Add basic language switching ability

osu.Game/Localisation/ResourceManagerLocalisationStore.cs

@@ -0,0 +1,57 @@
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using System;
+using System.Collections.Generic;
+using System.Globalization;
+using System.IO;
+using System.Resources;
+using System.Threading.Tasks;
+using osu.Framework.Localisation;
+
+namespace osu.Game.Localisation
+{
+    public class ResourceManagerLocalisationStore : ILocalisationStore
+    {
+        private readonly Dictionary<string, ResourceManager> resourceManagers = new Dictionary<string, ResourceManager>();
+
+        public ResourceManagerLocalisationStore(string cultureCode)
+        {
+            EffectiveCulture = new CultureInfo(cultureCode);
+        }
+
+        public void Dispose()
+        {
+        }
+
+        public string Get(string lookup)
+        {
+            var split = lookup.Split(':');
+
+            string ns = split[0];
+            string key = split[1];
+
+            if (!resourceManagers.TryGetValue(ns, out var manager))
+                resourceManagers[ns] = manager = new ResourceManager(ns, GetType().Assembly);
+
+            return manager.GetString(key, EffectiveCulture);
+        }
+
+        public Task<string> GetAsync(string lookup)
+        {
+            return Task.FromResult(Get(lookup));
+        }
+
+        public Stream GetStream(string name)
+        {
+            throw new NotImplementedException();
+        }
+
+        public IEnumerable<string> GetAvailableResources()
+        {
+            throw new NotImplementedException();
+        }
+
+        public CultureInfo EffectiveCulture { get; }
+    }
+}

osu.Game/OsuGame.cs

@@ -51,6 +51,7 @@ using osu.Game.Utils;
 using LogLevel = osu.Framework.Logging.LogLevel;
 using osu.Game.Database;
 using osu.Game.IO;
+using osu.Game.Localisation;
 
 namespace osu.Game
 {
@@ -541,6 +542,12 @@ namespace osu.Game
         {
             base.LoadComplete();
 
+            foreach (var language in Enum.GetValues(typeof(Language)).OfType<Language>())
+            {
+                var cultureCode = language.ToString();
+                Localisation.AddLanguage(cultureCode, new ResourceManagerLocalisationStore(cultureCode));
+            }
+
             // The next time this is updated is in UpdateAfterChildren, which occurs too late and results
             // in the cursor being shown for a few frames during the intro.
             // This prevents the cursor from showing until we have a screen with CursorVisible = true

osu.Game/Overlays/Settings/Sections/General/LanguageSettings.cs

@@ -1,27 +1,45 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
+using System;
 using osu.Framework.Allocation;
+using osu.Framework.Bindables;
 using osu.Framework.Configuration;
 using osu.Framework.Graphics;
+using osu.Game.Localisation;
 
 namespace osu.Game.Overlays.Settings.Sections.General
 {
     public class LanguageSettings : SettingsSubsection
     {
+        private SettingsDropdown<Language> languageSelection;
+        private Bindable<string> frameworkLocale;
+
         protected override string Header => "Language";
 
         [BackgroundDependencyLoader]
         private void load(FrameworkConfigManager frameworkConfig)
         {
+            frameworkLocale = frameworkConfig.GetBindable<string>(FrameworkSetting.Locale);
+
             Children = new Drawable[]
             {
+                languageSelection = new SettingsEnumDropdown<Language>
+                {
+                    LabelText = "Language",
+                },
                 new SettingsCheckbox
                 {
                     LabelText = "Prefer metadata in original language",
                     Current = frameworkConfig.GetBindable<bool>(FrameworkSetting.ShowUnicode)
                 },
             };
+
+            if (!Enum.TryParse<Language>(frameworkLocale.Value, out var locale))
+                locale = Language.en;
+            languageSelection.Current.Value = locale;
+
+            languageSelection.Current.BindValueChanged(val => frameworkLocale.Value = val.NewValue.ToString());
         }
     }
 }