extension UIView {
func addActivityIndicator() { // creating a view (let's call it "loading" view) which will be added on top of the view you want to have activity indicator on (parent view) let view = UIView() // setting up a background for a view so it would make content under it look like not active view.backgroundColor = UIColor.white.withAlphaComponent(0.7) // adding "loading" view to a parent view // setting up auto-layout anchors so it would cover whole parent view self.addSubview(view) view.translatesAutoresizingMaskIntoConstraints = false view.topAnchor.constraint(equalTo: self.topAnchor).isActive = true view.bottomAnchor.constraint(equalTo: self.bottomAnchor).isActive = true view.leftAnchor.constraint(equalTo: self.leftAnchor).isActive = true view.rightAnchor.constraint(equalTo: self.rightAnchor).isActive = true // creating array with images, which will be animated // in my case I have 30 images with names activity0.png ... activity29.png var imagesArray = [UIImage(named: "activity\(0)")!] for i in 1..<30 { imagesArray.append(UIImage(named: "activity\(i)")!) } // creating UIImageView with array of images // setting up animation duration and starting animation let activityImage = UIImageView() activityImage.animationImages = imagesArray activityImage.animationDuration = TimeInterval(0.7) activityImage.startAnimating() // adding UIImageView on "loading" view // setting up auto-layout anchors so it would be in center of "loading" view with 30x30 size view.addSubview(activityImage) activityImage.translatesAutoresizingMaskIntoConstraints = false activityImage.centerXAnchor.constraint(equalTo: view.centerXAnchor).isActive = true activityImage.centerYAnchor.constraint(equalTo: view.centerYAnchor).isActive = true activityImage.widthAnchor.constraint(equalToConstant: 30).isActive = true activityImage.heightAnchor.constraint(equalToConstant: 30).isActive = true
}
func removeActivityIndicator() { // checking if a view has subviews on it guard let lastSubView = self.subviews.last else { return } // removing last subview with an assumption that last view is a "loading" view lastSubView.removeFromSuperview()
} }