Track keyboard labels from host layout events

src/Ryujinx.Common/Configuration/Hid/KeyboardKeyExtensions.cs

@@ -1,19 +0,0 @@
-namespace Ryujinx.Common.Configuration.Hid
-{
-    public static class KeyboardKeyExtensions
-    {
-        public static Key ToKey(this PhysicalKey key)
-        {
-            return key is >= PhysicalKey.Unknown and < PhysicalKey.Count
-                ? (Key)(int)key
-                : Key.Unknown;
-        }
-
-        public static PhysicalKey ToPhysicalKey(this Key key)
-        {
-            return key is >= Key.Unknown and < Key.Count
-                ? (PhysicalKey)(int)key
-                : PhysicalKey.Unknown;
-        }
-    }
-}

src/Ryujinx/Input/AvaloniaKeyboardDriver.cs

@@ -1,6 +1,7 @@
 using Avalonia.Controls;
 using Avalonia.Input;
 using Ryujinx.Ava.Common.Locale;
+using Ryujinx.Ava.UI.Helpers;
 using Ryujinx.Input;
 using System;
 using System.Collections.Generic;
@@ -83,6 +84,7 @@ namespace Ryujinx.Ava.Input
         {
             UpdateKeyState(_semanticPressedKeys, GetInputKey(args, KeyboardInputMode.Semantic), true);
             UpdateKeyState(_physicalPressedKeys, GetInputKey(args, KeyboardInputMode.Physical), true);
+            PhysicalKeyLabelHelper.UpdateFromEvent(args);
 
             KeyPressed?.Invoke(this, args);
         }

src/Ryujinx/UI/Helpers/PhysicalKeyLabelHelper.cs

@@ -3,6 +3,7 @@ using Ryujinx.Ava.Common.Locale;
 using Ryujinx.Ava.Input;
 using Ryujinx.Common.Configuration.Hid;
 using System;
+using System.Collections.Concurrent;
 using System.Collections.Generic;
 using AvaPhysicalKey = Avalonia.Input.PhysicalKey;
 using ConfigPhysicalKey = Ryujinx.Common.Configuration.Hid.PhysicalKey;
@@ -12,6 +13,8 @@ namespace Ryujinx.Ava.UI.Helpers
 {
     internal static class PhysicalKeyLabelHelper
     {
+        private static readonly ConcurrentDictionary<ConfigPhysicalKey, string> _observedLayoutLabels = new();
+
         private static readonly Dictionary<ConfigPhysicalKey, LocaleKeys> _localizedKeysMap = new()
         {
             [ConfigPhysicalKey.Unknown] = LocaleKeys.KeyboardLayout_KeyUnknown,
@@ -70,6 +73,11 @@ namespace Ryujinx.Ava.UI.Helpers
                 return GetLocalizedString(localeKey);
             }
 
+            if (_observedLayoutLabels.TryGetValue(key, out string observedLabel))
+            {
+                return observedLabel;
+            }
+
             if (TryGetPrintableKeySymbol(key, out string label))
             {
                 return label;
@@ -78,6 +86,25 @@ namespace Ryujinx.Ava.UI.Helpers
             return key.ToString();
         }
 
+        public static void UpdateFromEvent(KeyEventArgs args)
+        {
+            if (args.KeyModifiers != KeyModifiers.None)
+            {
+                return;
+            }
+
+            InputKey inputKey = AvaloniaKeyboardMappingHelper.ToInputKey(args.PhysicalKey);
+            if (!TryConvertToConfigPhysicalKey(inputKey, out ConfigPhysicalKey physicalKey) || _localizedKeysMap.ContainsKey(physicalKey))
+            {
+                return;
+            }
+
+            if (TryNormalizePrintableSymbol(args.KeySymbol, out string label))
+            {
+                _observedLayoutLabels[physicalKey] = label;
+            }
+        }
+
         private static bool TryGetPrintableKeySymbol(ConfigPhysicalKey key, out string label)
         {
             // The legacy enum name for the ISO extra key is misleading, so give it a distinct physical label.
@@ -109,6 +136,33 @@ namespace Ryujinx.Ava.UI.Helpers
             return true;
         }
 
+        private static bool TryNormalizePrintableSymbol(string keySymbol, out string label)
+        {
+            if (string.IsNullOrEmpty(keySymbol) || keySymbol.Length != 1 || char.IsControl(keySymbol[0]))
+            {
+                label = string.Empty;
+                return false;
+            }
+
+            label = char.IsLetter(keySymbol[0])
+                ? char.ToUpperInvariant(keySymbol[0]).ToString()
+                : keySymbol;
+
+            return true;
+        }
+
+        private static bool TryConvertToConfigPhysicalKey(InputKey key, out ConfigPhysicalKey physicalKey)
+        {
+            if (key is >= InputKey.Unknown and < InputKey.Count)
+            {
+                physicalKey = (ConfigPhysicalKey)(int)key;
+                return true;
+            }
+
+            physicalKey = ConfigPhysicalKey.Unknown;
+            return false;
+        }
+
         private static string GetLocalizedString(LocaleKeys localeKey)
         {
             if (OperatingSystem.IsMacOS())