001/*-------------------------------------------------------------------------+
002|                                                                          |
003| Copyright 2005-2011 The ConQAT Project                                   |
004|                                                                          |
005| Licensed under the Apache License, Version 2.0 (the "License");          |
006| you may not use this file except in compliance with the License.         |
007| You may obtain a copy of the License at                                  |
008|                                                                          |
009|    http://www.apache.org/licenses/LICENSE-2.0                            |
010|                                                                          |
011| Unless required by applicable law or agreed to in writing, software      |
012| distributed under the License is distributed on an "AS IS" BASIS,        |
013| WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
014| See the License for the specific language governing permissions and      |
015| limitations under the License.                                           |
016+-------------------------------------------------------------------------*/
017package org.conqat.lib.commons.tree;
018
019/**
020 * This interface is used by {@link TreeUtils} to create tree structures. We use
021 * this factory-based approach as this allows us to create trees based on model
022 * elements that do not have to implement any specific interfaces.
023 * 
024 * @param <T>
025 *            the type of nodes this handler handles
026 * @param <K>
027 *            the key used by the nodes to identify children
028 * @author deissenb
029 */
030public interface ITreeNodeHandler<T, K> {
031        /**
032         * Get the nodes child identified by the provided key. If the node has no
033         * child with the specified key, one should be created.
034         */
035        public T getOrCreateChild(T node, K key);
036
037        /** Create root of node of the tree. */
038        public T createRoot();
039}