001/*
002 *  Licensed to the Apache Software Foundation (ASF) under one
003 *  or more contributor license agreements.  See the NOTICE file
004 *  distributed with this work for additional information
005 *  regarding copyright ownership.  The ASF licenses this file
006 *  to you under the Apache License, Version 2.0 (the
007 *  "License"); you may not use this file except in compliance
008 *  with the License.  You may obtain a copy of the License at
009 *
010 *        http://www.apache.org/licenses/LICENSE-2.0
011 *
012 *  Unless required by applicable law or agreed to in writing,
013 *  software distributed under the License is distributed on an
014 *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015 *  KIND, either express or implied.  See the License for the
016 *  specific language governing permissions and limitations
017 *  under the License.
018 */
019
020package org.apache.isis.core.metamodel.facetapi;
021
022import java.util.HashMap;
023import java.util.List;
024import java.util.Map;
025
026import org.apache.isis.applib.filter.Filter;
027
028/**
029 * For base subclasses or, more likely, to help write tests.
030 */
031public class FacetHolderImpl implements FacetHolder {
032
033    private final Map<Class<? extends Facet>, Facet> facetsByClass = new HashMap<Class<? extends Facet>, Facet>();
034
035    @Override
036    public boolean containsFacet(final Class<? extends Facet> facetType) {
037        return getFacet(facetType) != null;
038    }
039
040    @Override
041    public boolean containsDoOpFacet(final Class<? extends Facet> facetType) {
042        final Facet facet = getFacet(facetType);
043        return facet != null && !facet.isNoop();
044    }
045
046    @Override
047    public void addFacet(final Facet facet) {
048        addFacet(facet.facetType(), facet);
049    }
050
051    @Override
052    public void addFacet(final MultiTypedFacet facet) {
053        final Class<? extends Facet>[] facetTypes = facet.facetTypes();
054        for (final Class<? extends Facet> facetType : facetTypes) {
055            addFacet(facetType, facet.getFacet(facetType));
056        }
057    }
058
059    private void addFacet(final Class<? extends Facet> facetType, final Facet facet) {
060        final Facet existingFacet = getFacet(facetType);
061        if (existingFacet == null || existingFacet.isNoop()) {
062            facetsByClass.put(facetType, facet);
063            return;
064        }
065        if (!facet.alwaysReplace()) {
066            return;
067        }
068        if (facet.isDerived() && !existingFacet.isDerived()) {
069            return;
070        }
071        facet.setUnderlyingFacet(existingFacet);
072        facetsByClass.put(facetType, facet);
073    }
074
075    @Override
076    public void removeFacet(final Facet facet) {
077        FacetUtil.removeFacet(facetsByClass, facet);
078    }
079
080    @Override
081    public void removeFacet(final Class<? extends Facet> facetType) {
082        FacetUtil.removeFacet(facetsByClass, facetType);
083    }
084
085    @Override
086    @SuppressWarnings("unchecked")
087    public <T extends Facet> T getFacet(final Class<T> facetType) {
088        return (T) facetsByClass.get(facetType);
089    }
090
091    @Override
092    public Class<? extends Facet>[] getFacetTypes() {
093        return FacetUtil.getFacetTypes(facetsByClass);
094    }
095
096    @Override
097    public List<Facet> getFacets(final Filter<Facet> filter) {
098        return FacetUtil.getFacets(facetsByClass, filter);
099    }
100
101}