Add a feature flag for automatic back pagination. (#5445)

ElementX/Sources/Application/Settings/AppSettings.swift

@@ -80,6 +80,7 @@ final class AppSettings {
         case focusEventOnNotificationTap
         case linkNewDeviceEnabled
         case liveLocationSharingEnabled
+        case automaticBackPaginationEnabled
         
         // Doug's tweaks 🔧
         case hideUnreadMessagesBadge
@@ -447,6 +448,9 @@ final class AppSettings {
     
     let verifyWithClassicEnabled = appBuildType != .release
     
+    @UserPreference(key: UserDefaultsKeys.automaticBackPaginationEnabled, defaultValue: false, storageType: .userDefaults(store))
+    var automaticBackPaginationEnabled
+    
     @UserPreference(key: UserDefaultsKeys.developerOptionsEnabled, defaultValue: appBuildType == .debug, storageType: .userDefaults(store))
     var developerOptionsEnabled
 }

ElementX/Sources/Screens/Settings/DeveloperOptionsScreen/DeveloperOptionsScreenModels.swift

@@ -55,6 +55,7 @@ protocol DeveloperOptionsProtocol: AnyObject {
     var enableKeyShareOnInvite: Bool { get set }
     var hideQuietNotificationAlerts: Bool { get set }
     var focusEventOnNotificationTap: Bool { get set }
+    var automaticBackPaginationEnabled: Bool { get set }
     
     var hideUnreadMessagesBadge: Bool { get set }
     var elementCallBaseURLOverride: URL? { get set }

ElementX/Sources/Screens/Settings/DeveloperOptionsScreen/View/DeveloperOptionsScreen.swift

@@ -67,6 +67,11 @@ struct DeveloperOptionsScreen: View {
                 Toggle(isOn: $context.lowPriorityFilterEnabled) {
                     Text("Low priority filter")
                 }
+                
+                Toggle(isOn: $context.automaticBackPaginationEnabled) {
+                    Text("Automatic back pagination")
+                    Text("Requires app reboot")
+                }
             }
             
             Section("Room") {
@@ -135,6 +140,7 @@ struct DeveloperOptionsScreen: View {
                     Text("Hide quiet alerts")
                     Text("The badge count will still be updated")
                 }
+                
                 Toggle(isOn: $context.focusEventOnNotificationTap) {
                     Text("Focus event on notification tap")
                 }

ElementX/Sources/Services/Client/ClientProxy.swift

@@ -201,6 +201,11 @@ class ClientProxy: ClientProxyProtocol {
         self.appSettings = appSettings
         self.analyticsService = analyticsService
         
+        if appSettings.automaticBackPaginationEnabled {
+            // Must be called before creating the sync service, timelines etc.
+            client.enableAutomaticBackpagination()
+        }
+        
         clientQueue = .init(label: "ClientProxyQueue", attributes: .concurrent)
         
         mediaLoader = MediaLoader(client: client)