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

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Here is the source code for eu.numberfour.n4js.ui.workingsets.WorkingSetDiffBuilder.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 eu.numberfour.n4js.ui.workingsets.WorkingSetManager.EMPTY_ARRAY;
import static java.util.Collections.emptyMap;

import java.util.function.Function;

import com.google.common.collect.Iterables;

import eu.numberfour.n4js.utils.Diff;
import eu.numberfour.n4js.utils.DiffBuilder;

/**
 * Difference builder for {@link WorkingSetManager working set manager} instances and their {@link WorkingSet working
 * sets}.
 */
public class WorkingSetDiffBuilder extends DiffBuilder<WorkingSetManager, WorkingSet> {

    /**
     * Constant for representing an empty difference.
     */
    public static final Diff<WorkingSet> EMPTY_DIFF = new Diff<>(EMPTY_ARRAY, EMPTY_ARRAY, EMPTY_ARRAY, EMPTY_ARRAY,
            emptyMap(), EMPTY_ARRAY, EMPTY_ARRAY);

    /**
     * Builds the difference based on the new items and all new items arguments. This is just a sugar for
     * {@link #build(WorkingSet[], WorkingSet[])} method.
     */
    public Diff<WorkingSet> build(final Iterable<? extends WorkingSet> newItems,
            final Iterable<? extends WorkingSet> newAllItems) {

        return build(Iterables.toArray(newItems, WorkingSet.class),
                Iterables.toArray(newAllItems, WorkingSet.class));
    }

    /**
     * Creates a new diff builder instance with the given working set manager argument. The working set manager is used
     * to provide the initial state of the wrapped working sets.
     *
     * @param workingSetManager
     *            the working set manager for the initial state.
     */
    public WorkingSetDiffBuilder(final WorkingSetManager workingSetManager) {
        super(workingSetManager);
    }

    @Override
    protected Function<WorkingSetManager, WorkingSet[]> getOldItemsFunction() {
        return input -> input.getWorkingSets();
    }

    @Override
    protected Function<WorkingSetManager, WorkingSet[]> getAllOldItemsFunction() {
        return input -> input.getAllWorkingSets();
    }

}