Reverse Time Label

Question

I am looking for label which can give me functionality to count down reverse timer. I know there are Timer available to to count down, but I want reverse count down with Days, Hours, Minutes, Seconds like as following image.

Can anyone tell me how to implement this like as following image ?

Help will be appreciated. Thank You.

Answer 1

First you need to create an NSAttributedString with your time format requeriments something like this

func timeLeftExtended(date:Date) ->NSAttributedString{

    let cal = Calendar.current
    let now = Date()
    let calendarUnits:NSCalendar.Unit = [NSCalendar.Unit.day, NSCalendar.Unit.hour, NSCalendar.Unit.minute, NSCalendar.Unit.second]
    let components = (cal as NSCalendar).components(calendarUnits, from: now, to: date, options: [])

    let fullCountDownStr = "\(components.day!.description)d " + "\(components.hour!.description)h " + "\(components.minute!.description)m " + "\(components.second!.description)s "

    let mutableStr = NSMutableAttributedString(string: fullCountDownStr, attributes: [NSAttributedStringKey.foregroundColor:UIColor.white])

    for (index,char) in mutableStr.string.enumerated()
    {
        if(char == "d" || char == "h" || char == "m" || char == "s")
        {
            mutableStr.removeAttribute(NSAttributedStringKey.foregroundColor, range: NSMakeRange(index, 1))
            mutableStr.addAttributes([NSAttributedStringKey.foregroundColor : UIColor.lightGray], range: NSMakeRange(index, 1))
        }
    }

    return mutableStr
}

After that you need to declare the label where you want to update your time left

@IBOutlet weak var lblTimeRemaining: UILabel!

And add a timer and a flag to know when your timer is working

fileprivate var timeWorking : Bool = false
var timer:Timer?

Here we setup our timer

func setupWith()
{ 
    if(!timeWorking)
    {
        timer = Timer.scheduledTimer(timeInterval: 1.0, target: self, selector: #selector(self.updateCountDown), userInfo: nil, repeats: true)
        self.timeWorking = true
    }

}

This method will be executed 1 time every second to update our count

@objc func updateCountDown()
{
    self.lblTimeRemaining.attributedText = self.timeLeftExtended(date:Date.distantFuture)
}

RESULT