NxSwiftTimer

An NSTimer wrapper for Swift.

Overview

While you can use an NSTimer with Swift classes, they must inherit from (either directly or indirectly) NSObject. If you try to use an NSTimer on a pure Swift class the following error will occur when the timer attempts to fire:-

*** NSForwarding: warning: object 0x9fe0000 of class '_TtC17SwiftTimerExample9PureSwift' does not implement methodSignatureForSelector: -- trouble ahead

Enter NxSwiftTimer. A lightweight wrapper around NSTimer that can be used on Swift classes that don’t inherit from NSObject :)

Usage

It’s API follows that of NSTimer so it should be recognisable.

// Non-repeating timer with closure:
NxSwiftTimer.scheduledTimerWithTimeInterval(3.0) { 
  // Do something
}

// Repeating timer with closure:
NxSwiftTimer.scheduledTimerWithTimeInterval(3.0, userInfo: nil, repeats: true) { 
  // Do something
}

// Non-repeating timer with function reference on class that doesn't inherit from NSObject
class PureSwift {

  var timer: NxSwiftTimer?

  func startTimer() {
    self.nxTimer = NxSwiftTimer.scheduledTimerWithTimeInterval(3.0, userInfo: nil, repeats: false, closure: self.timerFired)
  }

  func timerFired() {
    println("PureSwift object says timer fired")
  }

}