feat: use cupertino loading again

lib/widgets/loading.dart

@@ -1,20 +1,32 @@
 import 'package:flutter/material.dart';
 import 'package:flutter/cupertino.dart';
+import 'package:git_touch/models/theme.dart';
+import 'package:provider/provider.dart';
 
 class Loading extends StatelessWidget {
   final bool more;
 
   Loading({this.more = false});
+
+  Widget _buildIndicator(BuildContext context) {
+    switch (Provider.of<ThemeModel>(context).theme) {
+      case AppThemeType.cupertino:
+        return CupertinoActivityIndicator(radius: 12);
+      default:
+        return SizedBox(
+          width: 24,
+          height: 24,
+          child: CircularProgressIndicator(),
+        );
+    }
+  }
+
   @override
   Widget build(BuildContext context) {
     return Center(
       child: Padding(
         padding: EdgeInsets.symmetric(vertical: more ? 20 : 100),
-        child: SizedBox(
+        child: _buildIndicator(context),
-          width: 24,
-          height: 24,
-          child: CircularProgressIndicator(),
-        ),
       ),
     );
   }