Create a share sheet in iOS 15 with swiftUI - xcode

I am trying to create a share sheet to share a Text, it was working fine in iOS 14 but in iOS 15 it tells me that
'windows' was deprecated in iOS 15.0: Use UIWindowScene.windows on a
relevant window scene instead.
how can I make it work on iOS 15 with SwiftUI
Button {
let TextoCompartido = "Hola 😀 "
let AV = UIActivityViewController(activityItems: [TextoCompartido], applicationActivities: nil)
UIApplication.shared.windows.first?.rootViewController?.present(AV, animated: true, completion: nil)
}

I think you would be best served using SwiftUI APIs directly. Generally, I would follow these steps.
Create SwiftUI View named ActivityView that adheres to UIViewControllerRepresentable. This will allow you to bring UIActivityViewController to SwiftUI.
Create an Identifiable struct to contain the text you'd like to display in the ActivityView. Making this type will allow you to use the SwiftUI sheet API and leverage SwiftUI state to tell the app when a new ActivityView to be shown.
Create an optional #State variable that will hold on to your Identifiable text construct. When this variable changes, the sheet API will perform the callback.
When the button is tapped, update the state of the variable set in step 3.
Use the sheet API to create an ActivityView which will be presented to your user.
The code below should help get you started.
import UIKit
import SwiftUI
// 1. Activity View
struct ActivityView: UIViewControllerRepresentable {
let text: String
func makeUIViewController(context: UIViewControllerRepresentableContext<ActivityView>) -> UIActivityViewController {
return UIActivityViewController(activityItems: [text], applicationActivities: nil)
}
func updateUIViewController(_ uiViewController: UIActivityViewController, context: UIViewControllerRepresentableContext<ActivityView>) {}
}
// 2. Share Text
struct ShareText: Identifiable {
let id = UUID()
let text: String
}
struct ContentView: View {
// 3. Share Text State
#State var shareText: ShareText?
var body: some View {
VStack {
Button("Show Activity View") {
// 4. New Identifiable Share Text
shareText = ShareText(text: "Hola 😀")
}
.padding()
}
// 5. Sheet to display Share Text
.sheet(item: $shareText) { shareText in
ActivityView(text: shareText.text)
}
}
}

For the future, iOS 16 will have the ShareLink view which works like this:
Gallery(...)
.toolbar {
ShareLink(item: image, preview: SharePreview("Birthday Effects"))
}
Source: https://developer.apple.com/videos/play/wwdc2022/10052/
Time code offset: 25 minutes 28 seconds

To avoid warning, change the way you retrieve the window scene.
Do the following:
Button {
let TextoCompartido = "Hola 😀 "
let AV = UIActivityViewController(activityItems: [TextoCompartido], applicationActivities: nil)
let scenes = UIApplication.shared.connectedScenes
let windowScene = scenes.first as? UIWindowScene
windowScene?.keyWindow?.rootViewController?.present(AV, animated: true, completion: nil)
}

Tested in in iOS 15 with SwiftUI
func shareViaActionSheet() {
if vedioData.vedioURL != nil {
let activityVC = UIActivityViewController(activityItems: [vedioData.vedioURL as Any], applicationActivities: nil)
UIApplication.shared.currentUIWindow()?.rootViewController?.present(activityVC, animated: true, completion: nil)
}
}
To avoid iOS 15 method deprecation warning use this extension
public extension UIApplication {
func currentUIWindow() -> UIWindow? {
let connectedScenes = UIApplication.shared.connectedScenes
.filter { $0.activationState == .foregroundActive }
.compactMap { $0 as? UIWindowScene }
let window = connectedScenes.first?
.windows
.first { $0.isKeyWindow }
return window
}
}

you could try the following using the answer from: How to get rid of message " 'windows' was deprecated in iOS 15.0: Use UIWindowScene.windows on a relevant window scene instead" with AdMob banner?
Note that your code works for me, but the compiler give the deprecation warning.
public extension UIApplication {
func currentUIWindow() -> UIWindow? {
let connectedScenes = UIApplication.shared.connectedScenes
.filter({
$0.activationState == .foregroundActive})
.compactMap({$0 as? UIWindowScene})
let window = connectedScenes.first?
.windows
.first { $0.isKeyWindow }
return window
}
}
struct ContentView: View {
let TextoCompartido = "Hola 😀 "
var body: some View {
Button(action: {
let AV = UIActivityViewController(activityItems: [TextoCompartido], applicationActivities: nil)
UIApplication.shared.currentUIWindow()?.rootViewController?.present(AV, animated: true, completion: nil)
// This works for me, but the compiler give the deprecation warning
// UIApplication.shared.windows.first?.rootViewController?.present(AV, animated: true, completion: nil)
}) {
Text("Hola click me")
}
}
}

Related

SwiftUI WindowGroup disable window persistence

Apple added new functionality to SwiftUI this year, bringing persistence and multiple windows to our SwiftUI apps. How can we disable window persistence. I'm looking for a windowing system very similar to Xcode, where there's a Welcome window on start, users can open new windows with the content they're looking for, then on the next start of the app only the Welcome window is shown.
The below code achieves all of these goals except the unwanted windows remain
import SwiftUI
#main
struct StackApp: App {
#Environment(\.openWindow) var openWindow
var body: some Scene {
Window("Welcome to App", id: "welcome-to-app") {
VStack {
Text("Welcome")
Button(action: {
openWindow(id: "app-content")
}) {
Text("Open Content")
}
}
}
.defaultSize(CGSize(width: 200, height: 200))
WindowGroup(id: "app-content") {
VStack {
Text("App Content")
}
}
.defaultSize(CGSize(width: 200, height: 200))
}
}
Help is much appreciated
Here's a quick hack proof-of-concept workaround. Can definitely be cleaned up, but it seems to work in macOS 12.6.1.
Not pretty but if you adopt the SwiftUI app lifecycle there just aren't as many ways too hook in and override the system default behavior (can't override the default NSDocumentController etc).
import SwiftUI
#main
struct TestWindowPersistenceApp: App {
#NSApplicationDelegateAdaptor(AppDelegate.self) var appDelegate
var body: some Scene {
DocumentGroup(newDocument: TestWindowPersistenceDocument()) { file in
ContentView(document: file.$document)
}
}
}
class AppDelegate: NSObject, NSApplicationDelegate {
func applicationWillFinishLaunching(_ notification: Notification) {
print("did finish launching")
flushSavedWindowState()
// trigger open new file or Welcome flow here
}
func flushSavedWindowState() {
do {
let libURL = try FileManager.default.url(for: .libraryDirectory, in: .userDomainMask, appropriateFor: nil, create: false)
guard let appPersistentStateDirName = Bundle.main.bundleIdentifier?.appending(".savedState") else { print("get bundleID failed"); return }
let windowsPlistFilePath = libURL.appendingPathComponent("Saved Application State", isDirectory: true)
.appendingPathComponent(appPersistentStateDirName, isDirectory: true)
.appendingPathComponent("windows.plist", isDirectory: false)
.path
print("path to remove: ", windowsPlistFilePath)
try FileManager.default.removeItem(atPath: windowsPlistFilePath)
} catch {
print("exception: \(error)")
}
}
}
Check out my Swift package which should solve this problem.
You could use it like this:
#main
struct MyApp: App {
var body: some Scene {
WindowGroup(id: "MyWindow") {
ContentView()
}
.register("MyWindow")
.disableRestoreOnLaunch()
}
}
It seems to work fine and achieved this by setting the isRestorable property of NSWindow to false. This should disable the default behavior.

Presenting View Controller in SwiftUI

How to achieve what the following Objective-C code achieves with SwiftUI? I haven't been able to get a firm grasp on the ideas presented.
[self presentViewController:messageViewController animated:YES completion:nil];
Until ios 13.x, there is no way provided by SwiftUI. As I had the same need, wrote a custom modifier of View to achieve it.
extension View {
func uiKitFullPresent<V: View>(isPresented: Binding<Bool>, style: UIModalPresentationStyle = .fullScreen, content: #escaping (_ dismissHandler: #escaping () -> Void) -> V) -> some View {
self.modifier(FullScreenPresent(isPresented: isPresented, style: style, contentView: content))
}
}
struct FullScreenPresent<V: View>: ViewModifier {
#Binding var isPresented: Bool
#State private var isAlreadyPresented: Bool = false
let style: UIModalPresentationStyle
let contentView: (_ dismissHandler: #escaping () -> Void) -> V
#ViewBuilder
func body(content: Content) -> some View {
if isPresented {
content
.onAppear {
if self.isAlreadyPresented == false {
let hostingVC = UIHostingController(rootView: self.contentView({
self.isPresented = false
self.isAlreadyPresented = false
UIViewController.topMost?.dismiss(animated: true, completion: nil)
}))
hostingVC.modalPresentationStyle = self.style
UIViewController.topMost?.present(hostingVC, animated: true) {
self.isAlreadyPresented = true
}
}
}
} else {
content
}
}
}
And, you can use it as the following.
.uiKitFullPresent(isPresented: $isShowingPicker, content: { closeHandler in
SomeFullScreenView()
.onClose(closeHandler) // '.onClose' is a custom extension function written. you can invent your own way to call 'closeHandler'.
})
content parameter of .uiKitFullPresent is a closure that has a callback handler as its parameter. you can use this callback to dismiss the presented view.
It's worked well so far. It looks a little bit tricky though.
As you may know, iOS 14 will bring us a method to present any view in the way you want. Check fullScreenCover() out.
Regarding presenting UIViewController written by Objective-C, it would be possible as Asperi mentioned in his post.
UPDATE
Here is the full source code I am using so far.
https://gist.github.com/fullc0de/3d68b6b871f20630b981c7b4d51c8373
UPDATE_2
Now, I'd like to say that it's not a good approach because the idea underlying doesn't actually seem to match well with the mechanism of SwiftUI.
As there is no provided related code, so in pseudo-code it would look like the following
struct YourParentView: View {
#State private var presented = false
var body: some View {
// some other code that activates `presented` state
SomeUIElement()
.sheet(isPresented: $presented) {
YourMessageViewControllerRepresentable()
}
}
}

SwiftUI Load View from SceneDelegate sceneDidBecomeActive

I'm trying to understand how to load a SwiftUI view from Swift function code. In this
case specifically, I want to load a view when returning from the background state to
cover sensitive data. I have created a biometric login and that works fine - pure
SwiftUI views for the app. When I put the app into the background and return, the
FaceID works as expected, but the underlying screen is visible. This is a generalized
question too - how can you load any SwiftUI view from any Swift function.
func sceneDidBecomeActive(_ scene: UIScene) {
if userDefaultsManager.wentToBackground {
if userDefaultsManager.enableBiometrics {
BiometricsLogin(userDefaultsManager: userDefaultsManager).authenticate()
//what I want is something like:
//BiometricsLogin(userDefaultsManager: userDefaultsManager)
//kinda like you would do in a TabView
//that would run the authentication just like starting the app
userDefaultsManager.wentToBackground = false
}
}
}
And the login code is pretty generic:
struct BiometricsLogin: View {
#ObservedObject var userDefaultsManager: UserDefaultsManager
var body: some View {
NavigationView {
VStack {
Image("CoifMeCrop180")
.onAppear {
self.authenticate()
}
}//vstack
}//nav
}
func authenticate() {
let context = LAContext()
var error: NSError?
if context.canEvaluatePolicy(.deviceOwnerAuthenticationWithBiometrics, error: &error) {
let reason = "The app uses Biometrics to unlock you data"
context.evaluatePolicy(.deviceOwnerAuthentication, localizedReason: reason) { (success, authenticationError)
in
DispatchQueue.main.async {
if success {
self.userDefaultsManager.isAuthenticated = true
self.userDefaultsManager.selectedTab = 1
} else {
if self.userDefaultsManager.enableBiometrics {
self.userDefaultsManager.isAuthenticated = false
self.userDefaultsManager.selectedTab = 3
} else {
self.userDefaultsManager.isAuthenticated = false
self.userDefaultsManager.selectedTab = 1
}
}
}
}
} else {
//no biometrics - deal with this elsewhere
//consider an alert here
}
}//authenticate
}
I also tried using a hosting controller like this, but it did not work either. Same
issue, the authentication worked but the data was visible.
//this does not work
let controller = UIHostingController(rootView: BiometricsLogin(userDefaultsManager: userDefaultsManager))
self.window!.addSubview(controller.view)
self.window?.makeKeyAndVisible()
Any guidance would be appreciated. Xcode 11.3.1 (11C504)
Here is possible approach
In sceneDidBecomeActive add presenting new controller with authentication in full screen to hide sensitive content
func sceneDidBecomeActive(_ scene: UIScene) {
let controller = UIHostingController(rootView: BiometricsLogin(userDefaultsManager: userDefaultsManager))
controller.modalPresentationStyle = .fullScreen
self.window?.rootViewController?.present(controller, animated: false)
}
now it needs to dismiss it when authentication will be done, so add notification for that purpose...
extension SceneDelegate {
static let didAuthenticate = Notification.Name(rawValue: "didAuthenticate")
}
... and subscriber for it in SceneDelegate
class SceneDelegate: UIResponder, UIWindowSceneDelegate {
var window: UIWindow?
private var authenticateObserver: AnyCancellable?
func scene(_ scene: UIScene, willConnectTo session: UISceneSession, options connectionOptions: UIScene.ConnectionOptions) {
let contentView = ContentView()
if let windowScene = scene as? UIWindowScene {
self.authenticateObserver = NotificationCenter.default.publisher(for: SceneDelegate.didAuthenticate)
.sink { _ in
self.window?.rootViewController?.dismiss(animated: true)
}
let window = UIWindow(windowScene: windowScene)
...
when authentication is done just post didAuthenticate notification to dismiss top controller
DispatchQueue.main.async {
if success {
self.userDefaultsManager.isAuthenticated = true
self.userDefaultsManager.selectedTab = 1
} else {
if self.userDefaultsManager.enableBiometrics {
self.userDefaultsManager.isAuthenticated = false
self.userDefaultsManager.selectedTab = 3
} else {
self.userDefaultsManager.isAuthenticated = false
self.userDefaultsManager.selectedTab = 1
}
}
NotificationCenter.default.post(name: SceneDelegate.didAuthenticate, object: nil)
}

How to display Game Center leaderboard with SwiftUI

I created a tester app to test adding a GameCenter leaderboard to a simple SwiftUI game I am creating. I have been unable to figure out how to display the Game Center leaderboard with all the scores.
I have created a class containing all the Game Center functions (authentication and adding score to the leaderboard. This is called from the main ContentView view. I can't figure out how to make it show the leaderboard (or even the gamecenter login screen if the player isn't already logged in.)
This is my GameCenterManager class:
class GameCenterManager {
var gcEnabled = Bool() // Check if the user has Game Center enabled
var gcDefaultLeaderBoard = String() // Check the default leaderboardID
var score = 0
let LEADERBOARD_ID = "grp.colorMatcherLeaderBoard_1" //Leaderboard ID from Itunes Connect
// MARK: - AUTHENTICATE LOCAL PLAYER
func authenticateLocalPlayer() {
let localPlayer: GKLocalPlayer = GKLocalPlayer.local
localPlayer.authenticateHandler = {(ViewController, error) -> Void in
if((ViewController) != nil) {
print("User is not logged into game center")
} else if (localPlayer.isAuthenticated) {
// 2. Player is already authenticated & logged in, load game center
self.gcEnabled = true
// Get the default leaderboard ID
localPlayer.loadDefaultLeaderboardIdentifier(completionHandler: { (leaderboardIdentifer, error) in
if error != nil { print(error ?? "error1")
} else { self.gcDefaultLeaderBoard = leaderboardIdentifer! }
})
print("Adding GameCenter user was a success")
} else {
// 3. Game center is not enabled on the users device
self.gcEnabled = false
print("Local player could not be authenticated!")
print(error ?? "error2")
}
}
} //authenticateLocalPlayer()
func submitScoreToGC(_ score: Int){
let bestScoreInt = GKScore(leaderboardIdentifier: LEADERBOARD_ID)
bestScoreInt.value = Int64(score)
GKScore.report([bestScoreInt]) { (error) in
if error != nil {
print(error!.localizedDescription)
} else {
print("Best Score submitted to your Leaderboard!")
}
}
}//submitScoreToGc()
}
and here is the ContentView struct:
struct ContentView: View {
//GameCenter
init() {
self.gameCenter = GameCenterManager()
self.gameCenter.authenticateLocalPlayer()
}
#State var score = 0
var gcEnabled = Bool() //Checks if the user had enabled GameCenter
var gcDefaultLeaderboard = String() //Checks the default leaderboard ID
let gameCenter: GameCenterManager
/*End GameCenter Variables */
var body: some View {
HStack {
Text("Hello, world!")
Button(action: {
self.score += 1
print("Score increased by 10. It is now \(self.score)")
self.gameCenter.submitScoreToGC(self.score)
}) {
Text("Increase Score")
}
}
}
}
Would greatly appreciate any help in fixing the problem.
I have a fix.
I use Game Center successfully in my SwiftUI App Sound Matcher. Code snippets to follow.
The code doesn't exactly follow the SwiftUI declarative philosophy but it works perfectly. I added snippets to SceneDelegate and ContentView plus used I used a GameKitHelper class similar to the one Thomas created for his test app. I based my version on code I found on raywenderlich.com.
I actually tried using a struct conforming to UIViewControllerRepresentable as my first attempt, following the same line of thought as bg2b, however it kept complaining that the game centre view controller needed to be presented modally. Eventually I gave up and tried my current more successful approach.
For SwiftUI 1.0 and iOS 13
class SceneDelegate: UIResponder, UIWindowSceneDelegate {
let contentView = ContentView()
.environmentObject(GameKitHelper.sharedInstance) // publish enabled state
func scene(_ scene: UIScene, willConnectTo session: UISceneSession,
options connectionOptions: UIScene.ConnectionOptions) {
if let windowScene = scene as? UIWindowScene {
let window = UIWindow(windowScene: windowScene)
window.rootViewController = UIHostingController(rootView: contentView)
// new code to create listeners for the messages
// you will be sending later
PopupControllerMessage.PresentAuthentication
.addHandlerForNotification(
self,
handler: #selector(SceneDelegate
.showAuthenticationViewController))
PopupControllerMessage.GameCenter
.addHandlerForNotification(
self,
handler: #selector(SceneDelegate
.showGameCenterViewController))
// now we are back to the standard template
// generated when your project was created
self.window = window
window.makeKeyAndVisible()
}
}
// pop's up the leaderboard and achievement screen
#objc func showGameCenterViewController() {
if let gameCenterViewController =
GameKitHelper.sharedInstance.gameCenterViewController {
self.window?.rootViewController?.present(
gameCenterViewController,
animated: true,
completion: nil)
}
}
// pop's up the authentication screen
#objc func showAuthenticationViewController() {
if let authenticationViewController =
GameKitHelper.sharedInstance.authenticationViewController {
self.window?.rootViewController?.present(
authenticationViewController, animated: true)
{ GameKitHelper.sharedInstance.enabled =
GameKitHelper.sharedInstance.gameCenterEnabled }
}
}
}
// content you want your app to display goes here
struct ContentView: View {
#EnvironmentObject var gameCenter : GameKitHelper
#State private var isShowingGameCenter = false { didSet {
PopupControllerMessage
.GameCenter
.postNotification() }}
var body: some View {
VStack {
if self.gameCenter.enabled
{
Button(action:{ self.isShowingGameCenter.toggle()})
{ Text(
"Press to show leaderboards and achievements")}
}
// The authentication popup will appear when you first enter
// the view
}.onAppear() {GameKitHelper.sharedInstance
.authenticateLocalPlayer()}
}
}
import GameKit
import UIKit
// Messages sent using the Notification Center to trigger
// Game Center's Popup screen
public enum PopupControllerMessage : String
{
case PresentAuthentication = "PresentAuthenticationViewController"
case GameCenter = "GameCenterViewController"
}
extension PopupControllerMessage
{
public func postNotification() {
NotificationCenter.default.post(
name: Notification.Name(rawValue: self.rawValue),
object: self)
}
public func addHandlerForNotification(_ observer: Any,
handler: Selector) {
NotificationCenter.default .
addObserver(observer, selector: handler, name:
NSNotification.Name(rawValue: self.rawValue), object: nil)
}
}
// based on code from raywenderlich.com
// helper class to make interacting with the Game Center easier
open class GameKitHelper: NSObject, ObservableObject, GKGameCenterControllerDelegate {
public var authenticationViewController: UIViewController?
public var lastError: Error?
private static let _singleton = GameKitHelper()
public class var sharedInstance: GameKitHelper {
return GameKitHelper._singleton
}
private override init() {
super.init()
}
#Published public var enabled :Bool = false
public var gameCenterEnabled : Bool {
return GKLocalPlayer.local.isAuthenticated }
public func authenticateLocalPlayer () {
let localPlayer = GKLocalPlayer.local
localPlayer.authenticateHandler = {(viewController, error) in
self.lastError = error as NSError?
self.enabled = GKLocalPlayer.local.isAuthenticated
if viewController != nil {
self.authenticationViewController = viewController
PopupControllerMessage
.PresentAuthentication
.postNotification()
}
}
}
public var gameCenterViewController : GKGameCenterViewController? { get {
guard gameCenterEnabled else {
print("Local player is not authenticated")
return nil }
let gameCenterViewController = GKGameCenterViewController()
gameCenterViewController.gameCenterDelegate = self
gameCenterViewController.viewState = .achievements
return gameCenterViewController
}}
open func gameCenterViewControllerDidFinish(_
gameCenterViewController: GKGameCenterViewController) {
gameCenterViewController.dismiss(
animated: true, completion: nil)
}
}
Update: For SwiftUI 2.0 and iOS 14 the code is lot easier
import GameKit
enum Authenticate
{
static func user() {
let localPlayer = GKLocalPlayer.local
localPlayer.authenticateHandler = { _, error in
guard error == nil else {
print(error?.localizedDescription ?? "")
return
}
GKAccessPoint.shared.location = .topLeading
GKAccessPoint.shared.isActive =
localPlayer.isAuthenticated
}
}
}
import SwiftUI
// content you want your app to display goes here
struct ContentView: View {
var body: some View {
Text( "Start Game")
// The authentication popup will appear when you first enter
// the view
}.onAppear() { Authenticate.user()}
}
}
EDIT 2023: as mentioned in comments, GKScore is now deprecated. I don't have an updated solution to present.
Partial answer for you here. I'm able to download leaderboard scores and display them in a SwiftUI list provided the device (or simulator) is logged into iCloud and has GameCenter already enabled in settings. I have not attempted to make a gameCenter authentication view controller appear if that is not the case.
Thank you for the code in your question. I used your GameCenterManager() but put it in my AppDelegate:
let gameCenter = GameCenterManager()
Below is my ShowRankings.swift SwiftUI View. I'm able to successfully authenticate and get the scores. But I still have "anomalies". The first time I run this (in simulator) I get the expected "User is not logged into Game Center" error indicating the ViewController in your GameCenterManager is not nil (I never even attempt to display it). But then I'm able to successfully get the scores and display them in a list.
import SwiftUI
import GameKit
struct ShowRankings: View {
let appDelegate = UIApplication.shared.delegate as! AppDelegate
let leaderBoard = GKLeaderboard()
#State var scores: [GKScore] = []
var body: some View {
VStack {
Button(action: {
self.updateLeader()
}) {
Text("Refresh leaderboard")
}
List(scores, id: \.self) { score in
Text("\(score.player.alias) \(score.value)")
}
}.onAppear() {
self.appDelegate.gameCenter.authenticateLocalPlayer()
self.updateLeader()
}
}
func updateLeader() {
let leaderBoard: GKLeaderboard = GKLeaderboard()
leaderBoard.identifier = "YOUR_LEADERBOARD_ID_HERE"
leaderBoard.timeScope = .allTime
leaderBoard.loadScores { (scores, error) in
if let error = error {
debugPrint("leaderboard loadScores error \(error)")
} else {
guard let scores = scores else { return }
self.scores = scores
}
}
}
}
An alternative solution is to create a UIViewControllerRepresentable for GameCenter which takes a leaderboard ID to open. This makes it simple to open a specific leader board.
public struct GameCenterView: UIViewControllerRepresentable {
let viewController: GKGameCenterViewController
public init(leaderboardID : String?) {
if leaderboardID != nil {
self.viewController = GKGameCenterViewController(leaderboardID: leaderboardID!, playerScope: GKLeaderboard.PlayerScope.global, timeScope: GKLeaderboard.TimeScope.allTime)
}
else{
self.viewController = GKGameCenterViewController(state: GKGameCenterViewControllerState.leaderboards)
}
}
public func makeUIViewController(context: Context) -> GKGameCenterViewController {
let gkVC = viewController
gkVC.gameCenterDelegate = context.coordinator
return gkVC
}
public func updateUIViewController(_ uiViewController: GKGameCenterViewController, context: Context) {
return
}
public func makeCoordinator() -> GKCoordinator {
return GKCoordinator(self)
}
}
public class GKCoordinator: NSObject, GKGameCenterControllerDelegate {
var view: GameCenterView
init(_ gkView: GameCenterView) {
self.view = gkView
}
public func gameCenterViewControllerDidFinish(_ gameCenterViewController: GKGameCenterViewController) {
gameCenterViewController.dismiss(animated: true, completion: nil)
}
}
To use just add the below wherever it is needed to display a leaderboard.
GameCenterView(leaderboardID: "leaderBoardID")

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

I've been looking through the docs with each beta but haven't seen a way to make a traditional paged ScrollView. I'm not familiar with AppKit so I am wondering if this doesn't exist in SwiftUI because it's primarily a UIKit construct. Anyway, does anyone have an example of this, or can anyone tell me it's definitely impossible so I can stop looking and roll my own?
You can now use a TabView and set the .tabViewStyle to PageTabViewStyle()
TabView {
View1()
View2()
View3()
}
.tabViewStyle(PageTabViewStyle())
As of Beta 3 there is no native SwiftUI API for paging. I've filed feedback and recommend you do the same. They changed the ScrollView API from Beta 2 to Beta 3 and I wouldn't be surprised to see a further update.
It is possible to wrap a UIScrollView in order to provide this functionality now. Unfortunately, you must wrap the UIScrollView in a UIViewController, which is further wrapped in UIViewControllerRepresentable in order to support SwiftUI content.
Gist here
class UIScrollViewViewController: UIViewController {
lazy var scrollView: UIScrollView = {
let v = UIScrollView()
v.isPagingEnabled = 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 then to use it:
var body: some View {
GeometryReader { proxy in
UIScrollViewWrapper {
VStack {
ForEach(0..<1000) { _ in
Text("Hello world")
}
}
.frame(width: proxy.size.width) // This ensures the content uses the available width, otherwise it will be pinned to the left
}
}
}
Apple's official tutorial covers this as an example. I find it easy to follow and suitable for my case. I really recommend you check this out and try to understand how to interface with UIKit. Since SwiftUI is so young, not every feature in UIKit would be covered at this moment. Interfacing with UIKit should address most if not all needs.
https://developer.apple.com/tutorials/swiftui/interfacing-with-uikit
Not sure if this helps your question but for the time being while Apple is working on adding a Paging View in SwiftUI I've written a utility library that gives you a SwiftUI feel while using a UIPageViewController under the hood tucked away.
You can use it like this:
Pages {
Text("Page 1")
Text("Page 2")
Text("Page 3")
Text("Page 4")
}
Or if you have a list of models in your application you can use it like this:
struct Car {
var model: String
}
let cars = [Car(model: "Ford"), Car(model: "Ferrari")]
ModelPages(cars) { index, car in
Text("The \(index) car is a \(car.model)")
.padding(50)
.foregroundColor(.white)
.background(Color.blue)
.cornerRadius(10)
}
You can simply track state using .onAppear() to load your next page.
struct YourListView : View {
#ObservedObject var viewModel = YourViewModel()
let numPerPage = 50
var body: some View {
NavigationView {
List(viewModel.items) { item in
NavigationLink(destination: DetailView(item: item)) {
ItemRow(item: item)
.onAppear {
if self.shouldLoadNextPage(currentItem: item) {
self.viewModel.fetchItems(limitPerPage: self.numPerPage)
}
}
}
}
.navigationBarTitle(Text("Items"))
.onAppear {
guard self.viewModel.items.isEmpty else { return }
self.viewModel.fetchItems(limitPerPage: self.numPerPage)
}
}
}
private func shouldLoadNextPage(currentItem item: Item) -> Bool {
let currentIndex = self.viewModel.items.firstIndex(where: { $0.id == item.id } )
let lastIndex = self.viewModel.items.count - 1
let offset = 5 //Load next page when 5 from bottom, adjust to meet needs
return currentIndex == lastIndex - offset
}
}
class YourViewModel: ObservableObject {
#Published private(set) items = [Item]()
// add whatever tracking you need for your paged API like next/previous and count
private(set) var fetching = false
private(set) var next: String?
private(set) var count = 0
func fetchItems(limitPerPage: Int = 30, completion: (([Item]?) -> Void)? = nil) {
// Do your stuff here based on the API rules for paging like determining the URL etc...
if items.count == 0 || items.count < count {
let urlString = next ?? "https://somePagedAPI?limit=/(limitPerPage)"
fetchNextItems(url: urlString, completion: completion)
} else {
completion?(pokemon)
}
}
private func fetchNextItems(url: String, completion: (([Item]?) -> Void)?) {
guard !fetching else { return }
fetching = true
Networking.fetchItems(url: url) { [weak self] (result) in
DispatchQueue.main.async { [weak self] in
self?.fetching = false
switch result {
case .success(let response):
if let count = response.count {
self?.count = count
}
if let newItems = response.results {
self?.items += newItems
}
self?.next = response.next
case .failure(let error):
// Error state tracking not implemented but would go here...
os_log("Error fetching data: %#", error.localizedDescription)
}
}
}
}
}
Modify to fit whatever API you are calling and handle errors based on your app architecture.
Checkout SwiftUIPager. It's a pager built on top of SwiftUI native components:
If you would like to exploit the new PageTabViewStyle of TabView, but you need a vertical paged scroll view, you can make use of effect modifiers like .rotationEffect().
Using this method I wrote a library called VerticalTabView 🔝 that turns a TabView vertical just by changing your existing TabView to VTabView.
You can use such custom modifier:
struct ScrollViewPagingModifier: ViewModifier {
func body(content: Content) -> some View {
content
.onAppear {
UIScrollView.appearance().isPagingEnabled = true
}
.onDisappear {
UIScrollView.appearance().isPagingEnabled = false
}
}
}
extension ScrollView {
func isPagingEnabled() -> some View {
modifier(ScrollViewPagingModifier())
}
}
To simplify Lorenzos answer, you can basically add UIScrollView.appearance().isPagingEnabled = true to your scrollview as below:
VStack{
ScrollView(showsIndicators: false){
VStack(spacing: 0){ // to remove spacing between rows
ForEach(1..<10){ i in
ZStack{
Text(String(i))
Circle()
} .frame(width: UIScreen.main.bounds.width, height: UIScreen.main.bounds.height)
}
}
}.onAppear {
UIScrollView.appearance().isPagingEnabled = true
}
.onDisappear {
UIScrollView.appearance().isPagingEnabled = false
}
}

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