feat: Background download on iOS (#1442)

ui/flutter/ios/Runner.xcodeproj/project.pbxproj

@@ -21,6 +21,8 @@
 		D0E623A929482D160001185E /* Libgopeed.xcframework in Frameworks */ = {isa = PBXBuildFile; fileRef = D0E623A729482D030001185E /* Libgopeed.xcframework */; };
 		D0E623AA29482D160001185E /* Libgopeed.xcframework in Embed Frameworks */ = {isa = PBXBuildFile; fileRef = D0E623A729482D030001185E /* Libgopeed.xcframework */; settings = {ATTRIBUTES = (RemoveHeadersOnCopy, ); }; };
 		DCA5B0FA95A8007ADEDACA1B /* Pods_Runner.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 70BC8D37FAC641C7F20125E8 /* Pods_Runner.framework */; };
+		A10000000000000000000001 /* LocationKeepAliveManager.swift in Sources */ = {isa = PBXBuildFile; fileRef = A10000000000000000000002 /* LocationKeepAliveManager.swift */;};
+		A10000000000000000000002 /* LocationKeepAliveManager.swift */ = {isa = PBXFileReference;lastKnownFileType = sourcecode.swift;path = LocationKeepAliveManager.swift;sourceTree = "<group>";};
 /* End PBXBuildFile section */
 
 /* Begin PBXContainerItemProxy section */
@@ -153,18 +155,19 @@
 			sourceTree = "<group>";
 		};
 		97C146F01CF9000F007C117D /* Runner */ = {
-			isa = PBXGroup;
-			children = (
-				0C585CC72D41E36800FF2EC0 /* Runner.entitlements */,
-				97C146FA1CF9000F007C117D /* Main.storyboard */,
-				97C146FD1CF9000F007C117D /* Assets.xcassets */,
-				97C146FF1CF9000F007C117D /* LaunchScreen.storyboard */,
-				97C147021CF9000F007C117D /* Info.plist */,
-				1498D2321E8E86230040F4C2 /* GeneratedPluginRegistrant.h */,
-				1498D2331E8E89220040F4C2 /* GeneratedPluginRegistrant.m */,
-				74858FAE1ED2DC5600515810 /* AppDelegate.swift */,
-				74858FAD1ED2DC5600515810 /* Runner-Bridging-Header.h */,
-			);
+    			isa = PBXGroup;
+    			children = (
+        			0C585CC72D41E36800FF2EC0 /* Runner.entitlements */,
+        			97C146FA1CF9000F007C117D /* Main.storyboard */,
+        			97C146FD1CF9000F007C117D /* Assets.xcassets */,
+        			97C146FF1CF9000F007C117D /* LaunchScreen.storyboard */,
+        			97C147021CF9000F007C117D /* Info.plist */,
+        			1498D2321E8E86230040F4C2 /* GeneratedPluginRegistrant.h */,
+        			1498D2331E8E89220040F4C2 /* GeneratedPluginRegistrant.m */,
+        			74858FAE1ED2DC5600515810 /* AppDelegate.swift */,
+        			A10000000000000000000002 /* LocationKeepAliveManager.swift */,
+        			74858FAD1ED2DC5600515810 /* Runner-Bridging-Header.h */,
+    			);
 			path = Runner;
 			sourceTree = "<group>";
 		};
@@ -376,12 +379,13 @@
 			runOnlyForDeploymentPostprocessing = 0;
 		};
 		97C146EA1CF9000F007C117D /* Sources */ = {
-			isa = PBXSourcesBuildPhase;
-			buildActionMask = 2147483647;
-			files = (
-				74858FAF1ED2DC5600515810 /* AppDelegate.swift in Sources */,
-				1498D2341E8E89220040F4C2 /* GeneratedPluginRegistrant.m in Sources */,
-			);
+    			isa = PBXSourcesBuildPhase;
+    			buildActionMask = 2147483647;
+    			files = (
+        			74858FAF1ED2DC5600515810 /* AppDelegate.swift in Sources */,
+        			A10000000000000000000001 /* LocationKeepAliveManager.swift in Sources */,
+        			1498D2341E8E89220040F4C2 /* GeneratedPluginRegistrant.m in Sources */,
+    		);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
 /* End PBXSourcesBuildPhase section */

ui/flutter/ios/Runner/AppDelegate.swift

@@ -32,6 +32,34 @@ import Libgopeed
             }
         })
         
+        let locationChannel = FlutterMethodChannel(
+            name: "gopeed/location_keep_alive",
+            binaryMessenger: controller.binaryMessenger
+)
+
+        locationChannel.setMethodCallHandler {
+            (call: FlutterMethodCall, result: @escaping FlutterResult) in
+
+        switch call.method {
+
+        case "requestPermission":
+          LocationKeepAliveManager.shared.requestPermission { authorized in
+            result(authorized)
+    }
+
+        case "start":
+            LocationKeepAliveManager.shared.start()
+            result(nil)
+
+        case "stop":
+            LocationKeepAliveManager.shared.stop()
+            result(nil)
+
+        default:
+            result(FlutterMethodNotImplemented)
+    }
+}
+        
         GeneratedPluginRegistrant.register(with: self)
 
         SwiftFlutterForegroundTaskPlugin.setPluginRegistrantCallback(registerPlugins)

ui/flutter/ios/Runner/Info.plist

@@ -106,5 +106,15 @@
 		<true/>
 		<key>LSSupportsOpeningDocumentsInPlace</key>
 		<true/>
+		<key>UIBackgroundModes</key>
+		<array>
+    			<string>location</string>
+		</array>
+		<key>NSLocationWhenInUseUsageDescription</key>
+		<string>Please go to Settings and change the location permission to "Always" so that the app can continue running in the background.</string>
+		<key>NSLocationAlwaysAndWhenInUseUsageDescription</key>
+		<string>Please go to Settings and change the location permission to "Always" so that the app can continue running in the background.</string>
+		<key>NSLocationAlwaysUsageDescription</key>
+		<string>Please go to Settings and change the location permission to "Always" so that the app can continue running in the background.</string>
 	</dict>
 </plist>

ui/flutter/ios/Runner/LocationKeepAliveManager.swift

@@ -0,0 +1,126 @@
+import Foundation
+import CoreLocation
+
+final class LocationKeepAliveManager: NSObject, CLLocationManagerDelegate {
+
+    static let shared = LocationKeepAliveManager()
+
+    private let locationManager = CLLocationManager()
+
+    private(set) var isRunning = false
+
+    private var permissionCompletion: ((Bool) -> Void)?
+
+    override init() {
+        super.init()
+
+        locationManager.delegate = self
+        locationManager.desiredAccuracy = kCLLocationAccuracyThreeKilometers
+        locationManager.distanceFilter = kCLDistanceFilterNone
+        locationManager.pausesLocationUpdatesAutomatically = false
+
+        if #available(iOS 9.0, *) {
+            locationManager.allowsBackgroundLocationUpdates = true
+        }
+
+        if #available(iOS 14.0, *) {
+            locationManager.showsBackgroundLocationIndicator = true
+        }
+    }
+
+    func requestPermission(completion: @escaping (Bool) -> Void) {
+        let status = CLLocationManager.authorizationStatus()
+
+        switch status {
+        case .authorizedAlways:
+            completion(true)
+
+        case .authorizedWhenInUse:
+            completion(false)
+
+        case .denied, .restricted:
+            completion(false)
+
+        case .notDetermined:
+            permissionCompletion = completion
+            locationManager.requestAlwaysAuthorization()
+
+        @unknown default:
+            completion(false)
+        }
+    }
+
+
+    func start() {
+        guard !isRunning else {
+            return
+        }
+
+        let status = CLLocationManager.authorizationStatus()
+
+        guard status == .authorizedAlways else {
+            return
+        }
+
+        if #available(iOS 9.0, *) {
+            locationManager.allowsBackgroundLocationUpdates = true
+        }
+
+        locationManager.startUpdatingLocation()
+        isRunning = true
+    }
+
+    func stop() {
+        locationManager.stopUpdatingLocation()
+        isRunning = false
+    }
+
+    private func handleAuthorizationStatus(
+        _ status: CLAuthorizationStatus
+    ) {
+        switch status {
+        case .authorizedAlways:
+            permissionCompletion?(true)
+            permissionCompletion = nil
+
+        case .authorizedWhenInUse,
+             .denied,
+             .restricted:
+            permissionCompletion?(false)
+            permissionCompletion = nil
+
+        case .notDetermined:
+            break
+
+        @unknown default:
+            permissionCompletion?(false)
+            permissionCompletion = nil
+        }
+    }
+
+    @available(iOS 14.0, *)
+    func locationManagerDidChangeAuthorization(
+        _ manager: CLLocationManager
+    ) {
+        handleAuthorizationStatus(manager.authorizationStatus)
+    }
+
+    func locationManager(
+        _ manager: CLLocationManager,
+        didChangeAuthorization status: CLAuthorizationStatus
+    ) {
+        handleAuthorizationStatus(status)
+    }
+
+    func locationManager(
+        _ manager: CLLocationManager,
+        didUpdateLocations locations: [CLLocation]
+    ) {
+    }
+
+    func locationManager(
+        _ manager: CLLocationManager,
+        didFailWithError error: Error
+    ) {
+    }
+}

ui/flutter/lib/api/api.dart

@@ -99,6 +99,17 @@ void init(String network, String address, String apiToken) {
   _client = _Client(network, address, apiToken);
 }
 
+/// Used by LocationKeepAliveCoordinator to reconcile keep-alive
+void Function()? _onTaskChanged;
+
+void setTaskChangedListener(void Function() listener) {
+  _onTaskChanged = listener;
+}
+
+void _notifyTaskChanged() {
+  _onTaskChanged?.call();
+}
+
 Future<T> _parse<T>(
   Future<Response> Function() fetch,
   T Function(dynamic json)? fromJsonT,
@@ -130,15 +141,19 @@ Future<ResolveResult> resolve(ResolveTask resolveTask) async {
 }
 
 Future<String> createTask(CreateTask createTask) async {
-  return _parse<String>(
+  final result = await _parse<String>(
       () => _client.dio.post("api/v1/tasks", data: createTask),
       (data) => data as String);
+  _notifyTaskChanged();
+  return result;
 }
 
 Future<List<String>> createTaskBatch(CreateTaskBatch createTaskBatch) async {
-  return _parse<List<String>>(
+  final result = await _parse<List<String>>(
       () => _client.dio.post("api/v1/tasks/batch", data: createTaskBatch),
       (data) => (data as List).map((e) => e as String).toList());
+  _notifyTaskChanged();
+  return result;
 }
 
 Future<void> patchTask(String id, ResolveTask patchTask) async {
@@ -154,41 +169,47 @@ Future<List<Task>> getTasks(List<Status> statuses) async {
 }
 
 Future<void> pauseTask(String id) async {
-  return _parse(() => _client.dio.put("api/v1/tasks/$id/pause"), null);
+  await _parse(() => _client.dio.put("api/v1/tasks/$id/pause"), null);
+  _notifyTaskChanged();
 }
 
 Future<void> continueTask(String id) async {
-  return _parse(() => _client.dio.put("api/v1/tasks/$id/continue"), null);
+  await _parse(() => _client.dio.put("api/v1/tasks/$id/continue"), null);
+  _notifyTaskChanged();
 }
 
 Future<void> pauseAllTasks(List<String>? ids) async {
-  return _parse(
+  await _parse(
       () => _client.dio.put("api/v1/tasks/pause", queryParameters: {
             "id": ids,
           }),
       null);
+  _notifyTaskChanged();
 }
 
 Future<void> continueAllTasks(List<String>? ids) async {
-  return _parse(
+  await _parse(
       () => _client.dio.put("api/v1/tasks/continue", queryParameters: {
             "id": ids,
           }),
       null);
+  _notifyTaskChanged();
 }
 
 Future<void> deleteTask(String id, bool force) async {
-  return _parse(
+  await _parse(
       () => _client.dio.delete("api/v1/tasks/$id?force=$force"), null);
+  _notifyTaskChanged();
 }
 
 Future<void> deleteTasks(List<String>? ids, bool force) async {
-  return _parse(
+  await _parse(
       () => _client.dio.delete("api/v1/tasks", queryParameters: {
             "id": ids,
             "force": force,
           }),
       null);
+  _notifyTaskChanged();
 }
 
 Future<DownloaderConfig> getConfig() async {

ui/flutter/lib/api/model/downloader_config.dart

@@ -113,6 +113,7 @@ class ExtraConfig {
   bool notifyWhenNewVersion;
   bool autoStartTasks;
   bool desktopNotification;
+  bool backgroundLocationKeepAlive;
   List<DownloadCategory> downloadCategories;
 
   ExtraConfigBt bt = ExtraConfigBt();
@@ -127,6 +128,7 @@ class ExtraConfig {
     this.notifyWhenNewVersion = true,
     this.autoStartTasks = false,
     this.desktopNotification = true,
+    this.backgroundLocationKeepAlive = false,
     this.downloadCategories = const [],
   });
 

ui/flutter/lib/api/model/downloader_config.g.dart

@@ -111,6 +111,8 @@ ExtraConfig _$ExtraConfigFromJson(Map<String, dynamic> json) => ExtraConfig(
       notifyWhenNewVersion: json['notifyWhenNewVersion'] as bool? ?? true,
       autoStartTasks: json['autoStartTasks'] as bool? ?? false,
       desktopNotification: json['desktopNotification'] as bool? ?? true,
+      backgroundLocationKeepAlive:
+          json['backgroundLocationKeepAlive'] as bool? ?? false,
       downloadCategories: (json['downloadCategories'] as List<dynamic>?)
               ?.map((e) => DownloadCategory.fromJson(e as Map<String, dynamic>))
               .toList() ??
@@ -130,6 +132,7 @@ Map<String, dynamic> _$ExtraConfigToJson(ExtraConfig instance) =>
       'notifyWhenNewVersion': instance.notifyWhenNewVersion,
       'autoStartTasks': instance.autoStartTasks,
       'desktopNotification': instance.desktopNotification,
+      'backgroundLocationKeepAlive': instance.backgroundLocationKeepAlive,
       'downloadCategories':
           instance.downloadCategories.map((e) => e.toJson()).toList(),
       'bt': instance.bt.toJson(),

ui/flutter/lib/app/modules/setting/views/setting_view.dart

@@ -32,6 +32,8 @@ import '../../../views/outlined_button_loading.dart';
 import '../../../views/text_button_loading.dart';
 import '../../app/controllers/app_controller.dart';
 import '../controllers/setting_controller.dart';
+import '../../../services/location_keep_alive.dart';
+import '../../../services/location_keep_alive_coordinator.dart';
 
 const _padding = SizedBox(height: 10);
 final _divider = const Divider().paddingOnly(left: 10, right: 10);
@@ -521,6 +523,44 @@ class SettingView extends GetView<SettingController> {
             );
           });
 
+    final buildBackgroundLocationKeepAlive = !Platform.isIOS
+        ? () => const SizedBox.shrink()
+        : _buildConfigItem(
+            'backgroundLocationKeepAlive',
+            () {
+              return appController
+                      .downloaderConfig.value.extra.backgroundLocationKeepAlive
+                  ? 'on'.tr
+                  : 'off'.tr;
+            },
+            (Key key) {
+              return Container(
+                alignment: Alignment.centerLeft,
+                child: Switch(
+                  value: appController
+                      .downloaderConfig.value.extra.backgroundLocationKeepAlive,
+                  onChanged: (bool value) async {
+                    if (value) {
+                      final authorized =
+                        await LocationKeepAlive.requestPermission();
+
+                    if (!authorized) {
+                      return;
+                      }
+                    }
+
+                    appController.downloaderConfig.update((val) {
+                      val!.extra.backgroundLocationKeepAlive = value;
+                    });
+
+                    await debounceSave();
+                    await Get.find<LocationKeepAliveCoordinator>().reconcile();
+                  },
+                ),
+              );
+            },
+          );
+
     // http config items start
     final httpConfig = downloaderCfg.value.protocolConfig.http;
     final buildHttpUa =
@@ -1748,6 +1788,7 @@ class SettingView extends GetView<SettingController> {
                             buildAutoStartup(),
                             buildMenubarMode(),
                             buildDesktopNotification(),
+                            buildBackgroundLocationKeepAlive(),
                           ]),
                         )),
                         Text('archives'.tr),

ui/flutter/lib/app/modules/task/controllers/task_list_controller.dart

@@ -50,4 +50,5 @@ abstract class TaskListController extends GetxController {
     tasks.sort(compare);
     this.tasks.value = tasks;
   }
+
 }

ui/flutter/lib/app/services/location_keep_alive.dart

@@ -0,0 +1,32 @@
+//for ios
+import 'dart:io';
+
+import 'package:flutter/services.dart';
+
+class LocationKeepAlive {
+  static const _channel = MethodChannel('gopeed/location_keep_alive');
+
+  static Future<bool> requestPermission() async {
+    if (!Platform.isIOS) return false;
+
+    try {
+      final result = await _channel.invokeMethod<bool>('requestPermission');
+
+      return result ?? false;
+    } catch (_) {
+      return false;
+    }
+  }
+
+  static Future<void> start() async {
+    if (!Platform.isIOS) return;
+
+    await _channel.invokeMethod('start');
+  }
+
+  static Future<void> stop() async {
+    if (!Platform.isIOS) return;
+
+    await _channel.invokeMethod('stop');
+  }
+}

ui/flutter/lib/app/services/location_keep_alive_coordinator.dart

@@ -0,0 +1,75 @@
+import 'dart:async';
+import 'package:get/get.dart';
+import '../../../api/api.dart' as api;
+import '../../../api/model/task.dart';
+import '../modules/app/controllers/app_controller.dart';
+import 'location_keep_alive.dart';
+
+class LocationKeepAliveCoordinator extends GetxService {
+  Timer? _pollTimer;
+  bool _reconciling = false;
+
+  /// Overridable for testing, defaults to reading from AppController.
+  bool Function() keepAliveEnabledProvider = () => Get.find<AppController>()
+      .downloaderConfig
+      .value
+      .extra
+      .backgroundLocationKeepAlive;
+
+  /// Overridable for testing so polling tests don't need to wait 10s.
+  Duration pollInterval = const Duration(seconds: 10);
+
+  bool get _keepAliveEnabled => keepAliveEnabledProvider();
+
+  @override
+  void onInit() {
+    super.onInit();
+    api.setTaskChangedListener(() {
+      reconcile();
+    });
+  }
+
+  Future<int> _fetchGlobalRunningCount() async {
+    try {
+      final tasks = await api.getTasks([Status.running]);
+      return tasks.length;
+    } catch (_) {
+      return -1;
+    }
+  }
+
+  Future<void> reconcile() async {
+    if (_reconciling) return;
+    _reconciling = true;
+    try {
+      if (!_keepAliveEnabled) {
+        await LocationKeepAlive.stop();
+        return;
+      }
+      final count = await _fetchGlobalRunningCount();
+      if (count < 0) return;
+      if (count > 0) {
+        await LocationKeepAlive.start();
+      } else {
+        await LocationKeepAlive.stop();
+      }
+    } finally {
+      _reconciling = false;
+    }
+  }
+
+  void startPolling() {
+    _pollTimer?.cancel();
+    _pollTimer = Timer.periodic(pollInterval, (_) => reconcile());
+  }
+
+  void stopPolling() {
+    _pollTimer?.cancel();
+  }
+
+  @override
+  void onClose() {
+    stopPolling();
+    super.onClose();
+  }
+}

ui/flutter/lib/i18n/langs/en_us.dart

@@ -226,6 +226,7 @@ const enUS = {
     'ed2kServerMetHint': 'Server.met URL or ed2k serverlist link, one per line',
     'ed2kNodesDatHint': 'nodes.dat path or URL, one per line',
     'desktopNotification': 'Desktop Notifications',
+    'backgroundLocationKeepAlive': 'Background Download Keep Alive',
     'notificationTaskDone': 'Task completed',
     'notificationTaskError': 'Task error',
   },

ui/flutter/lib/i18n/langs/zh_cn.dart

@@ -221,6 +221,7 @@ const zhCN = {
     'ed2kServerMetHint': '请输入 Server.met 地址或 ed2k 服务器列表链接，每行一条',
     'ed2kNodesDatHint': '请输入 nodes.dat 本地路径或 URL，每行一条',
     'desktopNotification': '桌面通知',
+    'backgroundLocationKeepAlive': '常驻后台',
     'notificationTaskDone': '任务完成',
     'notificationTaskError': '任务失败',
   }

ui/flutter/lib/main.dart

@@ -22,6 +22,7 @@ import 'util/package_info.dart';
 import 'util/scheme_register/scheme_register.dart';
 import 'util/updater.dart';
 import 'util/util.dart';
+import 'app/services/location_keep_alive_coordinator.dart';
 
 class StartupArgs {
   static const flagHidden = "hidden";
@@ -135,6 +136,17 @@ Future<void> init(StartupArgs args) async {
       logger.w("auto-start tasks fail", e);
     }
   }
+  
+  // iOS location keep-alive coordinator
+  if (Util.isIOS()) {
+    try {
+      await Get.putAsync(() async => LocationKeepAliveCoordinator());
+      await Get.find<LocationKeepAliveCoordinator>().reconcile();
+      Get.find<LocationKeepAliveCoordinator>().startPolling();
+    } catch (e) {
+      logger.e("location keep-alive coordinator init fail", e);
+    }
+  }
 
   () async {
     if (Util.isDesktop()) {