Timer scope issue with #selector - swift

Question

I'm stuck with getting this into the right scope. I'm sure its something super simple but I'm banging my head against a wall with it. any answers i'm finding are in earlier version of swift so im struggling to understand how to solve this
My current issue is trying to get the timer initialised correctly and counting. the "selector" is causing the most issues. the rest i'm sure ill be able to figure out afterwards
code is as follows.
#IBOutlet weak var shortTimerLabel: UILabel!
#IBOutlet weak var longTimerLabel: UILabel!
var seconds = 60 //This variable will hold a starting value of seconds. It could be any amount above 0.
var timer = Timer()
var isTimerRunning = false //This will be used to make sure only one timer is created at a time.
#IBAction func longpressed(_ gestureRecognizer: UILongPressGestureRecognizer) {
shortTimerLabel.text = "longPressed"
}
#IBAction func tappedShortTimer(_ gestureRecognizer: UITapGestureRecognizer) {
shortTimerLabel.text = "ShortPressed"
}
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
func runTimer() {
timer = Timer.scheduledTimer(timeInterval: 1, target: self, selector: #selector(updateTimer), userInfo: nil, repeats: true)
}
func updateTimer() {
seconds += 1 //This will decrement(count down)the seconds.
shortTimerLabel.text = "\(seconds)" //This will update the label.
}
}
im trying to create a stopwatch which can be controlled using gestures. short pressed on label for stop/start and long press to reset time.

Answer 1

In your updateTimer() method, the first line should read seconds -= 1 instead (if you want to count down).
Also, you may want to update your updateTimer() method like this:
func updateTimer() {
seconds -= 1
if seconds == 0 {
timer.invalidate()
isTimerRunning = false
}
shortTimerLabel.text = String(describing: seconds)
}
An other issue here is that you added your runTimer() and updateTimer() method to the wrong place. You should not add them inside your viewDidLoad method.
Your final code would look like this:
var seconds = 60
var timer = Timer()
var isTimerRunning = false
#IBAction func longpressed(_ gestureRecognizer: UILongPressGestureRecognizer) {
resetTimer()
}
#IBAction func tappedShortTimer(_ gestureRecognizer: UITapGestureRecognizer) {
stopStartTimer()
}
override func viewDidLoad() {
super.viewDidLoad()
// ...
}
func stopStartTimer() {
if !isTimerRunning {
timer = Timer.scheduledTimer(timeInterval: 1.0, target: self, selector: #selector(updateTimer), userInfo: nil, repeats: true)
isTimerRunning = true
} else {
timer.invalidate()
isTimerRunning = false
}
}
func updateTimer() {
seconds -= 1
if seconds == 0 {
timer.invalidate()
isTimerRunning = false
}
shortTimerLabel.text = String(describing: seconds)
}
func resetTimer() {
if isTimerRunning {
seconds = 60
timer.invalidate()
isTimerRunning = false
stopStartTimer()
}
}

Answer 2

The selector should be given in the form #selector(ViewController.updateTimer)
You shouldn't declare functions in the viewDidLoad but outside
You only set the timer in the longpressed function
For stoping it is timer.invalidate()