flutter_application_1/lib/widgets/language_switcher_widget.dart

import 'package:flutter/material.dart';
import 'package:flutter/cupertino.dart';
import 'package:flutter_gen/gen_l10n/app_localizations.dart';

class LanguageSwitcher extends StatefulWidget {
  final Locale currentLocale;
  final Function(Locale) onLocaleChanged;

  const LanguageSwitcher({
    super.key,
    required this.currentLocale,
    required this.onLocaleChanged,
  });

  @override
  LanguageSwitcherState createState() => LanguageSwitcherState();
}

class LanguageSwitcherState extends State<LanguageSwitcher> {
  late Locale _selectedLocale;

  @override
  void initState() {
    super.initState();
    _selectedLocale = widget.currentLocale;
  }

  @override
  Widget build(BuildContext context) {
    final localizations = AppLocalizations.of(context)!;
    final isMobile = Theme.of(context).platform == TargetPlatform.iOS || Theme.of(context).platform == TargetPlatform.android;

    return Theme(
      data: ThemeData.light().copyWith(
        popupMenuTheme: PopupMenuThemeData(
          color: CupertinoColors.extraLightBackgroundGray,
          shape: RoundedRectangleBorder(
            borderRadius: BorderRadius.circular(8),
          ),
          textStyle: const TextStyle(color: CupertinoColors.black),
        ),
        tooltipTheme: TooltipThemeData(
          decoration: BoxDecoration(
            color: CupertinoColors.black,
            borderRadius: BorderRadius.circular(4.0),
          ),
          textStyle: const TextStyle(color: CupertinoColors.white),
        ),
      ),
      child: Container(
        decoration: BoxDecoration(
          color: CupertinoColors.extraLightBackgroundGray,
          borderRadius: BorderRadius.circular(100.0),
          boxShadow: const [
            BoxShadow(
              color: Colors.black26,
              blurRadius: 8.0,
              offset: Offset(0, 4),
            ),
          ],
        ),
        child: PopupMenuButton<Locale>(
          key: const Key('languagePopupMenu'),
          offset: Offset(0.0, isMobile ? 55 : 45),
          onSelected: (Locale locale) {
            setState(() {
              _selectedLocale = locale;
            });
            widget.onLocaleChanged(locale);
          },
          tooltip: localizations.choose_language,
          icon: const Icon(
            CupertinoIcons.globe,
            color: CupertinoColors.black,
          ),
          itemBuilder: (BuildContext context) {
            return [
              PopupMenuItem<Locale>(
                value: const Locale('en'),
                child: Row(
                  mainAxisAlignment: MainAxisAlignment.spaceBetween,
                  children: [
                    Text(AppLocalizations.of(context)!.language_english),
                    if (_selectedLocale.languageCode == 'en') const Icon(CupertinoIcons.checkmark_alt, size: 20),
                  ],
                ),
              ),
              PopupMenuItem<Locale>(
                value: const Locale('de'),
                child: Row(
                  mainAxisAlignment: MainAxisAlignment.spaceBetween,
                  children: [
                    Text(AppLocalizations.of(context)!.language_german),
                    if (_selectedLocale.languageCode == 'de') const Icon(CupertinoIcons.checkmark_alt, size: 20),
                  ],
                ),
              ),
            ];
          },
        ),
      ),
    );
  }
}