Swift Animation - button with circle behind - swift

Question

I'm trying to create de same effect than the app "Music" :
When I click on a button, there is a view behind and when the button is not focused anymore, the view is hidden. I do this with TouchUpInside and TouchDown funcs.
#IBAction func pressed(_ sender: UIButton) {
UIView.animate(withDuration: 0.25, animations: {
self.backgroundMoreView.alpha = 0.0
self.backgroundMoreView.transform = CGAffineTransform(scaleX:
1.2, y: 1.2)
sender.transform = CGAffineTransform.identity
}) { (_) in
self.backgroundMoreView.transform = CGAffineTransform.identity
}
}
#IBAction func unpressed(_ sender: UIButton) {
UIView.animate(withDuration: 0.25) {
self.backgroundMoreView.alpha = 0.3
sender.transform = CGAffineTransform(scaleX: 0.8, y:
0.8)
}
}
The problem is that, when I click and hold focus, and then I swipe out of the button, the function unpressed() is not called and the button stay "focused".
I tried also to add touchUpOutside function but no result. I don't know how to fix it.

Answer 1

For me this works (I prefer the exit on leaving the button)
#IBAction func touchDown(_ sender: UIButton) {
UIView.animate(withDuration: 0.25, animations: {
self.background.alpha = 1.0
}) { (_) in
print("do")
}
}
#IBAction func touchDragExit(_ sender: UIButton) {
UIView.animate(withDuration: 0.25, animations: {
self.background.alpha = 0.0
}) { (_) in
print("away")
}
}