Use new columns

src/NexusMods.App.UI/Controls/TreeDataGrid/TreeDataGridAdapter.cs

@@ -12,7 +12,7 @@ namespace NexusMods.App.UI.Controls;
 /// Adapter class for working with <see cref="TreeDataGrid"/>.
 /// </summary>
 public abstract class TreeDataGridAdapter<TModel, TKey> : ReactiveR3Object
-    where TModel : TreeDataGridItemModel<TModel, TKey>
+    where TModel : class, ITreeDataGridItemModel<TModel, TKey>
     where TKey : notnull
 {
     public Subject<(TModel model, bool isActivating)> ModelActivationSubject { get; } = new();

src/NexusMods.App.UI/Controls/TreeDataGrid/TreeDataGridItemModel.cs

@@ -10,23 +10,51 @@
 namespace NexusMods.App.UI.Controls;
 
 [PublicAPI]
-public interface ITreeDataGridItemModel : IReactiveR3Object;
+public interface ITreeDataGridItemModel : IReactiveR3Object
+{
+    ReactiveProperty<bool> IsSelected { get; }
+}
 
 /// <summary>
 /// Base class for models of <see cref="Avalonia.Controls.TreeDataGrid"/> items.
 /// </summary>
-public class TreeDataGridItemModel : ReactiveR3Object, ITreeDataGridItemModel;
+public class TreeDataGridItemModel : ReactiveR3Object, ITreeDataGridItemModel
+{
+    public ReactiveProperty<bool> IsSelected { get; } = new(value: false);
+}
+
+public interface ITreeDataGridItemModel<out TModel, TKey> : ITreeDataGridItemModel
+    where TModel : class, ITreeDataGridItemModel<TModel, TKey>
+    where TKey : notnull
+{
+    BindableReactiveProperty<bool> HasChildren { get; }
+
+    IEnumerable<TModel> Children { get; }
+
+    bool IsExpanded { get; [UsedImplicitly] set; }
+
+    public static HierarchicalExpanderColumn<TModel> CreateExpanderColumn(IColumn<TModel> innerColumn)
+    {
+        return new HierarchicalExpanderColumn<TModel>(
+            inner: innerColumn,
+            childSelector: static model => model.Children,
+            hasChildrenSelector: static model => model.HasChildren.Value,
+            isExpandedSelector: static model => model.IsExpanded
+        )
+        {
+            Tag = "expander",
+        };
+    }
+}
 
 /// <summary>
 /// Generic variant of <see cref="TreeDataGridItemModel"/>.
 /// </summary>
 [PublicAPI]
-public class TreeDataGridItemModel<TModel, TKey> : TreeDataGridItemModel
-    where TModel : TreeDataGridItemModel<TModel, TKey>
+public class TreeDataGridItemModel<TModel, TKey> : TreeDataGridItemModel, ITreeDataGridItemModel<TModel, TKey>
+    where TModel : class, ITreeDataGridItemModel<TModel, TKey>
     where TKey : notnull
 {
-    public ReactiveProperty<bool> IsSelected { get; } = new(value: false);
-
     public IObservable<bool> HasChildrenObservable { get; init; } = Observable.Return(false);
     public BindableReactiveProperty<bool> HasChildren { get; } = new();
 
@@ -152,17 +180,4 @@ [MustDisposeResource] protected static IDisposable WhenModelActivated<TItemModel
     {
         return model.WhenActivated(block);
     }
-
-    public static HierarchicalExpanderColumn<TModel> CreateExpanderColumn(IColumn<TModel> innerColumn)
-    {
-        return new HierarchicalExpanderColumn<TModel>(
-            inner: innerColumn,
-            childSelector: static model => model.Children,
-            hasChildrenSelector: static model => model.HasChildren.Value,
-            isExpandedSelector: static model => model.IsExpanded
-        )
-        {
-            Tag = "expander",
-        };
-    }
 }

src/NexusMods.App.UI/Controls/TreeDataGrid/TreeDataGridViewHelper.cs

@@ -16,7 +16,7 @@ public static void SetupTreeDataGridAdapter<TView, TViewModel, TItemModel, TKey>
         Func<TViewModel, TreeDataGridAdapter<TItemModel, TKey>> getAdapter)
         where TView : ReactiveUserControl<TViewModel>
         where TViewModel : class, IViewModelInterface
-        where TItemModel : TreeDataGridItemModel<TItemModel, TKey>
+        where TItemModel : class, ITreeDataGridItemModel<TItemModel, TKey>
         where TKey : notnull
     {
         treeDataGrid.ElementFactory = new CustomElementFactory();

src/NexusMods.App.UI/Extensions/FormatExtensions.cs

@@ -0,0 +1,30 @@
+using System.Globalization;
+using Humanizer;
+using Humanizer.Bytes;
+using NexusMods.Paths;
+using R3;
+
+namespace NexusMods.App.UI.Extensions;
+
+public static class FormatExtensions
+{
+    public static string FormatDate(this DateTimeOffset date, DateTimeOffset now)
+    {
+        if (date == DateTimeOffset.MinValue || date == DateTimeOffset.MaxValue || date == DateTimeOffset.UnixEpoch) return "-";
+        return date.Humanize(dateToCompareAgainst: now, culture: CultureInfo.CurrentUICulture);
+    }
+
+    public static BindableReactiveProperty<string> ToFormattedProperty(this Observable<DateTimeOffset> source)
+    {
+        return source
+            .Select(static date => date.FormatDate(now: TimeProvider.System.GetLocalNow()))
+            .ToBindableReactiveProperty(initialValue: "");
+    }
+
+    public static BindableReactiveProperty<string> ToFormattedProperty(this Observable<Size> source)
+    {
+        return source
+            .Select(static size => ByteSize.FromBytes(size.Value).Humanize())
+            .ToBindableReactiveProperty(initialValue: "");
+    }
+}

src/NexusMods.App.UI/Extensions/R3Extensions.cs

@@ -16,23 +16,40 @@ [MustDisposeResource] public static IDisposable WhenActivated<T>(
         this T obj,
         Action<T, CompositeDisposable> block)
         where T : IReactiveR3Object
+    {
+        return WhenActivated(obj, state: block, static (obj, block, disposables) =>
+        {
+            block(obj, disposables);
+        });
+    }
+
+    /// <summary>
+    /// Provides an activation block for <see cref="ReactiveR3Object"/>.
+    /// </summary>
+    [MustDisposeResource]
+    public static IDisposable WhenActivated<T, TState>(
+        this T obj,
+        TState state,
+        Action<T, TState, CompositeDisposable> block)
+        where T : IReactiveR3Object
+        where TState : notnull
     {
         var d = Disposable.CreateBuilder();
 
         var serialDisposable = new SerialDisposable();
         serialDisposable.AddTo(ref d);
 
-        obj.Activation.DistinctUntilChanged().Subscribe((obj, serialDisposable, block), onNext: static (isActivated, state) =>
+        obj.Activation.DistinctUntilChanged().Subscribe(((obj, state), serialDisposable, block), onNext: static (isActivated, state) =>
         {
-            var (model, serialDisposable, block) = state;
+            var (wrapper, serialDisposable, block) = state;
 
             serialDisposable.Disposable = null;
             if (isActivated)
             {
                 var compositeDisposable = new CompositeDisposable();
                 serialDisposable.Disposable = compositeDisposable;
 
-                block(model, compositeDisposable);
+                block(wrapper.obj, wrapper.state, compositeDisposable);
             }
         }, onCompleted: static (_, state) =>
         {

src/NexusMods.App.UI/NexusMods.App.UI.csproj

@@ -596,12 +596,6 @@
         <Compile Update="Pages\LibraryPage\LibraryViewModel.cs">
           <DependentUpon>ILibraryViewModel.cs</DependentUpon>
         </Compile>
-        <Compile Update="Pages\LibraryPage\FakeParentLibraryItemModel.cs">
-            <DependentUpon>LibraryItemModel.cs</DependentUpon>
-        </Compile>
-        <Compile Update="Pages\LibraryPage\NexusModsModPageLibraryItemModel.cs">
-            <DependentUpon>LibraryItemModel.cs</DependentUpon>
-        </Compile>
         <Compile Update="Pages\LoadoutPage\FakeParentLoadoutItemModel.cs">
             <DependentUpon>LoadoutItemModel.cs</DependentUpon>
         </Compile>

src/NexusMods.App.UI/Pages/ILibraryDataProvider.cs

@@ -12,9 +12,9 @@ namespace NexusMods.App.UI.Pages;
 
 public interface ILibraryDataProvider
 {
-    IObservable<IChangeSet<LibraryItemModel, EntityId>> ObserveFlatLibraryItems(LibraryFilter libraryFilter);
+    IObservable<IChangeSet<ILibraryItemModel, EntityId>> ObserveFlatLibraryItems(LibraryFilter libraryFilter);
 
-    IObservable<IChangeSet<LibraryItemModel, EntityId>> ObserveNestedLibraryItems(LibraryFilter libraryFilter);
+    IObservable<IChangeSet<ILibraryItemModel, EntityId>> ObserveNestedLibraryItems(LibraryFilter libraryFilter);
 }
 
 public class LibraryFilter

src/NexusMods.App.UI/Pages/LibraryPage/ILibraryItemModel.cs

@@ -1,5 +1,79 @@
+using System.Diagnostics;
+using System.Diagnostics.CodeAnalysis;
+using DynamicData;
+using JetBrains.Annotations;
+using NexusMods.Abstractions.Library.Models;
+using NexusMods.Abstractions.Loadouts;
+using NexusMods.Abstractions.MnemonicDB.Attributes.Extensions;
 using NexusMods.App.UI.Controls;
+using NexusMods.App.UI.Extensions;
+using NexusMods.MnemonicDB.Abstractions;
+using ObservableCollections;
+using R3;
 
 namespace NexusMods.App.UI.Pages.LibraryPage;
 
-public interface ILibraryItemModel : ITreeDataGridItemModel;
+public interface ILibraryItemModel : ITreeDataGridItemModel<ILibraryItemModel, EntityId>;
+
+public interface IHasTicker
+{
+    Observable<DateTimeOffset>? Ticker { get; set; }
+}
+
+public interface IHasLinkedLoadoutItems
+{
+    IObservable<IChangeSet<LibraryLinkedLoadoutItem.ReadOnly, EntityId>> LinkedLoadoutItemsObservable { get; }
+    ObservableDictionary<EntityId, LibraryLinkedLoadoutItem.ReadOnly> LinkedLoadoutItems { get; }
+
+    [MustDisposeResource] static IDisposable SetupLinkedLoadoutItems<TModel>(TModel self, SerialDisposable serialDisposable)
+        where TModel : IHasLinkedLoadoutItems, ILibraryItemWithInstallAction, ILibraryItemWithInstalledDate
+    {
+        var disposable = self.LinkedLoadoutItems
+            .ObserveCountChanged(notifyCurrentCount: true)
+            .Subscribe(self, static (count, self) =>
+            {
+                var isInstalled = count > 0;
+                self.IsInstalled.Value = isInstalled;
+                self.InstallButtonText.Value = ILibraryItemWithInstallAction.GetButtonText(isInstalled);
+                self.InstalledDate.Value = isInstalled ? self.LinkedLoadoutItems.Select(static kv => kv.Value.GetCreatedAt()).Max() : DateTimeOffset.MinValue;
+            });
+
+        if (serialDisposable.Disposable is null)
+        {
+            serialDisposable.Disposable = self.LinkedLoadoutItemsObservable.OnUI().SubscribeWithErrorLogging(changes => self.LinkedLoadoutItems.ApplyChanges(changes));
+        }
+
+        return disposable;
+    }
+}
+
+public interface IIsParentLibraryItemModel : ILibraryItemModel
+{
+    IReadOnlyList<LibraryItemId> LibraryItemIds { get; }
+}
+
+public interface IIsChildLibraryItemModel : ILibraryItemModel
+{
+    LibraryItemId LibraryItemId { get; }
+}
+
+[SuppressMessage("ReSharper", "PossibleInterfaceMemberAmbiguity")]
+public interface ILibraryItemWithDates : IHasTicker, ILibraryItemWithDownloadedDate, ILibraryItemWithInstalledDate
+{
+    [MustDisposeResource]
+    static IDisposable SetupDates<TModel>(TModel self) where TModel : class, ILibraryItemWithDates
+    {
+        return self.WhenActivated(static (self, disposables) =>
+        {
+            Debug.Assert(self.Ticker is not null, "should've been set before activation");
+            self.Ticker.Subscribe(self, static (now, self) =>
+            {
+                ILibraryItemWithDownloadedDate.FormatDate(self, now: now);
+                ILibraryItemWithInstalledDate.FormatDate(self, now: now);
+            }).AddTo(disposables);
+
+            ILibraryItemWithDownloadedDate.FormatDate(self, now: TimeProvider.System.GetLocalNow());
+            ILibraryItemWithInstalledDate.FormatDate(self, now: TimeProvider.System.GetLocalNow());
+        });
+    }
+}