Nested UIStackView child in UIScrollView does not stretch to fill

Question

I have a UIStackView.

I have added some views.

The last view should be at to the bottom of the screen. To achieve this I have added a view that acts as a spacer, I have set a height on the first and last view with the idea that the middle view stretches to fill the space.

This works.

    let topView = UIView(frame: .zero)
        topView.withSize(.init(width: 0, height: 100))
        topView.backgroundColor = .lightGray

        let spacerView = UIView(frame: .zero)
        spacerView.backgroundColor = .darkGray

        let bottomView = UIView(frame: .zero)
        bottomView.withSize(.init(width: 0, height: 200))
        bottomView.backgroundColor = .lightGray

        let stackView = UIStackView()
        stackView.axis = .vertical
        stackView.alignment = .fill
        stackView.spacing = 0
        stackView.distribution = .fill

        addSubview(stackView)

        stackView.translatesAutoresizingMaskIntoConstraints = false

        NSLayoutConstraint.activate([
            stackView.leadingAnchor.constraint(equalTo: leadingAnchor),
            stackView.trailingAnchor.constraint(equalTo: trailingAnchor),
            stackView.topAnchor.constraint(equalTo: topAnchor),
            stackView.bottomAnchor.constraint(equalTo: bottomAnchor),
        ])

        [topView, spacerView, bottomView].forEach { stackView.addArrangedSubview($0) }

I have a scenario however where the screen size may be smaller than the size of the views.

I am trying to embed my UIStackView in a UIScrollView however when I do this, the spacer view no longer stretches itself. It is as if the height is now zero. (I have added spacing to show the top and bottom views)

        let topView = UIView(frame: .zero)
        topView.withSize(.init(width: 0, height: 100))
        topView.backgroundColor = .lightGray

        let spacerView = UIView(frame: .zero)
        spacerView.backgroundColor = .darkGray

        let bottomView = UIView(frame: .zero)
        bottomView.withSize(.init(width: 0, height: 200))
        bottomView.backgroundColor = .lightGray


        let scrollView = UIScrollView(frame: .zero)
        addSubviews(scrollView)

        NSLayoutConstraint.activate([
            scrollView.leadingAnchor.constraint(equalTo: leadingAnchor),
            scrollView.trailingAnchor.constraint(equalTo: trailingAnchor),
            scrollView.topAnchor.constraint(equalTo: topAnchor),
            scrollView.bottomAnchor.constraint(equalTo: bottomAnchor)
        ])

        let stackView = UIStackView()
        stackView.axis = .vertical
        stackView.alignment = .fill
        stackView.spacing = 8
        stackView.distribution = .fill
        scrollView.addSubview(stackView)

        stackView.translatesAutoresizingMaskIntoConstraints = false
        NSLayoutConstraint.activate([
            // Attaching the content's edges to the scroll view's edges
            stackView.leadingAnchor.constraint(equalTo: scrollView.leadingAnchor),
            stackView.trailingAnchor.constraint(equalTo: scrollView.trailingAnchor),
            stackView.topAnchor.constraint(equalTo: scrollView.topAnchor),
            stackView.bottomAnchor.constraint(equalTo: scrollView.bottomAnchor),

            // Satisfying size constraints
            stackView.widthAnchor.constraint(equalTo: scrollView.widthAnchor)
        ])

        [topView, spacerView, bottomView].forEach { stackView.addArrangedSubview($0) }

I would expect in this case my UIStackView to still fill the view and only be scrollable if a child view causes it to grow in height beyond the visible bounds of the view.

Answer 1

Use a UITableView with a UICollectionView as a Footer.

You can find a tutorial here: https://ashfurrow.com/blog/putting-a-uicollectionview-in-a-uitableviewcell-in-swift/

This is for adding a collectionView as a header but works the same for footer.

private let tableView: UITableView = {
    let view = UITableView(frame: .zero, style: .plain)
    view.translatesAutoresizingMaskIntoConstraints = false
    view.estimatedRowHeight = 44
    view.rowHeight = UITableView.automaticDimension
    view.keyboardDismissMode = .interactive
    view.tableFooterView = //Your Custom View with CollectionView here
    return view
}()