/*
    * 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
    *
    *     https://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;
  
  import java.util.List;
  import java.util.Set;
  
  /**
   * <p>
   * An abstract base class for decorators of a {@code NodeHandler}.
   * </p>
   * <p>
   * This class implements all methods of the {@code NodeHandler} interface by delegating to another instance. This is
   * convenient if specific functionality of a {@code NodeHandler} is to be adapted for a special use case. Concrete sub
   * classes have to implement the {@code getDecoratedNodeHandler()} method to provide the underlying handler.
   * </p>
   *
   * @param <T> the type of the nodes supported by this handler
   * @since 2.0
   */
  public abstract class NodeHandlerDecorator<T> implements NodeHandler<T> {
  
      /**
       * Constructs a new instance.
       */
      public NodeHandlerDecorator() {
          // empty
      }
  
      @Override
      public Set<String> getAttributes(final T node) {
          return getDecoratedNodeHandler().getAttributes(node);
      }
  
      @Override
      public Object getAttributeValue(final T node, final String name) {
          return getDecoratedNodeHandler().getAttributeValue(node, name);
      }
  
      @Override
      public T getChild(final T node, final int index) {
          return getDecoratedNodeHandler().getChild(node, index);
      }
  
      @Override
      public List<T> getChildren(final T node) {
          return getDecoratedNodeHandler().getChildren(node);
      }
  
      @Override
      public List<T> getChildren(final T node, final String name) {
          return getDecoratedNodeHandler().getChildren(node, name);
      }
  
      @Override
      public int getChildrenCount(final T node, final String name) {
          return getDecoratedNodeHandler().getChildrenCount(node, name);
      }
  
      /**
       * Gets the {@code NodeHandler} object that is decorated by this instance. All method calls are delegated to this
       * object.
       *
       * @return the decorated {@code NodeHandler}
       */
      protected abstract NodeHandler<T> getDecoratedNodeHandler();
  
      @Override
      public <C> List<T> getMatchingChildren(final T node, final NodeMatcher<C> matcher, final C criterion) {
          return getDecoratedNodeHandler().getMatchingChildren(node, matcher, criterion);
      }
  
      @Override
      public <C> int getMatchingChildrenCount(final T node, final NodeMatcher<C> matcher, final C criterion) {
          return getDecoratedNodeHandler().getMatchingChildrenCount(node, matcher, criterion);
      }
  
      @Override
      public T getParent(final T node) {
          return getDecoratedNodeHandler().getParent(node);
      }
  
      @Override
      public T getRootNode() {
          return getDecoratedNodeHandler().getRootNode();
     }
 
     @Override
     public Object getValue(final T node) {
         return getDecoratedNodeHandler().getValue(node);
     }
 
     @Override
     public boolean hasAttributes(final T node) {
         return getDecoratedNodeHandler().hasAttributes(node);
     }
 
     @Override
     public int indexOfChild(final T parent, final T child) {
         return getDecoratedNodeHandler().indexOfChild(parent, child);
     }
 
     @Override
     public boolean isDefined(final T node) {
         return getDecoratedNodeHandler().isDefined(node);
     }
 
     @Override
     public String nodeName(final T node) {
         return getDecoratedNodeHandler().nodeName(node);
     }
 }