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.progmodel.facets.properties.event;
021
022import com.google.common.base.Objects;
023import com.google.common.collect.Lists;
024
025import org.apache.isis.applib.FatalException;
026import org.apache.isis.applib.Identifier;
027import org.apache.isis.applib.services.eventbus.EventBusService;
028import org.apache.isis.applib.services.eventbus.PropertyChangedEvent;
029import org.apache.isis.core.metamodel.adapter.ObjectAdapter;
030import org.apache.isis.core.metamodel.facetapi.Facet;
031import org.apache.isis.core.metamodel.facetapi.FacetHolder;
032import org.apache.isis.core.metamodel.facets.accessor.PropertyOrCollectionAccessorFacet;
033import org.apache.isis.core.metamodel.facets.properties.event.PostsPropertyChangedEventClearFacet;
034import org.apache.isis.core.metamodel.facets.properties.event.PostsPropertyChangedEventClearFacetAbstract;
035import org.apache.isis.core.metamodel.facets.properties.modify.PropertyClearFacet;
036import org.apache.isis.core.metamodel.runtimecontext.ServicesInjector;
037
038public class PostsPropertyChangedEventClearFacetAnnotation 
039        extends PostsPropertyChangedEventClearFacetAbstract {
040
041    private final PropertyOrCollectionAccessorFacet getterFacet;
042    private final PropertyClearFacet clearFacet;
043    private final Helper helper;
044    
045    public PostsPropertyChangedEventClearFacetAnnotation(
046            final Class<? extends PropertyChangedEvent<?, ?>> eventType, 
047            final PropertyOrCollectionAccessorFacet getterFacet, 
048            final PropertyClearFacet clearFacet, 
049            final ServicesInjector servicesInjector,
050            final FacetHolder holder) {
051        super(eventType, holder);
052        this.getterFacet = getterFacet;
053        this.clearFacet = clearFacet;
054        this.helper = new Helper(servicesInjector);
055    }
056
057    @Override
058    public void clearProperty(ObjectAdapter targetAdapter) {
059        if(clearFacet == null) {
060            return;
061        }
062
063        if(helper.getEventBusService() == null) {
064            clearFacet.clearProperty(targetAdapter);
065            return;
066        }
067
068        final Object oldValue = getterFacet.getProperty(targetAdapter);
069        clearFacet.clearProperty(targetAdapter);
070        final Object newValue = getterFacet.getProperty(targetAdapter);
071        
072        postEventIfChanged(targetAdapter, getIdentified().getIdentifier(), oldValue, newValue);
073    }
074
075
076    @SuppressWarnings({ "rawtypes", "unchecked" })
077    private void postEventIfChanged(
078            final ObjectAdapter targetAdapter, 
079            final Identifier identifier, 
080            final Object oldValue, 
081            final Object newValue) {
082        
083        if(Objects.equal(oldValue, newValue)) {
084            // do nothing.
085            return;
086        }
087        try {
088            final Class type = value();
089            final Object source = ObjectAdapter.Util.unwrap(targetAdapter);
090            final PropertyChangedEvent<?, ?> event = Util.newEvent(type, source, identifier, oldValue, newValue);
091            
092            helper.postEvent(event);
093        } catch (Exception e) {
094            throw new FatalException(e);
095        }
096    }
097
098    // //////////////////////////////////////
099    // MultiTypedFacet
100    // //////////////////////////////////////
101
102    @SuppressWarnings("unchecked")
103    @Override
104    public Class<? extends Facet>[] facetTypes() {
105        return Lists.newArrayList(
106                    type(),
107                    PostsPropertyChangedEventClearFacet.class
108                ).toArray(new Class[]{});
109    }
110
111    @SuppressWarnings("unchecked")
112    @Override
113    public <T extends Facet> T getFacet(Class<T> facet) {
114        return (T) this;
115    }
116
117
118}