notif ios: Navigate when app launched from notification

Introduces a new Pigeon API file, and adds the corresponding
bindings in Swift. Unlike the `pigeon/android_notifications.dart`
API this doesn't use the ZulipPlugin hack, as that is
only needed when we want the Pigeon functions to be available
inside a background isolate (see doc in `zulip_plugin/pubspec.yaml`).

Since the notification tap will trigger an app launch first
(if not running already) anyway, we can be sure that these new
functions won't be running on a Dart background isolate, thus not
needing the ZulipPlugin hack.

Author: rajveermalviya

ios/Runner.xcodeproj/project.pbxproj

@@ -13,6 +13,7 @@
 		97C146FC1CF9000F007C117D /* Main.storyboard in Resources */ = {isa = PBXBuildFile; fileRef = 97C146FA1CF9000F007C117D /* Main.storyboard */; };
 		97C146FE1CF9000F007C117D /* Assets.xcassets in Resources */ = {isa = PBXBuildFile; fileRef = 97C146FD1CF9000F007C117D /* Assets.xcassets */; };
 		97C147011CF9000F007C117D /* LaunchScreen.storyboard in Resources */ = {isa = PBXBuildFile; fileRef = 97C146FF1CF9000F007C117D /* LaunchScreen.storyboard */; };
+		B34E9F092D776BEB0009AED2 /* Notifications.g.swift in Sources */ = {isa = PBXBuildFile; fileRef = B34E9F082D776BEB0009AED2 /* Notifications.g.swift */; };
 		F311C174AF9C005CE4AADD72 /* Pods_Runner.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 3EAE3F3F518B95B7BFEB4FE7 /* Pods_Runner.framework */; };
 /* End PBXBuildFile section */
 
@@ -48,6 +49,7 @@
 		97C146FD1CF9000F007C117D /* Assets.xcassets */ = {isa = PBXFileReference; lastKnownFileType = folder.assetcatalog; path = Assets.xcassets; sourceTree = "<group>"; };
 		97C147001CF9000F007C117D /* Base */ = {isa = PBXFileReference; lastKnownFileType = file.storyboard; name = Base; path = Base.lproj/LaunchScreen.storyboard; sourceTree = "<group>"; };
 		97C147021CF9000F007C117D /* Info.plist */ = {isa = PBXFileReference; lastKnownFileType = text.plist.xml; path = Info.plist; sourceTree = "<group>"; };
+		B34E9F082D776BEB0009AED2 /* Notifications.g.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Notifications.g.swift; sourceTree = "<group>"; };
 		B3AF53A72CA20BD10039801D /* Zulip.xcconfig */ = {isa = PBXFileReference; lastKnownFileType = text.xcconfig; name = Zulip.xcconfig; path = Flutter/Zulip.xcconfig; sourceTree = "<group>"; };
 /* End PBXFileReference section */
 
@@ -115,6 +117,7 @@
 				1498D2321E8E86230040F4C2 /* GeneratedPluginRegistrant.h */,
 				1498D2331E8E89220040F4C2 /* GeneratedPluginRegistrant.m */,
 				74858FAE1ED2DC5600515810 /* AppDelegate.swift */,
+				B34E9F082D776BEB0009AED2 /* Notifications.g.swift */,
 				74858FAD1ED2DC5600515810 /* Runner-Bridging-Header.h */,
 			);
 			path = Runner;
@@ -297,6 +300,7 @@
 			buildActionMask = 2147483647;
 			files = (
 				74858FAF1ED2DC5600515810 /* AppDelegate.swift in Sources */,
+				B34E9F092D776BEB0009AED2 /* Notifications.g.swift in Sources */,
 				1498D2341E8E89220040F4C2 /* GeneratedPluginRegistrant.m in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;

ios/Runner/AppDelegate.swift

@@ -8,6 +8,28 @@ import Flutter
     didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?
   ) -> Bool {
     GeneratedPluginRegistrant.register(with: self)
+    guard let controller = window?.rootViewController as? FlutterViewController else {
+      fatalError("rootViewController is not type FlutterViewController")
+    }
+
+    // Retrieve the remote notification data from launch options,
+    // this will be null if the launch wasn't triggered by a notification.
+    let notificationData = launchOptions?[.remoteNotification] as? [AnyHashable : Any]
+    let api = NotificationHostApiImpl(notificationData.map { NotificationPayloadForOpen(payload: $0) })
+    NotificationHostApiSetup.setUp(binaryMessenger: controller.binaryMessenger, api: api)
+
     return super.application(application, didFinishLaunchingWithOptions: launchOptions)
   }
 }
+
+private class NotificationHostApiImpl: NotificationHostApi {
+  private let maybeNotifPayload: NotificationPayloadForOpen?
+
+  init(_ maybeNotifPayload: NotificationPayloadForOpen?) {
+    self.maybeNotifPayload = maybeNotifPayload
+  }
+
+  func getNotificationDataFromLaunch() -> NotificationPayloadForOpen? {
+    maybeNotifPayload
+  }
+}

ios/Runner/Notifications.g.swift

@@ -0,0 +1,156 @@
+// Autogenerated from Pigeon (v24.2.1), do not edit directly.
+// See also: https://pub.dev/packages/pigeon
+
+import Foundation
+
+#if os(iOS)
+  import Flutter
+#elseif os(macOS)
+  import FlutterMacOS
+#else
+  #error("Unsupported platform.")
+#endif
+
+/// Error class for passing custom error details to Dart side.
+final class PigeonError: Error {
+  let code: String
+  let message: String?
+  let details: Sendable?
+
+  init(code: String, message: String?, details: Sendable?) {
+    self.code = code
+    self.message = message
+    self.details = details
+  }
+
+  var localizedDescription: String {
+    return
+      "PigeonError(code: \(code), message: \(message ?? "<nil>"), details: \(details ?? "<nil>")"
+      }
+}
+
+private func wrapResult(_ result: Any?) -> [Any?] {
+  return [result]
+}
+
+private func wrapError(_ error: Any) -> [Any?] {
+  if let pigeonError = error as? PigeonError {
+    return [
+      pigeonError.code,
+      pigeonError.message,
+      pigeonError.details,
+    ]
+  }
+  if let flutterError = error as? FlutterError {
+    return [
+      flutterError.code,
+      flutterError.message,
+      flutterError.details,
+    ]
+  }
+  return [
+    "\(error)",
+    "\(type(of: error))",
+    "Stacktrace: \(Thread.callStackSymbols)",
+  ]
+}
+
+private func isNullish(_ value: Any?) -> Bool {
+  return value is NSNull || value == nil
+}
+
+private func nilOrValue<T>(_ value: Any?) -> T? {
+  if value is NSNull { return nil }
+  return value as! T?
+}
+
+/// The payload that is attached to each notification and holds
+/// the information required to carry out the navigation.
+///
+/// On iOS, the notification payload will be the APNs data from
+/// the server.
+///
+/// Generated class from Pigeon that represents data sent in messages.
+struct NotificationPayloadForOpen {
+  var payload: [AnyHashable?: Any?]
+
+
+  // swift-format-ignore: AlwaysUseLowerCamelCase
+  static func fromList(_ pigeonVar_list: [Any?]) -> NotificationPayloadForOpen? {
+    let payload = pigeonVar_list[0] as! [AnyHashable?: Any?]
+
+    return NotificationPayloadForOpen(
+      payload: payload
+    )
+  }
+  func toList() -> [Any?] {
+    return [
+      payload
+    ]
+  }
+}
+
+private class NotificationsPigeonCodecReader: FlutterStandardReader {
+  override func readValue(ofType type: UInt8) -> Any? {
+    switch type {
+    case 129:
+      return NotificationPayloadForOpen.fromList(self.readValue() as! [Any?])
+    default:
+      return super.readValue(ofType: type)
+    }
+  }
+}
+
+private class NotificationsPigeonCodecWriter: FlutterStandardWriter {
+  override func writeValue(_ value: Any) {
+    if let value = value as? NotificationPayloadForOpen {
+      super.writeByte(129)
+      super.writeValue(value.toList())
+    } else {
+      super.writeValue(value)
+    }
+  }
+}
+
+private class NotificationsPigeonCodecReaderWriter: FlutterStandardReaderWriter {
+  override func reader(with data: Data) -> FlutterStandardReader {
+    return NotificationsPigeonCodecReader(data: data)
+  }
+
+  override func writer(with data: NSMutableData) -> FlutterStandardWriter {
+    return NotificationsPigeonCodecWriter(data: data)
+  }
+}
+
+class NotificationsPigeonCodec: FlutterStandardMessageCodec, @unchecked Sendable {
+  static let shared = NotificationsPigeonCodec(readerWriter: NotificationsPigeonCodecReaderWriter())
+}
+
+/// Generated protocol from Pigeon that represents a handler of messages from Flutter.
+protocol NotificationHostApi {
+  /// Retrieves notification data if the app was launched by tapping on a notification.
+  func getNotificationDataFromLaunch() throws -> NotificationPayloadForOpen?
+}
+
+/// Generated setup class from Pigeon to handle messages through the `binaryMessenger`.
+class NotificationHostApiSetup {
+  static var codec: FlutterStandardMessageCodec { NotificationsPigeonCodec.shared }
+  /// Sets up an instance of `NotificationHostApi` to handle messages through the `binaryMessenger`.
+  static func setUp(binaryMessenger: FlutterBinaryMessenger, api: NotificationHostApi?, messageChannelSuffix: String = "") {
+    let channelSuffix = messageChannelSuffix.count > 0 ? ".\(messageChannelSuffix)" : ""
+    /// Retrieves notification data if the app was launched by tapping on a notification.
+    let getNotificationDataFromLaunchChannel = FlutterBasicMessageChannel(name: "dev.flutter.pigeon.zulip.NotificationHostApi.getNotificationDataFromLaunch\(channelSuffix)", binaryMessenger: binaryMessenger, codec: codec)
+    if let api = api {
+      getNotificationDataFromLaunchChannel.setMessageHandler { _, reply in
+        do {
+          let result = try api.getNotificationDataFromLaunch()
+          reply(wrapResult(result))
+        } catch {
+          reply(wrapError(error))
+        }
+      }
+    } else {
+      getNotificationDataFromLaunchChannel.setMessageHandler(nil)
+    }
+  }
+}

lib/host/notifications.dart

@@ -0,0 +1 @@
+export './notifications.g.dart';

lib/host/notifications.g.dart

@@ -0,0 +1,107 @@
+// Autogenerated from Pigeon (v24.2.1), do not edit directly.
+// See also: https://pub.dev/packages/pigeon
+// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import, no_leading_underscores_for_local_identifiers
+
+import 'dart:async';
+import 'dart:typed_data' show Float64List, Int32List, Int64List, Uint8List;
+
+import 'package:flutter/foundation.dart' show ReadBuffer, WriteBuffer;
+import 'package:flutter/services.dart';
+
+PlatformException _createConnectionError(String channelName) {
+  return PlatformException(
+    code: 'channel-error',
+    message: 'Unable to establish connection on channel: "$channelName".',
+  );
+}
+
+/// The payload that is attached to each notification and holds
+/// the information required to carry out the navigation.
+///
+/// On iOS, the notification payload will be the APNs data from
+/// the server.
+class NotificationPayloadForOpen {
+  NotificationPayloadForOpen({
+    required this.payload,
+  });
+
+  Map<Object?, Object?> payload;
+
+  Object encode() {
+    return <Object?>[
+      payload,
+    ];
+  }
+
+  static NotificationPayloadForOpen decode(Object result) {
+    result as List<Object?>;
+    return NotificationPayloadForOpen(
+      payload: (result[0] as Map<Object?, Object?>?)!.cast<Object?, Object?>(),
+    );
+  }
+}
+
+
+class _PigeonCodec extends StandardMessageCodec {
+  const _PigeonCodec();
+  @override
+  void writeValue(WriteBuffer buffer, Object? value) {
+    if (value is int) {
+      buffer.putUint8(4);
+      buffer.putInt64(value);
+    }    else if (value is NotificationPayloadForOpen) {
+      buffer.putUint8(129);
+      writeValue(buffer, value.encode());
+    } else {
+      super.writeValue(buffer, value);
+    }
+  }
+
+  @override
+  Object? readValueOfType(int type, ReadBuffer buffer) {
+    switch (type) {
+      case 129: 
+        return NotificationPayloadForOpen.decode(readValue(buffer)!);
+      default:
+        return super.readValueOfType(type, buffer);
+    }
+  }
+}
+
+class NotificationHostApi {
+  /// Constructor for [NotificationHostApi].  The [binaryMessenger] named argument is
+  /// available for dependency injection.  If it is left null, the default
+  /// BinaryMessenger will be used which routes to the host platform.
+  NotificationHostApi({BinaryMessenger? binaryMessenger, String messageChannelSuffix = ''})
+      : pigeonVar_binaryMessenger = binaryMessenger,
+        pigeonVar_messageChannelSuffix = messageChannelSuffix.isNotEmpty ? '.$messageChannelSuffix' : '';
+  final BinaryMessenger? pigeonVar_binaryMessenger;
+
+  static const MessageCodec<Object?> pigeonChannelCodec = _PigeonCodec();
+
+  final String pigeonVar_messageChannelSuffix;
+
+  /// Retrieves notification data if the app was launched by tapping on a notification.
+  Future<NotificationPayloadForOpen?> getNotificationDataFromLaunch() async {
+    final String pigeonVar_channelName = 'dev.flutter.pigeon.zulip.NotificationHostApi.getNotificationDataFromLaunch$pigeonVar_messageChannelSuffix';
+    final BasicMessageChannel<Object?> pigeonVar_channel = BasicMessageChannel<Object?>(
+      pigeonVar_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: pigeonVar_binaryMessenger,
+    );
+    final Future<Object?> pigeonVar_sendFuture = pigeonVar_channel.send(null);
+    final List<Object?>? pigeonVar_replyList =
+        await pigeonVar_sendFuture as List<Object?>?;
+    if (pigeonVar_replyList == null) {
+      throw _createConnectionError(pigeonVar_channelName);
+    } else if (pigeonVar_replyList.length > 1) {
+      throw PlatformException(
+        code: pigeonVar_replyList[0]! as String,
+        message: pigeonVar_replyList[1] as String?,
+        details: pigeonVar_replyList[2],
+      );
+    } else {
+      return (pigeonVar_replyList[0] as NotificationPayloadForOpen?);
+    }
+  }
+}

lib/main.dart

@@ -1,20 +1,28 @@
+import 'dart:async';
+
 import 'package:flutter/foundation.dart';
 import 'package:flutter/widgets.dart';
 
 import 'licenses.dart';
 import 'log.dart';
 import 'model/binding.dart';
+import 'notifications/open.dart';
 import 'notifications/receive.dart';
 import 'widgets/app.dart';
 
-void main() {
+Future<void> main() async {
   assert(() {
     debugLogEnabled = true;
     return true;
   }());
   LicenseRegistry.addLicense(additionalLicenses);
   WidgetsFlutterBinding.ensureInitialized();
   LiveZulipBinding.ensureInitialized();
-  NotificationService.instance.start();
+
+  // TODO remove this await here
+  // TODO move this initialization to NotificationService.instance.start()
+  await NotificationOpenManager.instance.init();
+
+  unawaited(NotificationService.instance.start());
   runApp(const ZulipApp());
 }