Fix #1952: Use SafeArea Autolayout Constraints when FormViewController Is Presented Modally

Author: philipbel

Source/Core/Core.swift

@@ -458,12 +458,36 @@ open class FormViewController: UIViewController, FormViewControllerProtocol, For
 
         if tableView == nil {
             tableView = UITableView(frame: view.bounds, style: tableViewStyle)
-            tableView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
             tableView.cellLayoutMarginsFollowReadableWidth = false
         }
         if tableView.superview == nil {
             view.addSubview(tableView)
         }
+        /**
+         * Fix for #1952: `UITableView.scrollRectToVisible(, animated:)` and `UITableView.scrollToRow()` don't work properly
+         * in `keyboardWillShow()` due to, what seems to be, a bug in iOS when autoresizing mask is used for a `UIViewController` that is
+         * presented modally as `.formSheet/.pageSheet` within a `UINavigationController`.
+         * The check below preserves the existing behavior of using autoresizing masks in other cases.
+         */
+        var useAutoresizingMask = true
+        if #available(iOS 13, *) {
+            if presentingViewController != nil && navigationController != nil {
+                useAutoresizingMask = false
+
+                // Need to set the background color as otherwise black shows underneath the translucent navigation bar.
+                view.backgroundColor = .systemBackground
+                tableView.translatesAutoresizingMaskIntoConstraints = false
+                NSLayoutConstraint.activate([
+                    tableView.topAnchor.constraint(equalTo: tableView.superview!.safeAreaLayoutGuide.topAnchor),
+                    tableView.bottomAnchor.constraint(equalTo: tableView.superview!.safeAreaLayoutGuide.bottomAnchor),
+                    tableView.leadingAnchor.constraint(equalTo: tableView.superview!.safeAreaLayoutGuide.leadingAnchor),
+                    tableView.trailingAnchor.constraint(equalTo: tableView.superview!.safeAreaLayoutGuide.trailingAnchor)
+                ])
+            }
+        }
+        if useAutoresizingMask {
+            tableView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
+        }
         if tableView.delegate == nil {
             tableView.delegate = self
         }