Move background fetch to native code

README.md

@@ -21,7 +21,7 @@ This Flutter plugin provides a simple and easy-to-use interface for setting and
 
 [See screenshot 1](https://github.com/gdelataillade/alarm/assets/32983806/2ad67186-1f22-462c-b953-fe55a35fea09)
 
-2) Still in Xcode, open your Info.plist and add the key `Permitted background task scheduler identifiers`, with the item `com.transistorsoft.fetch` inside.
+2) Still in Xcode, open your Info.plist and add the key `Permitted background task scheduler identifiers`, with the item `com.gdelataillade.fetch` inside.
 
 [See screenshot 2](https://github.com/gdelataillade/alarm/assets/32983806/a7ab90be-4518-48a7-a21d-d2844b4b036c)
 

example/ios/Podfile.lock

@@ -3,8 +3,6 @@ PODS:
     - Flutter
   - audio_session (0.0.1):
     - Flutter
-  - background_fetch (1.2.1):
-    - Flutter
   - device_info_plus (0.0.1):
     - Flutter
   - Flutter (1.0.0)
@@ -28,7 +26,6 @@ PODS:
 DEPENDENCIES:
   - alarm (from `.symlinks/plugins/alarm/ios`)
   - audio_session (from `.symlinks/plugins/audio_session/ios`)
-  - background_fetch (from `.symlinks/plugins/background_fetch/ios`)
   - device_info_plus (from `.symlinks/plugins/device_info_plus/ios`)
   - Flutter (from `Flutter`)
   - flutter_fgbg (from `.symlinks/plugins/flutter_fgbg/ios`)
@@ -44,8 +41,6 @@ EXTERNAL SOURCES:
     :path: ".symlinks/plugins/alarm/ios"
   audio_session:
     :path: ".symlinks/plugins/audio_session/ios"
-  background_fetch:
-    :path: ".symlinks/plugins/background_fetch/ios"
   device_info_plus:
     :path: ".symlinks/plugins/device_info_plus/ios"
   Flutter:
@@ -68,7 +63,6 @@ EXTERNAL SOURCES:
 SPEC CHECKSUMS:
   alarm: 6c1f6a9688f94cd6bf8f104c67cc26e78c9d8d13
   audio_session: 4f3e461722055d21515cf3261b64c973c062f345
-  background_fetch: 896944864b038d2837fc750d470e9841e1e6a363
   device_info_plus: 7545d84d8d1b896cb16a4ff98c19f07ec4b298ea
   Flutter: f04841e97a9d0b0a8025694d0796dd46242b2854
   flutter_fgbg: 31c0d1140a131daea2d342121808f6aa0dcd879d

example/ios/Runner/AppDelegate.swift

@@ -1,6 +1,7 @@
 import UIKit
 import Flutter
 import UserNotifications
+import alarm
 
 @UIApplicationMain
 @objc class AppDelegate: FlutterAppDelegate {
@@ -11,6 +12,7 @@ import UserNotifications
     if #available(iOS 10.0, *) {
       UNUserNotificationCenter.current().delegate = self as UNUserNotificationCenterDelegate
     }
+    SwiftAlarmPlugin.registerBackgroundTasks()
 
     GeneratedPluginRegistrant.register(with: self)
     return super.application(application, didFinishLaunchingWithOptions: launchOptions)

example/ios/Runner/Info.plist

@@ -4,7 +4,7 @@
 <dict>
 	<key>BGTaskSchedulerPermittedIdentifiers</key>
 	<array>
-		<string>com.transistorsoft.fetch</string>
+		<string>com.gdelataillade.fetch</string>
 	</array>
 	<key>CADisableMinimumFrameDurationOnPhone</key>
 	<true/>

example/lib/screens/home.dart

@@ -1,7 +1,6 @@
 import 'dart:async';
 
 import 'package:alarm/alarm.dart';
-import 'package:alarm/service/background_fetch.dart';
 import 'package:alarm_example/screens/edit_alarm.dart';
 import 'package:alarm_example/screens/ring.dart';
 import 'package:alarm_example/screens/shortcut_button.dart';
@@ -72,24 +71,7 @@ class _ExampleAlarmHomeScreenState extends State<ExampleAlarmHomeScreen> {
   @override
   Widget build(BuildContext context) {
     return Scaffold(
-      appBar: AppBar(
-        title: const Text('alarm 2.0.0-dev.4'),
-        actions: [
-          IconButton(
-            onPressed: () {
-              final checksDt = AlarmBackgroundFetch.fetches.map((e) {
-                return '${e.year}-${e.month}-${e.day} ${e.hour}h${e.minute}';
-              });
-              final content =
-                  "Background App Checks done this session:\n$checksDt";
-              ScaffoldMessenger.of(context).showSnackBar(
-                SnackBar(content: Text(content)),
-              );
-            },
-            icon: const Icon(Icons.info),
-          ),
-        ],
-      ),
+      appBar: AppBar(title: const Text('alarm 2.0.0-dev.4')),
       body: SafeArea(
         child: alarms.isNotEmpty
             ? ListView.separated(

example/pubspec.lock

@@ -40,14 +40,6 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "0.1.16"
-  background_fetch:
-    dependency: transitive
-    description:
-      name: background_fetch
-      sha256: f70b28a0f7a3156195e9742229696f004ea3bf10f74039b7bf4c78a74fbda8a4
-      url: "https://pub.dev"
-    source: hosted
-    version: "1.2.1"
   boolean_selector:
     dependency: transitive
     description:

help/INSTALL-ANDROID.md

@@ -0,0 +1 @@
+# Android Setup

help/INSTALL-IOS.md

@@ -0,0 +1 @@
+# iOS Setup

ios/Classes/SwiftAlarmPlugin.swift

@@ -3,6 +3,7 @@ import UIKit
 import AVFoundation
 import AudioToolbox
 import MediaPlayer
+import BackgroundTasks
 
 public class SwiftAlarmPlugin: NSObject, FlutterPlugin {
     #if targetEnvironment(simulator)
@@ -12,6 +13,8 @@ public class SwiftAlarmPlugin: NSObject, FlutterPlugin {
     #endif
 
     private var registrar: FlutterPluginRegistrar!
+    static let sharedInstance = SwiftAlarmPlugin()
+    static let backgroundTaskIdentifier: String = "com.gdelataillade.fetch"
 
     public static func register(with registrar: FlutterPluginRegistrar) {
         let channel = FlutterMethodChannel(name: "com.gdelataillade/alarm", binaryMessenger: registrar.messenger())
@@ -50,10 +53,6 @@ public class SwiftAlarmPlugin: NSObject, FlutterPlugin {
                 let args = call.arguments as! Dictionary<String, Any>
                 let id = args["id"] as! Int
                 self.audioCurrentTime(id: id, result: result)
-            } else if call.method == "backgroundCheck" {
-                let args = call.arguments as! Dictionary<String, Any>
-                let ids = args["ids"] as! [Int]
-                self.backgroundCheck(ids: ids, result: result)
             } else {
                 DispatchQueue.main.sync {
                     result(FlutterMethodNotImplemented)
@@ -149,6 +148,7 @@ public class SwiftAlarmPlugin: NSObject, FlutterPlugin {
 
         DispatchQueue.main.async {
             self.timers[id] = Timer.scheduledTimer(timeInterval: delayInSeconds, target: self, selector: #selector(self.executeTask(_:)), userInfo: id, repeats: false)
+            SwiftAlarmPlugin.scheduleAppRefresh()
         }
 
         result(true)
@@ -280,6 +280,7 @@ public class SwiftAlarmPlugin: NSObject, FlutterPlugin {
             self.playSilent = false
             self.silentAudioPlayer?.stop()
             NotificationCenter.default.removeObserver(self)
+            SwiftAlarmPlugin.cancelBackgroundTasks()
         }
     }
 
@@ -316,14 +317,17 @@ public class SwiftAlarmPlugin: NSObject, FlutterPlugin {
         }
     }
 
-    private func backgroundCheck(ids: [Int], result: FlutterResult) {
-        self.mixOtherAudios()
+    // Runs when a background fetch event is triggered
+    private func backgroundFetch() {
+        NSLog("SwiftAlarmPlugin: -> Background fetch !")
 
-        let isPlaying = self.silentAudioPlayer?.isPlaying ?? false
+        self.mixOtherAudios()
 
         self.silentAudioPlayer?.pause()
         self.silentAudioPlayer?.play()
 
+        let ids = Array(self.audioPlayers.keys)
+
         for id in ids {
             NSLog("SwiftAlarmPlugin: Background check alarm with id \(id)")
             if let audioPlayer = self.audioPlayers[id] {
@@ -339,8 +343,6 @@ public class SwiftAlarmPlugin: NSObject, FlutterPlugin {
                 self.timers[id] = Timer.scheduledTimer(timeInterval: delayInSeconds, target: self, selector: #selector(self.executeTask(_:)), userInfo: id, repeats: false)
             }
         }
-
-        result(isPlaying)
     }
 
     private func stopNotificationOnKillService() {
@@ -349,6 +351,7 @@ public class SwiftAlarmPlugin: NSObject, FlutterPlugin {
             observerAdded = false
         }
     }
+
     @objc func applicationWillTerminate(_ notification: Notification) {
         let content = UNMutableNotificationContent()
         content.title = notificationTitleOnKill
@@ -382,4 +385,48 @@ public class SwiftAlarmPlugin: NSObject, FlutterPlugin {
             NSLog("SwiftAlarmPlugin: Error setting up audio session with option duckOthers: \(error.localizedDescription)")
         }
     }
-}
+
+    // Runs from AppDelegate when the app is launched
+    static public func registerBackgroundTasks() {
+        NSLog("SwiftAlarmPlugin: -> registerBackgroundTasks !")
+
+        if #available(iOS 13.0, *) {
+            BGTaskScheduler.shared.register(forTaskWithIdentifier: backgroundTaskIdentifier, using: nil) { task in
+                self.scheduleAppRefresh()
+                sharedInstance.backgroundFetch()
+                task.setTaskCompleted(success: true)
+            }
+        } else {
+            NSLog("SwiftAlarmPlugin: BGTaskScheduler not available for your version of iOS lower than 13.0")
+        }
+    }
+
+    // Enables background fetch
+    static func scheduleAppRefresh() {
+        NSLog("SwiftAlarmPlugin: -> scheduleAppRefresh !")
+
+        if #available(iOS 13.0, *) {
+            let request = BGAppRefreshTaskRequest(identifier: backgroundTaskIdentifier)
+
+            request.earliestBeginDate = Date(timeIntervalSinceNow: 15 * 60)
+            do {
+                try BGTaskScheduler.shared.submit(request)
+            } catch {
+                NSLog("SwiftAlarmPlugin: Could not schedule app refresh: \(error)")
+            }
+        } else {
+            NSLog("SwiftAlarmPlugin: BGTaskScheduler not available for your version of iOS lower than 13.0")
+        }
+    }
+
+    // Disable background fetch
+    static func cancelBackgroundTasks() {
+        NSLog("SwiftAlarmPlugin: -> cancelBackgroundTasks !")
+
+        if #available(iOS 13.0, *) {
+            BGTaskScheduler.shared.cancel(taskRequestWithIdentifier: backgroundTaskIdentifier)
+        } else {
+            NSLog("SwiftAlarmPlugin: BGTaskScheduler not available for your version of iOS lower than 13.0")
+        }
+    }
+}

lib/alarm.dart

@@ -4,7 +4,6 @@ export 'package:alarm/model/alarm_settings.dart';
 import 'dart:async';
 
 import 'package:alarm/model/alarm_settings.dart';
-import 'package:alarm/service/background_fetch.dart';
 import 'package:alarm/src/ios_alarm.dart';
 import 'package:alarm/src/android_alarm.dart';
 import 'package:alarm/service/notification.dart';
@@ -103,8 +102,6 @@ class Alarm {
     }
 
     if (iOS) {
-      AlarmBackgroundFetch.set();
-
       return IOSAlarm.setAlarm(
         alarmSettings.id,
         alarmSettings.dateTime,
@@ -153,8 +150,6 @@ class Alarm {
 
     AlarmNotification.instance.cancel(id);
 
-    if (iOS && !hasAlarm()) AlarmBackgroundFetch.stop();
-
     return iOS ? await IOSAlarm.stopAlarm(id) : await AndroidAlarm.stop(id);
   }
 

lib/src/ios_alarm.dart

@@ -114,20 +114,6 @@ class IOSAlarm {
     return pos2 > pos1;
   }
 
-  /// Checks if alarm audio players are still active during the background check.
-  static Future<bool> backgroundCheck() async {
-    final alarms = Alarm.getAlarms();
-    if (alarms.isEmpty) return true;
-
-    final alarmIds = alarms.map((e) => e.id).toList();
-
-    return await methodChannel.invokeMethod<bool?>(
-          'backgroundCheck',
-          {'ids': alarmIds},
-        ) ??
-        false;
-  }
-
   /// Listens when app goes foreground so we can check if alarm is ringing.
   /// When app goes background, periodical timer will be disposed.
   static void listenAppStateChange({

pubspec.yaml

@@ -9,7 +9,6 @@ environment:
 
 dependencies:
   android_alarm_manager_plus: ^3.0.1
-  background_fetch: ^1.2.1
   flutter:
     sdk: flutter
   flutter_fgbg: ^0.3.0