public void addItemAtIndex(T item,int index){
  if (index <= items.size()) {
    items.add(index,item);
    fireDataChangedEvent(DataChangedListener.ADDED,index);
  }
}

public void addItemAtIndex ( T item , int index ) { if ( index <= items . size ( ) ) { items . add ( index , item ) ; fireDataChangedEvent ( DataChangedListener . ADDED , index ) ; } }
adding an item to list at given index
