import TagsFlowLayout

class ViewController: UICollectionViewController {
   
    override func viewDidLoad() {
        super.viewDidLoad()
        
        let tagsFlowLayout = TagsFlowLayout(alignment: .left ,minimumInteritemSpacing: 10, minimumLineSpacing: 10, sectionInset: UIEdgeInsets(top: 10, left: 10, bottom: 10, right: 10))
        collectionView.collectionViewLayout = tagsFlowLayout
        
        // register cell
        collectionView.register(nib: UINib(nibName: "ExampleCell", bundle: nil), forCellWithReuseIdentifier: "ExampleCell")
    }
    
   override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "ExampleCell", for: indexPath) as! ExampleCell
        
        cell.maxWidth = collectionView.bounds.width - 30

        return cell
    }
}

class TagCollectionViewCell: UICollectionViewCell {
    
    @IBOutlet weak var tagLabel: UILabel!
    
    @IBOutlet private var maxWidthConstraint: NSLayoutConstraint! {
        didSet {
            maxWidthConstraint.isActive = false
        }
    }
    
    var maxWidth: CGFloat? = nil {
        didSet {
            guard let maxWidth = maxWidth else {
                return
            }
            maxWidthConstraint.isActive = true
            maxWidthConstraint.constant = maxWidth
        }
    }
}