001    // Copyright 2004, 2005 The Apache Software Foundation
002    //
003    // Licensed under the Apache License, Version 2.0 (the "License");
004    // you may not use this file except in compliance with the License.
005    // You may obtain a copy of the License at
006    //
007    //     http://www.apache.org/licenses/LICENSE-2.0
008    //
009    // Unless required by applicable law or agreed to in writing, software
010    // distributed under the License is distributed on an "AS IS" BASIS,
011    // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
012    // See the License for the specific language governing permissions and
013    // limitations under the License.
014    
015    package org.apache.hivemind.impl;
016    
017    import java.util.ArrayList;
018    import java.util.Collections;
019    import java.util.List;
020    
021    import org.apache.hivemind.internal.Contribution;
022    import org.apache.hivemind.internal.Module;
023    
024    /**
025     * Implements the {@link org.apache.hivemind.internal.Contribution} interface, a wrapper
026     * around objects that can provide values that plug into an extension point.
027     * 
028     * @author Howard Lewis Ship
029     */
030    public final class ContributionImpl implements Contribution
031    {
032        private Module _contributingModule;
033    
034        private List _elements;
035    
036        public Module getContributingModule()
037        {
038            return _contributingModule;
039        }
040    
041        public void setContributingModule(Module module)
042        {
043            _contributingModule = module;
044        }
045    
046        public void addElements(List elements)
047        {
048            if (_elements == null)
049                _elements = new ArrayList(elements);
050            else
051                _elements.addAll(elements);
052        }
053    
054        public List getElements()
055        {
056            if (_elements == null)
057                return Collections.EMPTY_LIST;
058    
059            return _elements;
060        }
061    }