Bindings in UIViewControllerRepresentable with Storyboard - swiftui

I have a UIViewControllerRepresentable with a UIStoryboard. How do I pass my #ObservedObject to the ViewController? It's currently not initialised, and I can't pass it to "as! ARView(model: model)"
struct ARViewContainer: UIViewControllerRepresentable {
#ObservedObject var model: Model
typealias UIViewControllerType = ARView
func makeUIViewController(context: Context) -> ARView {
UIStoryboard(name: "Main", bundle: Bundle.main).instantiateViewController(identifier: "Main") as! ARView
}
func updateUIViewController(_ uiViewController: ARViewContainer.UIViewControllerType, context: UIViewControllerRepresentableContext<ARViewContainer>) { }
}
class ARView: UIViewController, ARSCNViewDelegate {
// MARK: Object model
#ObservedObject var model: Model
// MARK: - Initalisation
init(model: Model) {
self.model = model
super.init(nibName: nil, bundle: nil)
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
}

There's no reason to use #ObservableObject inside a UIViewController. The property wrapper isn't doing you any good like it would inside a View, triggering updates.
An #ObservableObject can't be an Optional, but since it no longer has to have the property wrapper, you can make it an Optional. Obviously, you'll have to unwrap when it needs to be used.
struct ARViewContainer: UIViewControllerRepresentable {
#ObservedObject var model: Model
typealias UIViewControllerType = ARView
func makeUIViewController(context: Context) -> ARView {
let vc = UIStoryboard(name: "Main", bundle: Bundle.main).instantiateViewController(identifier: "Main") as! ARView
vc.model = model
return vc
}
func updateUIViewController(_ uiViewController: ARViewContainer.UIViewControllerType, context: UIViewControllerRepresentableContext<ARViewContainer>) {
}
}
class ARView: UIViewController, ARSCNViewDelegate {
var model: Model?
}

Related

Can't drag down/dismiss UIColorPickerViewController

I am displaying a UIColorPickerViewController as a sheet using the sheet() method, everything works fine but I can't drag down/dismiss the view anymore.
import Foundation
import SwiftUI
struct ColorPickerView: UIViewControllerRepresentable {
private var selectedColor: UIColor!
init(selectedColor: UIColor) {
self.selectedColor = selectedColor
}
func makeUIViewController(context: Context) -> UIColorPickerViewController {
let colorPicker = UIColorPickerViewController()
colorPicker.selectedColor = self.selectedColor
return colorPicker
}
func updateUIViewController(_ uiViewController: UIColorPickerViewController, context: Context) {
// Silent
}
}
.sheet(isPresented: self.$viewManager.showSheet, onDismiss: {
ColorPickerView()
}
Any idea how to make the drag/down dismiss gesture works?
Thanks!
Ran into the same problem when trying to build a color picker similar to above. What worked was "wrapping" the color picker in a view with a Dismiss button. And also discovered that the bar at the top of the view would allow the picker to now be dragged down and away. Below is my wrapper. (One could add more features such as a title to the bar.)
struct ColorWrapper: View {
var inputColor: UIColor
#Binding var isShowingColorPicker: Bool
#Binding var selectedColor: UIColor?
var body: some View {
VStack {
HStack {
Spacer()
Button("Dismiss", action: {
isShowingColorPicker = false
}).padding()
}
ColorPickerView(inputColor: inputColor, selectedColor: $selectedColor)
}
}
}
And for completeness, here is my version of the color picker:
import SwiftUI
struct ColorPickerView: UIViewControllerRepresentable {
typealias UIViewControllerType = UIColorPickerViewController
var inputColor: UIColor
#Binding var selectedColor: UIColor?
#Environment(\.presentationMode) var isPresented
func makeUIViewController(context: Context) -> UIColorPickerViewController {
let picker = UIColorPickerViewController()
picker.delegate = context.coordinator
picker.supportsAlpha = false
picker.selectedColor = inputColor
return picker
}
func updateUIViewController(_ uiViewController: UIColorPickerViewController, context: Context) {
uiViewController.supportsAlpha = false
}
func makeCoordinator() -> Coordinator {
return Coordinator(parent: self)
}
class Coordinator: NSObject, UINavigationControllerDelegate, UIColorPickerViewControllerDelegate {
var parent: ColorPickerView
init(parent: ColorPickerView) {
self.parent = parent
}
func colorPickerViewControllerDidFinish(_ viewController: UIColorPickerViewController) {
parent.isPresented.wrappedValue.dismiss()
}
func colorPickerViewController(_ viewController: UIColorPickerViewController, didSelect color: UIColor, continuously: Bool) {
parent.selectedColor = color
// parent.isPresented.wrappedValue.dismiss()
}
}
}

SwiftUI + UIPageViewController, multiple view types

I want to use a UIPageViewController in my SwiftUI app, as demonstrated in this tutorial. However, the tutorial passes in identical view types as pages, and I want to pass in any type of view.
struct PageViewController<Page: View>: UIViewControllerRepresentable {
var pages: [Page]
#Binding var currentPage: Int
func makeCoordinator() -> Coordinator {
Coordinator(self)
}
func makeUIViewController(context: Context) -> UIPageViewController {
let pageViewController = UIPageViewController(
transitionStyle: .scroll,
navigationOrientation: .horizontal)
pageViewController.delegate = context.coordinator
return pageViewController
}
func updateUIViewController(_ pageViewController: UIPageViewController, context: Context) {
pageViewController.setViewControllers(
[context.coordinator.controllers[currentPage]], direction: .forward, animated: true)
}
class Coordinator: NSObject, UIPageViewControllerDelegate {
var parent: PageViewController
var controllers = [UIViewController]()
init(_ pageViewController: PageViewController) {
parent = pageViewController
controllers = parent.pages.map { UIHostingController(rootView: $0) }
}
func pageViewController(
_ pageViewController: UIPageViewController,
didFinishAnimating finished: Bool,
previousViewControllers: [UIViewController],
transitionCompleted completed: Bool) {
if completed,
let visibleViewController = pageViewController.viewControllers?.first,
let index = controllers.firstIndex(of: visibleViewController) {
parent.currentPage = index
}
}
}
}
struct PageView<Page: View>: View {
var pages: [Page]
#State var currentPage = 0
var body: some View {
ZStack {
PageViewController(pages: pages, currentPage: $currentPage)
}
}
}
struct PageView_Previews: PreviewProvider {
static var previews: some View {
PageView(pages: [
Color.red,
Color.blue
// I want to add other view types here
])
}
}
If I change the array of pages in the PageView_Previews to something like [Color.red, Text("abc")], I get an error because they're not the same type. How do I get SwiftUI to allow heterogeneous View types here?
I can't use TabView with PageTabViewStyle (lots of bugs), so that's why I need to use this UIKit method.
You can wrap your pages in AnyView:
PageView(pages: [
AnyView(Color.red),
AnyView(Color.blue),
AnyView(Text("Hi"))
])

Custom UIViewController with UIViewcontrollerRepresentable that has a UITextView that crashes or is nil when called in SwiftUI

I have made a custom UIViewController called ViewControllerA and want to be able to use it so I made a UIViewControllerRepresentable called ViewControllerARepresentable as shown below, the problem though is that when I call ViewControllerARepresentable in my SwiftUI view and pass a value for stringToUpdateTextView, the ViewControllerA says the htmlTextView(UITextView) in ViewControllerA is nil and I'm not sure why.
ViewControllerARepresentable(stringToUpdateTextView: "<html>Send some Html Text as string here</html>")
ViewControllerARepresentable
public struct ViewControllerARepresentable: UIViewControllerRepresentable {
var stringToUpdateTextView: String
public func makeUIViewController(context: Context) -> ViewControllerA {
let viewcontrollerA = ViewControllerA(testString: testingString)
return viewcontrollerA
}
public func updateUIViewController(_ uiViewController: ViewControllerA, context: Context) {}
}
ViewControllerA
open class ViewControllerA: UIViewController {
public var stringToUpdateTextView: String
override open func viewDidLoad() {
super.viewDidLoad()
htmlTextView.text = stringToUpdateTextView
}
#IBOutlet weak var htmlTextView: UITextView!
public init(testString: String) {
self.testString = testString
super.init(nibName: nil, bundle: nil)
}
required public init?(coder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}
Crash occurs at htmlTextView.text = stringToUpdateTextView saying that htmlTextView.text is nil even though its an IBOutlet.
Any Change made to the htmlTextView like background color ,etc, also causes a crash if called in viewDidAppear or viewDidLoad
When instantiating your view controller in makeUIViewController, the outlets haven't been initialised yet.
The following code loads your view controller from the storyboard, and updates the properties in updateUIViewController:
ViewController.swift
import UIKit
import SwiftUI
class ViewController: UIViewController {
#IBOutlet weak var htmlTextView: UITextView!
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
}
}
struct ViewControllerWrapper: UIViewControllerRepresentable {
typealias UIViewControllerType = ViewController
#Binding var text: String
func makeUIViewController(context: Context) -> ViewController {
let storyboard = UIStoryboard(name: "Main", bundle: nil)
guard let viewController = storyboard.instantiateViewController(
identifier: "ViewController") as? ViewController else {
fatalError("Cannot load from storyboard")
}
return viewController
}
func updateUIViewController(_ uiViewController: ViewController, context: Context) {
uiViewController.htmlTextView.text = text
}
}
struct ViewControllerPreview: PreviewProvider {
static var previews: some View {
ViewControllerWrapper(text: .constant("hello world!"))
}
}
SwiftUIView.swift
struct SwiftUIView: View {
#State var text = "Text"
var body: some View {
HStack {
TextField("Text:", text: $text)
ViewControllerWrapper(text: $text)
}
}
}

SwiftUI - CNContactViewController NavigationBar problem

I am trying to implement CNContactViewDelegate to be able to show detail of the CNContact. And apparently, I am the first one to implement it with SwiftUI and getting problems. Anyway, I can see the detail of CNContact with using UIViewControllerRepresentable but I have an issue with the NavigationBar, which there is gap between the Contact's image and StatusBar -because of the NavigationBar and NavigationLink I think- and this gap is not there in the native Contacts app and apparently in this link that implemented the framework in UIKit.
Here is the code;
struct ContactsListView: View {
#ObservedObject var contactsModel: ContactsViewModel
var body: some View {
NavigationView{
List {
//After some ForEach's and Section's
//This view is working.
NavigationLink(destination: ContactDetailView(contact: self.$contactsModel.contacts[sectionIdx].contacts[contactIdx])) {
Text(self.contactsModel.contacts[sectionIdx].contacts[contactIdx].givenName)
}
}
.navigationBarTitle("Contacts")
}
}
}
struct ContactView: UIViewControllerRepresentable {
#Binding var contact: CNContact
func makeCoordinator() -> ContactView.Coordinator {
Coordinator(self)
}
func makeUIViewController(context: UIViewControllerRepresentableContext<ContactView>) -> CNContactViewController {
let controller = CNContactViewController(for: contact)
self.navigationBarHidden(true)
return controller
}
func updateUIViewController(_ uiViewController: CNContactViewController, context: UIViewControllerRepresentableContext<ContactView>) {
print(context)
}
class Coordinator: NSObject, CNContactViewControllerDelegate {
var parent: ContactView
init(_ contactDetail: ContactView) {
self.parent = contactDetail
self.parent.navigationBarHidden(true)
}
}
}
In the ContactView, both of those self.navigationBarHidden(true)'s are not working. As an example of the problem here is the native app's screenshot;
And here is the result of my code;
Posted my comment on the solution and then I came to the idea to wrap the contact view controller inside my custom NavigationController. And voila that fixed it!
struct ContactView: UIViewControllerRepresentable {
var contact: CNContact
func makeCoordinator() -> ContactView.Coordinator {
Coordinator(self)
}
func makeUIViewController(context: UIViewControllerRepresentableContext<ContactView>) -> NavigationController {
let controller = CNContactViewController(forUnknownContact: contact)
controller.contactStore = CNContactStore()
controller.delegate = context.coordinator
let navigationController = NavigationController(rootViewController: controller)
return navigationController
}
func updateUIViewController(_ uiViewController: NavigationController, context: UIViewControllerRepresentableContext<ContactView>) {
}
class Coordinator: NSObject, CNContactViewControllerDelegate {
var parent: ContactView
init(_ contactDetail: ContactView) {
self.parent = contactDetail
}
func contactViewController(_ viewController: CNContactViewController,
didCompleteWith contact: CNContact?) {
}
func contactViewController(_ viewController: CNContactViewController,
shouldPerformDefaultActionFor property: CNContactProperty) -> Bool {
return true
}
}
}
As the question is got an upvote I thought I can share my half way solution. This solves the gap however during the transition to detail there is a glitch of navigation bar with background color. After the transition it is becoming clear.
struct ContactDetailView: View {
var contact: CNContact
var body: some View {
ZStack {
Color.clear
ContactView(contact: self.contact)
.navigationBarTitle("", displayMode: .inline)
}.edgesIgnoringSafeArea(.top)
}
}
struct ContactView: UIViewControllerRepresentable {
var contact: CNContact
func makeCoordinator() -> ContactView.Coordinator {
Coordinator(self)
}
func makeUIViewController(context: UIViewControllerRepresentableContext<ContactView>) -> CNContactViewController {
let controller = CNContactViewController(forUnknownContact: contact)
controller.allowsActions = true
controller.allowsEditing = false
controller.delegate = context.coordinator
return controller
}
func updateUIViewController(_ uiViewController: CNContactViewController, context: UIViewControllerRepresentableContext<ContactView>) {
print("updated")
}
class Coordinator: NSObject, CNContactViewControllerDelegate {
var parent: ContactView
init(_ contactDetail: ContactView) {
self.parent = contactDetail
}
func contactViewController(_ viewController: CNContactViewController, didCompleteWith contact: CNContact?) {
}
func contactViewController(_ viewController: CNContactViewController, shouldPerformDefaultActionFor property: CNContactProperty) -> Bool {
return true
}
}
}

UIViewControllerRepresentable and CNContactPickerViewController

Can't seem to create a UIViewControllerRepresentable that works with CNContactPickerViewController.
Using Xcode 11 beta 4, I've created number of other UIViewControllerRepresentable using other UIViewController and those have worked fine. I've tried changing the features of the CNContactPickerViewController and different implementations of the delegate.
import SwiftUI
import ContactsUI
// Minimal version
struct LookupContactVCR : UIViewControllerRepresentable {
func makeUIViewController(context: Context) -> CNContactPickerViewController {
let contactPickerVC = CNContactPickerViewController()
contactPickerVC.delegate = context.coordinator
return contactPickerVC
}
func makeCoordinator() -> Coordinator {
return Coordinator()
}
func updateUIViewController(_ uiViewController: CNContactPickerViewController, context: Context) {}
class Coordinator: NSObject {}
}
extension LookupContactVCR.Coordinator : CNContactPickerDelegate {
func contactPicker(_ picker: CNContactPickerViewController, didSelect contact: CNContact) {
print("Chose: \(contact.givenName)")
}
}
#if DEBUG
struct LookupContact_Previews : PreviewProvider {
static var previews: some View {
LookupContactVCR()
}
}
#endif
No error messages. But the screen is always white with nothing rendered.
First of all, please file a [Bug Report][1] for this issue.
[1]: https://bugreport.apple.com
Secondly, there are 2 workarounds for this issue:
You can use ABPeoplePickerNavigationController which is deprecated but still works.
Create a UIViewController which presents CNContactPickerViewController on viewWillAppear and use this newly created view controller with SwiftUI.
1. ABPeoplePickerNavigationController
import SwiftUI
import AddressBookUI
struct PeoplePicker: UIViewControllerRepresentable {
typealias UIViewControllerType = ABPeoplePickerNavigationController
final class Coordinator: NSObject, ABPeoplePickerNavigationControllerDelegate, UINavigationControllerDelegate {
func peoplePickerNavigationController(_ peoplePicker: ABPeoplePickerNavigationController, didSelectPerson person: ABRecord) {
<#selected#>
}
func peoplePickerNavigationControllerDidCancel(_ peoplePicker: ABPeoplePickerNavigationController) {
<#cancelled#>
}
}
func makeCoordinator() -> Coordinator {
return Coordinator()
}
func makeUIViewController(context: UIViewControllerRepresentableContext<PeoplePicker>) -> PeoplePicker.UIViewControllerType {
let result = UIViewControllerType()
result.delegate = context.coordinator
return result
}
func updateUIViewController(_ uiViewController: PeoplePicker.UIViewControllerType, context: UIViewControllerRepresentableContext<PeoplePicker>) { }
}
2. CNContactPickerViewController
EmbeddedContactPickerViewController
import Foundation
import ContactsUI
import Contacts
protocol EmbeddedContactPickerViewControllerDelegate: AnyObject {
func embeddedContactPickerViewControllerDidCancel(_ viewController: EmbeddedContactPickerViewController)
func embeddedContactPickerViewController(_ viewController: EmbeddedContactPickerViewController, didSelect contact: CNContact)
}
class EmbeddedContactPickerViewController: UIViewController, CNContactPickerDelegate {
weak var delegate: EmbeddedContactPickerViewControllerDelegate?
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
self.open(animated: animated)
}
private func open(animated: Bool) {
let viewController = CNContactPickerViewController()
viewController.delegate = self
self.present(viewController, animated: false)
}
func contactPickerDidCancel(_ picker: CNContactPickerViewController) {
self.dismiss(animated: false) {
self.delegate?.embeddedContactPickerViewControllerDidCancel(self)
}
}
func contactPicker(_ picker: CNContactPickerViewController, didSelect contact: CNContact) {
self.dismiss(animated: false) {
self.delegate?.embeddedContactPickerViewController(self, didSelect: contact)
}
}
}
EmbeddedContactPicker
import SwiftUI
import Contacts
import Combine
struct EmbeddedContactPicker: UIViewControllerRepresentable {
typealias UIViewControllerType = EmbeddedContactPickerViewController
final class Coordinator: NSObject, EmbeddedContactPickerViewControllerDelegate {
func embeddedContactPickerViewController(_ viewController: EmbeddedContactPickerViewController, didSelect contact: CNContact) {
<#selected#>
}
func embeddedContactPickerViewControllerDidCancel(_ viewController: EmbeddedContactPickerViewController) {
<#cancelled#>
}
}
func makeCoordinator() -> Coordinator {
return Coordinator()
}
func makeUIViewController(context: UIViewControllerRepresentableContext<EmbeddedContactPicker>) -> EmbeddedContactPicker.UIViewControllerType {
let result = EmbeddedContactPicker.UIViewControllerType()
result.delegate = context.coordinator
return result
}
func updateUIViewController(_ uiViewController: EmbeddedContactPicker.UIViewControllerType, context: UIViewControllerRepresentableContext<EmbeddedContactPicker>) { }
}
What I did, is just wrapping it inside a NavigationController. Maybe not as clean as arturigor's answer, but works quite easily.
func makeUIViewController(context: Context) -> some UIViewController {
// needs to be wrapper in another controller. Else isn't displayed
let navController = UINavigationController()
let controller = CNContactPickerViewController()
controller.delegate = delegate
controller.predicateForEnablingContact = enablingPredicate
navController.present(controller, animated: false, completion: nil)
return navController
}
Regarding the questions, how it should be displayed. I Just have it displayed conditionally as a view inside a group
Group {
Text("Sharing is caring")
if showContactPicker {
ContactPicker(contactType: .email)
}
}
import SwiftUI
import Contacts
import ContactsUI
struct SomeView: View {
#State var contact: CNContact?
var body: some View {
VStack {
Text("Selected: \(contact?.givenName ?? "")")
ContactPickerButton(contact: $contact) {
Label("Select Contact", systemImage: "person.crop.circle.fill")
.fixedSize()
}
.fixedSize()
.buttonStyle(.borderedProminent)
}
}
}
struct SomeView_Previews: PreviewProvider {
static var previews: some View {
SomeView()
}
}
public struct ContactPickerButton<Label: View>: UIViewControllerRepresentable {
public class Coordinator: NSObject, CNContactPickerDelegate {
var onCancel: () -> Void
var viewController: UIViewController = .init()
var picker = CNContactPickerViewController()
#Binding var contact: CNContact?
// Possible take a binding
public init<Label: View>(contact: Binding<CNContact?>, onCancel: #escaping () -> Void, #ViewBuilder content: #escaping () -> Label) {
self._contact = contact
self.onCancel = onCancel
super.init()
let button = Button<Label>(action: showContactPicker, label: content)
let hostingController: UIHostingController<Button<Label>> = UIHostingController(rootView: button)
hostingController.view?.sizeToFit()
(hostingController.view?.frame).map {
hostingController.view!.widthAnchor.constraint(equalToConstant: $0.width).isActive = true
hostingController.view!.heightAnchor.constraint(equalToConstant: $0.height).isActive = true
viewController.preferredContentSize = $0.size
}
hostingController.willMove(toParent: viewController)
viewController.addChild(hostingController)
viewController.view.addSubview(hostingController.view)
hostingController.view.anchor(to: viewController.view)
picker.delegate = self
}
func showContactPicker() {
viewController.present(picker, animated: true)
}
public func contactPickerDidCancel(_ picker: CNContactPickerViewController) {
onCancel()
}
public func contactPicker(_ picker: CNContactPickerViewController, didSelect contact: CNContact) {
self.contact = contact
}
func makeUIViewController() -> UIViewController {
return viewController
}
func updateUIViewController(_ uiViewController: UIViewController, context: UIViewControllerRepresentableContext<ContactPickerButton>) {
}
}
#Binding var contact: CNContact?
#ViewBuilder
var content: () -> Label
var onCancel: () -> Void
public static func defaultContent() -> SwiftUI.Label<Text, Image> {
SwiftUI.Label("Select Contact", systemImage: "person.crop.circle.fill")
}
public init(contact: Binding<CNContact?>, onCancel: #escaping () -> () = {}, #ViewBuilder content: #escaping () -> Label) {
self._contact = contact
self.onCancel = onCancel
self.content = content
}
public func makeCoordinator() -> Coordinator {
.init(contact: $contact, onCancel: onCancel, content: content)
}
public func makeUIViewController(context: Context) -> UIViewController {
context.coordinator.makeUIViewController()
}
public func updateUIViewController(_ uiViewController: UIViewController, context: Context) {
context.coordinator.updateUIViewController(uiViewController, context: context)
}
}
fileprivate extension UIView {
func anchor(to other: UIView) {
self.translatesAutoresizingMaskIntoConstraints = false
self.topAnchor.constraint(equalTo: other.topAnchor).isActive = true
self.bottomAnchor.constraint(equalTo: other.bottomAnchor).isActive = true
self.leadingAnchor.constraint(equalTo: other.leadingAnchor).isActive = true
self.trailingAnchor.constraint(equalTo: other.trailingAnchor).isActive = true
}
}
The #youjin solution have an issue when you use it inside a Sheet with navigationView.
For example, first I present an .sheet view, inside this sheet view I have and NavigationView as child, then, inside all this, I present the Contact Picker. For this scenario when Contact Picker dismiss, also dismiss my sheet view parent.
I added an #Environment(\.presentationMode) variable and I dismissed using the Coordinator approach. Look my solution here:
import SwiftUI
import ContactsUI
/**
Presents a CNContactPickerViewController view modally.
- Parameters:
- showPicker: Binding variable for presenting / dismissing the picker VC
- onSelectContact: Use this callback for single contact selection
- onSelectContacts: Use this callback for multiple contact selections
*/
public struct ContactPicker: UIViewControllerRepresentable {
#Environment(\.presentationMode) var presentationMode
#Binding var showPicker: Bool
#State private var viewModel = ContactPickerViewModel()
public var onSelectContact: ((_: CNContact) -> Void)?
public var onSelectContacts: ((_: [CNContact]) -> Void)?
public var onCancel: (() -> Void)?
public init(showPicker: Binding<Bool>, onSelectContact: ((_: CNContact) -> Void)? = nil, onSelectContacts: ((_: [CNContact]) -> Void)? = nil, onCancel: (() -> Void)? = nil) {
self._showPicker = showPicker
self.onSelectContact = onSelectContact
self.onSelectContacts = onSelectContacts
self.onCancel = onCancel
}
public func makeUIViewController(context: UIViewControllerRepresentableContext<ContactPicker>) -> ContactPicker.UIViewControllerType {
let dummy = _DummyViewController()
viewModel.dummy = dummy
return dummy
}
public func updateUIViewController(_ uiViewController: _DummyViewController, context: UIViewControllerRepresentableContext<ContactPicker>) {
guard viewModel.dummy != nil else {
return
}
// able to present when
// 1. no current presented view
// 2. current presented view is being dismissed
let ableToPresent = viewModel.dummy.presentedViewController == nil || viewModel.dummy.presentedViewController?.isBeingDismissed == true
// able to dismiss when
// 1. cncpvc is presented
let ableToDismiss = viewModel.vc != nil
if showPicker && viewModel.vc == nil && ableToPresent {
let pickerVC = CNContactPickerViewController()
pickerVC.delegate = context.coordinator
viewModel.vc = pickerVC
viewModel.dummy.present(pickerVC, animated: true)
} else if !showPicker && ableToDismiss {
// viewModel.dummy.dismiss(animated: true)
self.viewModel.vc = nil
}
}
public func makeCoordinator() -> CNContactPickerDelegate {
if self.onSelectContacts != nil {
return MultipleSelectionCoordinator(self)
} else {
return SingleSelectionCoordinator(self)
}
}
public final class SingleSelectionCoordinator: NSObject, CNContactPickerDelegate {
var parent : ContactPicker
init(_ parent: ContactPicker){
self.parent = parent
}
public func contactPickerDidCancel(_ picker: CNContactPickerViewController) {
parent.showPicker = false
parent.onCancel?()
}
public func contactPicker(_ picker: CNContactPickerViewController, didSelect contact: CNContact) {
parent.showPicker = false
parent.onSelectContact?(contact)
}
}
public final class MultipleSelectionCoordinator: NSObject, CNContactPickerDelegate {
var parent : ContactPicker
init(_ parent: ContactPicker){
self.parent = parent
}
public func contactPickerDidCancel(_ picker: CNContactPickerViewController) {
parent.showPicker = false
parent.onCancel?()
parent.presentationMode.wrappedValue.dismiss()
}
public func contactPicker(_ picker: CNContactPickerViewController, didSelect contacts: [CNContact]) {
parent.showPicker = false
parent.onSelectContacts?(contacts)
parent.presentationMode.wrappedValue.dismiss()
}
}
}
class ContactPickerViewModel {
var dummy: _DummyViewController!
var vc: CNContactPickerViewController?
}
//Don't use it any more 😐
//public protocol Coordinator: CNContactPickerDelegate {}
public class _DummyViewController: UIViewController {}
UPDATE
We only replace the Coordinator protocol by the CNContactPickerDelegate, and this way we avoid the error that Xcode show us.
"Inheritance from non-protocol, non-class type 'ContactPicker.Coordinator' (aka 'any Coordinator')."
A similar workaround
Please see below for a similar workaround that perhaps offers more flexibility around the delegate and event handling.
import SwiftUI
import ContactsUI
/// `UIViewRepresentable` to port `CNContactPickerViewController` for use with SwiftUI.
struct ContactPicker: UIViewControllerRepresentable {
#Binding var delegate: ContactPickerDelegate
public var displayedPropertyKeys: [String]?
// Sadly, we need to present the `CNContactPickerViewController` from another `UIViewController`.
// This is due to a confirmed bug -- see https://openradar.appspot.com/7103187.
class Presenter: UIViewController {}
public var presenter = Presenter()
typealias UIViewControllerType = Presenter
func makeUIViewController(context: Context) -> UIViewControllerType {
let picker = CNContactPickerViewController()
picker.delegate = delegate
picker.displayedPropertyKeys = displayedPropertyKeys
presenter.present(picker, animated: true)
return presenter
}
func updateUIViewController(_ uiViewController: UIViewControllerType, context: Context) {
if !delegate.showPicker {
presenter.dismiss(animated: true)
}
}
}
/// Delegate required by `ContactPicker` to handle `CNContactPickerViewController` events.
/// Extend `ContactPickerDelegate` and implement/override its methods to provide custom functionality as required.
/// Listen/subscribe to `showPicker` in a `View` or `UIViewController`, e.g. to control whether `CNContactPickerViewController` is presented.
class ContactPickerDelegate: NSObject, CNContactPickerDelegate, ObservableObject {
#Published var showPicker: Bool = false
func contactPickerDidCancel(_ picker: CNContactPickerViewController) {
self.showPicker = false
}
}
Example of usage in a SwiftUI View
import SwiftUI
import ContactsUI
struct ContactPickerView: View {
#ObservedObject var delegate = Delegate()
var body: some View {
VStack {
Text("Hi")
Button(action: {
delegate.showPicker = true
}, label: {
Text("Pick contact")
})
.sheet(isPresented: $delegate.showPicker, onDismiss: {
delegate.showPicker = false
}) {
ContactPicker(delegate: .constant(delegate))
}
if let contact = delegate.contact {
Text("Selected: \(contact.givenName)")
}
}
}
/// Provides `CNContactPickerDelegate` functionality tailored to this view's requirements.
class Delegate: ContactPickerDelegate {
#Published var contact: CNContact? = nil
func contactPicker(_ picker: CNContactPickerViewController, didSelect contact: CNContact) {
print(contact.givenName)
self.contact = contact
self.showPicker = false
}
}
}
struct ContactPickerView_Previews: PreviewProvider {
static var previews: some View {
ContactPickerView()
}
}
Remarks
Unfortunately, this workaround suffers from the same issue where a blank white/gray screen (the additional UIViewController) is shown temporarily after the picker is dismissed.