Create context in a situation where you may not have access to it. For example, if need to pass a translated message (requiring context) using `AppLocalizations.of(context)!.message` to a SnackBar from a function where we have no context, we can make the SnackBar argument a function that takes BuildContext as a param, and later get that param fr…

creating_context_from_thin_air.dart

import 'package:flutter/material.dart';

const Color darkBlue = Color.fromARGB(255, 18, 32, 47);

/// Global Scaffold Messenger Key (SnackBars)
final GlobalKey<ScaffoldMessengerState> rootScaffoldMessengerKey = GlobalKey<ScaffoldMessengerState>();

void main() {
  runApp(MyApp());
}

class ShowSnackBar {
  static builtSnackBar({required String Function(BuildContext context) stringBuilder}) {
    Widget _content = Builder(
      builder: (BuildContext context) {
        String _message = stringBuilder(context);

        return Text(_message);
      },
    );

    final snackBar = SnackBar(content: _content);
    final scaffoldMessengerState = rootScaffoldMessengerKey.currentState;
    if (scaffoldMessengerState != null) {
      scaffoldMessengerState.showSnackBar(snackBar);
    } else {
      print("SnackBar root state is null, cannot display SnackBar.");
    }
  }
}



class MyApp extends StatelessWidget {

  
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      theme: ThemeData.dark().copyWith(
        scaffoldBackgroundColor: darkBlue,
      ),
      scaffoldMessengerKey: rootScaffoldMessengerKey,
      debugShowCheckedModeBanner: false,
      home: Scaffold(
        body: Center(
          child: MyWidget(),
        ),
      ),
    );
  }
}

class MyWidget extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return ElevatedButton(onPressed: () { showSnackBar(); }, child: const Text("Show SnackBar"),
      
    );
  }

  void showSnackBar() {
    ShowSnackBar.builtSnackBar(stringBuilder: (BuildContext context) { return AppLocalizations.of(context)!.errorsProcessing; });
  }
}