Whether the drag is performing a move or a copy is determined by the value of the MayBeCopying and MayBeMoving predicates. This method is sensitive to the GoView.DragsRealtime property. When this property is false, dragging uses the DragSelection selection instead of the normal GoView.Selection collection. It calls MakeDragSelection to create the drag selection if needed and then moves the drag selection. When not copying and when GoView.DragsRealtime is true, it calls ClearDragSelection to stop using any drag selection and then it moves the regular GoView.Selection.