Swift : Pause and Resume NSTimer

Question

I know this has been posted before, but I'm new to swift and i would like to find help as per my situation. So i need to run a timer, and when the stopMusic() is called(somewhere in my app), i need to pause the timer, then when the playMusic() is called, i need to resume the timer.

Here is what i have:

override func viewDidLoad() {

runFirstDropTimer = NSTimer.scheduledTimerWithTimeInterval(38.2, target: self, selector: "runAnimation", userInfo: nil, repeats: false)

}

func stopMusic() {
//Pause Timer
}

func playMusic() {
//Resume Timer
}

Thank you for any help you can provide!!!

Answer 1

Short answer: You can't. Timers can't be paused.

Instead you need to record the current time when you start the timer:

let startTime = NSDate.timeIntervalSinceReferenceDate()
let interval = 38.2
//Start your timer 
runFirstDropTimer = NSTimer.scheduledTimerWithTimeInterval(interval, 
  target: self, 
  selector: "runAnimation", 
  userInfo: nil, 
  repeats: false)

Then, when you want to pause your timer, invalidate it and figure out how much time is left:

runFirstDropTimer.invalidate()
let elapsed = NSDate.timeIntervalSinceReferenceDate() - startTime
let remaining = interval - elapsed

And finally when you want to resume your timer create a new timer with the remaining value.