The number of staff lines the XML gives (), undefined if it gives none. The percussion one-line layout keeps it, see EngravingRules.PercussionKeepXMLStafflineCount.
Checks whether Staff.Visible and Staff.ParentInstrument.Visible.
The number of staff lines the XML gives (), undefined if it gives none.
The percussion one-line layout keeps it, see EngravingRules.PercussionKeepXMLStafflineCount.