iPhone X keyboard appear showing extra space

Question

I have created a chat UI in which I have added a constraint for the tableView to the bottom of the screen. I am changing the constraint value by ad

Answer 1

This worked for me

TL;DR: self.view.safeAreaInsets.bottom returned 0. The key was to use UIApplication.shared.keyWindow.safeAreaInsets.bottom instead [Source].

Let replyField be the UITextField of interest.

1) Add the observers in viewDidLoad().

NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillShow(notification:)), name: UIResponder.keyboardWillShowNotification, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillHide(notification:)), name: UIResponder.keyboardWillHideNotification, object: nil)

2) Set global variables within the class as the constraints.

var textFieldBottomConstraintKeyboardActive : NSLayoutConstraint?
var textFieldBottomConstraintKeyboardInactive : NSLayoutConstraint?

3) Set the constraints in a function called in viewDidLoad.

let replyFieldKeyboardActiveConstraint = self.replyField.bottomAnchor.constraint(
    equalTo: self.view.safeAreaLayoutGuide.bottomAnchor,
    constant: -1 * Constants.DEFAULT_KEYBOARD_HEIGHT /* whatever you want, we will change with actual height later */ + UITabBar.appearance().frame.size.height
)

let replyFieldKeyboardInactiveConstraint = self.replyField.bottomAnchor.constraint(
    equalTo: self.view.safeAreaLayoutGuide.bottomAnchor
)

self.textFieldBottomConstraintKeyboardActive = replyFieldKeyboardActiveConstraint
self.textFieldBottomConstraintKeyboardInactive = replyFieldKeyboardInactiveConstraint

self.textFieldBottomConstraintKeyboardActive?.isActive = false
self.textFieldBottomConstraintKeyboardInactive?.isActive = true

4) Define the keyboardWillShow and keyboardWillHide methods. They key here is how we define the heightOffset in the keyboardWillShow method.

@objc func keyboardWillShow(notification: NSNotification) {
    guard let userinfo = notification.userInfo else {
        return
    }
    guard let keyboardSize = userinfo[UIResponder.keyboardFrameEndUserInfoKey] as? NSValue else {
        return
    }
    let keyboardFrame = keyboardSize.cgRectValue

    self.view.layoutIfNeeded()

    let heightOffset = keyboardFrame.height - UITabBar.appearance().frame.height - (UIApplication.shared.keyWindow?.safeAreaInsets.bottom ?? 0)

    self.textFieldBottomConstraintKeyboardActive?.constant = -1 * heightOffset

    self.textFieldBottomConstraintKeyboardActive?.isActive = true
    self.textFieldBottomConstraintKeyboardInactive?.isActive = false

    self.view.setNeedsLayout()
}


@objc func keyboardWillHide(notification: NSNotification) {
    self.textFieldBottomConstraintKeyboardActive?.isActive = false
    self.textFieldBottomConstraintKeyboardInactive?.isActive = true
}