    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 Set<String> getAttributes(final T node) {
    038        return getDecoratedNodeHandler().getAttributes(node);
    039    }
    040
    041    @Override
    042    public Object getAttributeValue(final T node, final String name) {
    043        return getDecoratedNodeHandler().getAttributeValue(node, name);
    044    }
    045
    046    @Override
    047    public T getChild(final T node, final int index) {
    048        return getDecoratedNodeHandler().getChild(node, index);
    049    }
    050
    051    @Override
    052    public List<T> getChildren(final T node) {
    053        return getDecoratedNodeHandler().getChildren(node);
    054    }
    055
    056    @Override
    057    public List<T> getChildren(final T node, final String name) {
    058        return getDecoratedNodeHandler().getChildren(node, name);
    059    }
    060
    061    @Override
    062    public int getChildrenCount(final T node, final String name) {
    063        return getDecoratedNodeHandler().getChildrenCount(node, name);
    064    }
    065
    066    /**
    067     * Gets the {@code NodeHandler} object that is decorated by this instance. All method calls are delegated to this
    068     * object.
    069     *
    070     * @return the decorated {@code NodeHandler}
    071     */
    072    protected abstract NodeHandler<T> getDecoratedNodeHandler();
    073
    074    @Override
    075    public <C> List<T> getMatchingChildren(final T node, final NodeMatcher<C> matcher, final C criterion) {
    076        return getDecoratedNodeHandler().getMatchingChildren(node, matcher, criterion);
    077    }
    078
    079    @Override
    080    public <C> int getMatchingChildrenCount(final T node, final NodeMatcher<C> matcher, final C criterion) {
    081        return getDecoratedNodeHandler().getMatchingChildrenCount(node, matcher, criterion);
    082    }
    083
    084    @Override
    085    public T getParent(final T node) {
    086        return getDecoratedNodeHandler().getParent(node);
    087    }
    088
    089    @Override
    090    public T getRootNode() {
    091        return getDecoratedNodeHandler().getRootNode();
    092    }
    093
    094    @Override
    095    public Object getValue(final T node) {
    096        return getDecoratedNodeHandler().getValue(node);
    097    }
    098
    099    @Override
    100    public boolean hasAttributes(final T node) {
    101        return getDecoratedNodeHandler().hasAttributes(node);
    102    }
    103
    104    @Override
    105    public int indexOfChild(final T parent, final T child) {
    106        return getDecoratedNodeHandler().indexOfChild(parent, child);
    107    }
    108
    109    @Override
    110    public boolean isDefined(final T node) {
    111        return getDecoratedNodeHandler().isDefined(node);
    112    }
    113
    114    @Override
    115    public String nodeName(final T node) {
    116        return getDecoratedNodeHandler().nodeName(node);
    117    }
    118}