Swift: Bring custom alert view over nav bar - ios

Question

I use UIView as alert view in my app, and i want to show it as banner on top of screen, when device is not connected to internet. So my issue that this view appears under my nav bar, how can i bring it to front ? I've tried to us UIApplication.shared.keyWindow! and add my backgroundView as subview to it, but it causes other issues.
This is my alert view class: I'll provide all class, but my realisation is in show() method.
import Foundation
import UIKit
import SnapKit
class ConnectionAlertView: UIView, UIGestureRecognizerDelegate {
internal var backgroundView: UIView = {
let view = UIView()
view.backgroundColor = Theme.Color.alertLabelBackgroundColor
view.alpha = 0
view.layer.cornerRadius = 15
return view
}()
internal var dismissButton: UIImageView = {
let imageView = UIImageView()
imageView.image = UIImage(named: "close_icon")
imageView.layer.cornerRadius = 15
imageView.isUserInteractionEnabled = true
return imageView
}()
internal var descriptionTitleLabel: UILabel = {
let label = UILabel()
label.text = "Відсутнє підключення до Інтернету"
label.font = Theme.Font.fontBodyLarge
label.textColor = .white
return label
}()
internal var descriptionLabel: UILabel = {
let label = UILabel()
label.text = "Перевірте налаштування мережі"
label.font = Theme.Font.fontBodyMedium
label.textColor = .white
return label
}()
// MARK: - Private Methods -
internal func layout() {
backgroundView.addSubview(descriptionTitleLabel)
backgroundView.addSubview(descriptionLabel)
backgroundView.addSubview(dismissButton)
descriptionTitleLabel.snp.makeConstraints { make in
make.trailing.equalTo(backgroundView).offset(54)
make.leading.equalTo(backgroundView).offset(16)
make.top.equalTo(backgroundView).offset(12)
}
descriptionLabel.snp.makeConstraints { make in
make.leading.equalTo(descriptionTitleLabel.snp.leading)
make.top.equalTo(descriptionTitleLabel.snp.bottom).offset(4)
}
dismissButton.snp.makeConstraints { make in
make.width.height.equalTo(30)
make.centerY.equalTo(backgroundView)
make.trailing.equalTo(backgroundView).offset(-16)
}
}
internal func configure() {
let tap = UITapGestureRecognizer(target: self, action: #selector(dismiss(sender:)))
tap.delegate = self
dismissButton.addGestureRecognizer(tap)
}
// MARK: - Public Methods -
func show(viewController: UIViewController) {
guard let targetView = viewController.view else { return }
backgroundView.frame = CGRect(x: 10, y: 50, width: targetView.frame.width - 20 , height: 67)
targetView.addSubview(targetView)
layout()
configure()
// show view
DispatchQueue.main.asyncAfter(deadline: .now() + 1) {
UIView.transition(with: self.backgroundView, duration: 0.6,
options: .transitionCrossDissolve,
animations: {
self.backgroundView.alpha = 1
})
}
// hide view after 5 sec delay
DispatchQueue.main.asyncAfter(deadline: .now() + 5) {
UIView.transition(with: self.backgroundView, duration: 1,
options: .transitionCrossDissolve,
animations: {
self.backgroundView.alpha = 0
})
}
}
// MARK: - Objc Methods -
#objc internal func dismiss(sender: UITapGestureRecognizer) {
DispatchQueue.main.asyncAfter(deadline: .now() + 1) {
UIView.transition(with: self.backgroundView, duration: 1,
options: .transitionCrossDissolve,
animations: {
self.backgroundView.alpha = 0
})
}
}
}
My viewController:
class PhoneNumViewController: UIViewController {
let alert = ConnectionAlertView()
private func checkInternetConnection() {
if !NetworkingMonitor.isConnectedToInternet {
log.error("No internet connection!")
alert.show(viewController: self)
}
}
}

Answer 1

Since you have a navigation controller and do not wish to add this view to the window directly, I can offer the following idea which could work.
Your UIViewController is contained with the UINavigationController so if you add the alert to your UIViewController, you will notice it below the UINavigationBar.
You could instead show the alert from your UINavigationController instead with the following changes.
1.
In the func show(viewController: UIViewController) in your class ConnectionAlertView: UIView I changed the following line:
targetView.addSubview(targetView)
to
targetView.addSubview(backgroundView)
This does not directly relate to your issue but seems to be a bug and causes a crash as it seems like you want to add the background view on the target view.
2.
In your class ViewController: UIViewController, when you want to show your alert view, pass the UINavigationController instead like this:
if let navigationController = self.navigationController
{
alert.show(viewController: navigationController)
}
This should give you the desired result I believe (The image and font looks different as I do not have these files but should work fine at your end):