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
028 * delegating to another instance. This is convenient if specific functionality
029 * of a {@code NodeHandler} is to be adapted for a special use case. Concrete
030 * sub classes have to implement the {@code getDecoratedNodeHandler()} method to
031 * provide the underlying handler.
032 * </p>
033 *
034 * @version $Id: NodeHandlerDecorator.java 1636036 2014-11-01 20:49:13Z oheger $
035 * @since 2.0
036 * @param <T> the type of the nodes supported by this handler
037 */
038public abstract class NodeHandlerDecorator<T> implements NodeHandler<T>
039{
040    @Override
041    public String nodeName(T node)
042    {
043        return getDecoratedNodeHandler().nodeName(node);
044    }
045
046    @Override
047    public Object getValue(T node)
048    {
049        return getDecoratedNodeHandler().getValue(node);
050    }
051
052    @Override
053    public T getParent(T node)
054    {
055        return getDecoratedNodeHandler().getParent(node);
056    }
057
058    @Override
059    public List<T> getChildren(T node)
060    {
061        return getDecoratedNodeHandler().getChildren(node);
062    }
063
064    @Override
065    public <C> List<T> getMatchingChildren(T node, NodeMatcher<C> matcher,
066            C criterion)
067    {
068        return getDecoratedNodeHandler().getMatchingChildren(node, matcher,
069                criterion);
070    }
071
072    @Override
073    public <C> int getMatchingChildrenCount(T node, NodeMatcher<C> matcher,
074            C criterion)
075    {
076        return getDecoratedNodeHandler().getMatchingChildrenCount(node,
077                matcher, criterion);
078    }
079
080    @Override
081    public List<T> getChildren(T node, String name)
082    {
083        return getDecoratedNodeHandler().getChildren(node, name);
084    }
085
086    @Override
087    public T getChild(T node, int index)
088    {
089        return getDecoratedNodeHandler().getChild(node, index);
090    }
091
092    @Override
093    public int indexOfChild(T parent, T child)
094    {
095        return getDecoratedNodeHandler().indexOfChild(parent, child);
096    }
097
098    @Override
099    public int getChildrenCount(T node, String name)
100    {
101        return getDecoratedNodeHandler().getChildrenCount(node, name);
102    }
103
104    @Override
105    public Set<String> getAttributes(T node)
106    {
107        return getDecoratedNodeHandler().getAttributes(node);
108    }
109
110    @Override
111    public boolean hasAttributes(T node)
112    {
113        return getDecoratedNodeHandler().hasAttributes(node);
114    }
115
116    @Override
117    public Object getAttributeValue(T node, String name)
118    {
119        return getDecoratedNodeHandler().getAttributeValue(node, name);
120    }
121
122    @Override
123    public boolean isDefined(T node)
124    {
125        return getDecoratedNodeHandler().isDefined(node);
126    }
127
128    @Override
129    public T getRootNode()
130    {
131        return getDecoratedNodeHandler().getRootNode();
132    }
133
134    /**
135     * Returns the {@code NodeHandler} object that is decorated by this
136     * instance. All method calls are delegated to this object.
137     *
138     * @return the decorated {@code NodeHandler}
139     */
140    protected abstract NodeHandler<T> getDecoratedNodeHandler();
141}