| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You under the Apache License, Version 2.0 |
| * (the "License"); you may not use this file except in compliance with |
| * the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package org.apache.commons.configuration2.tree; |
| |
| /** |
| * <p> |
| * A special {@code NodeHandler} implementation for tracked nodes. |
| * </p> |
| * <p> |
| * While basic access to a tracked node works in the same way as for usual |
| * immutable nodes, there are differences for other operations. For instance, |
| * the root node of the hierarchy is always the tracked node itself. Also the |
| * parent mapping requires some special attention: as long as the node is not |
| * detached, the parent mapping of the model to which the node belongs can be |
| * used. |
| * </p> |
| * <p> |
| * This class inherits the major part of the {@code NodeHandler} implementation |
| * from its base class. In order to implement the parent mapping, an underlying |
| * {@code NodeHandler} object has to be passed at construction time which |
| * contains this information; requests for a node's parent are delegated to this |
| * handler. Further, the root node has to be provided explicitly. |
| * </p> |
| * |
| * @version $Id$ |
| * @since 2.0 |
| */ |
| class TrackedNodeHandler extends AbstractImmutableNodeHandler |
| { |
| /** The root node. */ |
| private final ImmutableNode rootNode; |
| |
| /** The handler for querying the parent mapping. */ |
| private final NodeHandler<ImmutableNode> parentHandler; |
| |
| /** |
| * Creates a new instance of {@code TrackedNodeHandler} and initializes it |
| * with all required information. |
| * |
| * @param root the root node of the represented hierarchy |
| * @param handler an underlying handler for delegation |
| */ |
| public TrackedNodeHandler(ImmutableNode root, |
| NodeHandler<ImmutableNode> handler) |
| { |
| rootNode = root; |
| parentHandler = handler; |
| } |
| |
| /** |
| * Returns the parent handler. This is the {@code NodeHandler} which is |
| * consulted for determining a node's parent node. |
| * |
| * @return the parent {@code NodeHandler} |
| */ |
| public NodeHandler<ImmutableNode> getParentHandler() |
| { |
| return parentHandler; |
| } |
| |
| /** |
| * {@inheritDoc} This implementation delegates to the handler with the |
| * parent mapping. |
| */ |
| @Override |
| public ImmutableNode getParent(ImmutableNode node) |
| { |
| return getParentHandler().getParent(node); |
| } |
| |
| /** |
| * {@inheritDoc} This implementation returns the root node passed at |
| * construction time. |
| */ |
| @Override |
| public ImmutableNode getRootNode() |
| { |
| return rootNode; |
| } |
| } |