UIViewRepresentable automatic size - Passing UIKit UIView size to SwiftUI

Question

Assume you have a UIKit view that wants to decide about its own size (via intrinsicContentSize or layout constraints, the size might change). For example:

Answer 1

The solution is to set explicitly compression/hugging priority for represented UIView

Tested with Xcode 11.4 / iOS 13.4

struct YellowBoxView : UIViewRepresentable {

    func makeUIView(context: Context) -> YellowBoxUIKitView {
        let view = YellowBoxUIKitView()

        view.setContentHuggingPriority(.required, for: .horizontal) // << here !!
        view.setContentHuggingPriority(.required, for: .vertical)

        // the same for compression if needed

        return view
    }

    func updateUIView(_ uiView: YellowBoxUIKitView, context: Context) {
    }
}