How to change the collor of a button once timer runs out?

Question

Here is the code that I am using, at the bottom of the code is my timer it is a timer counting up and once it hits 60 minutes I would like for a button to turn red.

import UIKit
import AVFoundation

class ViewController: UIViewController {
    
    override func viewDidLoad() {
       super.viewDidLoad()
        // Do any additional setup after loading the view.
    }
    

    @IBAction func btnPressed1(_ sender: UIButton) {
    
    sender.backgroundColor  = sender.backgroundColor == UIColor.red ? UIColor.black : UIColor.red
    }
    
    
    @IBOutlet weak var titleLabel: UILabel!
    
    @IBOutlet weak var progressBar1: UIProgressView!
    
           
     let start = 5
    var timer = Timer()
    var player: AVAudioPlayer!
    var totalTime = 0
    var secondsPassed = 0
    
    @IBAction func startButtonPressed(_ sender: UIButton) {
   
        let startB = sender.titleLabel?.text
        totalTime = start
        
        progressBar1.progress = 0.0
        secondsPassed = 0
        titleLabel.text = "coffee timer"
        
        timer = Timer.scheduledTimer(timeInterval: 1.0, target:self, selector: #selector(updateTimer), userInfo:nil, repeats: true)
    }
    
    @objc func updateTimer() {
        if secondsPassed < totalTime {
            secondsPassed += 1
            progressBar1.progress = Float(secondsPassed) / Float(totalTime)
            print(Float(secondsPassed) / Float(totalTime))
        } else {
            timer.invalidate()
            titleLabel.text = "check coffee"
            
            let url = Bundle.main.url(forResource: "alarm_sound", withExtension: "mp3")
            player = try! AVAudioPlayer(contentsOf: url!)
            player.play()
        }
    
    }
}

I need the button to turn the color red after my timer ends and if possible when the button is pressed have the color turn back to black.

You probably want another [`@IBOutlet`](https://developer.apple.com/library/archive/documentation/ToolsLanguages/Conceptual/Xcode_Overview/ConnectingObjectstoCode.html) for your button so you can change its color. — jtbandes, Jan 02 '22 at 18:06
where would I put that button and what code would I use to change the color? — Kaleb Zimmerman, Jan 02 '22 at 18:07
See: https://supereasyapps.com/blog/2016/3/1/60-how-to-create-outlets-and-actions-in-xcode-using-swift & https://stackoverflow.com/questions/24427284/change-button-background-color-using-swift-language — jtbandes, Jan 02 '22 at 18:11

vacawama · Accepted Answer · 2022-01-02T23:04:22.243

You could add an IBOutlet to the button, and then use that outlet to update the button in your updateTimer routine.

An alternative to adding an IBOutlet to the button is to pass the button as the userInfo: parameter of the Timer.

You can pass anything you want as the userInfo: and right now you're just passing nil. If you change nil to sender, then the button will be passed along to the Timer.

timer = Timer.scheduledTimer(timeInterval: 1.0, target:self,
    selector: #selector(updateTimer), userInfo: sender,
    repeats: true)

Then, add the Timer parameter to updateTimer:

@objc func updateTimer(t: Timer) {
    if let button = t.userInfo as? UIButton {
        button.backgroundColor = .red
    }
}

Making use of userInfo makes even better sense if you have multiple buttons that share the same updateTimer code. By creating a structure to hold the secondsPassed and button and passing that structure as userInfo:, you could have multiple buttons using multiple timers at the same time and each Timer would know which button it was assigned to.

How to change the collor of a button once timer runs out?

1 Answers1