Why does my UITapGestureRecognizer does not get called when animating the UIView? - ios

Question

I made a toast view with a UIImageView in it, what I want to do is everytime the user taps the image view, the toast dismisses itself. Naturally I configured a UITapGestureRecognizer to my image view, but the selector function is not getting called. Here's what I did:
class ToastView: UIView {
private var icon: UIImageView!
init() {
super.init(frame: .zero)
setupViews()
}
required init?(coder: NSCoder) {
super.init(coder: coder)
setupViews()
}
override func layoutSubviews() {
super.layoutSubviews()
setupConstraints()
}
private func setupViews() {
translatesAutoresizingMaskIntoConstraints = false
layer.cornerRadius = 8
isUserInteractionEnabled = true
icon = UIImageView()
icon.translatesAutoresizingMaskIntoConstraints = false
icon.image = UIImage(named: "someImage")
icon.isUserInteractionEnabled = true
let tapGesture = UITapGestureRecognizer(target: self, action: #selector(iconHandler))
icon.addGestureRecognizer(tapGesture)
addSubview(icon)
}
private func setupConstraints() {
NSLayoutConstraint.activate([
topAnchor.constraint(equalTo: superview!.topAnchor, constant: 55),
leadingAnchor.constraint(equalTo: superview!.leadingAnchor, constant: 16),
trailingAnchor.constraint(equalTo: superview!.trailingAnchor, constant: -16),
icon.heightAnchor.constraint(equalToConstant: 16),
icon.widthAnchor.constraint(equalToConstant: 16),
icon.trailingAnchor.constraint(equalTo: trailingAnchor, constant: -16),
icon.centerYAnchor.constraint(equalTo: centerYAnchor),
])
}
#objc private func iconHandler(_ sender: UITapGestureRecognizer) {
// This function is not called
print("handle icon")
}
}
After some research, I tried to give the ToastView a gesture recognizer instead of the image view. So I did give the tap gesture recognizer when showing the toast in my custom UIViewController class like this:
class CustomViewController: UIViewController {
private var isShowingToast: Bool = false
private lazy var toast: ToastView = {
let toast = ToastView()
toast.isUserInteractionEnabled = true
toast.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(dismissToast)))
return toast
}()
func showToastWithMessage() {
if !isShowingToast {
view.addSubview(toast)
UIView.animate(withDuration: 0.5, delay: 0.0, usingSpringWithDamping: 1.0, initialSpringVelocity: 1.0, options: .curveEaseInOut, animations: { [weak self] in
self?.toast.alpha = 1
self?.toast.frame.origin.y += 10
self?.isShowingToast = true
}, completion: { _ in
UIView.animate(withDuration: 0.5, delay: 5.0, usingSpringWithDamping: 1.0, initialSpringVelocity: 1.0, options: .curveEaseInOut, animations: { [weak self] in
self?.toast.alpha = 0
self?.toast.frame.origin.y -= 10
}, completion: { [weak self] _ in
self?.isShowingToast = false
self?.toast.removeFromSuperview()
})
})
}
}
#objc private func dismissToast() {
// This functions does not get called as well
print("dismiss")
}
}
Unfortunately the dismiss function does not print to the console. Is there anyway to resolve this?

Answer 1

Looks like this occurs because of your animation. View is all the time in animation status and block tap gesture. U can try call it with delay instead of adding delay for your animation.
func showToastWithMessage() {
if !isShowingToast {
view.addSubview(toast)
UIView.animate(withDuration: 0.5, delay: 0.0, usingSpringWithDamping: 1.0, initialSpringVelocity: 1.0, options: .curveEaseInOut, animations: { [weak self] in
self?.toast.alpha = 1
self?.toast.frame.origin.y += 10
self?.isShowingToast = true
}, completion: { _ in
print("Completion")
})
DispatchQueue.main.asyncAfter(deadline: .now() + 5) {
UIView.animate(withDuration: 0.5, delay: 0.0, usingSpringWithDamping: 1.0, initialSpringVelocity: 1.0, options: .curveEaseInOut, animations: { [weak self] in
self?.toast.alpha = 0
self?.toast.frame.origin.y -= 10
}, completion: { [weak self] _ in
self?.isShowingToast = false
self?.toast.removeFromSuperview()
})
}
}
}
This way view going to animate status after 5 sec not with 5 sec delay.

Answer 2

This is how your controller look like:
class CustomViewController: UIViewController {
private var isShowingToast: Bool = false
lazy var toast: ToastView = {
let toast = ToastView()
toast.isUserInteractionEnabled = true
toast.backgroundColor = .red
toast.translatesAutoresizingMaskIntoConstraints = false
toast.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(dismissToast)))
return toast
}()
override func viewDidLoad() {
super.viewDidLoad()
// Add Toast constraints
view.addSubview(toast)
toast.heightAnchor.constraint(equalToConstant: 200).isActive = true
toast.widthAnchor.constraint(equalTo: toast.heightAnchor).isActive = true
toast.centerYAnchor.constraint(equalTo: view.centerYAnchor).isActive = true
toast.centerXAnchor.constraint(equalTo: view.centerXAnchor).isActive = true
}
func showToastWithMessage() {
if !isShowingToast {
view.addSubview(toast)
UIView.animate(withDuration: 0.5, delay: 0.0, usingSpringWithDamping: 1.0, initialSpringVelocity: 1.0, options: .curveEaseInOut, animations: { [weak self] in
self?.toast.alpha = 1
self?.toast.frame.origin.y += 10
self?.isShowingToast = true
}, completion: { _ in
UIView.animate(withDuration: 0.5, delay: 5.0, usingSpringWithDamping: 1.0, initialSpringVelocity: 1.0, options: .curveEaseInOut, animations: { [weak self] in
self?.toast.alpha = 0
self?.toast.frame.origin.y -= 10
}, completion: { [weak self] _ in
self?.isShowingToast = false
self?.toast.removeFromSuperview()
})
})
}
}
#objc private func dismissToast() {
// This functions does not get called as well
print("dismiss")
}
}
And this is your class:
class ToastView: UIView {
private var icon = UIImageView()
init() {
super.init(frame: .zero)
setupViews()
}
required init?(coder: NSCoder) {
super.init(coder: coder)
setupViews()
}
override func layoutSubviews() {
super.layoutSubviews()
setupConstraints()
}
private func setupViews() {
translatesAutoresizingMaskIntoConstraints = false
layer.cornerRadius = 8
isUserInteractionEnabled = true
icon.translatesAutoresizingMaskIntoConstraints = false
icon.image = UIImage(named: "profilo")?.withRenderingMode(.alwaysOriginal) //put your image here
icon.isUserInteractionEnabled = true
icon.layer.cornerRadius = 8
icon.layer.masksToBounds = true //set image masked round corner
icon.clipsToBounds = true
icon.contentMode = .scaleAspectFill //set image content mode
let tapGesture = UITapGestureRecognizer(target: self, action: #selector(iconHandler))
icon.addGestureRecognizer(tapGesture)
}
private func setupConstraints() {
// Setup the constraints for the subviews
addSubview(icon)
icon.topAnchor.constraint(equalTo: topAnchor).isActive = true
icon.trailingAnchor.constraint(equalTo: trailingAnchor).isActive = true
icon.leadingAnchor.constraint(equalTo: leadingAnchor).isActive = true
icon.bottomAnchor.constraint(equalTo: bottomAnchor).isActive = true
}
#objc private func iconHandler(_ sender: UITapGestureRecognizer) {
// This function is not called
print("handle icon")
}
}
this is the result: