri) {
        if (state.contains(uri))
            return getDescriptions().getResourceDescription(uri);
        return null;
    }

    @Override
    public Iterable<IResourceDescription> getResourceDescriptions() {
        if (state.getContents().isEmpty())
            return Collections.emptyList();
        return getUriToDescription().values();
    }

    @Override
    protected Map<URI, IResourceDescription> doGetUriToDescription() {
        Map<URI, IResourceDescription> result = Maps.newLinkedHashMap();
        for (URI uri : state.getContents()) {
            IResourceDescription description = getDescriptions().getResourceDescription(uri);
            if (description != null)
                result.put(uri, description);
        }
        return result;
    }

    @Override
    public Iterable<IEObjectDescription> getExportedObjects() {
        if (state.getContents().isEmpty())
            return emptyList();
        return super.getExportedObjects();
    }

    @Override
    public Iterable<IEObjectDescription> getExportedObjectsByType(EClass type) {
        if (state.getContents().isEmpty())
            return emptyList();
        return super.getExportedObjectsByType(type);
    }

    @Override
    public Iterable<IEObjectDescription> getExportedObjectsByObject(EObject object) {
        if (state.getContents().isEmpty())
            return emptyList();
        return super.getExportedObjectsByObject(object);
    }

    @Override
    public Iterable<IEObjectDescription> getExportedObjects(EClass type, QualifiedName qualifiedName,
            boolean ignoreCase) {
        if (state.getContents().isEmpty())
            return emptyList();
        return super.getExportedObjects(type, qualifiedName, ignoreCase);
    }

    /**
     * @since 2.4
     */
    @Override
    public String toString() {
        return "[" + getClass().getSimpleName() + "] " + state;
    }

}