fix: proxying image request properly

Author: w568w

lib/page/forum/image_viewer.dart

@@ -19,6 +19,7 @@ import 'dart:io';
 
 import 'package:cached_network_image/cached_network_image.dart';
 import 'package:dan_xi/generated/l10n.dart';
+import 'package:dan_xi/util/io/cache_manager_with_proxy.dart';
 import 'package:dan_xi/util/io/dio_utils.dart';
 import 'package:dan_xi/util/noticing.dart';
 import 'package:dan_xi/util/platform_universal.dart';
@@ -132,8 +133,8 @@ class ImageViewerPageState extends State<ImageViewerPage> {
   }
 
   Future<void> shareImage(BuildContext context) async {
-    File image =
-        await DefaultCacheManager().getSingleFile(_imageList[showIndex].hdUrl);
+    File image = await DefaultCacheManagerWithProxy()
+        .getSingleFile(_imageList[showIndex].hdUrl);
     if (!mounted) return;
 
     if (PlatformX.isMobile) {
@@ -159,8 +160,8 @@ class ImageViewerPageState extends State<ImageViewerPage> {
   }
 
   Future<void> saveImage(BuildContext context) async {
-    File image =
-        await DefaultCacheManager().getSingleFile(_imageList[showIndex].hdUrl);
+    File image = await DefaultCacheManagerWithProxy()
+        .getSingleFile(_imageList[showIndex].hdUrl);
     if (PlatformX.isAndroid) {
       bool hasPermission = await PlatformX.galleryStorageGranted;
       if (!hasPermission && !(await Permission.storage.request().isGranted)) {
@@ -309,7 +310,8 @@ class ImageViewerBodyViewState extends State<ImageViewerBodyView> {
   Future<void> cacheOriginalImage() async {
     if (widget.imageInfo.thumbUrl == null) return;
     try {
-      await DefaultCacheManager().getSingleFile(widget.imageInfo.hdUrl);
+      await DefaultCacheManagerWithProxy()
+          .getSingleFile(widget.imageInfo.hdUrl);
       setState(() => originalLoading = false);
     } catch (e, st) {
       setState(() {

lib/page/subpage_settings.dart

@@ -32,6 +32,7 @@ import 'package:dan_xi/repository/forum/forum_repository.dart';
 import 'package:dan_xi/util/browser_util.dart';
 import 'package:dan_xi/util/flutter_app.dart';
 import 'package:dan_xi/util/forum/clean_mode_filter.dart';
+import 'package:dan_xi/util/io/cache_manager_with_proxy.dart';
 import 'package:dan_xi/util/master_detail_view.dart';
 import 'package:dan_xi/util/noticing.dart';
 import 'package:dan_xi/util/platform_universal.dart';
@@ -51,7 +52,6 @@ import 'package:flutter/cupertino.dart';
 import 'package:flutter/gestures.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
-import 'package:flutter_cache_manager/flutter_cache_manager.dart';
 import 'package:flutter_email_sender/flutter_email_sender.dart';
 import 'package:flutter_layout_grid/flutter_layout_grid.dart';
 import 'package:flutter_platform_widgets/flutter_platform_widgets.dart';
@@ -797,7 +797,7 @@ class SettingsSubpageState extends PlatformSubpageState<SettingsSubpage> {
                   subtitle: Text(_clearCacheSubtitle ??
                       S.of(context).clear_cache_description),
                   onTap: () async {
-                    await DefaultCacheManager().emptyCache();
+                    await DefaultCacheManagerWithProxy().emptyCache();
                     setState(() {
                       _clearCacheSubtitle = S.of(context).cache_cleared;
                     });

lib/util/io/cache_manager_with_proxy.dart

@@ -0,0 +1,52 @@
+/*
+ *     Copyright (C) 2024  DanXi-Dev
+ *
+ *     This program is free software: you can redistribute it and/or modify
+ *     it under the terms of the GNU General Public License as published by
+ *     the Free Software Foundation, either version 3 of the License, or
+ *     (at your option) any later version.
+ *
+ *     This program is distributed in the hope that it will be useful,
+ *     but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *     GNU General Public License for more details.
+ *
+ *     You should have received a copy of the GNU General Public License
+ *     along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+import 'dart:io';
+
+import 'package:dan_xi/provider/settings_provider.dart';
+import 'package:dan_xi/util/platform_universal.dart';
+import 'package:flutter_cache_manager/flutter_cache_manager.dart';
+import 'package:http/io_client.dart';
+
+/// Exactly the same as [DefaultCacheManager], but also implements proxy support.
+///
+/// Note: It uses the same key as [DefaultCacheManager], so you can even
+/// manage the cache of this class with [DefaultCacheManager].
+class DefaultCacheManagerWithProxy extends CacheManager with ImageCacheManager {
+  static const key = DefaultCacheManager.key;
+
+  static final DefaultCacheManagerWithProxy _instance =
+      DefaultCacheManagerWithProxy._();
+
+  factory DefaultCacheManagerWithProxy() {
+    return _instance;
+  }
+
+  DefaultCacheManagerWithProxy._()
+      : super(Config(key, fileService: _buildProxiedHttpFileService()));
+
+  static _buildProxiedHttpFileService() {
+    String? proxy = SettingsProvider.getInstance().proxy;
+    if (PlatformX.isWeb) {
+      return HttpFileService();
+    } else {
+      return HttpFileService(
+          httpClient: IOClient(HttpClient()
+            ..findProxy = (uri) => proxy != null ? "PROXY $proxy" : "DIRECT"));
+    }
+  }
+}

lib/widget/forum/auto_bbs_image.dart

@@ -16,6 +16,7 @@
  */
 
 import 'package:cached_network_image/cached_network_image.dart';
+import 'package:dan_xi/util/io/cache_manager_with_proxy.dart';
 import 'package:dan_xi/util/io/dio_utils.dart';
 import 'package:dan_xi/widget/forum/render/base_render.dart';
 import 'package:dio/dio.dart';
@@ -70,6 +71,7 @@ class AutoBBSImage extends StatelessWidget {
                 imageUrl: src,
                 width: maxWidth,
                 height: maxWidth,
+                cacheManager: DefaultCacheManagerWithProxy(),
                 // Ensure shape is the same as the loading indicator
                 fit: BoxFit.contain,
                 errorWidget: (context, url, error) {