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/*
 * #%L
 * *********************************************************************************************************************
 * 
 * These Foolish Things - Miscellaneous utilities
 * http://thesefoolishthings.tidalwave.it - git clone [email protected]:tidalwave/thesefoolishthings-src.git
 * %%
 * Copyright (C) 2009 - 2016 Tidalwave s.a.s. (http://tidalwave.it)
 * %%
 * *********************************************************************************************************************
 * 
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * 
 *     http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
 * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations under the License.
 * 
 * *********************************************************************************************************************
 * 
 * $Id$
 * 
 * *********************************************************************************************************************
 * #L%
 */
package it.tidalwave.role.ui.spi;

import javax.annotation.Nonnull;
import java.util.List;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.stream.Stream;
import java.util.stream.StreamSupport;
import java.util.function.Function;
import it.tidalwave.util.As;
import it.tidalwave.util.spi.ArrayListCollectorSupport;
import it.tidalwave.role.spi.ArrayListSimpleComposite;
import it.tidalwave.role.Composite;
import it.tidalwave.role.ui.PresentationModel;
import static it.tidalwave.role.ui.Presentable.Presentable;

/***********************************************************************************************************************
 *
 * A {@link Collector} which collects a {@link Stream} of {@link PresentationModel}s into a single
 * {@code PresentationModel} with a {@link Composite<PresentationModel>} role containing them.
 * 
 * @author  Fabrizio Giudici
 * @version $Id$
 *
 **********************************************************************************************************************/
public class PresentationModelCollectors extends ArrayListCollectorSupport
  {
    @Nonnull
    private final List roles = new ArrayList<>();
    
    /*******************************************************************************************************************
     *
     * A {@link Collector} which collects a {@link Stream} of {@link PresentationModel}s into a single
     * {@code PresentationModel} with a {@link Composite} role containing them. In other words:
     * 
     * 
     * List<PresentationModel> pms = ...
     * PresentationModel compositePm = pms.stream().collect(toCompositePresentationModel());
     * // same contents as childrenPms
     * List<PresentationModel> childrenPms = compositePm.as(Composite).findChildren().results();
     * 
* * @param roles some extra roles included in the resulting {@code PresentationModel} * @return a {@code PresentationModel} * ******************************************************************************************************************/ @Nonnull public static PresentationModelCollectors toCompositePresentationModel (final @Nonnull Object ... roles) { return new PresentationModelCollectors(Arrays.asList(roles)); } /******************************************************************************************************************* * * A facility method that creates a composite {@link PresentationModel} out of a stream of objects. For each object * in the stream, its {@code PresentationModel} is created by means of invoking its {@link Presentable} role. * Then all the {@code PresentationModel}s are aggregated into the composite. * * This method accepts an {@link Iterable}. A function which creates specific roles for each * {@code PresentationModel} can be supplied. The function can return a single role or multiple roles in form of * an {@code Object[]}. * * @param i the {@code Iterable} * @param roleCreator the function to create roles * @return the composite {@code PresentationModel} * ******************************************************************************************************************/ @Nonnull public static PresentationModel toCompositePresentationModel ( final @Nonnull Iterable i, final @Nonnull Function roleCreator) { return StreamSupport.stream(i.spliterator(), false) .map(o -> o.as(Presentable).createPresentationModel(array(roleCreator.apply(o)))) .collect(PresentationModelCollectors.toCompositePresentationModel()); } /******************************************************************************************************************* * * A facility simplified version of * {@link #toCompositePresentationModel(java.lang.Iterable, java.util.function.Function)} without a function to * supply additional roles. * * @param i the {@code Iterable} * @return the composite {@code PresentationModel} * ******************************************************************************************************************/ @Nonnull public static PresentationModel toCompositePresentationModel (final @Nonnull Iterable i) { return toCompositePresentationModel(i, o -> new Object[0]); } /******************************************************************************************************************* * * {@inheritDoc} * ******************************************************************************************************************/ @Override @Nonnull public Function, PresentationModel> finisher() { return childrenPms -> { final List temp = new ArrayList<>(roles); temp.add(new ArrayListSimpleComposite<>(childrenPms)); // FIXME: "" triggers a NPE in RoleManagerSupport.java:341 return new DefaultPresentationModel("", temp.toArray()); }; } /******************************************************************************************************************* * * ******************************************************************************************************************/ private PresentationModelCollectors (final @Nonnull List roles) { this.roles.addAll(roles); } /******************************************************************************************************************* * * ******************************************************************************************************************/ @Nonnull private static Object[] array (final @Nonnull Object object) { return (object instanceof Object[]) ? (Object[])object : new Object[] { object }; } }