UIButton that accepts 1 finger and 2 finger tap events

Question

I'm keeping track of a game score, where the game points increment/decrement by 25.

I'm using UIButtons to show the score in the button label, take a tap gesture of 1 finger to increment the score by 25, and take a tap gesture of 2 fingers to decrement the score by 25.

I can't find a more modular way to write this code, the only function that is reusable for each button is:

func setButtonTitleAndIncrement(index: Int, button: UIButton) -> Int {
    var index = index
    index += 25
    button.setTitle(String(index), for: .normal)
    return index
}

func setButtonTitleAndDecrement(index: Int, button: UIButton) -> Int {
    var index = index
    index -= 25
    button.setTitle(String(index), for: .normal)
    return index
}

But for each button, I have to use this same code except specify specific buttons and methods, but I can't figure out a way around this. I'd love to take a general index and button at least. Any ideas?

var index1 = 0
var index2 = 0

override func viewDidLoad() {
    super.viewDidLoad()
    let oneFingerTapButtonTeam1 = UITapGestureRecognizer(target: self, action: #selector(incrementScoreTeam1))
    oneFingerTapButtonTeam1.numberOfTouchesRequired = 1
    buttonTeam1.addGestureRecognizer(oneFingerTapButtonTeam1)

    let twoFingerTapButtonTeam1 = UITapGestureRecognizer(target: self, action: #selector(decrementScoreTeam1))
    twoFingerTapButtonTeam1.numberOfTouchesRequired = 2
    buttonTeam1.addGestureRecognizer(twoFingerTapButtonTeam1)

    let oneFingerTapButtonTeam2 = UITapGestureRecognizer(target: self, action: #selector(incrementScoreTeam2))
    oneFingerTapButtonTeam2.numberOfTouchesRequired = 1
    buttonTeam2.addGestureRecognizer(oneFingerTapButtonTeam2)

    let twoFingerTapButtonTeam2 = UITapGestureRecognizer(target: self, action: #selector(decrementScoreTeam2))
    twoFingerTapButtonTeam2.numberOfTouchesRequired = 2
    buttonTeam2.addGestureRecognizer(twoFingerTapButtonTeam2)
}

func incrementScoreTeam1() {
    print("1 tapped")
    let ind = setButtonTitleAndIncrement(index: index1, button: buttonTeam1)
    index1 = ind
}

func incrementScoreTeam2() {
    print("2 tapped")
    let ind = setButtonTitleAndIncrement(index: index2, button: buttonTeam2)
    index2 = ind
}

func decrementScoreTeam1() {
    print("1 Two tapped")
    let ind = setButtonTitleAndDecrement(index: index1, button: buttonTeam1)
    index1 = ind
}

func decrementScoreTeam2() {
    print("2 Two tapped")
    let ind = setButtonTitleAndDecrement(index: index2, button: buttonTeam2)
    index2 = ind
}

Answer 1

How about subclassing the UIButton and then adding index as a property of the button. Something along the lines of:

import UIKit

@IBDesignable class BaseButton: UIButton {

    var index = 0

    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        setup()
    }

    override init(frame: CGRect) {
        super.init(frame: frame)
        setup()
    }

    override func prepareForInterfaceBuilder() {
        super.prepareForInterfaceBuilder()
        setup()
    }

    func setup() {
        let oneFingerTapButtonTeam1 = UITapGestureRecognizer(target: self, action: #selector(incrementScoreTeam))
        oneFingerTapButtonTeam1.numberOfTouchesRequired = 1
        addGestureRecognizer(oneFingerTapButtonTeam1)

        let twoFingerTapButtonTeam1 = UITapGestureRecognizer(target: self, action: #selector(decrementScoreTeam))
        twoFingerTapButtonTeam1.numberOfTouchesRequired = 2
        addGestureRecognizer(twoFingerTapButtonTeam1)
    }

    func incrementScoreTeam() {
        let ind = setButtonTitleAndIncrement(index: index, button: self)
        index = ind
    }

    func decrementScoreTeam() {
        let ind = setButtonTitleAndDecrement(index: index, button: self)
        index = ind
    }

    func setButtonTitleAndIncrement(index: Int, button: UIButton) -> Int {
        var index = index
        index += 25
        button.setTitle(String(index), for: .normal)
        return index
    }

    func setButtonTitleAndDecrement(index: Int, button: UIButton) -> Int {
        var index = index
        index -= 25
        button.setTitle(String(index), for: .normal)
        return index
    } 
}