                 
                 self.lineNumberView?.orientation = orientation
             }
-    }
-    
-    
-    override func viewDidDisappear() {
-        
-        super.viewDidDisappear()
-        
-        self.orientationObserver = nil
     }
     
     

    
    private var orientationObserver: AnyCancellable?
    
    @IBOutlet private weak var lineNumberView: LineNumberView?
    
    

    // MARK: -
    // MARK: Lifecycle
    
    override func viewDidLoad() {
        
        super.viewDidLoad()
        
        // observe text orientation for line number view
        self.orientationObserver = self.textView!.publisher(for: \.layoutOrientation, options: .initial)
