Fix a bug with DLC window; rework some logic

src/Ryujinx/UI/ViewModels/DownloadableContentManagerViewModel.cs

@@ -176,12 +176,22 @@ namespace Ryujinx.Ava.UI.ViewModels
                 .Filter(Filter)
                 .Bind(out var view).AsObservableList();
 
+            // NOTE(jpr): this works around a bug where calling _views.Clear also clears SelectedDownloadableContents for
+            // some reason. so we save the items here and add them back after
+            var items = SelectedDownloadableContents.ToArray();
+
             _views.Clear();
             _views.AddRange(view);
+            
+            foreach (DownloadableContentModel item in items)
+            {
+                SelectedDownloadableContents.ReplaceOrAdd(item, item);
+            }
+            
             OnPropertyChanged(nameof(Views));
         }
 
-        private bool Filter(object arg)
+        private bool Filter<T>(T arg)
         {
             if (arg is DownloadableContentModel content)
             {

src/Ryujinx/UI/ViewModels/TitleUpdateViewModel.cs

@@ -2,24 +2,14 @@ using Avalonia.Collections;
 using Avalonia.Controls.ApplicationLifetimes;
 using Avalonia.Platform.Storage;
 using Avalonia.Threading;
-using LibHac.Common;
-using LibHac.Fs;
-using LibHac.Fs.Fsa;
-using LibHac.Ncm;
-using LibHac.Ns;
-using LibHac.Tools.FsSystem;
-using LibHac.Tools.FsSystem.NcaUtils;
+using DynamicData.Kernel;
 using Ryujinx.Ava.Common.Locale;
 using Ryujinx.Ava.UI.Helpers;
-using Ryujinx.Ava.UI.Models;
 using Ryujinx.Common.Configuration;
 using Ryujinx.Common.Logging;
 using Ryujinx.Common.Utilities;
 using Ryujinx.HLE.FileSystem;
-using Ryujinx.HLE.Loaders.Processes.Extensions;
-using Ryujinx.HLE.Utilities;
 using Ryujinx.UI.App.Common;
-using Ryujinx.UI.Common.Configuration;
 using Ryujinx.UI.Common.Models;
 using System;
 using System.Collections.Generic;
@@ -27,14 +17,15 @@ using System.IO;
 using System.Linq;
 using System.Threading.Tasks;
 using Application = Avalonia.Application;
-using ContentType = LibHac.Ncm.ContentType;
 using Path = System.IO.Path;
-using SpanHelpers = LibHac.Common.SpanHelpers;
 
 namespace Ryujinx.Ava.UI.ViewModels
 {
+    public record TitleUpdateViewNoUpdateSentinal();
+    
     public class TitleUpdateViewModel : BaseModel
     {
+        
         public TitleUpdateMetadata TitleUpdateWindowData;
         public readonly string TitleUpdateJsonPath;
         private VirtualFileSystem VirtualFileSystem { get; }
@@ -43,7 +34,7 @@ namespace Ryujinx.Ava.UI.ViewModels
 
         private AvaloniaList<TitleUpdateModel> _titleUpdates = new();
         private AvaloniaList<object> _views = new();
-        private object _selectedUpdate;
+        private object _selectedUpdate = new TitleUpdateViewNoUpdateSentinal();
 
         private static readonly TitleUpdateMetadataJsonSerializerContext _serializerContext = new(JsonHelper.GetDefaultSerializerOptions());
 
@@ -123,9 +114,8 @@ namespace Ryujinx.Ava.UI.ViewModels
                 AddUpdate(path);
             }
 
-            TitleUpdateModel selected = TitleUpdates.FirstOrDefault(x => x.Path == TitleUpdateWindowData.Selected, null);
-
-            SelectedUpdate = selected;
+            var selected = TitleUpdates.FirstOrOptional(x => x.Path == TitleUpdateWindowData.Selected);
+            SelectedUpdate = selected.HasValue ? selected.Value : new TitleUpdateViewNoUpdateSentinal();
 
             // NOTE: Save the list again to remove leftovers.
             Save();
@@ -137,23 +127,16 @@ namespace Ryujinx.Ava.UI.ViewModels
             var sortedUpdates = TitleUpdates.OrderByDescending(update => update.Version);
 
             Views.Clear();
-            Views.Add(new BaseModel());
+            Views.Add(new TitleUpdateViewNoUpdateSentinal());
             Views.AddRange(sortedUpdates);
 
-            if (SelectedUpdate == null)
+            if (SelectedUpdate is TitleUpdateViewNoUpdateSentinal)
             {
                 SelectedUpdate = Views[0];
             }
-            else if (!TitleUpdates.Contains(SelectedUpdate))
+            else if (!TitleUpdates.Contains((TitleUpdateModel)SelectedUpdate))
             {
-                if (Views.Count > 1)
-                {
-                    SelectedUpdate = Views[1];
-                }
-                else
-                {
-                    SelectedUpdate = Views[0];
-                }
+                SelectedUpdate = Views.Count > 1 ? Views[1] : Views[0];
             }
         }
 

src/Ryujinx/UI/Windows/DownloadableContentManagerWindow.axaml

@@ -77,9 +77,8 @@
                 SelectionMode="Multiple, Toggle"
                 Background="Transparent"
                 SelectionChanged="OnSelectionChanged"
-                SelectedItems="{Binding SelectedDownloadableContents}"
+                SelectedItems="{Binding SelectedDownloadableContents, Mode=OneWay}"
                 ItemsSource="{Binding Views}">
-                <!-- SelectedItems="{Binding SelectedDownloadableContents, Mode=TwoWay}" -->
                 <ListBox.DataTemplates>
                     <DataTemplate
                         DataType="models:DownloadableContentModel">

src/Ryujinx/UI/Windows/TitleUpdateWindow.axaml

@@ -82,7 +82,7 @@
                         </Panel>
                     </DataTemplate>
                     <DataTemplate
-                        DataType="viewModels:BaseModel">
+                        DataType="viewModels:TitleUpdateViewNoUpdateSentinal">
                         <Panel
                             Height="33"
                             Margin="10">