001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  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.apache.commons.configuration2.tree;
018
019import java.util.List;
020import java.util.Set;
021
022/**
023 * <p>
024 * An abstract base class for decorators of a {@code NodeHandler}.
025 * </p>
026 * <p>
027 * This class implements all methods of the {@code NodeHandler} interface by delegating to another instance. This is
028 * convenient if specific functionality of a {@code NodeHandler} is to be adapted for a special use case. Concrete sub
029 * classes have to implement the {@code getDecoratedNodeHandler()} method to provide the underlying handler.
030 * </p>
031 *
032 * @since 2.0
033 * @param <T> the type of the nodes supported by this handler
034 */
035public abstract class NodeHandlerDecorator<T> implements NodeHandler<T> {
036    @Override
037    public String nodeName(final T node) {
038        return getDecoratedNodeHandler().nodeName(node);
039    }
040
041    @Override
042    public Object getValue(final T node) {
043        return getDecoratedNodeHandler().getValue(node);
044    }
045
046    @Override
047    public T getParent(final T node) {
048        return getDecoratedNodeHandler().getParent(node);
049    }
050
051    @Override
052    public List<T> getChildren(final T node) {
053        return getDecoratedNodeHandler().getChildren(node);
054    }
055
056    @Override
057    public <C> List<T> getMatchingChildren(final T node, final NodeMatcher<C> matcher, final C criterion) {
058        return getDecoratedNodeHandler().getMatchingChildren(node, matcher, criterion);
059    }
060
061    @Override
062    public <C> int getMatchingChildrenCount(final T node, final NodeMatcher<C> matcher, final C criterion) {
063        return getDecoratedNodeHandler().getMatchingChildrenCount(node, matcher, criterion);
064    }
065
066    @Override
067    public List<T> getChildren(final T node, final String name) {
068        return getDecoratedNodeHandler().getChildren(node, name);
069    }
070
071    @Override
072    public T getChild(final T node, final int index) {
073        return getDecoratedNodeHandler().getChild(node, index);
074    }
075
076    @Override
077    public int indexOfChild(final T parent, final T child) {
078        return getDecoratedNodeHandler().indexOfChild(parent, child);
079    }
080
081    @Override
082    public int getChildrenCount(final T node, final String name) {
083        return getDecoratedNodeHandler().getChildrenCount(node, name);
084    }
085
086    @Override
087    public Set<String> getAttributes(final T node) {
088        return getDecoratedNodeHandler().getAttributes(node);
089    }
090
091    @Override
092    public boolean hasAttributes(final T node) {
093        return getDecoratedNodeHandler().hasAttributes(node);
094    }
095
096    @Override
097    public Object getAttributeValue(final T node, final String name) {
098        return getDecoratedNodeHandler().getAttributeValue(node, name);
099    }
100
101    @Override
102    public boolean isDefined(final T node) {
103        return getDecoratedNodeHandler().isDefined(node);
104    }
105
106    @Override
107    public T getRootNode() {
108        return getDecoratedNodeHandler().getRootNode();
109    }
110
111    /**
112     * Gets the {@code NodeHandler} object that is decorated by this instance. All method calls are delegated to this
113     * object.
114     *
115     * @return the decorated {@code NodeHandler}
116     */
117    protected abstract NodeHandler<T> getDecoratedNodeHandler();
118}