fix #91

lib/foundation/image_provider/base_image_provider.dart

@@ -1,5 +1,6 @@
 import 'dart:async' show Future, StreamController, scheduleMicrotask;
 import 'dart:convert';
+import 'dart:math';
 import 'dart:ui' as ui show Codec;
 import 'dart:ui';
 import 'package:flutter/foundation.dart';
@@ -10,6 +11,39 @@ abstract class BaseImageProvider<T extends BaseImageProvider<T>>
     extends ImageProvider<T> {
   const BaseImageProvider();
 
+  static double? _effectiveScreenWidth;
+
+  static const double _normalComicImageRatio = 0.72;
+
+  static const double _minComicImageWidth = 1920 * _normalComicImageRatio;
+
+  static TargetImageSize _getTargetSize(width, height) {
+    if (_effectiveScreenWidth == null) {
+      final screens = PlatformDispatcher.instance.displays;
+      for (var screen in screens) {
+        if (screen.size.width > screen.size.height) {
+          _effectiveScreenWidth = max(
+            _effectiveScreenWidth ?? 0,
+            screen.size.height * _normalComicImageRatio,
+          );
+        } else {
+          _effectiveScreenWidth = max(
+            _effectiveScreenWidth ?? 0,
+            screen.size.width
+          );
+        }
+      }
+      if (_effectiveScreenWidth! < _minComicImageWidth) {
+        _effectiveScreenWidth = _minComicImageWidth;
+      }
+    }
+    if (width > _effectiveScreenWidth!) {
+      height = (height * _effectiveScreenWidth! / width).round();
+      width = _effectiveScreenWidth!.round();
+    }
+    return TargetImageSize(width: width, height: height);
+  }
+
   @override
   ImageStreamCompleter loadImage(T key, ImageDecoderCallback decode) {
     final chunkEvents = StreamController<ImageChunkEvent>();
@@ -45,19 +79,12 @@ abstract class BaseImageProvider<T extends BaseImageProvider<T>>
 
       while (data == null && !stop) {
         try {
-          if(_cache.containsKey(key.key)){
-            data = _cache[key.key];
-          } else {
-            data = await load(chunkEvents);
-            _checkCacheSize();
-            _cache[key.key] = data;
-            _cacheSize += data.length;
-          }
+          data = await load(chunkEvents);
         } catch (e) {
-          if(e.toString().contains("Invalid Status Code: 404")) {
+          if (e.toString().contains("Invalid Status Code: 404")) {
             rethrow;
           }
-          if(e.toString().contains("Invalid Status Code: 403")) {
+          if (e.toString().contains("Invalid Status Code: 403")) {
             rethrow;
           }
           if (e.toString().contains("handshake")) {
@@ -73,23 +100,24 @@ abstract class BaseImageProvider<T extends BaseImageProvider<T>>
         }
       }
 
-      if(stop) {
+      if (stop) {
         throw Exception("Image loading is stopped");
       }
 
-      if(data!.isEmpty) {
+      if (data!.isEmpty) {
         throw Exception("Empty image data");
       }
 
       try {
         final buffer = await ImmutableBuffer.fromUint8List(data);
-        return await decode(buffer);
+        return await decode(buffer, getTargetSize: _getTargetSize);
       } catch (e) {
         await CacheManager().delete(this.key);
         if (data.length < 2 * 1024) {
           // data is too short, it's likely that the data is text, not image
           try {
-            var text = const Utf8Codec(allowMalformed: false).decoder.convert(data);
+            var text =
+                const Utf8Codec(allowMalformed: false).decoder.convert(data);
             throw Exception("Expected image data, but got text: $text");
           } catch (e) {
             // ignore
@@ -107,30 +135,6 @@ abstract class BaseImageProvider<T extends BaseImageProvider<T>>
     }
   }
 
-  static final _cache = <String, Uint8List>{};
-
-  static var _cacheSize = 0;
-
-  static var _cacheSizeLimit = 50 * 1024 * 1024;
-
-  static void _checkCacheSize(){
-    while (_cacheSize > _cacheSizeLimit){
-      var firstKey = _cache.keys.first;
-      _cacheSize -= _cache[firstKey]!.length;
-      _cache.remove(firstKey);
-    }
-  }
-
-  static void clearCache(){
-    _cache.clear();
-    _cacheSize = 0;
-  }
-
-  static void setCacheSizeLimit(int size){
-    _cacheSizeLimit = size;
-    _checkCacheSize();
-  }
-
   Future<Uint8List> load(StreamController<ImageChunkEvent> chunkEvents);
 
   String get key;

lib/foundation/image_provider/reader_image.dart

@@ -2,6 +2,7 @@ import 'dart:async' show Future, StreamController;
 import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:venera/network/images.dart';
+import 'package:venera/utils/io.dart';
 import 'base_image_provider.dart';
 import 'reader_image.dart' as image_provider;
 
@@ -20,6 +21,14 @@ class ReaderImageProvider
 
   @override
   Future<Uint8List> load(StreamController<ImageChunkEvent> chunkEvents) async {
+    if (imageKey.startsWith('file://')) {
+      var file = File(imageKey);
+      if (await file.exists()) {
+        return file.readAsBytes();
+      }
+      throw "Error: File not found.";
+    }
+
     await for (var event
         in ImageDownloader.loadComicImage(imageKey, sourceKey, cid, eid)) {
       chunkEvents.add(ImageChunkEvent(

lib/pages/reader/images.dart

@@ -162,19 +162,22 @@ class _GalleryModeState extends State<_GalleryMode>
         } else {
           int pageIndex = index - 1;
           int startIndex = pageIndex * reader.imagesPerPage;
-          int endIndex = math.min(startIndex + reader.imagesPerPage, reader.images!.length);
-          List<String> pageImages = reader.images!.sublist(startIndex, endIndex);
+          int endIndex = math.min(
+              startIndex + reader.imagesPerPage, reader.images!.length);
+          List<String> pageImages =
+              reader.images!.sublist(startIndex, endIndex);
 
           cached[index] = true;
           cache(index);
 
           photoViewControllers[index] = PhotoViewController();
 
-          if(reader.imagesPerPage == 1) {
+          if (reader.imagesPerPage == 1) {
             return PhotoViewGalleryPageOptions(
               filterQuality: FilterQuality.medium,
               controller: photoViewControllers[index],
-              imageProvider: _createImageProviderFromKey(pageImages[0], context),
+              imageProvider:
+                  _createImageProviderFromKey(pageImages[0], context),
               fit: BoxFit.contain,
               errorBuilder: (_, error, s, retry) {
                 return NetworkError(message: error.toString(), retry: retry);
@@ -645,32 +648,19 @@ class _ContinuousModeState extends State<_ContinuousMode>
 
 ImageProvider _createImageProviderFromKey(
     String imageKey, BuildContext context) {
-  if (imageKey.startsWith('file://')) {
-    return FileImage(File(imageKey.replaceFirst("file://", '')));
-  } else {
-    var reader = context.reader;
-    return ReaderImageProvider(
-      imageKey,
-      reader.type.comicSource!.key,
-      reader.cid,
-      reader.eid,
-    );
-  }
+  var reader = context.reader;
+  return ReaderImageProvider(
+    imageKey,
+    reader.type.comicSource!.key,
+    reader.cid,
+    reader.eid,
+  );
 }
 
 ImageProvider _createImageProvider(int page, BuildContext context) {
   var reader = context.reader;
   var imageKey = reader.images![page - 1];
-  if (imageKey.startsWith('file://')) {
-    return FileImage(File(imageKey.replaceFirst("file://", '')));
-  } else {
-    return ReaderImageProvider(
-      imageKey,
-      reader.type.comicSource!.key,
-      reader.cid,
-      reader.eid,
-    );
-  }
+  return _createImageProviderFromKey(imageKey, context);
 }
 
 void _precacheImage(int page, BuildContext context) {

lib/pages/reader/reader.dart

@@ -9,6 +9,7 @@ import 'package:flutter/material.dart';
 import 'package:flutter/rendering.dart';
 import 'package:flutter/scheduler.dart';
 import 'package:flutter/services.dart';
+import 'package:flutter_memory_info/flutter_memory_info.dart';
 import 'package:photo_view/photo_view.dart';
 import 'package:photo_view/photo_view_gallery.dart';
 import 'package:scrollable_positioned_list/scrollable_positioned_list.dart';
@@ -21,6 +22,7 @@ import 'package:venera/foundation/comic_type.dart';
 import 'package:venera/foundation/history.dart';
 import 'package:venera/foundation/image_provider/reader_image.dart';
 import 'package:venera/foundation/local.dart';
+import 'package:venera/foundation/log.dart';
 import 'package:venera/pages/settings/settings_page.dart';
 import 'package:venera/utils/data_sync.dart';
 import 'package:venera/utils/file_type.dart';
@@ -142,9 +144,27 @@ class _ReaderState extends State<Reader> with _ReaderLocation, _ReaderWindow {
     if(appdata.settings['enableTurnPageByVolumeKey']) {
       handleVolumeEvent();
     }
+    setImageCacheSize();
     super.initState();
   }
 
+  void setImageCacheSize() async {
+    var availableRAM = await MemoryInfo.getFreePhysicalMemorySize();
+    if (availableRAM == null) return;
+    int maxImageCacheSize;
+    if (availableRAM < 1 << 30) {
+      maxImageCacheSize = 100 << 20;
+    } else if (availableRAM < 2 << 30) {
+      maxImageCacheSize = 200 << 20;
+    } else if (availableRAM < 4 << 30) {
+      maxImageCacheSize = 300 << 20;
+    } else {
+      maxImageCacheSize = 500 << 20;
+    }
+    Log.info("Reader", "Detect available RAM: $availableRAM, set image cache size to $maxImageCacheSize");
+    PaintingBinding.instance.imageCache.maximumSizeBytes = maxImageCacheSize;
+  }
+
   @override
   void dispose() {
     autoPageTurningTimer?.cancel();
@@ -154,6 +174,7 @@ class _ReaderState extends State<Reader> with _ReaderLocation, _ReaderWindow {
     Future.microtask(() {
       DataSync().onDataChanged();
     });
+    PaintingBinding.instance.imageCache.maximumSizeBytes = 100 << 20;
     super.dispose();
   }
 

pubspec.lock

@@ -388,6 +388,15 @@ packages:
     description: flutter
     source: sdk
     version: "0.0.0"
+  flutter_memory_info:
+    dependency: "direct main"
+    description:
+      path: "."
+      ref: HEAD
+      resolved-ref: a401e3f96dca6ab0ab07b6b2ec0b649833f04c14
+      url: "https://github.com/wgh136/flutter_memory_info"
+    source: git
+    version: "0.0.1"
   flutter_plugin_android_lifecycle:
     dependency: transitive
     description:
@@ -1070,10 +1079,10 @@ packages:
     dependency: transitive
     description:
       name: win32
-      sha256: "68d1e89a91ed61ad9c370f9f8b6effed9ae5e0ede22a270bdfa6daf79fc2290a"
+      sha256: "8b338d4486ab3fbc0ba0db9f9b4f5239b6697fcee427939a40e720cbb9ee0a69"
       url: "https://pub.dev"
     source: hosted
-    version: "5.5.4"
+    version: "5.9.0"
   window_manager:
     dependency: "direct main"
     description:

pubspec.yaml

@@ -72,6 +72,9 @@ dependencies:
   pdf: ^3.11.1
   dynamic_color: ^1.7.0
   shimmer: ^3.0.0
+  flutter_memory_info:
+    git:
+      url: https://github.com/wgh136/flutter_memory_info
 
 dev_dependencies:
   flutter_test: