UIView+Animation.swift

import UIKit

extension UIView {
    func fadeIn(_ duration: Double) {
        fadeIn(duration, 0)
    }
    
    func fadeOut(_ duration: Double) {
        fadeOut(duration, 0)
    }
    
    func fadeIn(_ duration: Double, _ delay: Double) {
        UIView.animate(withDuration: duration, delay: delay, options: UIViewAnimationOptions.curveEaseIn, animations: {
            self.alpha = 1.0
        }, completion: nil)
    }
    
    func fadeOut(_ duration: Double, _ delay: Double) {
        UIView.animate(withDuration: duration, delay: delay, options: UIViewAnimationOptions.curveEaseOut, animations: {
            self.alpha = 0.0
        }, completion: nil)
    }
}