Resolve issues with lock screen (#273)

* Make lock screen a View extension

- Reuse in global theme (apply to all modals)

- Use a ZStack rather than replace (retain content/navigation)

- Share lock state across all LockableView

CHANGELOG.md

@@ -9,7 +9,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
-- Option to lock app when entering background (iOS). [#270](https://github.com/passepartoutvpn/passepartout-apple/pull/270)
+- Option to lock app when entering background (iOS). [#270](https://github.com/passepartoutvpn/passepartout-apple/pull/270), [#271](https://github.com/passepartoutvpn/passepartout-apple/pull/271), [#273](https://github.com/passepartoutvpn/passepartout-apple/pull/273)
 - 3D Touch items (iOS). [#267](https://github.com/passepartoutvpn/passepartout-apple/pull/267)
 - Ukranian translations (Dmitry Chirkin). [#243](https://github.com/passepartoutvpn/passepartout-apple/pull/243)
 - Restore DNS "Domain" setting. [#260](https://github.com/passepartoutvpn/passepartout-apple/pull/260)

Passepartout/App/Constants/Theme.swift

@@ -25,6 +25,7 @@
 
 import SwiftUI
 import PassepartoutLibrary
+import LocalAuthentication
 
 extension View {
     var themeIdiom: UIUserInterfaceIdiom {
@@ -57,6 +58,9 @@ extension View {
 extension View {
     func themeGlobal() -> some View {
         themeNavigationViewStyle()
+            #if !targetEnvironment(macCatalyst)
+            .themeLockScreen()
+            #endif
             .themeTint()
             .listStyle(themeListStyleValue())
             .toggleStyle(themeToggleStyleValue())
@@ -490,6 +494,42 @@ extension View {
     }
 }
 
+// MARK: Lock screen
+
+extension View {
+    func themeLockScreen() -> some View {
+        @AppStorage(AppPreference.locksInBackground.rawValue) var locksInBackground = false
+        return LockableView(
+            locksInBackground: $locksInBackground,
+            content: {
+                self
+            },
+            lockedContent: LogoView.init,
+            unlockBlock: Self.themeUnlockScreenBlock
+        )
+    }
+
+    private static func themeUnlockScreenBlock(isLocked: Binding<Bool>) {
+        let context = LAContext()
+        let policy: LAPolicy = .deviceOwnerAuthentication
+        var error: NSError?
+        guard context.canEvaluatePolicy(policy, error: &error) else {
+            isLocked.wrappedValue = false
+            return
+        }
+        Task { @MainActor in
+            do {
+                let isAuthorized = try await context.evaluatePolicy(
+                    policy,
+                    localizedReason: L10n.Global.Messages.unlockApp
+                )
+                isLocked.wrappedValue = !isAuthorized
+            } catch {
+            }
+        }
+    }
+}
+
 // MARK: Validation
 
 extension View {

Passepartout/App/PassepartoutApp.swift

@@ -30,11 +30,9 @@ import PassepartoutLibrary
 struct PassepartoutApp: App {
     @UIApplicationDelegateAdaptor(AppDelegate.self) private var appDelegate
 
-    @AppStorage(AppPreference.locksInBackground.rawValue) private var locksInBackground = false
-
     @SceneBuilder var body: some Scene {
         WindowGroup {
-            mainView
+            MainView()
                 .withoutTitleBar()
                 .onIntentActivity(IntentDispatcher.connectVPN)
                 .onIntentActivity(IntentDispatcher.disableVPN)
@@ -46,19 +44,6 @@ struct PassepartoutApp: App {
                 .onIntentActivity(IntentDispatcher.untrustCurrentNetwork)
         }
     }
-
-    private var mainView: some View {
-        #if targetEnvironment(macCatalyst)
-        MainView()
-        #else
-        LockableView(
-            reason: L10n.Global.Messages.unlockApp,
-            locksInBackground: $locksInBackground,
-            content: MainView.init,
-            lockedContent: LogoView.init
-        )
-        #endif
-    }
 }
 
 extension View {

Passepartout/App/Reusable/LockableView.swift

@@ -24,37 +24,35 @@
 //
 
 import SwiftUI
-import LocalAuthentication
 
 struct LockableView<Content: View, LockedContent: View>: View {
-    let reason: String
-
     @Binding var locksInBackground: Bool
 
     let content: () -> Content
 
     let lockedContent: () -> LockedContent
 
+    let unlockBlock: (Binding<Bool>) -> Void
+
     @Environment(\.scenePhase) private var scenePhase
 
-    @State private var didAppear = false
+    @ObservedObject private var lock: Lock = .shared
 
-    @State private var isLocked = false
+    private var isLocked: Binding<Bool> {
+        .init {
+            Lock.shared.isActive
+        } set: {
+            Lock.shared.isActive = $0
+        }
+    }
 
     var body: some View {
-        Group {
-            if !isLocked {
+        ZStack {
             content()
-            } else {
+            if isLocked.wrappedValue {
                 lockedContent()
             }
         }.onChange(of: scenePhase, perform: onScenePhase)
-        .onAppear {
-            if !didAppear && locksInBackground {
-                didAppear = true
-                isLocked = true
-            }
-        }
     }
 
     private func onScenePhase(_ scenePhase: ScenePhase) {
@@ -74,30 +72,26 @@ struct LockableView<Content: View, LockedContent: View>: View {
         guard locksInBackground else {
             return
         }
-        isLocked = true
+        isLocked.wrappedValue = true
     }
 
     func unlockIfNeeded() {
         guard locksInBackground else {
-            isLocked = false
+            isLocked.wrappedValue = false
             return
         }
-        guard isLocked else {
+        guard isLocked.wrappedValue else {
             return
         }
-        let context = LAContext()
-        let policy: LAPolicy = .deviceOwnerAuthentication
-        var error: NSError?
-        guard context.canEvaluatePolicy(policy, error: &error) else {
-            isLocked = false
-            return
-        }
-        Task { @MainActor in
-            do {
-                let isAuthorized = try await context.evaluatePolicy(policy, localizedReason: reason)
-                isLocked = !isAuthorized
-            } catch {
+        unlockBlock(isLocked)
     }
 }
+
+private class Lock: ObservableObject {
+    static let shared = Lock()
+
+    @Published var isActive = true
+
+    private init() {
     }
 }