Localise the UI into Russian and English, switchable without a restart

Strings move into Localization/Strings.resx plus a Russian satellite. XAML uses a {l:Loc Key} markup extension that yields a binding through the localizer's indexer rather than a resolved string, so changing the language raises PropertyChanged for the indexer and every caption in the app re-reads at once. Resolving strings once at load would have been simpler and would have needed an app restart to take effect. Three places where this is more than a string swap: Russian has three plural forms, so counted messages are assembled from .One / .Few / .Many keys via Localizer.Plural instead of "{0} records" with an English plural glued on. "1 запись", "3 записи", "7 записей". Enum captions in pickers go through LocalizedOption<T>. A value converter would resolve the caption once and never notice a language change; the wrapper keeps identity on the enum value so the selection survives, while the label follows the localizer. It needed a non-generic base for DataTemplate x:DataType, since Avalonia 12 compiles bindings by default and cannot infer one for an open generic. Text originating in the domain would otherwise have stayed English under a Russian UI — the screenshots showed exactly that. AvParser.Core still knows nothing about languages: ParseError now carries a Code and Arguments, and the UI translates Parse.Error.{Code} with a fallback to the English message. Parser names work the same way (Parser.{id}.Name falling back to DisplayName), which keeps "add a parser = one registration line" true — an untranslated parser shows its own name rather than a missing-key marker. Both .resx files are generated from one table so a key cannot exist in one and be missing from the other, and the tests assert that, plus no blank translations and identical {0} placeholder sets — a translation that drops a placeholder throws at runtime rather than merely reading oddly. A headless test switches language on a live shell and asserts the rendered text changes without the tree being rebuilt. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-08-13 18:15:01 +03:00
parent 9bf2ea5532
commit 8b552470b7
42 changed files with 2216 additions and 226 deletions
@@ -0,0 +1,90 @@
+using Avalonia;
+using Avalonia.Controls;
+using Avalonia.Headless.XUnit;
+using Avalonia.Threading;
+using Avalonia.VisualTree;
+using AvParser.Core.Settings;
+using AvParser.UI.Localization;
+using AvParser.UI.Navigation;
+using AvParser.UI.ViewModels;
+using AvParser.UI.Views;
+using ReactiveUI.Primitives.Concurrency;
+
+namespace AvParser.UI.HeadlessTests;
+
+public sealed class LocalizationViewTests : IDisposable
+{
+    /// <summary>Leaves the localizer where the rest of the assembly expects it.</summary>
+    public void Dispose() => Localizer.Instance.SetLanguage(AppLanguage.English);
+
+    private static (ShellView View, ShellViewModel ViewModel) ShowShell()
+    {
+        var navigation = new NavigationService([new FakePage("Page.Dashboard"), new FakePage("Page.Parse")]);
+        var viewModel = new ShellViewModel(navigation, new FakeThemeService(), ImmediateSequencer.Instance);
+        var view = new ShellView { DataContext = viewModel };
+
+        new Window
+        {
+            Width = 1400,
+            Height = 800,
+            Content = view,
+        }.Show();
+
+        Dispatcher.UIThread.RunJobs();
+        return (view, viewModel);
+    }
+
+    private static IReadOnlyList<string> RailLabels(Visual view) =>
+        [
+            .. view.GetVisualDescendants()
+                .OfType<TextBlock>()
+                .Where(block => block.Classes.Contains("navLabel"))
+                .Select(block => block.Text ?? string.Empty),
+        ];
+
+    [AvaloniaFact]
+    public void Rendered_text_follows_the_language_without_rebuilding_the_view()
+    {
+        Localizer.Instance.SetLanguage(AppLanguage.English);
+        var (view, _) = ShowShell();
+
+        var english = RailLabels(view);
+        english.ShouldBe(["Dashboard", "Parse"]);
+
+        Localizer.Instance.SetLanguage(AppLanguage.Russian);
+        Dispatcher.UIThread.RunJobs();
+
+        // The same controls, not a rebuilt tree: this is the whole point of binding through the
+        // localizer's indexer rather than resolving strings once at load.
+        RailLabels(view).ShouldBe(["Обзор", "Разбор"]);
+    }
+
+    [AvaloniaFact]
+    public void The_title_bar_follows_the_language_too()
+    {
+        Localizer.Instance.SetLanguage(AppLanguage.English);
+        var (view, viewModel) = ShowShell();
+
+        var title = view.GetVisualDescendants().OfType<TextBlock>().Single(block => block.Name == "ShellTitle");
+        title.Text.ShouldBe("Dashboard");
+
+        Localizer.Instance.SetLanguage(AppLanguage.Russian);
+        Dispatcher.UIThread.RunJobs();
+
+        viewModel.Title.ShouldBe("Обзор");
+        title.Text.ShouldBe("Обзор");
+    }
+
+    [AvaloniaFact]
+    public void Loc_markup_resolves_a_static_caption()
+    {
+        Localizer.Instance.SetLanguage(AppLanguage.Russian);
+        var (view, _) = ShowShell();
+
+        // Tooltips come from {l:Loc} rather than from a view model, so they exercise the markup
+        // extension itself.
+        var toggle = view.GetVisualDescendants().OfType<Button>().Single(button => button.Name == "PaneToggle");
+
+        ToolTip.GetTip(toggle).ShouldBe("Показать или скрыть навигацию");
+    }
+}