eu.numberfour.n4js.ui.workingsets.DefaultWorkingSetImpl.java Source code

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Here is the source code for eu.numberfour.n4js.ui.workingsets.DefaultWorkingSetImpl.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.ui.workingsets;

import static com.google.common.collect.FluentIterable.from;
import static com.google.common.collect.Sets.newHashSet;
import static java.util.Arrays.asList;

import java.util.Arrays;
import java.util.Collection;
import java.util.Map;

import org.eclipse.core.resources.IProject;
import org.eclipse.core.resources.ResourcesPlugin;
import org.eclipse.core.runtime.IAdaptable;

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

/**
 * Default working set implementation that provides a convenient {@link #getElements() element providing} logic for the
 * built-in '{@link WorkingSet#OTHERS_WORKING_SET_ID Other Projects}' working set. These dynamic working sets depends on
 * all the other working sets provided by the container manager.
 */
public abstract class DefaultWorkingSetImpl extends WorkingSetImpl implements Predicate<IProject> {

    /**
     * Creates a new working set manager with the given ID and the container manager.
     *
     * @param id
     *            the unique identifier of the working set.
     * @param manager
     *            the container manager where this working set belongs to.
     */
    protected DefaultWorkingSetImpl(final String id, final WorkingSetManager manager) {
        super(id, manager);
    }

    @Override
    public IAdaptable[] getElements() {
        final IProject[] projects = getAllProjects();
        if (OTHERS_WORKING_SET_ID.equals(getId())) {

            // No other working sets are available at all.
            final WorkingSet[] allWorkingSets = getWorkingSetManager().getAllWorkingSets();
            if (allWorkingSets.length == 1) {
                return projects;
            } else {

                // We have to exclude all those projects that are associatedwith at least one other working set.
                final FluentIterable<WorkingSet> others = from(asList(allWorkingSets))
                        .filter(ws -> !OTHERS_WORKING_SET_ID.equals(ws.getId()));

                // Mapping between non-built-in working sets and their elements.
                final Map<WorkingSet, Collection<IAdaptable>> elementMapping = Maps.toMap(others,
                        ws -> newHashSet(ws.getElements()));

                final IProject[] elements = new IProject[projects.length];
                int elementCount = 0;
                for (int i = 0, size = projects.length; i < size; i++) {
                    final IProject project = projects[i];
                    // If the project is not assigned to any other working set, then assign it to the built-in one.
                    if (!Iterables.any(others, ws -> elementMapping.get(ws).contains(project))) {
                        elements[elementCount++] = project;
                    }
                }

                return Arrays.copyOfRange(elements, 0, elementCount);
            }

        } else {
            final IProject[] elements = new IProject[projects.length];
            int elementCount = 0;
            for (int i = 0, size = projects.length; i < size; i++) {
                final IProject project = projects[i];
                if (apply(project)) {
                    elements[elementCount++] = project;
                }
            }
            return Arrays.copyOfRange(elements, 0, elementCount);
        }
    }

    /**
     * Sugar for getting all workspace projects from the workspace root.
     *
     * @return all projects from the workspace root.
     */
    protected IProject[] getAllProjects() {
        return ResourcesPlugin.getWorkspace().getRoot().getProjects();
    }

}