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I tried to mix the UISearchBar and the UIScrollView with SwiftUI. I found this code in the web and it is working so far but the problem is, that if tapping on the searchbar the scrollview behind is jumping to the new position. How is it possible to avoid this behavior?

Video: https://i.stack.imgur.com/Y1AYP.jpg

SearchBar: (Also from the internet)

class SearchBar: NSObject, ObservableObject {

@Published var text: String = ""
let searchController: UISearchController = UISearchController(searchResultsController: nil)

override init() {
    super.init()
    self.searchController.obscuresBackgroundDuringPresentation = false
    self.searchController.searchResultsUpdater = self
    
}
}

extension SearchBar: UISearchResultsUpdating {

func updateSearchResults(for searchController: UISearchController) {
    // Publish search bar text changes.
    if let searchBarText = searchController.searchBar.text {
        self.text = searchBarText
    }
}
}

struct SearchBarModifier: ViewModifier {

let searchBar: SearchBar

func body(content: Content) -> some View {
    content
        .overlay(
            ViewControllerResolver { viewController in
                viewController.navigationItem.searchController = self.searchBar.searchController
                viewController.navigationItem.hidesSearchBarWhenScrolling = false
            }
            .frame(width: 0, height: 0)
        )
}
}

extension View {
func add(_ searchBar: SearchBar) -> some View {
    return self.modifier(SearchBarModifier(searchBar: searchBar))

}
}

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 {
        onResolve(parent)
    }
}
}

ScrollViewWrapper: Is there any way to make a paged ScrollView in SwiftUI?

class UIScrollViewViewController: UIViewController {

lazy var scrollView: UIScrollView = {
    let v = UIScrollView()
    v.isPagingEnabled = false
    v.alwaysBounceVertical = true
    return v
}()

var hostingController: UIHostingController<AnyView> = UIHostingController(rootView: AnyView(EmptyView()))

override func viewDidLoad() {
    super.viewDidLoad()
    self.view.addSubview(self.scrollView)
    self.pinEdges(of: self.scrollView, to: self.view)

    self.hostingController.willMove(toParent: self)
    self.scrollView.addSubview(self.hostingController.view)
    self.pinEdges(of: self.hostingController.view, to: self.scrollView)
    self.hostingController.didMove(toParent: self)

}

func pinEdges(of viewA: UIView, to viewB: UIView) {
    viewA.translatesAutoresizingMaskIntoConstraints = false
    viewB.addConstraints([
        viewA.leadingAnchor.constraint(equalTo: viewB.leadingAnchor),
        viewA.trailingAnchor.constraint(equalTo: viewB.trailingAnchor),
        viewA.topAnchor.constraint(equalTo: viewB.topAnchor),
        viewA.bottomAnchor.constraint(equalTo: viewB.bottomAnchor),
    ])
}

}

struct UIScrollViewWrapper<Content: View>: UIViewControllerRepresentable {

var content: () -> Content

init(@ViewBuilder content: @escaping () -> Content) {
    self.content = content
}

func makeUIViewController(context: Context) -> UIScrollViewViewController {
    let vc = UIScrollViewViewController()
    vc.hostingController.rootView = AnyView(self.content())
    return vc
}

func updateUIViewController(_ viewController: UIScrollViewViewController, context: Context) {
    viewController.hostingController.rootView = AnyView(self.content())
}
}

And the SwiftUI View:

struct ContentView: View{
    @ObservedObject var search = SearchBar()
    var body: some View{
       NavigationView{
        GeometryReader{geo in
            UIScrollViewWrapper{      //<-----------------
                VStack{
                    ForEach(0..<10){i in
                        Text("lskdfj")
                    }
                }
                .frame(width: geo.size.width)
            }
            .navigationBarTitle("Test")
            .navigationViewStyle(StackNavigationViewStyle())           
        }
        .add(search)      //<-------------
    }
}
}
sheldor
  • 115
  • 12

1 Answers1

0

Ok don't know why but adding .ignoesSafeArea() fixed it. Perhaps anybody know why exactly.

struct ContentView: View{
    @ObservedObject var search = SearchBar()
    var body: some View{
       NavigationView{
        GeometryReader{geo in
            UIScrollViewWrapper{     
                VStack{
                    ForEach(0..<10){i in
                        Text("lskdfj")
                    }
                }
                .frame(width: geo.size.width)
            }
            .navigationBarTitle("Test")
            .navigationViewStyle(StackNavigationViewStyle())           
        }
        .ignoresSafeArea() //<-----
        .add(search) 

    }
}
}
sheldor
  • 115
  • 12