001    /*--------------------------------------------------------------------------+
002    $Id: SimpleTreeNodeHandler.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     * Handler for {@link SimpleTreeNode}.
022     * 
023     * @author deissenb
024     * @author $Author: juergens $
025     * @version $Rev: 26268 $
026     * @levd.rating GREEN Hash: EAE7ADE3588C81DB8F6FEBF4403F0C91
027     */
028    public class SimpleTreeNodeHandler<K> implements
029                    ITreeNodeHandler<SimpleTreeNode<K>, K> {
030    
031            /** The key used for the root. */
032            private final K rootKey;
033    
034            /**
035             * Create new handler.
036             * 
037             * @param rootKey
038             *            the key used for the root node.
039             */
040            public SimpleTreeNodeHandler(K rootKey) {
041                    this.rootKey = rootKey;
042            }
043    
044            /** {@inheritDoc} */
045            public SimpleTreeNode<K> createRoot() {
046                    return new SimpleTreeNode<K>(rootKey);
047            }
048    
049            /** {@inheritDoc} */
050            public SimpleTreeNode<K> getOrCreateChild(SimpleTreeNode<K> node, K key) {
051                    SimpleTreeNode<K> child = node.getChild(key);
052                    if (child != null) {
053                            return child;
054                    }
055    
056                    child = new SimpleTreeNode<K>(key);
057                    node.addChild(child);
058                    return child;
059            }
060    
061    }