Console ItemPreview, select item after delete

src/AppCommon/FileTime.App.Core.Abstraction/ViewModels/ItemPreview/IElementPreviewViewModel.cs

@@ -5,4 +5,6 @@ namespace FileTime.App.Core.ViewModels.ItemPreview;
 public interface IElementPreviewViewModel : IItemPreviewViewModel
 {
     ItemPreviewMode Mode { get; }
+    string TextContent { get; }
+    string TextEncoding { get; }
 }

src/AppCommon/FileTime.App.Core/Services/ItemPreviewService.cs

@@ -6,20 +6,17 @@ namespace FileTime.App.Core.Services;
 
 public class ItemPreviewService : IItemPreviewService
 {
-    private readonly IServiceProvider _serviceProvider;
     private readonly IEnumerable<IItemPreviewProvider> _itemPreviewProviders;
     public IDeclarativeProperty<IItemPreviewViewModel?> ItemPreview { get; }
 
     public ItemPreviewService(
         IAppState appState,
-        IServiceProvider serviceProvider,
         IEnumerable<IItemPreviewProvider> itemPreviewProviders)
     {
-        _serviceProvider = serviceProvider;
         _itemPreviewProviders = itemPreviewProviders;
         ItemPreview = appState
             .SelectedTab
-            .Map(t => t.CurrentSelectedItem)
+            .Map(t => t?.CurrentSelectedItem)
             .Switch()
             .Debounce(TimeSpan.FromMilliseconds(250))
             .Map(async (item, _) =>

src/ConsoleApp/FileTime.ConsoleUI.App.Abstractions/IRootViewModel.cs

@@ -1,5 +1,6 @@
 using DeclarativeProperty;
 using FileTime.App.CommandPalette.ViewModels;
+using FileTime.App.Core.Services;
 using FileTime.App.Core.ViewModels;
 using FileTime.App.Core.ViewModels.Timeline;
 using FileTime.App.FrequencyNavigation.ViewModels;
@@ -20,5 +21,6 @@ public interface IRootViewModel
     ITimelineViewModel TimelineViewModel { get; }
     IDeclarativeProperty<VolumeSizeInfo?> VolumeSizeInfo { get; }
     IFrequencyNavigationViewModel FrequencyNavigation { get; }
+    IItemPreviewService ItemPreviewService { get; }
     event Action<IInputElement>? FocusReadInputElement;
 }

src/ConsoleApp/FileTime.ConsoleUI.App/App.cs

@@ -117,6 +117,8 @@ public class App : IApplication
 
             Thread.Sleep(10);
         }
+        
+        Task.Run(async () => await _lifecycleService.ExitAsync()).Wait();
     }
 
     private void Render() => _applicationContext.RenderEngine.Run();

src/ConsoleApp/FileTime.ConsoleUI.App/Controls/ItemPreviews.cs

@@ -0,0 +1,110 @@
+using FileTime.App.Core.Models;
+using FileTime.App.Core.Services;
+using FileTime.App.Core.ViewModels.ItemPreview;
+using FileTime.ConsoleUI.App.Styling;
+using TerminalUI.Controls;
+using TerminalUI.Extensions;
+using TerminalUI.Models;
+using TerminalUI.ViewExtensions;
+
+namespace FileTime.ConsoleUI.App.Controls;
+
+public class ItemPreviews
+{
+    private readonly ITheme _theme;
+
+    public ItemPreviews(ITheme theme)
+    {
+        _theme = theme;
+    }
+
+    public IView<IRootViewModel> View()
+    {
+        var view = new Grid<IRootViewModel>()
+        {
+            ChildInitializer =
+            {
+                new TextBlock<IRootViewModel>
+                {
+                    TextAlignment = TextAlignment.Center,
+                    Text = "Empty",
+                    Foreground = _theme.ErrorForegroundColor,
+                }.Setup(t => t.Bind(
+                    t,
+                    dc => dc.AppState.SelectedTab.Value.SelectedsChildren.Value.Count == 0,
+                    t => t.IsVisible,
+                    fallbackValue: false)),
+                ElementPreviews()
+                    .WithDataContextBinding<IRootViewModel, IElementPreviewViewModel>(
+                        dc => (IElementPreviewViewModel)dc.ItemPreviewService.ItemPreview.Value
+                    )
+            }
+        };
+
+        return view;
+    }
+
+    private IView<IElementPreviewViewModel> ElementPreviews()
+    {
+        var view = new Grid<IElementPreviewViewModel>
+        {
+            ChildInitializer =
+            {
+                new TextBlock<IElementPreviewViewModel>
+                {
+                    TextAlignment = TextAlignment.Center,
+                    Text = "Don't know how to preview this item.",
+                }.Setup(t => t.Bind(
+                    t,
+                    dc => dc.Mode == ItemPreviewMode.Unknown,
+                    t => t.IsVisible,
+                    v => v,
+                    fallbackValue: false)),
+                new TextBlock<IElementPreviewViewModel>
+                {
+                    TextAlignment = TextAlignment.Center,
+                    Text = "Empty",
+                }.Setup(t => t.Bind(
+                    t,
+                    dc => dc.Mode == ItemPreviewMode.Empty,
+                    t => t.IsVisible,
+                    v => v,
+                    fallbackValue: false)),
+                new Grid<IElementPreviewViewModel>
+                {
+                    RowDefinitionsObject = "* Auto",
+                    ChildInitializer =
+                    {
+                        new TextBlock<IElementPreviewViewModel>()
+                            .Setup(t => t.Bind(
+                                t,
+                                dc => dc.TextContent,
+                                t => t.Text)),
+                        new TextBlock<IElementPreviewViewModel>
+                        {
+                            Extensions = {new GridPositionExtension(0, 1)}
+                        }.Setup(t => t.Bind(
+                            t,
+                            dc => dc.TextEncoding,
+                            t => t.Text,
+                            v => $"Encoding: {v}"))
+                    }
+                }.Setup(t => t.Bind(
+                    t,
+                    dc => dc.Mode == ItemPreviewMode.Text,
+                    t => t.IsVisible,
+                    v => v,
+                    fallbackValue: false)),
+            }
+        };
+
+        view.Bind(
+            view,
+            dc => dc.Name == ElementPreviewViewModel.PreviewName,
+            v => v.IsVisible,
+            v => v
+        );
+
+        return view;
+    }
+}

src/ConsoleApp/FileTime.ConsoleUI.App/MainWindow.cs

@@ -34,6 +34,7 @@ public class MainWindow
     private readonly FrequencyNavigation _frequencyNavigation;
     private readonly Dialogs _dialogs;
     private readonly Timeline _timeline;
+    private readonly ItemPreviews _itemPreviews;
     private readonly Lazy<IView> _root;
 
 
@@ -44,7 +45,8 @@ public class MainWindow
         CommandPalette commandPalette,
         FrequencyNavigation frequencyNavigation,
         Dialogs dialogs,
-        Timeline timeline)
+        Timeline timeline,
+        ItemPreviews itemPreviews)
     {
         _rootViewModel = rootViewModel;
         _applicationContext = applicationContext;
@@ -53,6 +55,7 @@ public class MainWindow
         _frequencyNavigation = frequencyNavigation;
         _dialogs = dialogs;
         _timeline = timeline;
+        _itemPreviews = itemPreviews;
         _root = new Lazy<IView>(Initialize);
     }
 
@@ -141,7 +144,18 @@ public class MainWindow
                     {
                         ParentsItemsView().WithExtension(new GridPositionExtension(0, 0)),
                         SelectedItemsView().WithExtension(new GridPositionExtension(1, 0)),
-                        SelectedsItemsView().WithExtension(new GridPositionExtension(2, 0)),
+                        new Grid<IRootViewModel>
+                        {
+                            Extensions =
+                            {
+                                new GridPositionExtension(2, 0)
+                            },
+                            ChildInitializer =
+                            {
+                                SelectedsItemsView(),
+                                _itemPreviews.View()
+                            }
+                        }
                     }
                 },
                 new ItemsControl<IRootViewModel, string>
@@ -347,15 +361,21 @@ public class MainWindow
     {
         var list = new ListView<IRootViewModel, IItemViewModel>
         {
-            ListPadding = 8
+            ListPadding = 8,
+            ItemTemplate = item => ItemItemTemplate(item, new ItemViewRenderOptions())
         };
 
-        list.ItemTemplate = item => ItemItemTemplate(item, new ItemViewRenderOptions());
-
         list.Bind(
             list,
-            root => root.AppState.SelectedTab.Value.SelectedsChildren.Value,
+            dc => dc.AppState.SelectedTab.Value.SelectedsChildren.Value.Count > 0,
-            v => v.ItemsSource);
+            l => l.IsVisible,
+            fallbackValue: false);
+
+        list.Bind(
+            list,
+            dc => dc.AppState.SelectedTab.Value.SelectedsChildren.Value,
+            v => v.ItemsSource,
+            fallbackValue: null);
 
         return list;
     }
@@ -364,14 +384,13 @@ public class MainWindow
     {
         var list = new ListView<IRootViewModel, IItemViewModel>
         {
-            ListPadding = 8
+            ListPadding = 8,
+            ItemTemplate = item => ItemItemTemplate(item, new ItemViewRenderOptions())
         };
 
-        list.ItemTemplate = item => ItemItemTemplate(item, new ItemViewRenderOptions());
-
         list.Bind(
             list,
-            root => root.AppState.SelectedTab.Value.ParentsChildren.Value,
+            dc => dc.AppState.SelectedTab.Value.ParentsChildren.Value,
             v => v.ItemsSource);
 
         return list;

src/ConsoleApp/FileTime.ConsoleUI.App/RootViewModel.cs

@@ -1,5 +1,6 @@
 using DeclarativeProperty;
 using FileTime.App.CommandPalette.ViewModels;
+using FileTime.App.Core.Services;
 using FileTime.App.Core.ViewModels;
 using FileTime.App.Core.ViewModels.Timeline;
 using FileTime.App.FrequencyNavigation.ViewModels;
@@ -17,6 +18,7 @@ public class RootViewModel : IRootViewModel
     public IConsoleAppState AppState { get; }
     public ICommandPaletteViewModel CommandPalette { get; }
     public IFrequencyNavigationViewModel FrequencyNavigation { get; }
+    public IItemPreviewService ItemPreviewService { get; }
     public IDialogService DialogService { get; }
     public ITimelineViewModel TimelineViewModel { get; }
     public IDeclarativeProperty<VolumeSizeInfo?> VolumeSizeInfo { get;}
@@ -29,7 +31,8 @@ public class RootViewModel : IRootViewModel
         ICommandPaletteViewModel commandPalette,
         IDialogService dialogService,
         ITimelineViewModel timelineViewModel,
-        IFrequencyNavigationViewModel frequencyNavigation)
+        IFrequencyNavigationViewModel frequencyNavigation,
+        IItemPreviewService itemPreviewService)
     {
         AppState = appState;
         PossibleCommands = possibleCommands;
@@ -37,6 +40,7 @@ public class RootViewModel : IRootViewModel
         DialogService = dialogService;
         TimelineViewModel = timelineViewModel;
         FrequencyNavigation = frequencyNavigation;
+        ItemPreviewService = itemPreviewService;
 
         DialogService.ReadInput.PropertyChanged += (o, e) =>
         {

src/ConsoleApp/FileTime.ConsoleUI.App/Startup.cs

@@ -45,6 +45,7 @@ public static class Startup
         services.TryAddSingleton<Dialogs>();
         services.TryAddSingleton<Timeline>();
         services.TryAddSingleton<FrequencyNavigation>();
+        services.TryAddSingleton<ItemPreviews>();
         return services;
     }
 }

src/Core/FileTime.Core.Services/Tab.cs

@@ -1,5 +1,6 @@
 using System.Collections.ObjectModel;
 using System.ComponentModel;
+using System.Linq.Expressions;
 using CircularBuffer;
 using DeclarativeProperty;
 using DynamicData;
@@ -14,6 +15,8 @@ namespace FileTime.Core.Services;
 
 public class Tab : ITab
 {
+    private record LastItemSelectingContext(IContainer? CurrentLocationValue);
+
     private readonly ITimelessContentProvider _timelessContentProvider;
     private readonly ITabEvents _tabEvents;
     private readonly DeclarativeProperty<IContainer?> _currentLocation = new();
@@ -22,9 +25,11 @@ public class Tab : ITab
     private readonly ObservableCollection<ItemFilter> _itemFilters = new();
     private readonly CircularBuffer<FullName> _history = new(20);
     private readonly CircularBuffer<FullName> _future = new(20);
+    private readonly List<AbsolutePath> _selectedItemCandidates = new();
     private AbsolutePath? _currentSelectedItemCached;
     private PointInTime _currentPointInTime;
     private CancellationTokenSource? _setCurrentLocationCancellationTokenSource;
+    private LastItemSelectingContext? _lastItemSelectingContext;
 
     public IDeclarativeProperty<IContainer?> CurrentLocation { get; }
     public IDeclarativeProperty<ObservableCollection<IItem>?> CurrentItems { get; }
@@ -81,47 +86,32 @@ public class Tab : ITab
                 return Task.FromResult(items);
             }
         ).CombineLatest(
-            Ordering,
+            Ordering.Map(ordering =>
+            {
+                var (itemComparer, order) = ordering switch
+                {
+                    ItemOrdering.Name => ((Expression<Func<IItem, IComparable>>) (i => i.DisplayName), ListSortDirection.Ascending),
+                    ItemOrdering.NameDesc => (i => i.DisplayName, ListSortDirection.Descending),
+                    ItemOrdering.CreationDate => (i => i.CreatedAt ?? DateTime.MinValue, ListSortDirection.Ascending),
+                    ItemOrdering.CreationDateDesc => (i => i.CreatedAt ?? DateTime.MinValue, ListSortDirection.Descending),
+                    ItemOrdering.LastModifyDate => (i => i.ModifiedAt ?? DateTime.MinValue, ListSortDirection.Ascending),
+                    ItemOrdering.LastModifyDateDesc => (i => i.ModifiedAt ?? DateTime.MinValue, ListSortDirection.Descending),
+                    ItemOrdering.Size => (i => GetSize(i), ListSortDirection.Ascending),
+                    ItemOrdering.SizeDesc => (i => GetSize(i), ListSortDirection.Descending),
+                    _ => throw new NotImplementedException()
+                };
+
+                return (itemComparer, order);
+            }),
             (items, ordering) =>
             {
                 if (items is null) return Task.FromResult<ObservableCollection<IItem>?>(null);
 
-                ObservableCollection<IItem>? orderedItems = ordering switch
+                var (itemComparer, order) = ordering;
-                {
+
-                    ItemOrdering.Name =>
+                ObservableCollection<IItem>? orderedItems = items
-                        items
+                    .Ordering(i => i.Type)
-                            .Ordering(i => i.Type)
+                    .ThenOrdering(itemComparer, order);
-                            .ThenOrdering(i => i.DisplayName),
-                    ItemOrdering.NameDesc =>
-                        items
-                            .Ordering(i => i.Type)
-                            .ThenOrdering(i => i.DisplayName, ListSortDirection.Descending),
-                    ItemOrdering.CreationDate =>
-                        items
-                            .Ordering(i => i.Type)
-                            .ThenOrdering(i => i.CreatedAt),
-                    ItemOrdering.CreationDateDesc =>
-                        items
-                            .Ordering(i => i.Type)
-                            .ThenOrdering(i => i.CreatedAt, ListSortDirection.Descending),
-                    ItemOrdering.LastModifyDate =>
-                        items
-                            .Ordering(i => i.Type)
-                            .ThenOrdering(i => i.ModifiedAt),
-                    ItemOrdering.LastModifyDateDesc =>
-                        items
-                            .Ordering(i => i.Type)
-                            .ThenOrdering(i => i.ModifiedAt, ListSortDirection.Descending),
-                    ItemOrdering.Size =>
-                        items
-                            .Ordering(i => i.Type)
-                            .ThenOrdering(i => GetSize(i)),
-                    ItemOrdering.SizeDesc =>
-                        items
-                            .Ordering(i => i.Type)
-                            .ThenOrdering(i => GetSize(i), ListSortDirection.Descending),
-                    _ => throw new NotImplementedException()
-                };
 
                 return Task.FromResult(orderedItems);
             }
@@ -132,8 +122,25 @@ public class Tab : ITab
             _currentRequestItem.DistinctUntilChanged(),
             (items, selected) =>
             {
-                if (selected != null && (items?.Any(i => i.FullName == selected.Path) ?? true)) return Task.FromResult<AbsolutePath?>(selected);
+                var itemSelectingContext = new LastItemSelectingContext(CurrentLocation.Value);
+                var lastItemSelectingContext = _lastItemSelectingContext;
+                _lastItemSelectingContext = itemSelectingContext;
                 if (items == null || items.Count == 0) return Task.FromResult<AbsolutePath?>(null);
+                if (selected != null)
+                {
+                    if (items.Any(i => i.FullName == selected.Path))
+                        return Task.FromResult<AbsolutePath?>(selected);
+                }
+
+                if (lastItemSelectingContext != null
+                    && itemSelectingContext == lastItemSelectingContext)
+                {
+                    var candidate = _selectedItemCandidates.FirstOrDefault(c => items.Any(i => i.FullName?.Path == c.Path.Path));
+                    if (candidate != null)
+                    {
+                        return Task.FromResult(candidate);
+                    }
+                }
 
                 return Task.FromResult(GetSelectedItemByItems(items));
             }).DistinctUntilChanged();
@@ -141,8 +148,31 @@ public class Tab : ITab
         CurrentSelectedItem.Subscribe(async (s, _) =>
         {
             _currentSelectedItemCached = s;
+
             await _currentRequestItem.SetValue(s);
         });
+
+        DeclarativePropertyHelpers.CombineLatest(
+            CurrentItems,
+            CurrentSelectedItem,
+            (items, selected) =>
+            {
+                if(items is null || selected is null) return Task.FromResult<IEnumerable<AbsolutePath>?>(null);
+                var primaryCandidates = items.SkipWhile(i => i.FullName is {Path: var p} && p != selected.Path.Path).Skip(1);
+                var secondaryCandidates = items.TakeWhile(i => i.FullName is {Path: var p} && p != selected.Path.Path).Reverse();
+                var candidates = primaryCandidates
+                    .Concat(secondaryCandidates)
+                    .Select(c => new AbsolutePath(_timelessContentProvider, c));
+
+                return Task.FromResult(candidates);
+            })
+            .Subscribe(candidates =>
+            {
+                if(candidates is null) return;
+                
+                _selectedItemCandidates.Clear();
+                _selectedItemCandidates.AddRange(candidates);
+            });
     }
 
     private static long GetSize(IItem item)

src/GuiApp/Avalonia/FileTime.GuiApp.App/Views/MainWindow.axaml

@@ -27,6 +27,7 @@
     xmlns:ia="clr-namespace:Avalonia.Xaml.Interactions.Core;assembly=Avalonia.Xaml.Interactions"
     xmlns:interactions="using:FileTime.Core.Interactions"
     xmlns:itemPreview="clr-namespace:FileTime.App.Core.ViewModels.ItemPreview;assembly=FileTime.App.Core"
+    xmlns:itemPreviewInterface="clr-namespace:FileTime.App.Core.ViewModels.ItemPreview;assembly=FileTime.App.Core.Abstraction"
     xmlns:local="using:FileTime.GuiApp.App.Views"
     xmlns:local1="clr-namespace:FileTime.Providers.Local;assembly=FileTime.Providers.Local.Abstractions"
     xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
@@ -557,7 +558,7 @@
                                         </TextBlock>
                                     </Grid>
 
-                                    <Grid IsVisible="{Binding AppState.SelectedTab.Value.SelectedsChildren.Value, Converter={x:Static ObjectConverters.IsNull}, ConverterParameter=0, FallbackValue=False}" RowDefinitions="Auto, Auto">
+                                    <Grid IsVisible="{Binding AppState.SelectedTab.Value.CurrentSelectedItem.Value.BaseItem.Exceptions.Count, Converter={StaticResource GreaterThanConverter}, ConverterParameter=0, FallbackValue=False}" RowDefinitions="Auto, Auto">
                                         <TextBlock
                                             Foreground="{DynamicResource ErrorBrush}"
                                             HorizontalAlignment="Center"
@@ -579,7 +580,7 @@
                                 </Grid>
                                 <Grid DataContext="{Binding ItemPreviewService.ItemPreview.Value}" IsVisible="{Binding FallbackValue=false, Converter={x:Static ObjectConverters.IsNotNull}}">
                                     <Grid IsVisible="{Binding Name, FallbackValue=false, Converter={StaticResource EqualsConverter}, ConverterParameter={x:Static itemPreview:ElementPreviewViewModel.PreviewName}}">
-                                        <Grid x:DataType="itemPreview:ElementPreviewViewModel">
+                                        <Grid x:DataType="itemPreviewInterface:IElementPreviewViewModel">
                                             <TextBlock
                                                 HorizontalAlignment="Center"
                                                 IsVisible="{Binding Mode, Converter={StaticResource EqualsConverter}, ConverterParameter={x:Static appCoreModels:ItemPreviewMode.Unknown}, FallbackValue={x:Static appCoreModels:ItemPreviewMode.Unknown}}"

src/Library/TerminalUI/Controls/ChildCollectionView.cs

@@ -44,6 +44,12 @@ public abstract class ChildCollectionView<TConcrete, T>
         };
     }
 
+    public override void AddChild(IView child)
+    {
+        base.AddChild(child);
+        _children.Add(child);
+    }
+
     public override TChild AddChild<TChild>(TChild child)
     {
         child = base.AddChild(child);

src/Library/TerminalUI/Controls/ChildInitializer.cs

@@ -1,8 +1,11 @@
 using System.Collections;
+using System.Linq.Expressions;
+using TerminalUI.Extensions;
 
 namespace TerminalUI.Controls;
 
 public record ChildWithDataContextMapper<TSourceDataContext, TTargetDataContext>(IView<TTargetDataContext> Child, Func<TSourceDataContext?, TTargetDataContext?> DataContextMapper);
+public record ChildWithDataContextBinding<TSourceDataContext, TTargetDataContext>(IView<TTargetDataContext> Child, Expression<Func<TSourceDataContext?, TTargetDataContext?>> DataContextExpression);
 
 public class ChildInitializer<T> : IEnumerable<IView>
 {
@@ -18,6 +21,16 @@ public class ChildInitializer<T> : IEnumerable<IView>
     public void Add<TDataContext>(ChildWithDataContextMapper<T, TDataContext> item)
         => _childContainer.AddChild(item.Child, item.DataContextMapper);
     
+    public void Add<TDataContext>(ChildWithDataContextBinding<T, TDataContext> item)
+    {
+        item.Child.Bind(
+            _childContainer,
+            item.DataContextExpression,
+            c => c.DataContext
+        );
+        _childContainer.AddChild(item.Child);
+    }
+
     public IEnumerator<IView> GetEnumerator() => _childContainer.Children.GetEnumerator();
 
     IEnumerator IEnumerable.GetEnumerator() => GetEnumerator();

src/Library/TerminalUI/Controls/IView.cs

@@ -55,6 +55,7 @@ public interface IView<T> : IView
     TChild CreateChild<TChild, TDataContext>(Func<T?, TDataContext?> dataContextMapper)
         where TChild : IView<TDataContext>, new();
 
+    void AddChild(IView child);
     TChild AddChild<TChild>(TChild child) where TChild : IView<T>;
 
     TChild AddChild<TChild, TDataContext>(TChild child, Func<T?, TDataContext?> dataContextMapper)

src/Library/TerminalUI/Controls/TextBlock.cs

@@ -26,12 +26,14 @@ public sealed partial class TextBlock<T> : View<TextBlock<T>, T>, IDisplayView
     [Notify] private string? _text = string.Empty;
     [Notify] private TextAlignment _textAlignment = TextAlignment.Left;
     [Notify] private ITextFormat? _textFormat;
+    [Notify] private int _textStartIndex;
 
     public TextBlock()
     {
         RerenderProperties.Add(nameof(Text));
         RerenderProperties.Add(nameof(TextAlignment));
         RerenderProperties.Add(nameof(TextFormat));
+        RerenderProperties.Add(nameof(TextStartIndex));
 
         ((INotifyPropertyChanged) this).PropertyChanged += (o, e) =>
         {
@@ -78,7 +80,17 @@ public sealed partial class TextBlock<T> : View<TextBlock<T>, T>, IDisplayView
 
         SetStyleColor(renderContext, foreground, background, _textFormat);
 
-        RenderText(_textLines, renderContext, position, size, skipRender, TransformText);
+        var textLines = _textLines;
+        if (_textStartIndex < _textLines.Length)
+        {
+            textLines = _textLines[_textStartIndex..];
+        }
+        else
+        {
+            _textStartIndex = _textLines.Length - size.Height;
+        }
+
+        RenderText(textLines, renderContext, position, size, skipRender, TransformText);
 
         return !skipRender;
     }

src/Library/TerminalUI/Controls/View.cs

@@ -376,6 +376,12 @@ public abstract partial class View<TConcrete, T> : IView<T> where TConcrete : Vi
         return child;
     }
 
+    public virtual void AddChild(IView child)
+    {
+        Debug.Assert(child != null);
+        SetupNewChild(child, null);
+    }
+
     public virtual TChild AddChild<TChild, TDataContext>(TChild child, Func<T?, TDataContext?> dataContextMapper)
         where TChild : IView<TDataContext>
     {
@@ -387,15 +393,18 @@ public abstract partial class View<TConcrete, T> : IView<T> where TConcrete : Vi
         return child;
     }
 
-    private void SetupNewChild(IView child, IDisposable dataContextmapper)
+    private void SetupNewChild(IView child, IDisposable? dataContextMapper)
     {
         child.ApplicationContext = ApplicationContext;
         child.Attached = Attached;
         child.VisualParent = this;
         VisualChildren.Add(child);
 
-        AddDisposable(dataContextmapper);
+        if (dataContextMapper is not null)
-        child.AddDisposable(dataContextmapper);
+        {
+            AddDisposable(dataContextMapper);
+            child.AddDisposable(dataContextMapper);
+        }
     }
 
     public virtual void RemoveChild<TDataContext>(IView<TDataContext> child)

src/Library/TerminalUI/ExpressionTrackers/BinaryTracker.cs

@@ -1,4 +1,5 @@
-using System.Linq.Expressions;
+using System.Collections;
+using System.Linq.Expressions;
 
 namespace TerminalUI.ExpressionTrackers;
 
@@ -26,6 +27,10 @@ public class BinaryTracker : ExpressionTrackerBase
         {
             ExpressionType.Equal => (v1, v2) => Equals(v1, v2),
             ExpressionType.NotEqual => (v1, v2) => !Equals(v1, v2),
+            ExpressionType.GreaterThan => (v1, v2) => Comparer.Default.Compare(v1, v2) > 0,
+            ExpressionType.GreaterThanOrEqual => (v1, v2) => Comparer.Default.Compare(v1, v2) >= 0,
+            ExpressionType.LessThan => (v1, v2) => Comparer.Default.Compare(v1, v2) < 0,
+            ExpressionType.LessThanOrEqual => (v1, v2) => Comparer.Default.Compare(v1, v2) <= 0,
             _ => throw new NotImplementedException()
         };
 

src/Library/TerminalUI/Extensions/ViewExtensions.cs

@@ -19,6 +19,11 @@ public static class ViewExtensions
         Func<TSourceDataContext?, TTargetDataContext?> dataContextMapper)
         => new(view, dataContextMapper);
 
+    public static ChildWithDataContextBinding<TSourceDataContext, TTargetDataContext> WithDataContextBinding<TSourceDataContext, TTargetDataContext>(
+        this IView<TTargetDataContext> view,
+        Expression<Func<TSourceDataContext?, TTargetDataContext?>> dataContextMapper)
+        => new(view, dataContextMapper);
+
     public static TView Setup<TView>(this TView view, Action<TView> action)
     {
         action(view);