import UIKit

//defining a enum to track cell state

enum  CellState {
    case selected
    case unselected

    init() {
        self = .unselected
    }
}

class yourCell: UICollectionViewCell {

 @IBOutlet weak var yourBtn: UIButton!

// creating our func
 var buttonAction: (() -> ())?

 override func awakeFromNib() {
        super.awakeFromNib()
    }



@IBAction func sliderAction(_ sender: UISlider) {

    // defining our func where we want to use it
    buttonAction()
 }

}


// inside our viewController
import UIKit

class yourViewController: UIViewController, UICollectionViewDelegate, UICollectionViewDataSource {
    @IBOutlet weak var collectionView: UICollectionView!

    // you data source that you fill the cells
    var yourDataArray: [yourDataSource]()

    // the array that will hold status of our cells
    private var  cellStateArray: [CellState]?


    override func viewDidLoad() {
        super.viewDidLoad()

        //confirming our delegate and dataSource
        collectionView.dataSource = self
        collectionView.delegate = self

       //filling your cellStateArray as many as your cell count
       self.cellStateArray = Array(repeating: .unselected, count: self.yourDataArray!.count )
    }


    func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        if yourDataArray?.isEmpty == false {
            return yourDataArray!.count
        } else {
            print("Caution yourDataArray IS EMPTY")
            return 0
        }
    }

 func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {

        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "yourCell", for: indexPath) as! yourCell

// checking your button selected or not while reuse it (while scrolling)

     if  cellStateArray![indexPath.row] == .selected  {
            cell.yourBtn.backgroundColor = .red
        } else {
            cell.yourBtn.backgroundColor = .blue
       }


    cell.buttonAction = {

  //calling button function
       button_Select(_ sender: cell.yourBtn, cellStateArray: cellStateArray, indexPath: IndexPath)

 }

}


// Defining the function what you want to do with your button in each cell

func button_Select(_ sender: UIButton, cellStateArray: [CellState], indexPath: IndexPath ) {
        sender.isSelected = !sender.isSelected
        if sender.isSelected{
            sender.backgroundColor = .red

           //setting value when your button selected
            cellStateArray[indexPath.row] = .selected
        }
        else{
            sender.backgroundColor = .blue

          //setting value when your button unselected
            cellStateArray[indexPath.row] = .unselected
        }
     collectionView.reloadData()
}


}