Busy event. Will be fired regularly during long-drawn operations. If end value will be zero, the meaning is: long-drawn with unknown end time. Close long-drawn operation by calling with parameters (-1,-1).
# Python @property def BusyEvent( self ) -> TGIS_BusyEvent: @BusyEvent.setter def BusyEvent( self _value: typing.Callable[[TObject, Integer, Integer, Boolean], None] ) -> None: