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

Code found here:

https://www.snip2code.com/Snippet/777050/iOS---Swift---UIButton-subclass-for-show/

import UIKit

class LoadingButton: UIButton {
private var originalButtonText: String?
var activityIndicator: UIActivityIndicatorView!

func showLoading() {
    originalButtonText = self.titleLabel?.text
    self.setTitle("", for: .normal)
    
    if (activityIndicator == nil) {
        activityIndicator = createActivityIndicator()
    }
    
    showSpinning()
}

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

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

Answer 2

Excellent @Steve,

Can use below implementation instead of line,

var activityIndicator: UIActivityIndicatorView!

use this, so that if we configure the activity indicator before calling showLoading(), the app wont crash.

private var _activityIndicator:UIActivityIndicatorView! = nil
var activityIndicator: UIActivityIndicatorView{
    set{
        _activityIndicator = newValue

    }
    get{
        if _activityIndicator == nil{
            _activityIndicator = createActivityIndicator()
        }
        return _activityIndicator
    }
}

Answer 3

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)
    }

}

Answer 4

Here is my edit with little less code.

class Button: UIButton {
    private var originalButtonText: String?

    private lazy var activityIndicator: UIActivityIndicatorView = {
        let activityIndicator = UIActivityIndicatorView()
        activityIndicator.translatesAutoresizingMaskIntoConstraints = false
        activityIndicator.color = .black
        addSubview(activityIndicator)

        NSLayoutConstraint.activate([
            activityIndicator.centerYAnchor.constraint(equalTo: self.centerYAnchor),
            activityIndicator.centerXAnchor.constraint(equalTo: self.centerXAnchor)
        ])

        return activityIndicator
    }()

    func loading(_ isLoading: Bool) {
        isEnabled = !isLoading

        if isLoading {
            originalButtonText = titleLabel?.text
            setTitle("", for: .normal)
            activityIndicator.startAnimating()
        } else {
            setTitle(originalButtonText, for: .normal)
            activityIndicator.stopAnimating()
        }
    }
}

Usage: button.loading(true/false)

Answer 5

Updated selected answer( steve-rosenberg ) for Apple Swift version 3.0.1 (swiftlang-800.0.58.6 clang-800.0.42.1) Xcode 8.1 (8B62)

import ObjectiveC

private var originalButtonText: String?
private var activityIndicator: UIActivityIndicatorView!

extension UIButton{

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

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

        showSpinning()
    }

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

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

    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)
    }
}

Answer 6

@Boris: This should not be in an extension.

Here it is in swift 3/4, with improved code: disables button, works with images and titles.

class LoadingButton: UIButton {

    struct ButtonState {
        var state: UIControlState
        var title: String?
        var image: UIImage?
    }

    private (set) var buttonStates: [ButtonState] = []
    private lazy var activityIndicator: UIActivityIndicatorView = {
        let activityIndicator = UIActivityIndicatorView()
        activityIndicator.hidesWhenStopped = true
        activityIndicator.color = self.titleColor(for: .normal)
        self.addSubview(activityIndicator)
        activityIndicator.translatesAutoresizingMaskIntoConstraints = false
        let xCenterConstraint = NSLayoutConstraint(item: self, attribute: .centerX, relatedBy: .equal, toItem: activityIndicator, attribute: .centerX, multiplier: 1, constant: 0)
        let yCenterConstraint = NSLayoutConstraint(item: self, attribute: .centerY, relatedBy: .equal, toItem: activityIndicator, attribute: .centerY, multiplier: 1, constant: 0)
        self.addConstraints([xCenterConstraint, yCenterConstraint])
        return activityIndicator
    }()

    func showLoading() {
        activityIndicator.startAnimating()
        var buttonStates: [ButtonState] = []
        for state in [UIControlState.disabled] {
            let buttonState = ButtonState(state: state, title: title(for: state), image: image(for: state))
            buttonStates.append(buttonState)
            setTitle("", for: state)
            setImage(UIImage(), for: state)
        }
        self.buttonStates = buttonStates
        isEnabled = false
    }

    func hideLoading() {
        activityIndicator.stopAnimating()
        for buttonState in buttonStates {
            setTitle(buttonState.title, for: buttonState.state)
            setImage(buttonState.image, for: buttonState.state)
        }
        isEnabled = true
    }

}