Swift, playing multiple animations consecutively from an array? - swift

Question

Sorry, I am new to swift. I can't get each animation to play consecutively and not all at once. I have tried using sleep(), but that then doesn't seem to allow the animation to play. This is how I find which animation to play.
for number in sequence {
switch number {
case 1:
print("blue")
animateB()
case 2:
print("green")
animateG()
case 3:
print("magenta")
animateM()
case 4:
print("orange")
animateO()
case 5:
print("yellow")
animateY()
case 6:
print("red")
animateR()
case 7:
print("purple")
animateP()
case 8:
print("cyan")
animateC()
default:
print("error")
}
}
And this is one of the functions i am using to animate. I realize this is probably very inefficient too, but wasn't sure how to make the function better.
private func animateB(){
let animation = CABasicAnimation(keyPath: "transform.scale")
animation.toValue = 1.3
animation.duration = 0.5
animation.autoreverses = true
self.pulsatingB.add(animation, forKey: "pulsing")
}
Any help would be great thanks. :)

Answer 1

You can use CATransaction to chain the CAAnimations:
class ViewController: UIViewController {
// The animations, to be applied in order
var animationQueue = [() -> Void]()
#IBAction func animate(_ sender: Any) {
animationQueue.removeAll()
// Build the animation queue
for number in sequence {
switch number {
case 1:
print("blue")
animationQueue.append(animateB)
case 2:
print("green")
animationQueue.append(animateG)
// ....
default:
break
}
}
// Start the animation
applyNextAnimation()
}
func applyNextAnimation() {
guard !animationQueue.isEmpty else { return }
let animation = animationQueue.removeFirst()
// When an animation completes, call this function again to apply the next animation
CATransaction.begin()
CATransaction.setCompletionBlock({ self.applyNextAnimation() })
animation()
CATransaction.commit()
}
}

Answer 2

For a sequence of animations, a block based keyframe animation can often do the job, too, e.g.:
UIView.animateKeyframes(withDuration: 4.0, delay: 0, options: .repeat, animations: {
UIView.addKeyframe(withRelativeStartTime: 0, relativeDuration: 0.25, animations: {
self.subview.transform = .init(scaleX: 0.5, y: 0.5)
})
UIView.addKeyframe(withRelativeStartTime: 0.25, relativeDuration: 0.25, animations: {
self.subview.transform = .init(scaleX: 1.3, y: 1.3)
})
UIView.addKeyframe(withRelativeStartTime: 0.5, relativeDuration: 0.25, animations: {
self.subview.transform = .init(scaleX: 0.75, y: 0.75)
})
UIView.addKeyframe(withRelativeStartTime: 0.75, relativeDuration: 0.25, animations: {
self.subview.transform = .identity
})
}, completion: nil)
Or, if you have an array of functions:
let animations = [animateA, animateB, animateC, animateD]
UIView.animateKeyframes(withDuration: 4.0, delay: 0, options: .repeat, animations: {
for (index, animation) in animations.enumerated() {
UIView.addKeyframe(withRelativeStartTime: Double(index) / Double(animations.count), relativeDuration: 1 / Double(animations.count), animations: {
animation()
})
}
}, completion: nil)
Where,
func animateA() {
subview.transform = .init(scaleX: 0.5, y: 0.5)
}
func animateB() {
subview.transform = .init(scaleX: 1.3, y: 1.3)
}
...