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;
021
022import java.util.AbstractList;
023import java.util.Collections;
024import java.util.List;
025
026import org.apache.isis.core.commons.util.ToString;
027import org.apache.isis.core.metamodel.adapter.ObjectAdapter;
028
029/**
030 * A list returned from an action, ie not associated or owned by any entity.
031 */
032public class FreeStandingList extends AbstractList<ObjectAdapter> {
033
034    private final List<ObjectAdapter> instances;
035    private final ObjectSpecification instanceSpecification;
036
037    public FreeStandingList(final ObjectSpecification instanceSpecification, final List<ObjectAdapter> instances) {
038        this.instanceSpecification = instanceSpecification;
039        this.instances = Collections.unmodifiableList(instances);
040    }
041
042    /**
043     * Required implementation of {@link AbstractList}.
044     */
045    @Override
046    public ObjectAdapter get(final int index) {
047        return instances.get(index);
048    }
049
050    /**
051     * Required implementation of {@link AbstractList}.
052     */
053    @Override
054    public int size() {
055        return instances.size();
056    }
057
058    public ObjectSpecification getElementSpecification() {
059        return instanceSpecification;
060    }
061
062    public String titleString() {
063        return instanceSpecification.getPluralName() + ", " + size();
064    }
065
066    @Override
067    public String toString() {
068        final ToString s = new ToString(this);
069        s.append("elements", instanceSpecification.getFullIdentifier());
070
071        // title
072        String title;
073        try {
074            title = "'" + this.titleString() + "'";
075        } catch (final NullPointerException e) {
076            title = "none";
077        }
078        s.append("title", title);
079
080        s.append("vector", instances);
081
082        return s.toString();
083    }
084
085}