[feat] 앱 Lifecycle 관리 및 네트워크 상태 체크 추가

android/app/src/main/AndroidManifest.xml

@@ -9,6 +9,7 @@
     </queries>
 
     <uses-permission android:name="android.permission.INTERNET" />
+    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
     <uses-permission android:name="android.permission.CAMERA"/>
     <uses-permission android:name="android.permission.READ_MEDIA_IMAGES" />
     <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>

ios/Podfile.lock

@@ -1,4 +1,6 @@
 PODS:
+  - connectivity_plus (0.0.1):
+    - Flutter
   - Firebase/CoreOnly (11.6.0):
     - FirebaseCore (~> 11.6.0)
   - Firebase/Messaging (11.6.0):
@@ -95,6 +97,7 @@ PODS:
     - FlutterMacOS
 
 DEPENDENCIES:
+  - connectivity_plus (from `.symlinks/plugins/connectivity_plus/ios`)
   - firebase_core (from `.symlinks/plugins/firebase_core/ios`)
   - firebase_messaging (from `.symlinks/plugins/firebase_messaging/ios`)
   - Flutter (from `Flutter`)
@@ -123,6 +126,8 @@ SPEC REPOS:
     - PromisesObjC
 
 EXTERNAL SOURCES:
+  connectivity_plus:
+    :path: ".symlinks/plugins/connectivity_plus/ios"
   firebase_core:
     :path: ".symlinks/plugins/firebase_core/ios"
   firebase_messaging:
@@ -151,6 +156,7 @@ EXTERNAL SOURCES:
     :path: ".symlinks/plugins/webview_flutter_wkwebview/darwin"
 
 SPEC CHECKSUMS:
+  connectivity_plus: cb623214f4e1f6ef8fe7403d580fdad517d2f7dd
   Firebase: 374a441a91ead896215703a674d58cdb3e9d772b
   firebase_core: 2337982fb78ee4d8d91e608b0a3d4f44346a93c8
   firebase_messaging: f3bddfa28c2cad70b3341bf461e987a24efd28d6

lib/ui/offline_screen.dart

@@ -0,0 +1,76 @@
+import 'package:flutter/material.dart';
+import '../main.dart';
+
+class OfflineScreen extends StatelessWidget {
+  final VoidCallback onRetry;
+
+  const OfflineScreen({
+    super.key,
+    required this.onRetry,
+  });
+
+  @override
+  Widget build(BuildContext context) {
+    final colors = Theme.of(context).extension<BottleNoteColors>()!;
+
+    return Container(
+      color: Colors.white,
+      child: Center(
+        child: Padding(
+          padding: const EdgeInsets.all(32.0),
+          child: Column(
+            mainAxisAlignment: MainAxisAlignment.center,
+            children: [
+              Icon(
+                Icons.wifi_off_rounded,
+                size: 80,
+                color: colors.brightGray,
+              ),
+              const SizedBox(height: 24),
+              Text(
+                '인터넷 연결 없음',
+                style: TextStyle(
+                  fontSize: 20,
+                  fontWeight: FontWeight.bold,
+                  color: colors.mainBlack,
+                ),
+              ),
+              const SizedBox(height: 12),
+              Text(
+                '네트워크 연결 상태를 확인하고\n다시 시도해 주세요.',
+                textAlign: TextAlign.center,
+                style: TextStyle(
+                  fontSize: 14,
+                  color: colors.mainGray,
+                  height: 1.5,
+                ),
+              ),
+              const SizedBox(height: 32),
+              ElevatedButton(
+                onPressed: onRetry,
+                style: ElevatedButton.styleFrom(
+                  backgroundColor: colors.subCoral,
+                  foregroundColor: Colors.white,
+                  padding: const EdgeInsets.symmetric(
+                    horizontal: 48,
+                    vertical: 16,
+                  ),
+                  shape: RoundedRectangleBorder(
+                    borderRadius: BorderRadius.circular(8),
+                  ),
+                ),
+                child: const Text(
+                  '다시 시도',
+                  style: TextStyle(
+                    fontSize: 16,
+                    fontWeight: FontWeight.w600,
+                  ),
+                ),
+              ),
+            ],
+          ),
+        ),
+      ),
+    );
+  }
+}

lib/utils/network/connectivity_service.dart

@@ -0,0 +1,60 @@
+import 'dart:async';
+import 'package:connectivity_plus/connectivity_plus.dart';
+import 'package:logger/logger.dart';
+
+enum NetworkStatus { online, offline }
+
+class ConnectivityService {
+  final Connectivity _connectivity = Connectivity();
+  final Logger _logger;
+
+  final StreamController<NetworkStatus> _networkStatusController =
+      StreamController<NetworkStatus>.broadcast();
+
+  Stream<NetworkStatus> get networkStatusStream =>
+      _networkStatusController.stream;
+  NetworkStatus _currentStatus = NetworkStatus.online;
+  NetworkStatus get currentStatus => _currentStatus;
+
+  StreamSubscription<List<ConnectivityResult>>? _subscription;
+  bool _isDisposed = false;
+
+  ConnectivityService({required Logger logger}) : _logger = logger;
+
+  Future<void> initialize() async {
+    final results = await _connectivity.checkConnectivity();
+    _updateStatus(results);
+
+    _subscription = _connectivity.onConnectivityChanged.listen((results) {
+      _updateStatus(results);
+    });
+  }
+
+  void _updateStatus(List<ConnectivityResult> results) {
+    if (_isDisposed) return;
+
+    final isConnected =
+        results.any((result) => result != ConnectivityResult.none);
+
+    final newStatus = isConnected ? NetworkStatus.online : NetworkStatus.offline;
+
+    if (newStatus != _currentStatus) {
+      _currentStatus = newStatus;
+      if (!_networkStatusController.isClosed) {
+        _networkStatusController.add(newStatus);
+      }
+      _logger.d('Network status changed: $newStatus');
+    }
+  }
+
+  Future<bool> checkConnectivity() async {
+    final results = await _connectivity.checkConnectivity();
+    return results.any((result) => result != ConnectivityResult.none);
+  }
+
+  void dispose() {
+    _isDisposed = true;
+    _subscription?.cancel();
+    _networkStatusController.close();
+  }
+}

lib/web_view/web_view.dart

@@ -1,6 +1,9 @@
+import 'dart:async';
 import 'dart:collection';
 
 import 'package:app/bridge/web_view_bridge_handler.dart';
+import 'package:app/utils/network/connectivity_service.dart';
+import 'package:app/ui/offline_screen.dart';
 import 'package:app/bridge/web_view_navigation_handler.dart';
 import 'package:app/main.dart';
 import 'package:app/utils/env/env.dart';
@@ -40,12 +43,25 @@ class BottleNoteWebViewState extends State<BottleNoteWebView>
 
   bool _isAppLoading = false;
   late String _url = '';
+  bool _isWebViewCreated = false;
+
+  // Network status
+  late ConnectivityService _connectivityService;
+  StreamSubscription<NetworkStatus>? _networkSubscription;
+  bool _isOffline = false;
+  bool _initialLoadCompleted = false;
+
+  // Lifecycle
+  DateTime? _backgroundTime;
+  static const Duration _refreshThreshold = Duration(minutes: 5);
 
   @override
   void initState() {
     super.initState();
     WidgetsBinding.instance.addObserver(this);
     _navigationHandler = WebViewNavigationHandler(logger: logger);
+    _connectivityService = ConnectivityService(logger: logger);
+    _initializeConnectivity();
     _permissionWithNotification();
     _setupPullToRefresh();
     _initialUserScripts = UnmodifiableListView([
@@ -56,13 +72,75 @@ class BottleNoteWebViewState extends State<BottleNoteWebView>
     ]);
   }
 
+  Future<void> _initializeConnectivity() async {
+    await _connectivityService.initialize();
+
+    if (!mounted) return;
+
+    final isConnected = await _connectivityService.checkConnectivity();
+    if (!mounted) return;
+
+    if (!isConnected) {
+      setState(() {
+        _isOffline = true;
+      });
+    }
+
+    _networkSubscription =
+        _connectivityService.networkStatusStream.listen((status) {
+      if (!mounted) return;
+
+      final wasOffline = _isOffline;
+      setState(() {
+        _isOffline = status == NetworkStatus.offline;
+      });
+
+      // Offline -> Online: auto reload
+      if (wasOffline &&
+          status == NetworkStatus.online &&
+          _initialLoadCompleted &&
+          _isWebViewCreated) {
+        _webviewController.reload();
+      }
+    });
+  }
+
+  @override
+  void didChangeAppLifecycleState(AppLifecycleState state) {
+    super.didChangeAppLifecycleState(state);
+
+    switch (state) {
+      case AppLifecycleState.paused:
+        _backgroundTime = DateTime.now();
+        break;
+      case AppLifecycleState.resumed:
+        _handleAppResumed();
+        break;
+      default:
+        break;
+    }
+  }
+
+  void _handleAppResumed() {
+    if (_backgroundTime != null && _initialLoadCompleted && _isWebViewCreated) {
+      final duration = DateTime.now().difference(_backgroundTime!);
+      if (duration > _refreshThreshold) {
+        logger.d('Long background duration: ${duration.inSeconds}s. Reloading WebView.');
+        _webviewController.reload();
+      }
+      _backgroundTime = null;
+    }
+  }
+
   void _setupPullToRefresh() {
     _pullToRefreshController = PullToRefreshController(
       settings: PullToRefreshSettings(
         color: const Color(0xffe58257),
         backgroundColor: Colors.white,
       ),
       onRefresh: () async {
+        if (!_isWebViewCreated) return;
+
         if (Platform.isAndroid) {
           _webviewController.reload();
         } else if (Platform.isIOS) {
@@ -77,11 +155,37 @@ class BottleNoteWebViewState extends State<BottleNoteWebView>
   @override
   void dispose() {
     WidgetsBinding.instance.removeObserver(this);
+    // Cancel network subscription first to prevent callbacks on disposed controller
+    _networkSubscription?.cancel();
+    _connectivityService.dispose();
     _pullToRefreshController.dispose();
-    _webviewController.dispose();
+    if (_isWebViewCreated) {
+      _webviewController.dispose();
+    }
     super.dispose();
   }
 
+  Future<void> _retryConnection() async {
+    final isConnected = await _connectivityService.checkConnectivity();
+    if (!mounted) return;
+
+    if (isConnected) {
+      setState(() {
+        _isOffline = false;
+      });
+      if (_initialLoadCompleted && _isWebViewCreated) {
+        _webviewController.reload();
+      }
+    } else {
+      ScaffoldMessenger.of(context).showSnackBar(
+        const SnackBar(
+          content: Text('인터넷 연결을 확인해 주세요.'),
+          duration: Duration(seconds: 2),
+        ),
+      );
+    }
+  }
+
   @override
   Widget build(BuildContext context) {
     final colors = Theme.of(context).extension<BottleNoteColors>()!;
@@ -106,7 +210,9 @@ class BottleNoteWebViewState extends State<BottleNoteWebView>
       },
       child: Scaffold(
         backgroundColor: Colors.white,
-        body: _buildBody(colors),
+        body: _isOffline && !_initialLoadCompleted
+            ? OfflineScreen(onRetry: _retryConnection)
+            : _buildBody(colors),
       ),
     );
   }
@@ -131,6 +237,7 @@ class BottleNoteWebViewState extends State<BottleNoteWebView>
               pullToRefreshController: _pullToRefreshController,
               onWebViewCreated: (controller) {
                 _webviewController = controller;
+                _isWebViewCreated = true;
                 _webViewBridgeHandler = WebViewBridgeHandler(
                   controller: controller,
                   logger: logger,
@@ -153,6 +260,7 @@ class BottleNoteWebViewState extends State<BottleNoteWebView>
               onLoadStart: (controller, url) {},
               onLoadStop: (controller, url) async {
                 _pullToRefreshController.endRefreshing();
+                _initialLoadCompleted = true;
 
                 // 웹뷰가 완전히 로드된 후 JavaScript 초기화
                 if (_webViewBridgeHandler != null) {

pubspec.lock

@@ -185,6 +185,22 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "1.19.1"
+  connectivity_plus:
+    dependency: "direct main"
+    description:
+      name: connectivity_plus
+      sha256: b5e72753cf63becce2c61fd04dfe0f1c430cc5278b53a1342dc5ad839eab29ec
+      url: "https://pub.dev"
+    source: hosted
+    version: "6.1.5"
+  connectivity_plus_platform_interface:
+    dependency: transitive
+    description:
+      name: connectivity_plus_platform_interface
+      sha256: "42657c1715d48b167930d5f34d00222ac100475f73d10162ddf43e714932f204"
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.0.1"
   convert:
     dependency: transitive
     description:
@@ -848,6 +864,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "2.0.0"
+  nm:
+    dependency: transitive
+    description:
+      name: nm
+      sha256: "2c9aae4127bdc8993206464fcc063611e0e36e72018696cd9631023a31b24254"
+      url: "https://pub.dev"
+    source: hosted
+    version: "0.5.0"
   package_config:
     dependency: transitive
     description: