change button language

covas_mobile/lib/locale_provider.dart

@@ -0,0 +1,21 @@
+import 'package:flutter/material.dart';
+
+class LocaleProvider with ChangeNotifier {
+  Locale _locale = const Locale('en');
+
+  Locale get locale => _locale;
+
+  void setLocale(Locale locale) {
+    if (!L10n.all.contains(locale)) return;
+
+    _locale = locale;
+    notifyListeners();
+  }
+}
+
+class L10n {
+  static final all = [
+    const Locale('en'),
+    const Locale('fr'),
+  ];
+}