limit cache size

assets/translation.json

@@ -129,7 +129,10 @@
     "Move favorite after reading": "阅读后移动收藏",
     "Are you sure you want to delete this folder?" : "确定要删除这个收藏夹吗？",
     "Import from file": "从文件导入",
-    "Failed to import": "导入失败"
+    "Failed to import": "导入失败",
+    "Cache Limit": "缓存限制",
+    "Set Cache Limit": "设置缓存限制",
+    "Size in MB": "大小（MB）"
   },
   "zh_TW": {
     "Home": "首頁",
@@ -261,6 +264,9 @@
     "Move favorite after reading": "閱讀後移動收藏",
     "Are you sure you want to delete this folder?" : "確定要刪除這個收藏夾嗎？",
     "Import from file": "從文件匯入",
-    "Failed to import": "匯入失敗"
+    "Failed to import": "匯入失敗",
+    "Cache Limit": "緩存限制",
+    "Set Cache Limit": "設置緩存限制",
+    "Size in MB": "大小（MB）"
   }
 }

lib/foundation/appdata.dart

@@ -108,6 +108,7 @@ class _Settings {
     'enableTapToTurnPages': true,
     'enablePageAnimation': true,
     'language': 'system', // system, zh-CN, zh-TW, en-US
+    'cacheSize': 2048, // in MB
   };
 
   operator [](String key) {

lib/init.dart

@@ -22,5 +22,5 @@ Future<void> init() async {
   await ComicSource.init();
   await LocalManager().init();
   await TagsTranslation.readData();
-  CacheManager();
+  CacheManager().setLimitSize(appdata.settings['cacheSize']);
 }

lib/pages/settings/app.dart

@@ -25,8 +25,8 @@ class _AppSettingsState extends State<AppSettings> {
           title: "Set New Storage Path".tl,
           actionTitle: "Set".tl,
           callback: () async {
-            if(App.isIOS) {
+            if (App.isMobile) {
-              context.showMessage(message: "Not supported on iOS".tl);
+              context.showMessage(message: "Not supported".tl);
               return;
             }
             var result = await selectDirectory();
@@ -65,6 +65,27 @@ class _AppSettingsState extends State<AppSettings> {
             setState(() {});
           },
         ).toSliver(),
+        _CallbackSetting(
+          title: "Cache Limit".tl,
+          subtitle: "${appdata.settings['cacheSize']} MB",
+          callback: () {
+            showInputDialog(
+              context: context,
+              title: "Set Cache Limit".tl,
+              hintText: "Size in MB".tl,
+              inputValidator: RegExp(r"^\d+$"),
+              onConfirm: (value) {
+                appdata.settings['cacheSize'] = int.parse(value);
+                appdata.saveData();
+                setState(() {});
+                CacheManager()
+                    .setLimitSize(appdata.settings['cacheSize'] * 1024 * 1024);
+                return null;
+              },
+            );
+          },
+          actionTitle: 'Set'.tl,
+        ).toSliver(),
         _SettingPartTitle(
           title: "Log".tl,
           icon: Icons.error_outline,