move json serializing out of UI code

Author: ScanMountGoat

ArcExplorer/Models/ApplicationSettings.cs

@@ -1,11 +1,13 @@
 using Newtonsoft.Json;
 using Newtonsoft.Json.Converters;
+using System;
 
 namespace ArcExplorer.Models
 {
     public sealed class ApplicationSettings
     {
-        public static ApplicationSettings Instance { get; } = FromJson("ApplicationPreferences.json");
+        private const string preferencesFilePath = "ApplicationPreferences.json";
+        public static ApplicationSettings Instance { get; } = FromJson(preferencesFilePath);
 
         public enum VisualTheme
         {
@@ -23,7 +25,6 @@ public enum IntegerDisplayFormat
         [JsonConverter(typeof(StringEnumConverter))]
         public VisualTheme Theme { get; set; } = VisualTheme.Dark;
 
-
         [JsonConverter(typeof(StringEnumConverter))]
         public IntegerDisplayFormat DisplayFormat { get; set; } = IntegerDisplayFormat.Decimal;
 
@@ -43,5 +44,11 @@ private static ApplicationSettings FromJson(string path)
 
             return JsonConvert.DeserializeObject<ApplicationSettings>(System.IO.File.ReadAllText(path));
         }
+
+        internal void SaveToFile()
+        {
+            var json = JsonConvert.SerializeObject(this);
+            System.IO.File.WriteAllText(preferencesFilePath, json);
+        }
     }
 }

ArcExplorer/Views/PreferencesWindow.axaml.cs

@@ -30,9 +30,7 @@ private void PreferencesWindow_Closing(object? sender, System.ComponentModel.Can
             e.Cancel = true;
             Hide();
 
-            // TODO: This is probably not the best place for this.
-            var json = JsonConvert.SerializeObject(ApplicationSettings.Instance);
-            System.IO.File.WriteAllText("ApplicationPreferences.json", json);
+            ApplicationSettings.Instance.SaveToFile();
         }
 
         public async void OpenFolderClick()