Dark Mode in Flutter

Rishabh Sharma

28 April 2023

Now a days, dark mode in apps have become very popular. Mostly all major apps give choice to users to switch to dark mode. Now let’s see how we can add this feature to our Flutter apps.

Flutter was build with theming, so dealing with OS level dark mode is pretty simple.

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If you check the MaterialApp widget you will see we have the theme and darkTheme parameter where we can provide the dark ThemeData in darkTheme and light ThemeData in theme if we want our app to change the theme according to the system preferences.

MaterialApp(
  theme: ThemeData.light(),
  darkTheme: ThemeData.dark(),
  home: MyApp(),  //Your home screen
)

MaterialApp(

theme: ThemeData.light(),

darkTheme: ThemeData.dark(),

home: MyApp(), //Your home screen

)

So here as mentioned in the widget we can set theme and darkTheme.

Below an example of main.dart representing the complete implementation:

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  final ValueNotifier<ThemeMode> _notifier = ValueNotifier(ThemeMode.light);

  @override
  Widget build(BuildContext context) {

    return ValueListenableBuilder<ThemeMode>(
      valueListenable: _notifier,
      builder: (_, mode, __) {
        return MaterialApp(
          theme: ThemeData.light(),
          darkTheme: ThemeData.dark(),
          themeMode: mode, // Decides which theme to show, light or dark.
          home: Scaffold(
            appBar: AppBar(title: Text("Home")),
            body: Center(
              child: ElevatedButton(
                onPressed: () => _notifier.value = mode == ThemeMode.light ? ThemeMode.dark : ThemeMode.light,
                child: Text('Toggle Theme'),
              ),
            ),
          ),
        );
      },
    );
  }
}

import 'package:flutter/material.dart';

void main() {

runApp(MyApp());

}

class MyApp extends StatelessWidget {

final ValueNotifier<ThemeMode> _notifier = ValueNotifier(ThemeMode.light);

@override

Widget build(BuildContext context) {

return ValueListenableBuilder<ThemeMode>(

valueListenable: _notifier,

builder: (_, mode, __) {

return MaterialApp(

theme: ThemeData.light(),

darkTheme: ThemeData.dark(),

themeMode: mode, // Decides which theme to show, light or dark.

home: Scaffold(

appBar: AppBar(title: Text("Home")),

body: Center(

child: ElevatedButton(

onPressed: () => _notifier.value = mode == ThemeMode.light ? ThemeMode.dark : ThemeMode.light,

child: Text('Toggle Theme'),

);

}

Here, I have create a toggle button to switch theme mode using ValueNotifier.

Thanks for reading this article ❤

If I got something wrong 🙈, let me know in the comments. I would love to improve.