[AOT]Clean up some AOT build issues in PowerAccent.Core (#36264)

* init

* Use AotCompatibility instead

* Replace typeof(Lanaguge) with GetValues<Language>

* Create new folder to place source generation context file.

---------

Co-authored-by: Yu Leng (from Dev Box) <yuleng@microsoft.com>

src/modules/poweraccent/PowerAccent.Core/Languages.cs

@@ -57,7 +57,7 @@ namespace PowerAccent.Core
     {
         public static string[] GetDefaultLetterKey(LetterKey letter, Language[] langs)
         {
-            if (langs.Length == Enum.GetValues(typeof(Language)).Length)
+            if (langs.Length == Enum.GetValues<Language>().Length)
             {
                 return GetDefaultLetterKeyALL(letter);
             }

src/modules/poweraccent/PowerAccent.Core/PowerAccent.Core.csproj

@@ -2,6 +2,7 @@
   <!-- Look at Directory.Build.props in root for common stuff as well -->
   <Import Project="..\..\..\Common.Dotnet.CsWinRT.props" />
   <Import Project="..\..\..\Common.SelfContained.props" />
+  <Import Project="..\..\..\Common.Dotnet.AotCompatibility.props" />
 
   <PropertyGroup>
     <ImplicitUsings>enable</ImplicitUsings>

src/modules/poweraccent/PowerAccent.Core/PowerAccent.cs

@@ -14,7 +14,7 @@ using PowerToys.PowerAccentKeyboardService;
 
 namespace PowerAccent.Core;
 
-public class PowerAccent : IDisposable
+public partial class PowerAccent : IDisposable
 {
     private readonly SettingsService _settingService;
 

src/modules/poweraccent/PowerAccent.Core/SerializationContext/SourceGenerationContext.cs

@@ -0,0 +1,14 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.Text.Json.Serialization;
+using PowerAccent.Core.Services;
+
+namespace PowerAccent.Core.SerializationContext;
+
+[JsonSourceGenerationOptions(WriteIndented = true)]
+[JsonSerializable(typeof(SettingsService))]
+public partial class SourceGenerationContext : JsonSerializerContext
+{
+}

src/modules/poweraccent/PowerAccent.Core/Services/SettingsService.cs

@@ -9,6 +9,7 @@ using ManagedCommon;
 using Microsoft.PowerToys.Settings.UI.Library;
 using Microsoft.PowerToys.Settings.UI.Library.Enumerations;
 using Microsoft.PowerToys.Settings.UI.Library.Utilities;
+using PowerAccent.Core.SerializationContext;
 using PowerToys.PowerAccentKeyboardService;
 
 namespace PowerAccent.Core.Services;
@@ -29,11 +30,6 @@ public class SettingsService
         _watcher = Helper.GetFileWatcher(PowerAccentModuleName, "settings.json", () => { ReadSettings(); });
     }
 
-    private static readonly JsonSerializerOptions _serializerOptions = new JsonSerializerOptions
-    {
-        WriteIndented = true,
-    };
-
     private void ReadSettings()
     {
         // TODO this IO call should by Async, update GetFileWatcher helper to support async
@@ -46,9 +42,8 @@ public class SettingsService
                     {
                         Logger.LogInfo("QuickAccent settings.json was missing, creating a new one");
                         var defaultSettings = new PowerAccentSettings();
-                        var options = _serializerOptions;
 
-                        _settingsUtils.SaveSettings(JsonSerializer.Serialize(this, options), PowerAccentModuleName);
+                        _settingsUtils.SaveSettings(JsonSerializer.Serialize(this, SourceGenerationContext.Default.SettingsService), PowerAccentModuleName);
                     }
 
                     var settings = _settingsUtils.GetSettingsOrDefault<PowerAccentSettings>(PowerAccentModuleName);