Display activity indicator inside UIButton

Question

I would like to change the content of a UIButton to an ActivityIndicator after it is pressed.

I know buttons have an imageView and a titleLabel, but I don\'t know how to

Answer 1

Swift 4.0 with a little modification

class LoadingUIButton: UIButton {

    @IBInspectable var indicatorColor : UIColor = .lightGray

    var originalButtonText: String?
    var activityIndicator: UIActivityIndicatorView!

    func showLoading() {
        originalButtonText = self.titleLabel?.text
        self.setTitle("", for: .normal)

        if (activityIndicator == nil) {
            activityIndicator = createActivityIndicator()
        }

        showSpinning()
    }

    func hideLoading() {
        DispatchQueue.main.async(execute: {
            self.setTitle(self.originalButtonText, for: .normal)
            self.activityIndicator.stopAnimating()
        })
    }

    private func createActivityIndicator() -> UIActivityIndicatorView {
        let activityIndicator = UIActivityIndicatorView()
        activityIndicator.hidesWhenStopped = true
        activityIndicator.color = indicatorColor
        return activityIndicator
    }

    private func showSpinning() {
        activityIndicator.translatesAutoresizingMaskIntoConstraints = false
        self.addSubview(activityIndicator)
        centerActivityIndicatorInButton()
        activityIndicator.startAnimating()
    }

    private func centerActivityIndicatorInButton() {
        let xCenterConstraint = NSLayoutConstraint(item: self, attribute: .centerX, relatedBy: .equal, toItem: activityIndicator, attribute: .centerX, multiplier: 1, constant: 0)
        self.addConstraint(xCenterConstraint)

        let yCenterConstraint = NSLayoutConstraint(item: self, attribute: .centerY, relatedBy: .equal, toItem: activityIndicator, attribute: .centerY, multiplier: 1, constant: 0)
        self.addConstraint(yCenterConstraint)
    }

}