CODEWITHSUNDEEP
iosswift
Cesare
Cesare

Reputation: 9419

Make collection view height dynamic depending on content

I have a collection view that contains a cell with varying width (it has a label inside it):

public class TagView: UIView {

    let textLabel: UILabel = {
        let label = UILabel()
        label.textColor = .black
        label.textAlignment = .center
        label.font = UIFont.systemFont(ofSize: 15)
        return label
    }()

    override init(frame: CGRect) {
        super.init(frame: frame)
        setupView()
        setupLabel()
    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    private func setupView() {
        backgroundColor = #colorLiteral(red: 0.03529411765, green: 0.6862745098, blue: 0.003921568627, alpha: 1)
        backgroundColor = backgroundColor
        layer.cornerRadius = 3
        layer.masksToBounds = true
    }

    private func setupLabel() {
        addSubview(textLabel)
        textLabel.fillToSuperview(constant: 3)
    }
}

How do I make the collection view's height dynamic? The problem is that at init time I don't know what frame I should give to the collection view, so I just give zero:

let layout = UICollectionViewFlowLayout()
let collectionView = UICollectionView(frame: .zero, collectionViewLayout: layout)

How do I make the collection view height dynamic?

I have also looked into the sizeForItem method:

public func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
    let view = TagView()
    let data = tags[indexPath.row]
    view.textLabel.text = data
    view.layoutSubviews()
    return view.frame.size
}

but I think this returns a size of zero width and heigth.

Upvotes: 0

Views: 81

Answers (1)

Shehata Gamal
Shehata Gamal

Reputation: 100533

First here set an assumption height , but the width should be known 

let collectionView = UICollectionView(frame:CGRect(x:0,y:20,width:self.view.frame.width,height:300), collectionViewLayout: layout)

Then in sizeForItemAt

let fixedWidth = (collectionView.frame.width - 40 ) / 5   // say here you need 5 items / row
let label = UILabel() 
label.numberOfLines = 0
label.font = UIFont.systemFont(ofSize: 15)
let si = label.sizeThatFits(CGSize(width:fixedWidth, height: CGFloat.greatestFiniteMagnitude))
// si.height is the needed height with 6 padding from top and bottom according to your constant in tagView
return CGSize(width:fixedWidth + 6.0 ,height:si.height)

For a total height , create a function from above and call it with all your items then add the heights and set them to collectionView's height

Upvotes: 1

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