Cleanup

lib/main.dart

@@ -132,15 +132,10 @@ class _MainState extends State<Main> {
 
     return ColoredSafeArea(
       key: GlobalKey(),
-      child: WillPopScope(
-        onWillPop: () async {
-          if (contentStack.isNotEmpty) {
-            _popContentView();
-
-            return false;
-          } else {
-            return true;
-          }
+      child: PopScope(
+        canPop: contentStack.isNotEmpty,
+        onPopInvoked: (didPop) => {
+          _popContentView()
         },
         child: Scaffold(
           appBar: PreferredSize(