double ring timer

ViewController.swift

//
//  ViewController.swift
//  DoubleRing
//
//  Created by MizushimaYusuke on 8/22/16.
//  Copyright © 2016 MizushimaYusuke. All rights reserved.
//

import UIKit
import SpriteKit

class ViewController: UIViewController {

    weak var scene: SKScene?
    
    lazy var timerLabel: SKLabelNode = {
        let l = SKLabelNode(text: "")
        l.fontSize = 30
        l.position = CGPoint(x: self.view.frame.midX, y: 200)
        self.scene!.addChild(l)
        return l
    }()
    
    override func viewDidLoad() {
        super.viewDidLoad()
        setupScene()
        createBigCircle()
        createSmallCircle()
        self.timerLabel.text = "10.00"
    }

    func setupScene() {
        let sv = SKView(frame: view.bounds)
        let s = SKScene(size: sv.frame.size)
        sv.presentScene(s)
        view.addSubview(sv)
        scene = s
    }
    
    func createBigCircle() {
        let num = 120
        let dw = 2.0 * M_PI / Double(num)
        for i in 0...num {
            let path = UIBezierPath()
            path.moveToPoint(CGPoint.zero)
            path.addLineToPoint(CGPoint(x: 100, y: 1))
            path.addLineToPoint(CGPoint(x: 100, y: -1))
            path.closePath()
            
            let bar = SKShapeNode(path: path.CGPath)
            bar.fillColor =  UIColor(hue: 0.5, saturation: 0.5, brightness: 1, alpha: 1)
            bar.strokeColor = bar.fillColor
            bar.position = CGPoint(x: view.frame.midX, y: view.frame.midY)
            bar.zRotation = CGFloat(i) * CGFloat(dw)
            scene?.addChild(bar)
        }
    }

    func createSmallCircle() {
        UIGraphicsBeginImageContextWithOptions(CGSize(width: 150, height: 150), false, 0)
        UIColor(hue: 0.5, saturation: 0.8, brightness: 0.7, alpha: 0.7).set()
        CGContextFillEllipseInRect(UIGraphicsGetCurrentContext(), CGRect(x: 0, y: 0, width: 150, height: 150))
        let img = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        
        let texture = SKTexture(image: img)
        let blueCircle = SKSpriteNode(texture: texture)
        blueCircle.name = "blue circle"
        blueCircle.anchorPoint = CGPoint(x: 1.0 / 3.0, y: 0.5)
        blueCircle.position = CGPointMake(view.frame.midX, view.frame.midY)
        scene?.addChild(blueCircle)
        
        let hole = SKShapeNode(circleOfRadius: 50)
        hole.fillColor = scene!.backgroundColor
        hole.lineWidth = 0
        blueCircle.addChild(hole)
    }
    
    override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?) {
        if let circle = scene?.childNodeWithName("blue circle") {
            circle.runAction(
                SKAction.group([
                    SKAction.rotateByAngle(-2.0 * CGFloat(M_PI), duration: 10.0),
                    SKAction.customActionWithDuration(10.0, actionBlock: { (n, t) in
                        let time = String(format: "%.2f", 10.0 - t)
                        self.timerLabel.text = time
                    })
            ]))
        }
    }
}

http://lepetit-prince.net/ios/?p=5433