blob: b7f65bf787f05851ab7f9f37758c0e0d8b7b9ffe [file] [log] [blame]
// Copyright 2014 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
import 'package:flutter/widgets.dart';
import 'localizations.dart';
/// Asserts that the given context has a [Localizations] ancestor that contains
/// a [CupertinoLocalizations] delegate.
/// To call this function, use the following pattern, typically in the
/// relevant Widget's build method:
/// ```dart
/// assert(debugCheckHasCupertinoLocalizations(context));
/// ```
/// Does nothing if asserts are disabled. Always returns true.
bool debugCheckHasCupertinoLocalizations(BuildContext context) {
assert(() {
if (Localizations.of<CupertinoLocalizations>(context, CupertinoLocalizations) == null) {
throw FlutterError.fromParts(<DiagnosticsNode>[
ErrorSummary('No CupertinoLocalizations found.'),
'${context.widget.runtimeType} widgets require CupertinoLocalizations '
'to be provided by a Localizations widget ancestor.',
'The cupertino library uses Localizations to generate messages, '
'labels, and abbreviations.',
'To introduce a CupertinoLocalizations, either use a '
'CupertinoApp at the root of your application to include them '
'automatically, or add a Localization widget with a '
'CupertinoLocalizations delegate.',
...context.describeMissingAncestor(expectedAncestorType: CupertinoLocalizations),
return true;
return true;