feat: update localization handling and improve UI responsiveness

Author: serhii-londar

Example/AppleReminders/Controllers/MainVC.swift

@@ -11,6 +11,7 @@ import SwiftUI
 import UIKit
 
 final class MainVC: UIViewController {
+    private let footerHeight: CGFloat = 75
 
     let realm = MyRealm.getConfig()
 
@@ -23,7 +24,6 @@ final class MainVC: UIViewController {
         let tv = UITableView(frame: .zero, style: .insetGrouped)
         tv.separatorStyle = .none
         tv.backgroundColor = .systemGroupedBackground
-        tv.contentInset = UIEdgeInsets(top: 0, left: 0, bottom: 50, right: 0)
         return tv
     }()
 
@@ -102,6 +102,14 @@ final class MainVC: UIViewController {
         setupNavBar()
         setupSearch()
     }
+
+    override func viewDidLayoutSubviews() {
+        super.viewDidLayoutSubviews()
+        layoutTableHeaderIfNeeded()
+        // Keep the footer controls above any table/search content after layout updates.
+        view.bringSubviewToFront(footerView)
+        updateTableInsetsForFooter()
+    }
 
     deinit {
         realmListToken?.invalidate()
@@ -157,7 +165,17 @@ final class MainVC: UIViewController {
         footerView.bottomAnchor.constraint(equalTo: self.view.bottomAnchor, constant: 0).isActive = true
         footerView.leadingAnchor.constraint(equalTo: self.view.safeAreaLayoutGuide.leadingAnchor, constant: 0).isActive = true
         footerView.trailingAnchor.constraint(equalTo: self.view.safeAreaLayoutGuide.trailingAnchor,constant: 0).isActive = true
-        footerView.heightAnchor.constraint(equalToConstant: 75).isActive = true
+        footerView.heightAnchor.constraint(equalToConstant: footerHeight).isActive = true
+    }
+
+    private func updateTableInsetsForFooter() {
+        // Compute real overlap between the table and footer to avoid rows appearing under controls.
+        let overlap = max(0, tableView.frame.maxY - footerView.frame.minY)
+        let bottomInset = overlap + 12
+        if tableView.contentInset.bottom != bottomInset {
+            tableView.contentInset.bottom = bottomInset
+            tableView.scrollIndicatorInsets.bottom = bottomInset
+        }
     }
 
     private func setupNavBar() {
@@ -186,8 +204,21 @@ final class MainVC: UIViewController {
         searchController = UISearchController(searchResultsController: searchControllerVC)
         searchController?.searchResultsUpdater = self
         searchController?.obscuresBackgroundDuringPresentation = false
+        searchController?.hidesNavigationBarDuringPresentation = false
         searchController?.searchBar.placeholder = "Search".localized
-        navigationItem.searchController = searchController
+        searchController?.searchBar.sizeToFit()
+        tableView.tableHeaderView = searchController?.searchBar
+        definesPresentationContext = true
+    }
+
+    private func layoutTableHeaderIfNeeded() {
+        guard let headerView = tableView.tableHeaderView else { return }
+        let targetSize = CGSize(width: tableView.bounds.width, height: UIView.layoutFittingCompressedSize.height)
+        let height = headerView.sizeThatFits(targetSize).height
+        if headerView.frame.width != tableView.bounds.width || headerView.frame.height != height {
+            headerView.frame = CGRect(x: 0, y: 0, width: tableView.bounds.width, height: height)
+            tableView.tableHeaderView = headerView
+        }
     }
 }
 

Example/AppleReminders/Controllers/SettingsVC.swift

@@ -11,6 +11,14 @@ import CrowdinSDK
 
 class SettingsVC: UITableViewController {
     var localizations = CrowdinSDK.allAvailableLocalizations
+    private var isLocalizationLoading = false
+    
+    private let loadingIndicator: UIActivityIndicatorView = {
+        let indicator = UIActivityIndicatorView(style: .large)
+        indicator.hidesWhenStopped = true
+        indicator.translatesAutoresizingMaskIntoConstraints = false
+        return indicator
+    }()
 
     enum Strings: String {
         case settings
@@ -27,6 +35,7 @@ class SettingsVC: UITableViewController {
         self.title = Strings.settings.rawValue.capitalized.localized
         self.navigationItem.rightBarButtonItem = UIBarButtonItem(title: Strings.done.rawValue.capitalized.localized, style: .done, target: self, action: #selector(cancelBtnTapped))
         self.tableView.register(UITableViewCell.self, forCellReuseIdentifier: "SettingsCell")
+        setupLoadingIndicator()
         self.tableView.reloadData()
     }
 
@@ -56,12 +65,64 @@ class SettingsVC: UITableViewController {
     }
 
     override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
-        let localization = localizations[indexPath.row]
-        if localization == Strings.auto.rawValue.capitalized.localized {
-            CrowdinSDK.currentLocalization = nil
+        tableView.deselectRow(at: indexPath, animated: true)
+        
+        guard !isLocalizationLoading else { return }
+        
+        let localization = localizationCode(for: indexPath)
+        guard localization != CrowdinSDK.currentLocalization else {
+            self.tableView.reloadData()
+            return
+        }
+        
+        setLocalizationLoading(true)
+        CrowdinSDK.setCurrentLocalization(localization) { [weak self] error in
+            DispatchQueue.main.async {
+                guard let self = self else { return }
+                self.setLocalizationLoading(false)
+                
+                if let error = error {
+                    self.alert(message: error.localizedDescription, title: "Error")
+                    self.tableView.reloadData()
+                    return
+                }
+                
+                self.reloadLocalizedUI()
+            }
+        }
+    }
+
+    private func setupLoadingIndicator() {
+        view.addSubview(loadingIndicator)
+        
+        NSLayoutConstraint.activate([
+            loadingIndicator.centerXAnchor.constraint(equalTo: view.centerXAnchor),
+            loadingIndicator.centerYAnchor.constraint(equalTo: view.centerYAnchor)
+        ])
+    }
+    
+    private func setLocalizationLoading(_ loading: Bool) {
+        isLocalizationLoading = loading
+        tableView.allowsSelection = !loading
+        tableView.isUserInteractionEnabled = !loading
+        navigationItem.rightBarButtonItem?.isEnabled = !loading
+        
+        if loading {
+            loadingIndicator.startAnimating()
         } else {
-            CrowdinSDK.currentLocalization = localization
+            loadingIndicator.stopAnimating()
+        }
+    }
+    
+    private func localizationCode(for indexPath: IndexPath) -> String? {
+        return indexPath.row == 0 ? nil : localizations[indexPath.row]
+    }
+    
+    private func reloadLocalizedUI() {
+        if let sceneDelegate = view.window?.windowScene?.delegate as? SceneDelegate {
+            sceneDelegate.reloadLocalizedUI()
+        } else {
+            tableView.reloadData()
         }
-        self.tableView.reloadData()
     }
 }

Example/AppleReminders/SceneDelegate.swift

@@ -39,18 +39,12 @@ class SceneDelegate: UIResponder, UIWindowSceneDelegate {
                 .with(accessToken: Self.accessToken)
                 .with(screenshotsEnabled: true)
 
-            CrowdinSDK.currentLocalization = locale
+            CrowdinSDK.setCurrentLocalization(locale) { _ in }
 
             CrowdinSDK.startWithConfig(crowdinSDKConfig) {
                 DispatchQueue.main.async {
                     guard let windowScene = (scene as? UIWindowScene) else { return }
-                    
-                    let navController = UINavigationController(rootViewController: MainVC())
-
-                    self.window = UIWindow(frame: windowScene.coordinateSpace.bounds)
-                    self.window?.windowScene = windowScene
-                    self.window?.rootViewController = navController
-                    self.window?.makeKeyAndVisible()
+                    self.setupMainInterface(for: windowScene, animated: false)
                 }
             }
 
@@ -80,15 +74,7 @@ class SceneDelegate: UIResponder, UIWindowSceneDelegate {
         // If using a storyboard, the `window` property will automatically be initialized and attached to the scene.
         // This delegate does not imply the connecting scene or session are new (see `application:configurationForConnectingSceneSession` instead).
         guard let windowScene = (scene as? UIWindowScene) else { return }
-        
-        //Create Nav Controller
-        let navController = UINavigationController(rootViewController: MainVC())
-
-        //source: https://www.youtube.com/watch?v=Htn4h51BQsk
-        window = UIWindow(frame: windowScene.coordinateSpace.bounds)
-        window?.windowScene = windowScene
-        window?.rootViewController = navController
-        window?.makeKeyAndVisible()
+        setupMainInterface(for: windowScene, animated: false)
     }
 
     func sceneDidDisconnect(_ scene: UIScene) {
@@ -123,5 +109,31 @@ class SceneDelegate: UIResponder, UIWindowSceneDelegate {
         guard let url = URLContexts.first?.url else { return }
         CrowdinSDK.handle(url: url)
     }
-}
 
+    func reloadLocalizedUI() {
+        guard let windowScene = window?.windowScene else { return }
+        setupMainInterface(for: windowScene, animated: true)
+    }
+
+    private func setupMainInterface(for windowScene: UIWindowScene, animated: Bool) {
+        let navController = UINavigationController(rootViewController: MainVC())
+
+        if window == nil {
+            // source: https://www.youtube.com/watch?v=Htn4h51BQsk
+            window = UIWindow(frame: windowScene.coordinateSpace.bounds)
+            window?.windowScene = windowScene
+        }
+
+        guard let window = window else { return }
+
+        if animated {
+            UIView.transition(with: window, duration: 0.2, options: [.transitionCrossDissolve, .allowAnimatedContent], animations: {
+                window.rootViewController = navController
+            })
+        } else {
+            window.rootViewController = navController
+        }
+
+        window.makeKeyAndVisible()
+    }
+}

Example/AppleRemindersUITests/AppleRemindersUITestsCrowdinScreenhsotTests.swift

@@ -31,7 +31,7 @@ final class AppleRemindersUITestsCrowdinScreenhsotTests: XCTestCase {
             .with(accessToken: Self.accessToken)
             .with(screenshotsEnabled: true)
 
-        CrowdinSDK.currentLocalization = localization
+        CrowdinSDK.setCurrentLocalization(localization) { _ in }
 
         CrowdinSDK.startWithConfigSync(crowdinSDKConfig)
     }

Sources/CrowdinSDK/CrowdinSDK/CrowdinSDK.swift

@@ -29,6 +29,7 @@ public typealias CrowdinSDKLogMessage = (String) -> Void
     public var onLogCallback: ((String) -> Void)?
 
     /// Current localization language code. If SDK is started than after setting new localization it triggers localization download.
+    @available(*, deprecated, message: "Please use setCurrentLocalization(_:completion:) to update localization.")
 	public class var currentLocalization: String? {
 		get {
             return Localization.currentLocalization ?? Localization.current?.provider.localization
@@ -69,7 +70,7 @@ public typealias CrowdinSDKLogMessage = (String) -> Void
     /// - Parameter completion: Remote storage preparation completion handler. Called when all required data is downloaded.
     class func startWithRemoteStorage(_ remoteStorage: RemoteLocalizationStorageProtocol, completion: @escaping () -> Void) {
         let localizations = remoteStorage.localizations + self.inBundleLocalizations
-        let localization = self.currentLocalization ?? Bundle.main.preferredLanguage(with: localizations)
+        let localization = Localization.currentLocalization ?? Localization.current?.provider.localization ?? Bundle.main.preferredLanguage(with: localizations)
         let localStorage = LocalLocalizationStorage(localization: localization)
         let localizationProvider = LocalizationProvider(localization: localization, localStorage: localStorage, remoteStorage: remoteStorage)
 
@@ -90,7 +91,7 @@ public typealias CrowdinSDKLogMessage = (String) -> Void
     /// - Parameters:
     ///   - sdkLocalization: Bool value which indicate whether to use SDK localization or native in bundle localization.
     ///   - localization: Localization code to use.
-    @available(*, deprecated, message: "Please use currentLocalization instead.")
+    @available(*, deprecated, message: "Please use setCurrentLocalization(_:completion:) instead.")
     public class func enableSDKLocalization(_ sdkLocalization: Bool, localization: String?) {
         self.currentLocalization = localization
     }
@@ -104,6 +105,16 @@ public typealias CrowdinSDKLogMessage = (String) -> Void
         Localization.setCurrentLocalization(localization, completion: completion)
     }
 
+    /// Method for changing SDK localization and getting notified when localization refresh completes.
+    ///
+    /// - Parameters:
+    ///   - localization: Localization code to use. If `nil`, localization will be auto-detected.
+    ///   - completion: Completion handler called when localization refresh finishes.
+    @available(*, deprecated, message: "Please use setCurrentLocalization(_:completion:) instead.")
+    public class func setLocalization(_ localization: String?, completion: @escaping CrowdinSDKLocalizationChangeCompletion) {
+        self.setCurrentLocalization(localization, completion: completion)
+    }
+
     /// Utils method for extracting all localization strings and plurals to Documents folder.
     /// This method will extract all localization for all languages and store it in Extracted subfolder in Crowdin folder.
     public class func extractAllLocalization() {

Sources/CrowdinSDK/Features/RealtimeUpdateFeature/RealtimeUpdateFeature.swift

@@ -34,7 +34,7 @@ class RealtimeUpdateFeature: RealtimeUpdateFeatureProtocol {
     var disconnect: (() -> Void)?
     var localization: String {
         let localizations = Localization.current.provider.remoteStorage.localizations
-        return CrowdinSDK.currentLocalization ?? Bundle.main.preferredLanguage(with: localizations)
+        return Localization.currentLocalization ?? Localization.current?.provider.localization ?? Bundle.main.preferredLanguage(with: localizations)
     }
     let hashString: String
     let sourceLanguage: String

Sources/CrowdinSDK/Providers/Crowdin/CrowdinRemoteLocalizationStorage.swift

@@ -60,7 +60,7 @@ class CrowdinRemoteLocalizationStorage: RemoteLocalizationStorageProtocol {
             self.localizations = self.manifestManager.iOSLanguages
             // Only update localization if it wasn't explicitly set and if CrowdinSDK has a current localization
             // or if the current localization is not in the available localizations
-            if let currentLocalization = CrowdinSDK.currentLocalization,
+            if let currentLocalization = Localization.currentLocalization ?? Localization.current?.provider.localization,
                self.localizations.contains(currentLocalization) {
                 self.localization = currentLocalization
             } else if !self.localizations.contains(self.localization) {

Sources/CrowdinSDK/Providers/Crowdin/Extensions/CrowdinSDK+CrowdinProvider.swift

@@ -27,7 +27,7 @@ extension CrowdinSDK {
     public class func startWithConfig(_ config: CrowdinSDKConfig, completion: @escaping () -> Void) {
         self.config = config
         let crowdinProviderConfig = config.crowdinProviderConfig ?? CrowdinProviderConfig()
-        let localization = currentLocalization ?? Bundle.main.preferredLanguage
+        let localization = Localization.currentLocalization ?? Bundle.main.preferredLanguage
         let remoteStorage = CrowdinRemoteLocalizationStorage(localization: localization, config: crowdinProviderConfig)
         self.startWithRemoteStorage(remoteStorage, completion: completion)
     }