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// Checks that tappable nodes have a minimum size of 44 by 44 pixels
// for iOS.
await expectLater(tester, meetsGuideline(iOSTapTargetGuideline));
// Checks that touch targets with a tap or long press action are labeled.
await expectLater(tester, meetsGuideline(labeledTapTargetGuideline));
// Checks whether semantic nodes meet the minimum text contrast levels.
// The recommended text contrast is 3:1 for larger text
// (18 point and above regular).
await expectLater(tester, meetsGuideline(textContrastGuideline));
handle.dispose();<code_end>
You can add Guideline API tests
in test/widget_test.dart of your app directory, or as a separate test
file (such as test/a11y_test.dart in the case of the Name Generator).<topic_end>
<topic_start>
Testing accessibility on web
You can debug accessibility by visualizing the semantic nodes created for your web app
using the following command line flag in profile and release modes:With the flag activated, the semantic nodes appear on top of the widgets;
you can verify that the semantic elements are placed where they should be.
If the semantic nodes are incorrectly placed, please file a bug report.<topic_end>
<topic_start>
Accessibility release checklist
Here is a non-exhaustive list of things to consider as you prepare your
app for release.<topic_end>
<topic_start>
Learn more
To learn more about Flutter and accessibility, check out
the following articles written by community members:
<topic_end>
<topic_start>Internationalizing Flutter apps
<topic_end>
<topic_start>What you'll learn
If your app might be deployed to users who speak another
language then you’ll need to internationalize it.
That means you need to write the app in a way that makes
it possible to localize values like text and layouts
for each language or locale that the app supports.
Flutter provides widgets and classes that help with
internationalization and the Flutter libraries
themselves are internationalized.This page covers concepts and workflows necessary to
localize a Flutter application using the
MaterialApp and CupertinoApp classes,
as most apps are written that way.
However, applications written using the lower level
WidgetsApp class can also be internationalized
using the same classes and logic.<topic_end>
<topic_start>
Introduction to localizations in Flutter
This section provides a tutorial on how to create and
internationalize a new Flutter application,
along with any additional setup
that a target platform might require.You can find the source code for this example in
gen_l10n_example.<topic_end>
<topic_start>
Setting up an internation­alized app: the Flutter_localizations package
By default, Flutter only provides US English localizations.
To add support for other languages,
an application must specify additional
MaterialApp (or CupertinoApp) properties,
and include a package called flutter_localizations.
As of December 2023, this package supports 115 languages
and language variants.To begin, start by creating a new Flutter application
in a directory of your choice with the flutter create command.To use flutter_localizations,
add the package as a dependency to your pubspec.yaml file,
as well as the intl package:This creates a pubspec.yml file with the following entries:
<code_start>dependencies:
flutter:
sdk: flutter
flutter_localizations:
sdk: flutter
intl: any<code_end>
Then import the flutter_localizations library and specify
localizationsDelegates and supportedLocales for
your MaterialApp or CupertinoApp:
<code_start>import 'package:flutter_localizations/flutter_localizations.dart';<code_end>
<code_start>return const MaterialApp(
title: 'Localizations Sample App',
localizationsDelegates: [
GlobalMaterialLocalizations.delegate,
GlobalWidgetsLocalizations.delegate,
GlobalCupertinoLocalizations.delegate,
],
supportedLocales: [
Locale('en'), // English
Locale('es'), // Spanish
],
home: MyHomePage(),
);<code_end>
After introducing the flutter_localizations package
and adding the previous code,
the Material and Cupertino
packages should now be correctly localized in
one of the 115 supported locales.
Widgets should be adapted to the localized messages,
along with correct left-to-right or right-to-left layout.Try switching the target platform’s locale to
Spanish (es) and the messages should be localized.Apps based on WidgetsApp are similar except that the
GlobalMaterialLocalizations.delegate isn’t needed.The full Locale.fromSubtags constructor is preferred
as it supports scriptCode, though the Locale default
constructor is still fully valid.The elements of the localizationsDelegates list are
factories that produce collections of localized values.
GlobalMaterialLocalizations.delegate provides localized