org.eclipse.xtext.ui.generator.trace.ExtensibleTraceURIConverter.java Source code

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Here is the source code for org.eclipse.xtext.ui.generator.trace.ExtensibleTraceURIConverter.java

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/*******************************************************************************
 * Copyright (c) 2013 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.ui.generator.trace;

import org.eclipse.emf.common.util.URI;
import org.eclipse.jdt.annotation.Nullable;
import org.eclipse.xtext.generator.trace.DefaultTraceURIConverter;
import org.eclipse.xtext.resource.XtextResource;
import org.eclipse.xtext.ui.shared.contribution.ISharedStateContributionRegistry;

import com.google.common.collect.ImmutableList;
import com.google.inject.Inject;

/**
 * An extension of the {@link DefaultTraceURIConverter} that allows to use
 * {@link ITraceURIConverterContribution contributions} to resolve trace URIs.
 * 
 * The available contributions are used before the behavior of the {@link DefaultTraceURIConverter}
 * is used to resolve the URIs.
 * 
 * @author Moritz Eysholdt - Initial contribution and API
 * @author Holger Schill
 */
public class ExtensibleTraceURIConverter extends DefaultTraceURIConverter {

    public static class CompositeContribution implements ITraceURIConverterContribution {

        private ImmutableList<? extends ITraceURIConverterContribution> contributions;

        public CompositeContribution(ImmutableList<? extends ITraceURIConverterContribution> contributions) {
            this.contributions = contributions;
        }

        @Nullable
        public URI getURIForTrace(XtextResource context) {
            for (int i = 0, size = contributions.size(); i < size; i++) {
                URI result = contributions.get(i).getURIForTrace(context);
                if (result != null) {
                    return result;
                }
            }
            return null;
        }

        @Nullable
        public URI getURIForTrace(URI uri) {
            for (int i = 0, size = contributions.size(); i < size; i++) {
                URI result = contributions.get(i).getURIForTrace(uri);
                if (result != null) {
                    return result;
                }
            }
            return null;
        }

    }

    public static final class NullContribution implements ITraceURIConverterContribution {

        @Nullable
        public URI getURIForTrace(XtextResource context) {
            return null;
        }

        @Nullable
        public URI getURIForTrace(URI uri) {
            return null;
        }

    }

    private ITraceURIConverterContribution contribution;

    @Inject
    private void initializeContribution(ISharedStateContributionRegistry registry) {
        contribution = getContribution(registry.getContributedInstances(ITraceURIConverterContribution.class));
    }

    private ITraceURIConverterContribution getContribution(
            ImmutableList<? extends ITraceURIConverterContribution> allContributions) {
        switch (allContributions.size()) {
        case 0:
            return new NullContribution();
        case 1:
            return allContributions.get(0);
        default:
            return new CompositeContribution(allContributions);
        }
    }

    @Override
    public URI getURIForTrace(XtextResource context) {
        URI result = contribution.getURIForTrace(context);
        if (result != null) {
            return result;
        }
        return super.getURIForTrace(context);

    }

    @Override
    public URI getURIForTrace(URI uri) {
        URI result = contribution.getURIForTrace(uri);
        if (result != null) {
            return result;
        }
        return super.getURIForTrace(uri);
    }

}