swift background color animation loop - ios

Question

I want the background color of my iOS app to change between four colors over x amount of seconds
This is what I have so far (it does exactly what I want when I specify just 2 colors)
I also need the animation to run in a loop infinitely.
ViewController.swift
UIView.animateWithDuration(X.0, animations: {
// Color 1
self.view.backgroundColor = UIColor(rgba)
// Color 2
self.view.backgroundColor = UIColor(rgba)
// Color 3
self.view.backgroundColor = UIColor(rgba)
// Color 4
self.view.backgroundColor = UIColor(rgba)
})

Answer 1

Try this out:
UIView.animateWithDuration(1.0, animations: { () -> Void in
self.view.backgroundColor = UIColor.blackColor()
}) { (Bool) -> Void in
UIView.animateWithDuration(1.0, animations: { () -> Void in
self.view.backgroundColor = UIColor.greenColor()
}, completion: { (Bool) -> Void in
UIView.animateWithDuration(1.0, animations: { () -> Void in
self.view.backgroundColor = UIColor.grayColor()
}, completion: { (Bool) -> Void in
UIView.animateWithDuration(1.0, animations: { () -> Void in
self.view.backgroundColor = UIColor.redColor()
}, completion:nil)
})
})
}
In case you want a continuous repeating animation, try this out:
UIView.animate(withDuration: 2, delay: 0.0, options:[UIView.AnimationOptions.repeat, UIView.AnimationOptions.autoreverse], animations: {
self.view.backgroundColor = UIColor.black
self.view.backgroundColor = UIColor.green
self.view.backgroundColor = UIColor.darkGray
self.view.backgroundColor = UIColor.red
}, completion: nil)

Answer 2

Below code helps to keep enable user interaction with animated view. A random color generation (use in case its needed).
UIView.animateWithDuration(7, delay: 1, options:
[UIViewAnimationOptions.AllowUserInteraction,
UIViewAnimationOptions.Repeat,
UIViewAnimationOptions.Autoreverse],
animations: {
self.yourView.backgroundColor = self.randomColor()
self.yourView.backgroundColor = self.randomColor()
}, completion:nil )
func randomColor() -> UIColor {
let randomRed:CGFloat = CGFloat(drand48())
let randomGreen:CGFloat = CGFloat(drand48())
let randomBlue:CGFloat = CGFloat(drand48())
return UIColor(red: randomRed, green: randomGreen, blue: randomBlue,
alpha: 1.0)
}

Answer 3

You have to use NSTimer:
let timer = NSTimer.scheduledTimerWithTimeInterval(5, target: self, selector: "update", userInfo: nil, repeats: true)
func update() {
let nextCollor = getNextColor()
UIView.animateWithDuration(X.0, animations: {
self.view.backgroundColor = nextCollor
})
}
func getNextColor() -> UIColor {
let currentColor = self.view.backgroundColor
if currentColor == smaple1 {
return UIColor.redColor()
} else if currentColor == smaple2 {
return UIColor.grayColor()
} else {
return UIColor.whiteColor()
}
}
NSTimer.scheduledTimerWithTimeInterval runs your code every 5 seconds
PS: do not forget invalidate timer when you done with it. Just call timer.invalidate() for it. Otherwise you get a crash.

Answer 4

Swift 5
override func viewWillAppear(_ animated: Bool) {
self.customButton.backgroundColor = .red
UIView.animateKeyframes(withDuration: 0.5, delay: 0, options: [.repeat, .autoreverse], animations: {
self.customButton.backgroundColor = .none
}, completion: nil)
}

Answer 5

i had a dynamic / unknown amount of colors to cycle through, so i refactored the Swift 5 answer a bit:
Swift 5
UIView.animate(withDuration: 1.0, delay: 0.0, options: [.repeat, .autoreverse]) {
// colors is the dynamic [UIColor] array previously defined
for color in colors {
self.colorView.backgroundColor = color
}
} completion: { (finished) in
}
this will nicely cycle through the colors with a fade-style animation -- and with the .autoreverse option, it won't "snap" to the starting color.