    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     * Returns 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}