/*
    * 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.model;
  
  import java.util.Collection;
  
  public class CollectionDataModel<E> extends DataModel<E>
  {
  
      // FIELDS
      private int _rowIndex = -1;
      private Collection<E> _data;
      private E[] _dataArray;
  
      // CONSTRUCTORS
      public CollectionDataModel()
      {
          super();
      }
  
      public CollectionDataModel(Collection<E> collection)
      {
          if (collection == null)
          {
              throw new NullPointerException("collection");
          }
          setWrappedData(collection);
      }
  
      // METHODS
      @Override
      public int getRowCount()
      {
          if (_data == null)
          {
              return -1;
          }
          return _data.size();
      }
  
      @Override
      public E getRowData()
      {
          if (_data == null)
          {
              return null;
          }
          if (!isRowAvailable())
          {
              throw new IllegalArgumentException("row is unavailable");
          }
          return _dataArray[_rowIndex];
      }
  
      @Override
      public int getRowIndex()
      {
          return _rowIndex;
      }
  
      @Override
      public Object getWrappedData()
      {
          return _data;
      }
  
      @Override
      public boolean isRowAvailable()
      {
          return _data != null && _rowIndex >= 0 && _rowIndex < _data.size();
      }
  
      @Override
      public void setRowIndex(int rowIndex)
      {
          if (rowIndex < -1)
          {
              throw new IllegalArgumentException("illegal rowIndex " + rowIndex);
          }
          int oldRowIndex = _rowIndex;
          _rowIndex = rowIndex;
          if (_data != null && oldRowIndex != _rowIndex)
          {
             E data = isRowAvailable() ? getRowData() : null;
             DataModelEvent event = new DataModelEvent(this, _rowIndex, data);
             DataModelListener[] listeners = getDataModelListeners();
             for (int i = 0; i < listeners.length; i++)
             {
                 listeners[i].rowSelected(event);
             }
         }
     }
 
     @Override
     public void setWrappedData(Object data)
     {
         if (data == null)
         {
             setRowIndex(-1);
             _data = null;
             _dataArray = null;
         }
         else
         {
             _data = (Collection<E>)data;
             _dataArray = _data.toArray((E[]) new Object[_data.size()]);
             _rowIndex = -1;
             setRowIndex(0);
         }
     }
 
 }