locale_switcher

A widget for switching the locale of your application.

Content

• About
• Features
• Usage
• Example
• Todo
• FAQ

About

This package allows you to add locale-switching functionality to your app with just 2 lines of code.

This is NOT a localization package, it is just a few useful widgets that extend functionality of localization systems, such as: intl, easy_localization, etc...

Note: This package is already small, but if you still want to further reduce its size, you can use locale_switcher_dev package, which allow you to control what flags are included (or none) and which packages it depend on (or none).

Features

• LocaleManager widget:

  • optionally: load/stores the last selected locale in SharedPreferences,
  • update locale of app (listen to notifier and rebuild MaterialApp),
  • observes changes in the system locale,

• LocaleSwitcher - a widget to switch locale:

  • show a list of locales and special option to use system locale,
  • constructor LocaleSwitcher.segmentedButton,
  • constructor LocaleSwitcher.menu,
  • constructor LocaleSwitcher.custom,
  • constructor LocaleSwitcher.iconButton - button/indicator which open popup window to select locale,

• Some other helpers:

  • LangIconWithToolTip class with additional constructor forIconBuilder ,
  • showSelectLocaleDialog.
  • Extension for Locale which return flag - Locale.flag

• Can be generated via locale_switcher_dev package, in this case you control:

  • what flags are included (or none),
  • which packages it depend on (or none).

Usage

1. Wrap MaterialApp or CupertinoApp with LocaleManager (example for intl package):

  @override
Widget build(BuildContext context, WidgetRef ref) {
  return LocaleManager(
      child: MaterialApp(
          locale: LocaleSwitcher.localeBestMatch,
          supportedLocales: AppLocalizations.supportedLocales,
          localizationsDelegates: AppLocalizations.localizationsDelegates,
  //...

2. Add LocaleSwitcher widget anywhere into your app.

Troubleshooting

Note: localization should be set up before you start to use this package, if there some problems - please, check next section and/or documentation of localization system you use, before reporting bug.

Check that intl package is setup correctly:

The following instructions are from intl package, so you probably already did them:

In pubspec.yaml:

dependencies: # in this section
  intl:
  flutter_localizations:
    sdk: flutter
dev_dependencies: # in this section 
  build_runner:
flutter: # in this section 
  generate: true  

Optionally - in l10n.yaml:

arb-dir: lib/src/l10n
template-arb-file: intl_en.arb
output-dir: lib/src/l10n/generated
output-localization-file: app_localizations.dart
untranslated-messages-file: desiredFileName.txt
preferred-supported-locales: [ "en", "vi", "de" ]
nullable-getter: false

Example

With intl package:

Online Example here

• Example Code (recommended).

Another example code: LocaleSwitcher used without LocaleManager(not recommended).

Example with dynamic option switch: here.

With easy_localization package:

locale_switcher_dev + easy_localization: https://github.com/Alexqwesa/locale_switcher/tree/builder/examples/easy_localization (recommended)

locale_switcher + easy_localization: https://github.com/Alexqwesa/locale_switcher/tree/main/examples/easy_localization

TODO:

• Test with other localization system (currently: tested intl and easy_localization)
• Support slang
• Rectangle and oval flags, not just square and circle

FAQ

- How to change order of languages?

Languages are shown in the same order as they listed in l10n.yaml, or dynamically via LocaleSwitcher.custom.

- How to change flag of language?

Use LocaleManager.reassign parameter like this:

LocaleManager(
  reassign: {'en': ['GB', 'English', <Your_icon_optional>]}
  // (first two options are required, third is optional)
  // first option is the code of country which flag you want to use
...
)

- How to use localization outside of MaterialApp(or CupertinoApp)?

Here is a useful example, although it is not depend on this package:

import 'package:flutter_gen/gen_l10n/app_localizations.dart';

/// Access localization through locale
extension LocaleWithDelegate on Locale {
  /// Get class with translation strings for this locale.
  AppLocalizations get tr => lookupAppLocalizations(this);
}

Locale("en").tr.example
// or 
LocaleManager.locale.value.tr.example