Switching between UITextViews resets view Layout - swift

Question

I implemented some functions to move the UIView, whenever a TextField or a TextView is tapped. The height for the UIView to move upwards is calculated depending how much the keyboard would overlap the active TextField or TextView. When I tap outside of the TextField, or -View the keyboard will be dismissed and the View will be resetted. Now everything is working fine, but when I switch from one TextField directly to another above (without dismissing the keyboard) it seems like the UIView will return to the initial position, instead of just keeping the shifted view (because the now active TextView would not be overlapped by the keyboard since it is above the former). It looks like some method is called to reset the view, resulting in the keyboard overlapping the upper TextView. Is there a way to suppress this behavior?
private func observeKeyboardNotification(){
NotificationCenter.default.addObserver(self, selector: #selector(keyboardShow), name: .UIKeyboardWillShow, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(keyboardHide), name: .UIKeyboardWillHide, object: nil)
}
var distanceOfKeyboardToTextView: CGFloat = 0
var activeTextElement: UIView?
var viewIsShifted = false
func keyboardShow(notification: NSNotification){
findActiveTextField(subviews: self.view.subviews, textField : &activeTextElement)
if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue, let activeTextElement = activeTextElement, !viewIsShifted {
let viewYPosition = (activeTextElement.superview?.convert(activeTextElement.frame.origin, to: nil).y)! + activeTextElement.frame.height
let keyboardYPosition = view.frame.height - keyboardSize.height
distanceOfKeyboardToTextView = viewYPosition - keyboardYPosition
if distanceOfKeyboardToTextView > 0 {
UIView.animate(withDuration: 0.5,
delay: 0,
usingSpringWithDamping: 1,
initialSpringVelocity: 1, options: .curveEaseOut,
animations: {
self.customView.frame = CGRect(x: 0, y: self.customView.frame.origin.y - self.distanceOfKeyboardToTextView, width: self.customView.frame.width, height: self.customView.frame.height)
}, completion: nil)
viewIsShifted = true
}
}
activeTextElement = nil
}
func keyboardHide(){
UIView.animate(withDuration: 0.5,
delay: 0,
usingSpringWithDamping: 1,
initialSpringVelocity: 1, options: .curveEaseOut,
animations: {
self.customView.frame = CGRect(x: 0, y: self.customView.frame.origin.y + self.distanceOfKeyboardToTextView, width: self.customView.frame.width, height: self.customView.frame.height)
}, completion: nil)
viewIsShifted = false
distanceOfKeyboardToTextView = 0
}
func findActiveTextField (subviews : [UIView], textField : inout UIView?) {
guard textField == nil else { return }
for view in subviews {
if view.isFirstResponder {
textField = view
break
}
else if !view.subviews.isEmpty {
findActiveTextField (subviews: view.subviews, textField: &textField)
}
}
}
Update:
After tapping from an active textfield directly onto another textfield, keyboardShow is call, but since the view is already shifed, UIView.animate will not be performed. However, the view is resetted like no keyboard would be displayed, but since the other textfield is active, the keyboard is visible.
I dismiss the keyboard using this extension:
extension UIViewController {
//functions to hide the keyboard
func hideKeyboardWhenTappedAround() {
let tap: UITapGestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(UIViewController.dismissKeyboard))
view.addGestureRecognizer(tap)
}
func dismissKeyboard() {
view.endEditing(true)
}
}
and in my ViewController:
override func viewDidLoad() {
super.viewDidLoad()
observeKeyboardNotification()
self.hideKeyboardWhenTappedAround()
...
}