added frontend

hartmann-foto-documentation-frontend/lib/utils/main_utils.dart

@@ -0,0 +1,33 @@
+// needed for web horizontal scroll behavior
+import 'dart:convert' show jsonDecode;
+import 'dart:ui';
+
+import 'package:flutter/foundation.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
+import 'package:json_theme/json_theme.dart';
+import 'package:fotodocumentation/main.dart' show logger;
+
+class MyCustomScrollBehavior extends MaterialScrollBehavior {
+  // Override behavior methods and getters like dragDevices
+  @override
+  Set<PointerDeviceKind> get dragDevices => {
+        PointerDeviceKind.touch,
+        PointerDeviceKind.mouse,
+      };
+}
+
+class ThemeLoader {
+  static Future<ThemeData> loadTheme() async {
+    try {
+      String prefix = kDebugMode && kIsWeb ? "" : "assets/";
+      String url = "${prefix}theme/appainter_theme.json";
+      final themeStr = await rootBundle.loadString(url);
+      final themeJson = jsonDecode(themeStr);
+      return ThemeDecoder.decodeThemeData(themeJson)!;
+    } catch (e) {
+      logger.e("Failed to load theme $e", error: e);
+      return ThemeData.light();
+    }
+  }
+}