Animate buttons by looping over an array - arrays

Question

I am making a simple 'Simon Says' style app in Swift and I would like to flash buttons to show the sequence the user has to follow.
I have made this function which iterates over an array of the buttons to just change the background colour for now.
func animateButtons() {
for (index, button) in buttonSequence.enumerated() {
UIButton.animate(withDuration: 1, delay: TimeInterval(index)) {
button.backgroundColor = UIColor(red: 63/255, green: 255/255, blue: 0/255, alpha: 1.0)
button.backgroundColor = UIColor(red: 168/255, green: 61/255, blue: 164/255, alpha: 0.85)
}
}
}
Right now though when the function is called it lights up all the buttons at once but animates them returning back to their normal colour one by one. Ideally I want it to animate one button completely, then the next etc.
I looked into using a Timer for this but couldn't find exactly how to use it properly when searching documentation.

Answer 1

The problem with your code is that you set the button color to 2 different values inside your animation block. The first color will be overridden and have no effect.
If you want each button to change to the first color in your animation block, hold for 1 second, and then revert to the 2nd color, change your code like this:
func animateButtons() {
for (index, button) in buttonSequence.enumerated() {
UIButton.animate(
withDuration: 1,
delay: TimeInterval(index),
animations: {
button.backgroundColor = UIColor(red: 63/255, green: 255/255, blue: 0/255, alpha: 1.0)
},
completion: { finished in
button.backgroundColor = UIColor(red: 168/255, green: 61/255, blue: 164/255, alpha: 0.85)
}
)
}
}