Nested UIStackViews Broken Constraints

Question

I have a complex view hierarchy, built in Interface Builder, with nested UIStackViews. I get \"unsatisfiable constraints\" notices every time I hide some of my inner stackviews.

Answer 1

Here's implementation of Senseful's suggestion #3 written as Swift 3 class using SnapKit constraints. I also tried overriding the properties, but never got it working without warnings, so I'll stick with wrapping UIStackView:

class NestableStackView: UIView {
    private var actualStackView = UIStackView()

    override init(frame: CGRect) {
        super.init(frame: frame);
        addSubview(actualStackView);
        actualStackView.snp.makeConstraints { (make) in
            // Lower edges priority to allow hiding when spacing > 0
            make.edges.equalToSuperview().priority(999);
        }
    }

    convenience init() {
        self.init(frame: CGRect.zero);
    }

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

    func addArrangedSubview(_ view: UIView) {
        actualStackView.addArrangedSubview(view);
    }

    func removeArrangedSubview(_ view: UIView) {
        actualStackView.removeArrangedSubview(view);
    }

    var axis: UILayoutConstraintAxis {
        get {
            return actualStackView.axis;
        }
        set {
            actualStackView.axis = newValue;
        }
    }

    open var distribution: UIStackViewDistribution {
        get {
            return actualStackView.distribution;
        }
        set {
            actualStackView.distribution = newValue;
        }
    }

    var alignment: UIStackViewAlignment {
        get {
            return actualStackView.alignment;
        }
        set {
            actualStackView.alignment = newValue;
        }
    }

    var spacing: CGFloat {
        get {
            return actualStackView.spacing;
        }
        set {
            actualStackView.spacing = newValue;
        }
    }
}