TagCloudView.swift

import SwiftUI

struct WrappingStack<T: View>: UIViewRepresentable {
    @Binding var views: [T]
    let spacing: CGFloat

    func makeUIView(context: Context) -> WrappingStackView {
        let view = WrappingStackView()
        view.spacing = spacing
        return view
    }

    func updateUIView(_ uiView: WrappingStackView, context: Context) {
        uiView.views = views.map { UIHostingController(rootView: $0).view }
    }
}

class WrappingStackView: UIStackView {
    var views: [UIView] = [] {
        didSet {
            render()
        }
    }

    override func layoutSubviews() {
        super.layoutSubviews()
        render()
    }

    private func removeAllArrangedSubviews() {
        arrangedSubviews.forEach {
            self.removeArrangedSubview($0)
            $0.removeFromSuperview()
        }
    }

    private func addRow() -> UIView {
        let view: UIView = UIView()
        addArrangedSubview(view)
        return view
    }

    private func render() {
        axis = .vertical
        removeAllArrangedSubviews()

        var row = addRow()
        var currentY: CGFloat = 0
        var copy = views
        while !copy.isEmpty {
            let column = copy.removeFirst()
            var currentX = row.subviews.reduce(CGFloat(row.subviews.count) * spacing) { current, view in
                current + view.intrinsicContentSize.width
            }
            if currentX + spacing + column.intrinsicContentSize.width > frame.width {
                currentX = 0
                currentY += column.intrinsicContentSize.height + spacing
                row = addRow()
            }
            row.addSubview(column)
            column.frame = CGRect(origin: .init(x: currentX, y: currentY), size: column.intrinsicContentSize)
        }
    }
}

struct TagView: View {
    let text: String

    var body: some View {
        Text(text)
            .lineLimit(1)
            .padding(10)
            .background(Color.blue)
            .foregroundColor(Color.white)
            .cornerRadius(15)
    }
}

struct TagCloudView: View {
    @Binding var texts: [String]

    var body: some View {
        WrappingStack(views: .constant(texts.map(TagView.init)), spacing: 5)
    }
}

struct TagCloudView_Previews: PreviewProvider {
    static var previews: some View {
        TagCloudView(texts: .constant([
            "alcohol", "stress", "binge", "lazy", "running", "car", "cycling", "boating", "mountain biking", "bus", "spelunking"
        ])).padding(10)
    }
}