Migrate encodings from Eto.Forms to Avalonia.

Aaru.Gui/ViewModels/EncodingsDialogViewModel.cs

@@ -0,0 +1,48 @@
+using System.Collections.Generic;
+using System.Collections.ObjectModel;
+using System.Linq;
+using System.Reactive;
+using System.Text;
+using System.Threading.Tasks;
+using Aaru.Gui.Models;
+using Aaru.Gui.Views;
+using ReactiveUI;
+
+namespace Aaru.Gui.ViewModels
+{
+    public class EncodingsDialogViewModel : ViewModelBase
+    {
+        readonly EncodingsDialog _view;
+        string                   _versionText;
+
+        public EncodingsDialogViewModel(EncodingsDialog view)
+        {
+            _view        = view;
+            Encodings    = new ObservableCollection<EncodingModel>();
+            CloseCommand = ReactiveCommand.Create(ExecuteCloseCommand);
+
+            Task.Run(() =>
+            {
+                List<EncodingModel> encodings = Encoding.GetEncodings().Select(info => new EncodingModel
+                {
+                    Name = info.Name, DisplayName = info.GetEncoding().EncodingName
+                }).ToList();
+
+                encodings.AddRange(Claunia.Encoding.Encoding.GetEncodings().Select(info => new EncodingModel
+                {
+                    Name = info.Name, DisplayName = info.DisplayName
+                }));
+
+                foreach(EncodingModel encoding in encodings.OrderBy(t => t.DisplayName))
+                    Encodings.Add(encoding);
+            });
+        }
+
+        public string                              Title        => "Encodings";
+        public string                              CloseLabel   => "Close";
+        public ReactiveCommand<Unit, Unit>         CloseCommand { get; }
+        public ObservableCollection<EncodingModel> Encodings    { get; }
+
+        void ExecuteCloseCommand() => _view.Close();
+    }
+}