This typically calls GoSelection.GoSelection.CreateBoundingHandle or GoSelection.CreateResizeHandle as needed. The standard implementation first calls RemoveSelectionHandles to make sure no obsolete handles remain for this object. If CanResize is false, it just creates a bounding handle. Otherwise if CanReshape is true, it creates eight resize handles at the eight standard spots along the object's bounds. If CanReshape is false, it only creates the four resize handles at the object's corners.