Improve image loading

lib/pages/settings/reader.dart

@@ -131,9 +131,10 @@ class _ReaderSettingsState extends State<ReaderSettings> {
               "On the image browsing page, you can quickly collect images by sliding horizontally or vertically according to your reading mode"
                   .tl,
         ).toSliver(),
-        _PopupWindowSetting(
+        _CallbackSetting(
           title: "Custom Image Processing".tl,
-          builder: () => _CustomImageProcessing(),
+          callback: () => context.to(() => _CustomImageProcessing()),
+          actionTitle: "Edit".tl,
         ).toSliver(),
       ],
     );
@@ -163,10 +164,25 @@ class __CustomImageProcessingState extends State<_CustomImageProcessing> {
     super.dispose();
   }
 
+  int resetKey = 0;
+
   @override
   Widget build(BuildContext context) {
-    return PopUpWidgetScaffold(
-      title: "Custom Image Processing".tl,
+    return Scaffold(
+      appBar: Appbar(
+        title: Text("Custom Image Processing".tl),
+        actions: [
+          TextButton(
+            onPressed: () {
+              current = defaultCustomImageProcessing;
+              appdata.settings['customImageProcessing'] = current;
+              resetKey++;
+              setState(() {});
+            },
+            child: Text("Reset".tl),
+          )
+        ],
+      ),
       body: Column(
         children: [
           _SwitchSetting(
@@ -182,6 +198,7 @@ class __CustomImageProcessingState extends State<_CustomImageProcessing> {
               ),
               child: SizedBox.expand(
                 child: CodeEditor(
+                  key: ValueKey(resetKey),
                   initialValue: appdata.settings['customImageProcessing'],
                   onChanged: (value) {
                     current = value;