fade in button so it won't automatically fade out again - ios

Question

I'm using a tap gesture recogniser so if the user taps on the screen the button fades out for 5 seconds and then if the user wants to see the buttons on the screen again they tap on the screen and the button fades in.
The Problem is:
I can't disable the button when it fades in so it won't automatically fade out again. I tried to invalidate the timer but that didn't work. To be more specific of what I want to do:
On app load, you see an enabled "Start Stop Button." - Tap anywhere on the screen and a 5 second timer starts to fade the button out and disables it. Once the button fades out and disables, I can tap anywhere on the screen to fade the button back in, enable it, and kill the timer so the button shows up as it was before I first tapped it.
class ViewController: UIViewController {
// Create these 3 properties in the top of your class
var secondToFadeOut = 5 // How many second do you want the view to idle before the button fades. You can change this to whatever you'd like.
var timer = Timer() // Create the timer!
var isTimerRunning: Bool = false // Need this to prevent multiple timers from running at the same time.
#IBOutlet weak var startStopButton: UIButton! // The outlet for your button. This is used to fade it in and out, and enable / disable it.
override func viewDidLoad() {
super.viewDidLoad()
startStopButton.isEnabled = true
runTimer()
// Add a tap gesture recognizer to the main view to determine when the screen was tapped (for the purpose of resetting the timer).
let tapRecognizer = UITapGestureRecognizer(target: self, action: #selector(self.tap(_:)))
self.view.addGestureRecognizer(tapRecognizer)
}
func runTimer() {
// Create the timer to run a method (in this case... updateTimer) every 1 second.
timer = Timer.scheduledTimer(timeInterval: 1, target: self, selector: (#selector(ViewController.updateTimer)), userInfo: nil, repeats: true)
// Set the isTimerRunning bool to true
isTimerRunning = true
}
#objc func updateTimer() {
// Every 1 second that this method runs, 1 second will be chopped off the secondToFadeOut property. If that hits 0 (< 1), then run the fadeOutButton and invalidate the timer so it stops running.
secondToFadeOut -= 1
print(secondToFadeOut)
if secondToFadeOut < 1 {
fadeOutButton()
timer.invalidate()
isTimerRunning = false
}
}
#objc func tap(_ gestureRecognizer: UITapGestureRecognizer) {
// When the view is tapped (based on the gesture recognizer), reset the secondToFadeOut property, fade in (and enable) the button.
//secondToFadeOut = 5
fadeInButton()
timer.invalidate()
//if isTimerRunning == false {
// runTimer()
//}
}
func fadeOutButton() {
// Fade out your button! I also disabled it here. But you can do whatever your little heart desires.
UIView.animate(withDuration: 0.5) {
self.startStopButton.alpha = 0.25
}
self.startStopButton.isEnabled = false
}
func fadeInButton() {
// Fade the button back in, and set it back to active (so it's tappable)
UIView.animate(withDuration: 0.5) {
self.startStopButton.alpha = 1
}
self.startStopButton.isEnabled = true
}
#IBAction func startStopButtonPressed(_ sender: UIButton) {
print("Start Stop Button Pressed")
}
}

Answer 1

My best guess is that you have a rogue Timer object that remains in memory even after you invalidate your current timer, and that is causing the button to fade out again after it fades in.
I have made several edits to your class. Check the code out:
class ViewController: UIViewController {
// Create these 3 properties in the top of your class
var secondToFadeOut = 5 // How many second do you want the view to idle before the button fades. You can change this to whatever you'd like.
var timer? = nil // Create the timer!
#IBOutlet weak var startStopButton: UIButton! // The outlet for your button. This is used to fade it in and out, and enable / disable it.
override func viewDidLoad() {
super.viewDidLoad()
startStopButton.isEnabled = true
runTimer()
// Add a tap gesture recognizer to the main view to determine when the screen was tapped (for the purpose of resetting the timer).
let tapRecognizer = UITapGestureRecognizer(target: self, action: #selector(self.tap(_:)))
self.view.addGestureRecognizer(tapRecognizer)
}
func runTimer() {
if timer == nil {
timer = Timer.scheduledTimer(timeInterval: secondToFadeOut, target: self, selector: (#selector(ViewController.timerFired)), userInfo: nil, repeats: false)
}
}
#objc func timerFired() {
timer = nil
if self.startStopButton.isEnabled {
fadeOutButton()
} else {
fadeInButton()
}
}
#objc func tap(_ gestureRecognizer: UITapGestureRecognizer) {
runTimer()
}
func fadeOutButton() {
UIView.animate(withDuration: 0.5) {
self.startStopButton.alpha = 0.25
}
self.startStopButton.isEnabled = false
}
func fadeInButton() {
UIView.animate(withDuration: 0.5) {
self.startStopButton.alpha = 1
}
self.startStopButton.isEnabled = true
}
#IBAction func startStopButtonPressed(_ sender: UIButton) {
print("Start Stop Button Pressed")
}
}