Merge pull request #728 from mrandhawa14/fix/cover-decode-resize

perf(library): decode covers at thumbnail resolution to cut image-cache RAM (refs #609)

lib/modules/library/widgets/library_entry_utils.dart

@@ -6,19 +6,21 @@ import 'package:mangayomi/modules/library/providers/library_filter_provider.dart
 import 'package:mangayomi/modules/library/providers/library_state_provider.dart';
 import 'package:mangayomi/models/manga.dart';
 import 'package:mangayomi/modules/manga/detail/providers/state_providers.dart';
-import 'package:mangayomi/modules/widgets/custom_extended_image_provider.dart';
 import 'package:mangayomi/modules/widgets/manga_image_card_widget.dart';
+import 'package:mangayomi/utils/cached_network.dart';
 import 'package:mangayomi/utils/constant.dart';
 import 'package:mangayomi/utils/extensions/build_context_extensions.dart';
 import 'package:mangayomi/utils/headers.dart';
 
 /// Resolves the correct [ImageProvider] for a manga entry, preferring a custom
-/// local cover over the remote URL.
+/// local cover over the remote URL. Remote covers are wrapped in
+/// [coverProvider] so they decode at thumbnail resolution rather than the
+/// source resolution — see refs #609.
 ImageProvider resolveCoverImage(Manga entry, WidgetRef ref) {
   if (entry.customCoverImage != null) {
     return MemoryImage(entry.customCoverImage as Uint8List);
   }
-  return CustomExtendedNetworkImageProvider(
+  return coverProvider(
     toImgUrl(entry.customCoverFromTracker ?? entry.imageUrl ?? ''),
     headers: (entry.isLocalArchive ?? false)
         ? null

lib/modules/widgets/manga_image_card_widget.dart

@@ -9,7 +9,7 @@ import 'package:mangayomi/models/manga.dart';
 import 'package:mangayomi/models/settings.dart';
 import 'package:mangayomi/models/source.dart';
 import 'package:mangayomi/modules/manga/detail/manga_detail_main.dart';
-import 'package:mangayomi/modules/widgets/custom_extended_image_provider.dart';
+import 'package:mangayomi/utils/cached_network.dart';
 import 'package:mangayomi/router/router.dart';
 import 'package:mangayomi/utils/extensions/build_context_extensions.dart';
 import 'package:mangayomi/utils/constant.dart';
@@ -46,7 +46,7 @@ class MangaImageCardWidget extends ConsumerWidget {
       image: hasData && libraryManga!.customCoverImage != null
           ? MemoryImage(libraryManga!.customCoverImage as Uint8List)
                 as ImageProvider
-          : CustomExtendedNetworkImageProvider(
+          : coverProvider(
               toImgUrl(
                 hasData
                     ? libraryManga!.customCoverFromTracker ??
@@ -61,7 +61,6 @@ class MangaImageCardWidget extends ConsumerWidget {
                   sourceId: source.id,
                 ),
               ),
-              cache: true,
               cacheMaxAge: const Duration(days: 7),
             ),
       onTap: () => _toMangaRdD(ref, context, false),
@@ -138,7 +137,7 @@ class MangaImageCardListTileWidget extends ConsumerWidget {
     final image = hasData && libraryManga!.customCoverImage != null
         ? MemoryImage(libraryManga!.customCoverImage as Uint8List)
               as ImageProvider
-        : CustomExtendedNetworkImageProvider(
+        : coverProvider(
             toImgUrl(
               hasData
                   ? libraryManga!.customCoverFromTracker ??

lib/utils/cached_network.dart

@@ -2,6 +2,47 @@ import 'package:extended_image/extended_image.dart';
 import 'package:flutter/material.dart';
 import 'package:mangayomi/modules/widgets/custom_extended_image_provider.dart';
 
+/// Default upper bound on the encoded byte size of a thumbnail-sized cover
+/// after `ExtendedResizeImage` resamples. 200 KB roughly maps to a 400x600
+/// JPEG / WebP — sharp enough at typical grid / list display sizes on
+/// high-DPR screens, while keeping the *decoded* RAM footprint small (the
+/// resampled image goes into Flutter's `imageCache` decoded, where every
+/// saved KB matters).
+const int _coverMaxBytes = 200 << 10;
+
+/// Returns an `ImageProvider` for a manga / anime cover URL that decodes at
+/// thumbnail resolution rather than the source resolution.
+///
+/// Source covers are commonly 720x1080 or larger (~3 MB decoded RGBA per
+/// cover). When used directly in a library grid or list, every visible
+/// thumbnail fills `imageCache` with a 3 MB blob even though it renders at
+/// ~150x220 logical pixels. Wrapping the provider in `ExtendedResizeImage`
+/// instructs the decoder to resample to a much smaller bitmap before it
+/// hits the cache, so the same in-memory budget holds far more thumbnails
+/// and scrolling stops thrashing.
+///
+/// Use this for thumbnail call sites (library grid / list, browse search
+/// cards, tracker results, calendar, etc.). Do *not* use it for large hero
+/// covers (manga detail page) or for reader pages, which need full
+/// resolution.
+ImageProvider coverProvider(
+  String url, {
+  Map<String, String>? headers,
+  int maxBytes = _coverMaxBytes,
+  bool cache = true,
+  Duration? cacheMaxAge,
+}) {
+  return ExtendedResizeImage(
+    CustomExtendedNetworkImageProvider(
+      url,
+      headers: headers,
+      cache: cache,
+      cacheMaxAge: cacheMaxAge,
+    ),
+    maxBytes: maxBytes,
+  );
+}
+
 Widget cachedNetworkImage({
   Map<String, String>? headers,
   required String imageUrl,