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    
020    package org.apache.isis.core.progmodel.facets.members.disable;
021    
022    import org.apache.isis.applib.events.UsabilityEvent;
023    import org.apache.isis.core.metamodel.adapter.ObjectAdapter;
024    import org.apache.isis.core.metamodel.facetapi.Facet;
025    import org.apache.isis.core.metamodel.facetapi.FacetHolder;
026    import org.apache.isis.core.metamodel.facets.SingleWhenValueFacetAbstract;
027    import org.apache.isis.core.metamodel.facets.When;
028    import org.apache.isis.core.metamodel.interactions.UsabilityContext;
029    
030    public abstract class DisabledFacetAbstract extends SingleWhenValueFacetAbstract implements DisabledFacet {
031    
032        public static Class<? extends Facet> type() {
033            return DisabledFacet.class;
034        }
035    
036        public DisabledFacetAbstract(final When value, final FacetHolder holder) {
037            super(type(), holder, value);
038        }
039    
040        @Override
041        public String disables(final UsabilityContext<? extends UsabilityEvent> ic) {
042            final ObjectAdapter target = ic.getTarget();
043            final String disabledReason = disabledReason(target);
044            if (disabledReason != null) {
045                return disabledReason;
046            }
047            if (getUnderlyingFacet() != null) {
048                final DisabledFacet underlyingFacet = (DisabledFacet) getUnderlyingFacet();
049                return underlyingFacet.disabledReason(target);
050            }
051            return null;
052        }
053    
054    }