swiftUI ScrollView UIRefreshControl overlay on navigation bar - ios

Question

Until iOS 15.2 ， the SwiftUI ScrollView doesn't support refreshable{}, so I using UIRefreshControl to solve this issues. Everything went smoothly and success was just one step away ;-(
full code ContentView.swift :
import SwiftUI
extension UIView {
func viewsInHierarchy<ViewType: UIView>() -> [ViewType]? {
var views: [ViewType] = []
viewsInHierarchy(views: &views)
return views.count > 0 ? views : nil
}
fileprivate func viewsInHierarchy<ViewType: UIView>(views: inout [ViewType]) {
subviews.forEach { eachSubView in
if let matchingView = eachSubView as? ViewType {
views.append(matchingView)
}
eachSubView.viewsInHierarchy(views: &views)
}
}
func searchViewAnchestorsFor<ViewType: UIView>(
_ onViewFound: (ViewType) -> Void
) {
if let matchingView = self.superview as? ViewType {
onViewFound(matchingView)
} else {
superview?.searchViewAnchestorsFor(onViewFound)
}
}
func searchViewAnchestorsFor<ViewType: UIView>() -> ViewType? {
if let matchingView = self.superview as? ViewType {
return matchingView
} else {
return superview?.searchViewAnchestorsFor()
}
}
func printViewHierarchyInformation(_ level: Int = 0) {
printViewInformation(level)
self.subviews.forEach { $0.printViewHierarchyInformation(level + 1) }
}
func printViewInformation(_ level: Int) {
let leadingWhitespace = String(repeating: " ", count: level)
let className = "\(Self.self)"
let superclassName = "\(self.superclass!)"
let frame = "\(self.frame)"
let id = (self.accessibilityIdentifier == nil) ? "" : " `\(self.accessibilityIdentifier!)`"
print("\(leadingWhitespace)\(className): \(superclassName)\(id) \(frame)")
}
}
final class ViewControllerResolver: UIViewControllerRepresentable {
let onResolve: (UIViewController) -> Void
init(onResolve: #escaping (UIViewController) -> Void) {
self.onResolve = onResolve
}
func makeUIViewController(context: Context) -> ParentResolverViewController {
ParentResolverViewController(onResolve: onResolve)
}
func updateUIViewController(_ uiViewController: ParentResolverViewController, context: Context) { }
}
class ParentResolverViewController: UIViewController {
let onResolve: (UIViewController) -> Void
init(onResolve: #escaping (UIViewController) -> Void) {
self.onResolve = onResolve
super.init(nibName: nil, bundle: nil)
}
required init?(coder: NSCoder) {
fatalError("Use init(onResolve:) to instantiate ParentResolverViewController.")
}
override func didMove(toParent parent: UIViewController?) {
super.didMove(toParent: parent)
if let parent = parent {
//parent.navigationController?.navigationBar.prefersLargeTitles = true
//parent.navigationItem.largeTitleDisplayMode = .never
self.onResolve(parent)
// print("didMove(toParent: \(parent)")
}
}
}
struct ContentView: View {
var body: some View {
NavigationView {
ScrollView {
VStack {
HStack {
Spacer()
Text("Content")
Spacer()
}
Spacer()
}
.background(Color.red)
}
.navigationTitle("title")
.navigationBarTitleDisplayMode(.inline)
.overlay(
ViewControllerResolver { parent in
var scrollView: UIScrollView?
if let scrollViewsInHierarchy: [UIScrollView] = parent.view.viewsInHierarchy() {
if scrollViewsInHierarchy.count == 1, let firstScrollViewInHierarchy = scrollViewsInHierarchy.first {
scrollView = firstScrollViewInHierarchy
}
}
if let scrollView = scrollView {
guard scrollView.refreshControl == nil else { return }
let refreshControl = UIRefreshControl()
refreshControl.transform = CGAffineTransform(scaleX: 0.75, y: 0.75)
refreshControl.layoutIfNeeded()
let uiAction = UIAction(handler: { uiAction in
DispatchQueue.main.asyncAfter(deadline: .now() + 3) {
refreshControl.endRefreshing()
}
})
refreshControl.addAction(uiAction, for: .primaryActionTriggered)
scrollView.refreshControl = refreshControl
}
}
.frame(width: 0, height: 0)
)
}
}
}