/*
    * 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
    *
   *   http://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 javax.faces.component;
  
  import java.io.Serializable;
  import java.util.AbstractList;
  import java.util.ArrayList;
  import java.util.Iterator;
  import java.util.List;
  import java.util.Map;
  import java.util.RandomAccess;
  
  class _ComponentChildrenList extends AbstractList<UIComponent> implements Serializable, RandomAccess
  {
      private static final long serialVersionUID = -6775078929331154224L;
      private UIComponent _component;
      private List<UIComponent> _list = new ArrayList<UIComponent>(4);
  
      _ComponentChildrenList(UIComponent component)
      {
          _component = component;
      }
  
      @Override
      public UIComponent get(int index)
      {
          return _list.get(index);
      }
  
      @Override
      public int size()
      {
          return _list.size();
      }
  
      @Override
      public UIComponent set(int index, UIComponent value)
      {
          checkValue(value);
          removeChildrenFromParent(value);
          UIComponent child = _list.set(index, value);
          if (child != value)
          {
              updateParent(value);
              if (child != null)
              {
                  childRemoved(child);
              }
          }
          
          return child;
      }
  
      @Override
      public boolean add(UIComponent value)
      {
          checkValue(value);
  
          removeChildrenFromParent(value);
          boolean res = _list.add(value);
          
          updateParent(value);
          
          return res;
      }
  
      @Override
      public void add(int index, UIComponent value)
      {
          checkValue(value);
          
          removeChildrenFromParent(value);
          
          _list.add(index, value);
          
          updateParent(value);
      }
  
      @Override
      public UIComponent remove(int index)
      {
          UIComponent child = _list.remove(index);
          if (child != null)
         {
             childRemoved(child);
         }
         
         return child;
     }
 
     private void checkValue(Object value)
     {
         if (value == null)
         {
             throw new NullPointerException("value");
         }
         
         // Not necessary anymore because  
         //if (!(value instanceof UIComponent))
         //{
         //    throw new ClassCastException("value is not a UIComponent");
         //}
     }
 
     private void childRemoved(UIComponent child)
     {
         child.setParent(null);
     }
 
     private void updateParent(UIComponent child)
     {
         child.setParent(_component);
     }
     
     private void removeChildrenFromParent(UIComponent child)
     {
         UIComponent oldParent = child.getParent();
         if (oldParent != null)
         {
             if (!oldParent.getChildren().remove(child))
             {
                 // Check if the component is inside a facet and remove from there
                 if (oldParent.getFacetCount() > 0)
                 {
                     for (Iterator< Map.Entry<String, UIComponent > > it = 
                         oldParent.getFacets().entrySet().iterator() ; it.hasNext() ; )
                     {
                         Map.Entry<String, UIComponent > entry = it.next();
                         
                         if (entry.getValue().equals(child))
                         {
                             it.remove();
                             break;
                         }
                     }
                 }
             }
         }
     }
 
     @Override
     public boolean remove(Object value)
     {
         if (!(value instanceof UIComponent))
         {
             throw new ClassCastException("value is not a UIComponent");
         }
         
         checkValue(value);
 
         if (_list.remove(value))
         {
             childRemoved((UIComponent)value);
             return true;
         }
         return false;
     }
 }