How to get actual keyboard height (keyboard height minus safe area insets)

Question

I tried getting the height of the keyboard to update the table contentInsets when the keyboard shows up; but the notification from UIResponder.keyboardWillShowNotification shows the frame with the safe area height. Is there a way to get the actual keyboard frame?

Code for the height of the keyboard height:

if let keyboardFrame: NSValue = notification.userInfo?[UIResponder.keyboardFrameEndUserInfoKey] as? NSValue {
    let keyboardRectangle = keyboardFrame.cgRectValue
    let keyboardHeight = keyboardRectangle.height

    print("show: \(keyboardHeight)")
    tableView.scrollIndicatorInsets = UIEdgeInsets(top: 0, left: 0, bottom: 18 + keyboardHeight, right: 0)
    tableView.contentInset = UIEdgeInsets(top: 8, left: 0, bottom: 18 + keyboardHeight, right: 0)
}

But this gives the height of the following keyboard: https://i.sstatic.net/Y3uqk.jpg

What I want: https://i.sstatic.net/3xUbW.jpg

Answer 1

First you have to get Safe Area bottom height and then exclude it from keyboard total height. In this way you will get only keyboard height without bottom safe area.

pesudo code:

let keyboardHeight = your keyboard height - bottomPadding

if #available(iOS 11.0, *) {
    let window = UIApplication.shared.keyWindow
    let bottomPadding = window?.safeAreaInsets.bottom
}

Hope it will help you.

Answer 2

Try subtracting the height of the safe area's bottom inset when calculating the value for your constraint.

Here is a sample implementation which handles a UIKeyboardWillChangeFrame notification.

@objc private func keyboardWillChange(_ notification: Notification) {
    guard let userInfo = (notification as Notification).userInfo, let value = userInfo[UIKeyboardFrameEndUserInfoKey] as? NSValue else { return }
    let newHeight: CGFloat
    if #available(iOS 11.0, *) {
        newHeight = value.cgRectValue.height - view.safeAreaInsets.bottom
    } else {
        newHeight = value.cgRectValue.height
    }
    myConstraint.value = newHeight
}