Simple ShimmerView.

ShimmerView.swift

/// View to give shimmering effects.
class ShimmerView: UIView {
    
  /// Start the shimmering animation.
  func start() {
    let light = UIColor.white.cgColor
    let alpha = UIColor(red: 206/255, green: 10/255, blue: 10/255, alpha: 0.7).cgColor
    let gradient = CAGradientLayer()
    gradient.frame = CGRect(x: -self.bounds.size.width, y: 0, width: 3 * self.bounds.size.width, height: self.bounds.size.height)
    gradient.colors = [light, alpha, light]
    gradient.startPoint = CGPoint(x: 0.0, y: 0.5)
    gradient.endPoint = CGPoint(x: 1.0,y: 0.525)
    gradient.locations = [0.35, 0.50, 0.65]
    self.layer.mask = gradient
    let animation = CABasicAnimation(keyPath: "locations")
    animation.fromValue = [0.0, 0.1, 0.2]
    animation.toValue = [0.8, 0.9,1.0]
    animation.duration = 1.5
    animation.repeatCount = HUGE
    gradient.add(animation, forKey: "shimmer")
  }
  
  /// Stop the shimmering animation.
  func stop() {
    self.layer.mask = nil
  }
}