package org.exolab.castor.mapping.loader.collection.handler;
   
   import java.util.ArrayList;
   import java.util.Collection;
   import java.util.Enumeration;
   
   import org.exolab.castor.mapping.CollectionHandler;
   import org.exolab.castor.mapping.loader.CollectionHandlers;
   import org.exolab.castor.mapping.loader.J2CollectionHandlers.IteratorEnumerator;
  
  public final class ListCollectionHandler<T> implements CollectionHandler<T> {
  
    @SuppressWarnings("unchecked")
    public Object add(Object collection, final T object) {
      if (collection == null) {
        collection = new ArrayList<T>();
        ((Collection<T>) collection).add(object);
        return collection;
      }
      ((Collection<T>) collection).add(object);
      return null;
    }
  
    @SuppressWarnings("unchecked")
    public Enumeration<T> elements(final Object collection) {
      if (collection == null) {
        return new CollectionHandlers.EmptyEnumerator<T>();
      }
      return new IteratorEnumerator<T>(((Collection<T>) collection).iterator());
    }
  
    @SuppressWarnings("unchecked")
    public int size(final Object collection) {
      if (collection == null) {
        return 0;
      }
      return ((Collection<T>) collection).size();
    }
  
    @SuppressWarnings("unchecked")
    public Object clear(final Object collection) {
      if (collection != null) {
        ((Collection<T>) collection).clear();
      }
      return null;
    }
  
    public String toString() {
      return "List";
    }
  }