Stopwatch

gistfile1.txt

//
//  ViewController.swift
//  Stopwatch new
//
//  Created by Samhan on 06/08/16.
//  Copyright © 2016 Samhan. All rights reserved.
//

import UIKit

protocol StopWatchDelegate : AnyObject
{
    func stopWatchTick(let string : String)
    func stopWatchDidStart()
    func stopWatchDidStop()
    
}

class Stopwatch
{
    var elapsedTimeSoFar : NSTimeInterval = 0
    var startTime : NSTimeInterval = 0
    
    weak var delegate : StopWatchDelegate?
    
    
    func start(date : NSDate)
    {
        self.startTime = NSDate.timeIntervalSinceReferenceDate()
        
        self.updateDelegate(date)
        self.delegate?.stopWatchDidStart()
        
    }
    
    func elapsed(date : NSDate) -> NSTimeInterval
    {
        
        return date.timeIntervalSinceReferenceDate - self.startTime
        
    }
    
    func displayString( time : NSTimeInterval) -> String
    {
        return "\(round(time * 10) / 10) sec"
    }
    
    func stop(date : NSDate)
    {
        self.updateDelegate(date)
        self.elapsedTimeSoFar = self.elapsedTimeSoFar + self.elapsed(date)
        self.startTime = 0
        self.delegate?.stopWatchDidStop()
        
        
    }
    
    func updateDelegate(date : NSDate)
    {
      self.delegate?.stopWatchTick(self.displayString(self.elapsed(date) + self.elapsedTimeSoFar))

    }
    func tick(date : NSDate)
    {
        self.updateDelegate(date)
    }
    
    
    
}


class ViewController: UIViewController,StopWatchDelegate {

    @IBOutlet weak var timeLabel: UILabel!
    
    @IBOutlet weak var button: UIButton!

    var timer : NSTimer?
    var stopWatch : Stopwatch = Stopwatch()
    
    
    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
        
        self.stopWatch.delegate = self
        
        self.button.layer.cornerRadius = self.button.frame.width / 2
        
    }

    @IBAction func buttonTapped(sender: AnyObject) {
        
        
        if self.timer != nil {
            self.timer?.invalidate()
            self.stopWatch.stop(NSDate())
            self.timer = nil
        }
        
        
        else {
            
            self.timer = NSTimer.scheduledTimerWithTimeInterval(0.1, target: self, selector: #selector(tick), userInfo: nil, repeats: true)
            
            self.stopWatch.start(NSDate())
        }
        
    }
    
    
    func stopWatchDidStart()
    {
     
        self.button.backgroundColor = UIColor.greenColor()
        self.button.setTitle("Stop", forState: .Normal)
    }
    
    func stopWatchDidStop()
    {
       self.button.backgroundColor = UIColor.redColor()
        self.button.setTitle("Start", forState: .Normal)
    }
    
    func tick()
    {
        self.stopWatch.tick(NSDate())
    }

    func stopWatchTick(let string : String)
    {
        self.timeLabel.text = string
    }

    
    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }


}