001    /*--------------------------------------------------------------------------+
002    $Id: ITreeNodeHandler.java 26268 2010-02-18 10:44:30Z juergens $
003    |                                                                          |
004    | Copyright 2005-2010 Technische Universitaet Muenchen                     |
005    |                                                                          |
006    | Licensed under the Apache License, Version 2.0 (the "License");          |
007    | you may not use this file except in compliance with the License.         |
008    | 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, software      |
013    | distributed under the License is distributed on an "AS IS" BASIS,        |
014    | WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
015    | See the License for the specific language governing permissions and      |
016    | limitations under the License.                                           |
017    +--------------------------------------------------------------------------*/
018    package edu.tum.cs.commons.tree;
019    
020    /**
021     * This interface is used by {@link TreeUtils} to create tree structures. We use
022     * this factory-based approach as this allows us to create trees based on model
023     * elements that do not have to implement any specific interfaces.
024     * 
025     * @param <T>
026     *            the type of nodes this handler handles
027     * @param <K>
028     *            the key used by the nodes to identify children
029     * @author deissenb
030     * @author $Author: juergens $
031     * @version $Rev: 26268 $
032     * @levd.rating GREEN Hash: 18A7ECBF6AD2E499BD9957FB39C6557D
033     */
034    public interface ITreeNodeHandler<T, K> {
035            /**
036             * Get the nodes child identified by the provided key. If the node has no
037             * child with the specified key, one should be created.
038             */
039            public T getOrCreateChild(T node, K key);
040    
041            /** Create root of node of the tree. */
042            public T createRoot();
043    }