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.spec.feature;
021
022import java.util.Collection;
023import java.util.Queue;
024
025/**
026 * Base interface for {@link OneToManyAssociation} only.
027 * 
028 * <p>
029 * Introduced for symmetry with {@link OneToOneFeature}; if we ever support
030 * collections as parameters then would also be the base interface for a
031 * <tt>OneToManyActionParameter</tt>.
032 * 
033 * <p>
034 * Is also the route up to the {@link ObjectFeature} superinterface.
035 * 
036 */
037public interface OneToManyFeature extends ObjectFeature {
038
039    public enum CollectionSemantics {
040        LIST, ARRAY, SET, OTHER;
041
042        /**
043         * The corresponding class is not a subclass of {@link Collection}.
044         */
045        public boolean isArray() {
046            return this == ARRAY;
047        }
048
049        public boolean isList() {
050            return this == LIST;
051        }
052
053        public boolean isSet() {
054            return this == SET;
055        }
056
057        /**
058         * For example, {@link Queue}, or some other 3rdparty implementation of
059         * {@link Collection}.
060         */
061        public boolean isOther() {
062            return this == OTHER;
063        }
064
065        public boolean isListOrArray() {
066            return isList() || isArray();
067        }
068    }
069
070    CollectionSemantics getCollectionSemantics();
071}