             
         _headerField = value;
         headerFieldOrFunctionChanged = true;
+        dataChanged = true;
+        
         invalidateProperties();
     }
     

                }
            }
            
            invalidateSize();
            invalidateDisplayList();
        }

            
        _headerFunction = value;
        headerFieldOrFunctionChanged = true;
        dataChanged = true;
        
        invalidateProperties(); 
    }
    
