UIButton that has an interupptable animation with UIViewPropertyAnimator - ios

Question

I want a button to expand (Scale up) when the user touches the button, and shrink back to normal when the touch leaves. Similar to iOS stock calculator before iOS 11. This is the class that I created a subclass of the button. It uses touchesbegan and touchesended to start, and or pause and revers the animation, but it does not shrink properly, and it doesn't animate.
class UIOutlineButton: UIButton {
var squishAnimation:UIPropertyAnimator!
override public func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
super.touchesBegan(touches, with: event)
squishAnimation = UIViewPropertyAnimator(duration: 0.5, dampingRatio: 30, animations: {
let scale = self.transform.scaledBy(x: 0.8, y: 0.8)
let rotate = self.transform.rotated(by: 0.3)
self.transform.concatenating(rotate)
self.transform = scale
})
squishAnimation.isReversed = true
squishAnimation.startAnimation()
self.next?.touchesBegan(touches, with: event)
}
override public func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {
super.touchesEnded(touches, with: event)
colorAnimation = UIViewPropertyAnimator(duration: 0.5, dampingRatio: 30, animations: {
})
squishAnimation = UIViewPropertyAnimator(duration: 0.5, dampingRatio: 30, animations: {
self.transform = CGAffineTransform.identity
})
squishAnimation.stopAnimation(true)
squishAnimation.startAnimation()
}
}

Answer 1

Here is an little snippet which will 'grow' a UIView and then return it to it's original size after a short delay:
/// Expands & Then Returns A UIView To It's Original Size
///
/// - Parameters:
/// - view: UIView
/// - duration: Double
/// - enable: (Void)
func animate(view: UIView, duration: Double, enable: #escaping () -> ()){
view.isUserInteractionEnabled = false
UIView.animate(withDuration: duration, animations: {
view.transform = CGAffineTransform(scaleX: 0.8, y: 0.8)
}) { (continueSequence) in
UIView.animate(withDuration: duration, animations: {
view.transform = .identity
}, completion: { (seqeunceFinished) in
enable()
})
}
}
You can then call it within an IBAction as follows:
#IBAction func enlargeButton(_ sender: UIButton){
sender.isUserInteractionEnabled = false
enlarge(view: sender duration: 1) { sender.isUserInteractionEnabled = true }
}