added image cache managing

lib/features/home/api/unsplash_images_api.dart

@@ -1,29 +1,37 @@
 import 'dart:async';
 import 'dart:math';
 
+import 'package:mc_gallery/features/core/services/logging_service.dart';
+import 'package:mc_gallery/locator.dart';
+
 import '/features/core/data/constants/const_values.dart';
 import '/l10n/generated/l10n.dart';
 import '../abstracts/images_api.dart';
 import '../data/models/image_model.dart';
 
-class UnsplashImagesApi implements ImagesApi {
+class UnsplashImagesApi with LoggingService implements ImagesApi {
   @override
   FutureOr<Iterable<ImageModel>> fetchImageUri({required String token}) {
     final random = Random();
 
-    return Iterable<int>.generate(ConstValues.numberOfImages).map((final imageIndex) {
-      // Drawing from a normal distribution
-      final imageSide = ConstValues.minImageSize +
-          random.nextInt((ConstValues.maxImageSize + 1) - ConstValues.minImageSize);
+    try {
+      return Iterable<int>.generate(ConstValues.numberOfImages).map((final imageIndex) {
+        // Drawing from a normal distribution
+        final imageSide = ConstValues.minImageSize +
+            random.nextInt((ConstValues.maxImageSize + 1) - ConstValues.minImageSize);
 
-      final imageUri = _imageUrlGenerator(imageSide: imageSide);
+        final imageUri = _imageUrlGenerator(imageSide: imageSide);
 
-      return ImageModel(
-        imageIndex: imageIndex,
-        uri: imageUri,
-        imageName: Strings.current.image,
-      );
-    });
+        return ImageModel(
+          imageIndex: imageIndex,
+          uri: imageUri,
+          imageName: Strings.current.image,
+        );
+      });
+    } on Exception catch (ex, stackTrace) {
+      handleException(ex, stackTrace);
+      return const Iterable.empty();
+    }
   }
 
   Uri _imageUrlGenerator({required int imageSide}) => Uri(
@@ -31,4 +39,6 @@ class UnsplashImagesApi implements ImagesApi {
         host: ConstValues.backendHost,
         pathSegments: [...ConstValues.backendUrlPathSegments, '${imageSide}x$imageSide'],
       );
+
+  static UnsplashImagesApi get locate => Locator.locate();
 }

lib/features/home/services/image_cache_manager_service.dart

@@ -0,0 +1,37 @@
+import 'dart:ui';
+
+import 'package:flutter_cache_manager/flutter_cache_manager.dart';
+import 'package:mc_gallery/features/core/services/app_lifecycle_service.dart';
+import 'package:mc_gallery/features/core/services/logging_service.dart';
+import 'package:mc_gallery/locator.dart';
+
+class ImageCacheManagerService with LoggingService {
+  ImageCacheManagerService({
+    required AppLifecycleService appLifecycleService,
+  }) : _appLifecycleService = appLifecycleService {
+    _init();
+  }
+
+  final AppLifecycleService _appLifecycleService;
+
+  Future<void> emptyCache() async => await DefaultCacheManager().emptyCache();
+
+  Future<void> _init() async {
+    _appLifecycleService.addListener(
+      tag: runtimeType.toString(),
+      listener: (final appLifecycleState) async {
+        switch (appLifecycleState) {
+          case AppLifecycleState.resumed:
+            break;
+          case AppLifecycleState.inactive:
+          case AppLifecycleState.paused:
+          case AppLifecycleState.detached:
+            info('Discarding cached images');
+            await DefaultCacheManager().emptyCache();
+        }
+      },
+    );
+  }
+
+  static ImageCacheManagerService get locate => Locator.locate();
+}

lib/features/home/services/images_service.dart

@@ -1,3 +1,4 @@
+import 'package:mc_gallery/features/core/services/logging_service.dart';
 import 'package:mc_gallery/features/home/data/models/image_model.dart';
 import 'package:mc_gallery/locator.dart';
 
@@ -8,18 +9,28 @@ import '../abstracts/images_api.dart';
 /// Since this is very simple use-case, this is the only interface. For complex (actual CRUD-based) I/O,
 /// an additional Repository layer interface can be used between [ImagesService] and [ImagesApi].
 class ImagesService {
-  ImagesService({required ImagesApi imagesApi}) : _imagesApi = imagesApi {
+  ImagesService({
+    required ImagesApi imagesApi,
+    required LoggingService loggingService,
+  })  : _imagesApi = imagesApi,
+        _loggingService = loggingService {
     _init();
   }
 
   final ImagesApi _imagesApi;
+  final LoggingService _loggingService;
 
   late final Iterable<ImageModel> _imageModels;
   Iterable<ImageModel> get imageModels => _imageModels;
 
   Future<void> _init() async {
+    _loggingService.info('Fetching and creating image models...');
     _imageModels = await _imagesApi.fetchImageUri(token: '');
 
+    _imageModels.isNotEmpty
+        ? _loggingService.good("Created ${_imageModels.length} images' models")
+        : _loggingService.warning('No images found');
+
     Locator.instance().signalReady(this);
   }
 

lib/features/home/views/gallery/gallery_view_model.dart

@@ -1,7 +1,7 @@
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/foundation.dart';
 import 'package:flutter_cache_manager/flutter_cache_manager.dart';
-import 'package:mc_gallery/features/core/services/app_lifecycle_service.dart';
+import 'package:mc_gallery/features/home/services/image_cache_manager_service.dart';
 
 import '/features/core/abstracts/base_view_model.dart';
 import '/features/core/services/logging_service.dart';
@@ -15,16 +15,16 @@ class GalleryViewModel extends BaseViewModel {
   GalleryViewModel({
     required ImagesService imagesService,
     required NavigationService navigationService,
-    required AppLifecycleService appLifecycleService,
+    required ImageCacheManagerService imageCacheManagerService,
     required LoggingService loggingService,
   })  : _imagesService = imagesService,
         _navigationService = navigationService,
-        _appLifecycleService = appLifecycleService,
+        _imageCacheManagerService = imageCacheManagerService,
         _loggingService = loggingService;
 
   final ImagesService _imagesService;
   final NavigationService _navigationService;
-  final AppLifecycleService _appLifecycleService;
+  final ImageCacheManagerService _imageCacheManagerService;
   final LoggingService _loggingService;
 
   final ValueNotifier<bool> _isDisplayingPressingPrompt = ValueNotifier(true);
@@ -32,27 +32,11 @@ class GalleryViewModel extends BaseViewModel {
 
   @override
   Future<void> initialise(bool Function() mounted, [arguments]) async {
-    _appLifecycleService.addListener(
-      tag: runtimeType.toString(),
-      listener: (final appLifecycleState) async {
-        switch (appLifecycleState) {
-          case AppLifecycleState.resumed:
-            break;
-          case AppLifecycleState.inactive:
-          case AppLifecycleState.paused:
-          case AppLifecycleState.detached:
-            await DefaultCacheManager().emptyCache();
-        }
-      },
-    );
-
     super.initialise(mounted, arguments);
   }
 
   @override
   Future<void> dispose() async {
-    await _appLifecycleService.removeListener(tag: runtimeType.toString());
-
     super.dispose();
   }
 

lib/features/home/views/image_carousel/image_carousel_view_model.dart

@@ -1,8 +1,5 @@
-import 'dart:ui';
-
 import 'package:flutter/foundation.dart';
 import 'package:flutter_cache_manager/flutter_cache_manager.dart';
-import 'package:mc_gallery/features/core/services/app_lifecycle_service.dart';
 
 import '/features/core/abstracts/base_view_model.dart';
 import '/features/core/services/logging_service.dart';
@@ -16,16 +13,13 @@ class ImageCarouselViewModel extends BaseViewModel {
   ImageCarouselViewModel({
     required ImagesService imagesService,
     required NavigationService navigationService,
-    required AppLifecycleService appLifecycleService,
     required LoggingService loggingService,
   })  : _imagesService = imagesService,
         _navigationService = navigationService,
-        _appLifecycleService = appLifecycleService,
         _loggingService = loggingService;
 
   final ImagesService _imagesService;
   final NavigationService _navigationService;
-  final AppLifecycleService _appLifecycleService;
   final LoggingService _loggingService;
 
   late final ValueNotifier<ImageModel> _currentImageModel;
@@ -33,19 +27,6 @@ class ImageCarouselViewModel extends BaseViewModel {
 
   @override
   Future<void> initialise(bool Function() mounted, [arguments]) async {
-    _appLifecycleService.addListener(
-        tag: runtimeType.toString(),
-        listener: (final appLifecycleState) async {
-          switch (appLifecycleState) {
-            case AppLifecycleState.resumed:
-              break;
-            case AppLifecycleState.inactive:
-            case AppLifecycleState.paused:
-            case AppLifecycleState.detached:
-              await DefaultCacheManager().emptyCache();
-          }
-        });
-
     _currentImageModel = ValueNotifier(_imagesService.imageModels
         .elementAt((arguments! as ImageCarouselViewArguments).imageIndexKey));
 
@@ -54,8 +35,6 @@ class ImageCarouselViewModel extends BaseViewModel {
 
   @override
   Future<void> dispose() async {
-    await _appLifecycleService.removeListener(tag: runtimeType.toString());
-
     super.dispose();
   }
 

lib/locator.dart

@@ -7,6 +7,7 @@ import 'package:mc_gallery/features/core/abstracts/router/app_router.dart';
 import 'package:mc_gallery/features/core/services/logging_service.dart';
 import 'package:mc_gallery/features/core/services/navigation_service.dart';
 import 'package:mc_gallery/features/home/api/unsplash_images_api.dart';
+import 'package:mc_gallery/features/home/services/image_cache_manager_service.dart';
 import 'package:mc_gallery/features/home/services/images_service.dart';
 import 'package:mc_gallery/features/home/views/gallery/gallery_view_model.dart';
 import 'package:mc_gallery/features/home/views/image_carousel/image_carousel_view_model.dart';
@@ -44,7 +45,7 @@ class Locator {
       () => GalleryViewModel(
         imagesService: ImagesService.locate,
         navigationService: NavigationService.locate,
-        appLifecycleService: AppLifecycleService.locate,
+        imageCacheManagerService: ImageCacheManagerService.locate,
         loggingService: LoggingService.locate,
       ),
     );
@@ -52,7 +53,6 @@ class Locator {
       () => ImageCarouselViewModel(
         imagesService: ImagesService.locate,
         navigationService: NavigationService.locate,
-        appLifecycleService: AppLifecycleService.locate,
         loggingService: LoggingService.locate,
       ),
     );
@@ -86,11 +86,14 @@ class Locator {
       dispose: (param) async => await param.dispose(),
     );
     it.registerSingleton(
-      ImagesService(
-        imagesApi: UnsplashImagesApi(),
-      ),
+      ImagesService(imagesApi: UnsplashImagesApi.locate, loggingService: LoggingService.locate),
       signalsReady: true,
     );
+    it.registerSingleton(
+      ImageCacheManagerService(
+        appLifecycleService: AppLifecycleService.locate,
+      ),
+    );
   }
 
   static FutureOr<void> _registerRepos(GetIt locator) {}