         self.document?.close(completionHandler: nil)
     }
     
+    @objc func didChangeOrientationHandler() {
+        if portraitScaleFactorForSizeToFit != 0.0 && UIApplication.shared.statusBarOrientation.isPortrait {
+            pdfView.minScaleFactor = portraitScaleFactorForSizeToFit
+            pdfView.scaleFactor = portraitScaleFactorForSizeToFit
+        } else if landscapeScaleFactorForSizeToFit != 0.0 && UIApplication.shared.statusBarOrientation.isLandscape {
+            pdfView.minScaleFactor = landscapeScaleFactorForSizeToFit
+            pdfView.scaleFactor = landscapeScaleFactorForSizeToFit
+        }
+    }
+    
     @IBAction func dismissDocumentViewController() {
         dismiss(animated: true) {
             self.saveAndClose()

                    if self.verticalWriting {
                        // ページ交換ファンクションを利用して、降順ソートして置き換える。
                        let actionCount = document.pageCount/2
                        for i in 0...actionCount{
                            document.exchangePage(at: i, withPageAt: document.pageCount-i)
                        }
                    }

                    self.moveToLastReadingProsess()
                }
            } else {
                // Make sure to handle the failed import appropriately, e.g., by presenting an error message to the user.

    var document: Document?
    
    let userDeaults = UserDefaults.standard
    
    var portraitScaleFactorForSizeToFit: CGFloat = 0.0
    var landscapeScaleFactorForSizeToFit: CGFloat = 0.0
    
//    縦書き
    var verticalWriting = false
