     header.removeObserver(self, forKeyPath: "contentSize")
     NSNotificationCenter.defaultCenter().removeObserver(self, name: UIKeyboardWillShowNotification, object: nil)
     NSNotificationCenter.defaultCenter().removeObserver(self, name: UIKeyboardWillHideNotification, object: nil)
+    NSNotificationCenter.defaultCenter().removeObserver(self, name: UIDeviceOrientationDidChangeNotification, object: nil)
   }
   
   // MARK: - open

    body.delegate = self
    NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(keyboardWillShow(_:)), name: UIKeyboardWillShowNotification, object: nil)
    NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(keyboardWillHide(_:)), name: UIKeyboardWillHideNotification, object: nil)
    let tap = UITapGestureRecognizer(target: self, action: #selector(dismissKeyboard))
    view.addGestureRecognizer(tap)
  }
  
  internal func dismissKeyboard() {

    super.viewDidAppear(animated)
    handleTitlePlaceholderAndCursor()
  }
  
  // MARK: - create
  private func createViews() {
