Refactor: items with DynamicData

src/AppCommon/FileTime.App.Core.Abstraction/Models/BindedCollection.cs

@@ -0,0 +1,26 @@
+using System.Collections.ObjectModel;
+using DynamicData;
+
+namespace FileTime.App.Core.Models
+{
+    public class BindedCollection<T> : IDisposable
+    {
+        private readonly IDisposable _disposable;
+        public ReadOnlyObservableCollection<T> Collection { get; }
+        public BindedCollection(IObservable<IChangeSet<T>> dynamicList)
+        {
+            _disposable = dynamicList
+                .Bind(out var collection)
+                .DisposeMany()
+                .Subscribe();
+
+            Collection = collection;
+        }
+
+        public void Dispose()
+        {
+            _disposable.Dispose();
+            GC.SuppressFinalize(this);
+        }
+    }
+}

src/AppCommon/FileTime.App.Core.Abstraction/ViewModels/IContainerSizeContainerViewModel.cs

@@ -3,7 +3,7 @@ using InitableService;
 
 namespace FileTime.App.Core.ViewModels
 {
-    public interface IContainerSizeContainerViewModel : IItemViewModel, IInitable<IContainer, ITabViewModel, int>
+    public interface IContainerSizeContainerViewModel : IItemViewModel, IInitable<IContainer, ITabViewModel>
     {
         long Size { get; set; }
     }

src/AppCommon/FileTime.App.Core.Abstraction/ViewModels/IContainerViewModel.cs

@@ -3,7 +3,7 @@ using InitableService;
 
 namespace FileTime.App.Core.ViewModels
 {
-    public interface IContainerViewModel : IItemViewModel, IInitable<IContainer, ITabViewModel, int>
+    public interface IContainerViewModel : IItemViewModel, IInitable<IContainer, ITabViewModel>
     {
         IContainer? Container { get; }
     }

src/AppCommon/FileTime.App.Core.Abstraction/ViewModels/IElementViewModel.cs

@@ -3,7 +3,7 @@ using InitableService;
 
 namespace FileTime.App.Core.ViewModels
 {
-    public interface IElementViewModel : IItemViewModel, IInitable<IElement, ITabViewModel, int>
+    public interface IElementViewModel : IItemViewModel, IInitable<IElement, ITabViewModel>
     {
         long? Size { get; set; }
     }

src/AppCommon/FileTime.App.Core.Abstraction/ViewModels/IFileViewModel.cs

@@ -3,7 +3,7 @@ using InitableService;
 
 namespace FileTime.App.Core.ViewModels
 {
-    public interface IFileViewModel : IElementViewModel, IInitable<IFileElement, ITabViewModel, int>
+    public interface IFileViewModel : IElementViewModel, IInitable<IFileElement, ITabViewModel>
     {
     }
 }

src/AppCommon/FileTime.App.Core.Abstraction/ViewModels/IItemViewModel.cs

@@ -1,4 +1,3 @@
-using System.Reactive.Subjects;
 using FileTime.App.Core.Models;
 using FileTime.App.Core.Models.Enums;
 using FileTime.Core.Models;
@@ -6,16 +5,17 @@ using InitableService;
 
 namespace FileTime.App.Core.ViewModels
 {
-    public interface IItemViewModel : IInitable<IItem, ITabViewModel, int>
+    public interface IItemViewModel : IInitable<IItem, ITabViewModel>
     {
         IItem? BaseItem { get; set; }
         IObservable<IReadOnlyList<ItemNamePart>>? DisplayName { get; set; }
         string? DisplayNameText { get; set; }
         IObservable<bool>? IsSelected { get; set; }
         IObservable<bool>? IsMarked { get; set; }
-        BehaviorSubject<bool> IsAlternative { get; }
+        IObservable<bool> IsAlternative { get; }
         IObservable<ItemViewMode> ViewMode { get; set; }
         DateTime? CreatedAt { get; set; }
         string? Attributes { get; set; }
+        bool EqualsTo(IItemViewModel? itemViewModel);
     }
 }

src/AppCommon/FileTime.App.Core.Abstraction/ViewModels/ITabViewModel.cs

@@ -1,4 +1,6 @@
 
+using DynamicData;
+using FileTime.App.Core.Models;
 using FileTime.Core.Models;
 using FileTime.Core.Services;
 using InitableService;
@@ -12,9 +14,13 @@ namespace FileTime.App.Core.ViewModels
         IObservable<bool> IsSelected { get; }
         IObservable<IContainer?> CurrentLocation { get; }
         IObservable<IItemViewModel?> CurrentSelectedItem { get; }
-        IObservable<IReadOnlyList<IItemViewModel>> CurrentItems { get; }
+        IObservable<IObservable<IChangeSet<IItemViewModel>>?> CurrentItems { get; }
         IObservable<IEnumerable<FullName>> MarkedItems { get; }
-        IObservable<IReadOnlyList<IItemViewModel>?> SelectedsChildren { get; }
+        IObservable<IObservable<IChangeSet<IItemViewModel>>?> SelectedsChildren { get; }
-        IObservable<IReadOnlyList<IItemViewModel>?> ParentsChildren { get; }
+        IObservable<IObservable<IChangeSet<IItemViewModel>>?> ParentsChildren { get; }
+        BindedCollection<IItemViewModel>? CurrentItemsCollection { get; }
+        BindedCollection<IItemViewModel>? SelectedsChildrenCollection { get; }
+        BindedCollection<IItemViewModel>? ParentsChildrenCollection { get; }
+        IObservable<IReadOnlyCollection<IItemViewModel>?> CurrentItemsCollectionObservable { get; }
     }
 }

src/AppCommon/FileTime.App.Core/Extensions/ViewModelExtensions.cs

@@ -8,7 +8,7 @@ namespace FileTime.App.Core.Extensions
         public static IAbsolutePath ToAbsolutePath(this IItemViewModel itemViewModel)
         {
             var item = itemViewModel.BaseItem ?? throw new ArgumentException($"{nameof(itemViewModel)} does not have {nameof(IItemViewModel.BaseItem)}");
-            return new AbsolutePath(item.Provider, item.FullName ?? throw new ArgumentException($"Parameter does not have {nameof(IItem.FullName)}"), item.Type);
+            return new AbsolutePath(item);
         }
     }
 }

src/AppCommon/FileTime.App.Core/FileTime.App.Core.csproj

@@ -16,6 +16,7 @@
   <ItemGroup>
     <ProjectReference Include="..\..\Core\FileTime.Core.Abstraction\FileTime.Core.Abstraction.csproj" />
     <ProjectReference Include="..\..\Core\FileTime.Core.Models\FileTime.Core.Models.csproj" />
+    <ProjectReference Include="..\..\Tools\FileTime.Tools\FileTime.Tools.csproj" />
     <ProjectReference Include="..\FileTime.App.Core.Abstraction\FileTime.App.Core.Abstraction.csproj" />
   </ItemGroup>
 

src/AppCommon/FileTime.App.Core/Services/CommandHandler/NavigationCommandHandler.cs

@@ -12,7 +12,7 @@ namespace FileTime.App.Core.Services.CommandHandler
         private ITabViewModel? _selectedTab;
         private IContainer? _currentLocation;
         private IItemViewModel? _currentSelectedItem;
-        private List<IItemViewModel> _currentItems = new();
+        private IEnumerable<IItemViewModel> _currentItems = Enumerable.Empty<IItemViewModel>();
 
         public NavigationCommandHandler(IAppState appState)
         {
@@ -21,7 +21,7 @@ namespace FileTime.App.Core.Services.CommandHandler
             _appState.SelectedTab.Subscribe(t => _selectedTab = t);
             _appState.SelectedTab.Select(t => t == null ? Observable.Return<IContainer?>(null) : t.CurrentLocation).Switch().Subscribe(l => _currentLocation = l);
             _appState.SelectedTab.Select(t => t == null ? Observable.Return<IItemViewModel?>(null) : t.CurrentSelectedItem).Switch().Subscribe(l => _currentSelectedItem = l);
-            _appState.SelectedTab.Select(t => t == null ? Observable.Return(Enumerable.Empty<IItemViewModel>()) : t.CurrentItems).Switch().Subscribe(i => _currentItems = i.ToList());
+            _appState.SelectedTab.Select(t => t?.CurrentItemsCollectionObservable ?? Observable.Return((IEnumerable<IItemViewModel>?)Enumerable.Empty<IItemViewModel>())).Switch().Subscribe(i => _currentItems = i ?? Enumerable.Empty<IItemViewModel>());
 
             AddCommandHandlers(new (Commands, Func<Task>)[]
             {
@@ -48,13 +48,13 @@ namespace FileTime.App.Core.Services.CommandHandler
 
         private Task MoveCursorDown()
         {
-            SelectNewSelectedItem(i => i.SkipWhile(i => i != _currentSelectedItem).Skip(1).FirstOrDefault());
+            SelectNewSelectedItem(i => i.SkipWhile(i => i.EqualsTo(_currentSelectedItem)).Skip(1).FirstOrDefault());
             return Task.CompletedTask;
         }
 
         private Task MoveCursorUp()
         {
-            SelectNewSelectedItem(i => i.TakeWhile(i => i != _currentSelectedItem).LastOrDefault());
+            SelectNewSelectedItem(i => i.TakeWhile(i => i.EqualsTo(_currentSelectedItem)).LastOrDefault());
             return Task.CompletedTask;
         }
 

src/AppCommon/FileTime.App.Core/ViewModels/AppStateBase.cs

@@ -2,7 +2,6 @@ using System.Collections.ObjectModel;
 using System.Reactive.Linq;
 using System.Reactive.Subjects;
 using FileTime.App.Core.Models.Enums;
-using FileTime.App.Core.ViewModels;
 using MvvmGen;
 using MoreLinq;
 

src/AppCommon/FileTime.App.Core/ViewModels/ContainerSizeContainerViewModel.cs

@@ -14,9 +14,9 @@ namespace FileTime.App.Core.ViewModels
         {
         }
 
-        public void Init(IContainer item, ITabViewModel parentTab, int index)
+        public void Init(IContainer item, ITabViewModel parentTab)
         {
-            Init((IItem)item, parentTab, index);
+            Init((IItem)item, parentTab);
         }
     }
 }

src/AppCommon/FileTime.App.Core/ViewModels/ContainerViewModel.cs

@@ -13,9 +13,9 @@ namespace FileTime.App.Core.ViewModels
         {
         }
 
-        public void Init(IContainer item, ITabViewModel parentTab, int index)
+        public void Init(IContainer item, ITabViewModel parentTab)
         {
-            Init((IItem)item, parentTab, index);
+            Init((IItem)item, parentTab);
         }
     }
 }

src/AppCommon/FileTime.App.Core/ViewModels/ElementViewModel.cs

@@ -14,9 +14,9 @@ namespace FileTime.App.Core.ViewModels
         {
         }
 
-        public void Init(IElement item, ITabViewModel parentTab, int index)
+        public void Init(IElement item, ITabViewModel parentTab)
         {
-            Init((IItem)item, parentTab, index);
+            Init((IItem)item, parentTab);
         }
     }
 }

src/AppCommon/FileTime.App.Core/ViewModels/FileViewModel.cs

@@ -11,9 +11,9 @@ namespace FileTime.App.Core.ViewModels
         {
         }
 
-        public void Init(IFileElement item, ITabViewModel parentTab, int index)
+        public void Init(IFileElement item, ITabViewModel parentTab)
         {
-            Init((IElement)item, parentTab, index);
+            Init((IElement)item, parentTab);
         }
     }
 }

src/AppCommon/FileTime.App.Core/ViewModels/ItemViewModel.cs

@@ -1,9 +1,9 @@
 using System.Reactive.Linq;
-using System.Reactive.Subjects;
 using FileTime.App.Core.Models;
 using FileTime.App.Core.Models.Enums;
 using FileTime.App.Core.Services;
 using FileTime.Core.Models;
+using MoreLinq;
 using MvvmGen;
 
 namespace FileTime.App.Core.ViewModels
@@ -38,16 +38,16 @@ namespace FileTime.App.Core.ViewModels
         private string? _attributes;
 
         [Property]
-        private BehaviorSubject<bool> _isAlternative = new(false);
+        private IObservable<bool> _isAlternative;
 
-        public void Init(IItem item, ITabViewModel parentTab, int index)
+        public void Init(IItem item, ITabViewModel parentTab)
         {
             BaseItem = item;
             DisplayName = _appState.SearchText.Select(s => _itemNameConverterService.GetDisplayName(item.DisplayName, s));
             DisplayNameText = item.DisplayName;
             IsMarked = parentTab.MarkedItems.Select(m => m.Contains(item.FullName));
-            IsSelected = parentTab.CurrentSelectedItem.Select(i => i == this);
+            IsSelected = parentTab.CurrentSelectedItem.Select(EqualsTo);
-            IsAlternative.OnNext(index % 2 == 0);
+            IsAlternative = parentTab.CurrentItemsCollectionObservable.Select(c => c?.Index().FirstOrDefault(i => EqualsTo(i.Value)).Key % 2 == 0);
             ViewMode = Observable.CombineLatest(IsMarked, IsSelected, IsAlternative, GenerateViewMode);
             Attributes = item.Attributes;
             CreatedAt = item.CreatedAt;
@@ -63,5 +63,10 @@ namespace FileTime.App.Core.ViewModels
             (true, false, false) => ItemViewMode.Marked,
             _ => ItemViewMode.Default
         };
+
+        public bool EqualsTo(IItemViewModel? itemViewModel)
+        {
+            return BaseItem?.FullName?.Path is string path && path == itemViewModel?.BaseItem?.FullName?.Path;
+        }
     }
 }

src/AppCommon/FileTime.App.Core/ViewModels/TabViewModel.cs

@@ -1,15 +1,19 @@
-using System.Reactive.Concurrency;
 using System.Reactive.Linq;
 using System.Reactive.Subjects;
+using DynamicData;
 using FileTime.App.Core.Extensions;
+using FileTime.App.Core.Models;
 using FileTime.App.Core.Services;
 using FileTime.Core.Models;
 using FileTime.Core.Services;
+using FileTime.Tools.Extensions;
 using Microsoft.Extensions.DependencyInjection;
+using MvvmGen;
 
 namespace FileTime.App.Core.ViewModels
 {
-    public class TabViewModel : ITabViewModel, IDisposable
+    [ViewModel]
+    public partial class TabViewModel : ITabViewModel, IDisposable
     {
         private readonly IServiceProvider _serviceProvider;
         private readonly IItemNameConverterService _itemNameConverterService;
@@ -26,10 +30,22 @@ namespace FileTime.App.Core.ViewModels
 
         public IObservable<IContainer?> CurrentLocation { get; private set; } = null!;
         public IObservable<IItemViewModel?> CurrentSelectedItem { get; private set; } = null!;
-        public IObservable<IReadOnlyList<IItemViewModel>> CurrentItems { get; private set; } = null!;
+        public IObservable<IObservable<IChangeSet<IItemViewModel>>?> CurrentItems { get; private set; } = null!;
         public IObservable<IEnumerable<FullName>> MarkedItems { get; }
-        public IObservable<IReadOnlyList<IItemViewModel>?> SelectedsChildren { get; private set; } = null!;
+        public IObservable<IObservable<IChangeSet<IItemViewModel>>?> SelectedsChildren { get; private set; } = null!;
-        public IObservable<IReadOnlyList<IItemViewModel>?> ParentsChildren { get; private set; } = null!;
+        public IObservable<IObservable<IChangeSet<IItemViewModel>>?> ParentsChildren { get; private set; } = null!;
+
+        public IObservable<IReadOnlyCollection<IItemViewModel>?> CurrentItemsCollectionObservable { get; private set; } = null!;
+
+        [Property]
+        private BindedCollection<IItemViewModel>? _currentItemsCollection;
+
+        [Property]
+        private BindedCollection<IItemViewModel>? _parentsChildrenCollection;
+
+        [Property]
+        private BindedCollection<IItemViewModel>? _selectedsChildrenCollection;
+
 
         public TabViewModel(
             IServiceProvider serviceProvider,
@@ -53,100 +69,125 @@ namespace FileTime.App.Core.ViewModels
 
             CurrentLocation = tab.CurrentLocation.AsObservable();
             CurrentItems = tab.CurrentItems
-                .Select(items =>
+                .Select(items => items?.Transform(MapItemToViewModel))
-                    items == null
-                    ? new List<IItemViewModel>()
-                    : items.Select(MapItemToViewModel).ToList())
                 .ObserveOn(_rxSchedulerService.GetWorkerScheduler())
                 .SubscribeOn(_rxSchedulerService.GetUIScheduler())
-                .Publish(new List<IItemViewModel>())
+                .Publish(null)
                 .RefCount();
 
             CurrentSelectedItem =
                 Observable.CombineLatest(
                     CurrentItems,
                     tab.CurrentSelectedItem,
-                    (currentItems, currentSelectedItemPath) => currentItems.FirstOrDefault(i => i.BaseItem?.FullName == currentSelectedItemPath?.Path)
+                    (currentItems, currentSelectedItemPath) =>
+                        currentItems == null
+                        ? Observable.Return((IItemViewModel?)null)
+                        : currentItems
+                            .ToCollection()
+                            .Select(items => items.FirstOrDefault(i => i.BaseItem?.FullName == currentSelectedItemPath?.Path))
                 )
+                .Switch()
                 .Publish(null)
                 .RefCount();
 
-            var currentSelectedItemThrottled = CurrentSelectedItem.Throttle(TimeSpan.FromMilliseconds(250)).Publish(null).RefCount();
+            SelectedsChildren = InitSelectedsChildren();
-            SelectedsChildren = Observable.Merge(
+            ParentsChildren = InitParentsChildren();
-                currentSelectedItemThrottled
-                    .WhereNotNull()
-                    .OfType<IContainerViewModel>()
-                    .Where(c => c?.Container is not null)
-                    .Select(c => c.Container!.Items)
-                    .Switch()
-                    .Select(items => Observable.FromAsync(async () => await Map(items)))
-                    .Switch()
-                    .Select(items => items?.Select(MapItemToViewModel).ToList()),
-                currentSelectedItemThrottled
-                    .Where(c => c is null || c is not IContainerViewModel)
-                    .Select(_ => (IReadOnlyList<IItemViewModel>?)null)
-            )
-            .ObserveOn(_rxSchedulerService.GetWorkerScheduler())
-            .SubscribeOn(_rxSchedulerService.GetUIScheduler())
-            .Publish(null)
-            .RefCount();
 
-            var parentThrottled = CurrentLocation
+            CurrentItemsCollectionObservable = CurrentItems
-                .Select(l => l?.Parent)
+                .Select(c => c != null ? c.ToCollection() : Observable.Return((IReadOnlyCollection<IItemViewModel>?)null))
-                .DistinctUntilChanged()
+                .Switch()
                 .Publish(null)
                 .RefCount();
 
-            ParentsChildren = Observable.Merge(
+            CurrentItems.Subscribe(children =>
-                parentThrottled
+            {
-                    .Where(p => p is not null)
+                CurrentItemsCollection?.Dispose();
-                    .Select(p => Observable.FromAsync(async () => (IContainer)await p!.ResolveAsync()))
+                CurrentItemsCollection = children.MapNull(c => new BindedCollection<IItemViewModel>(c!));
-                    .Switch()
+            });
-                    .Select(p => p.Items)
+
-                    .Switch()
+            ParentsChildren.Subscribe(children =>
-                    .Select(items => Observable.FromAsync(async () => await Map(items)))
+            {
-                    .Switch()
+                ParentsChildrenCollection?.Dispose();
-                    .Select(items => items?.Select(MapItemToViewModel).ToList()),
+                ParentsChildrenCollection = children.MapNull(c => new BindedCollection<IItemViewModel>(c!));
-                parentThrottled
+            });
-                    .Where(p => p is null)
+
-                    .Select(_ => (IReadOnlyList<IItemViewModel>?)null)
+            SelectedsChildren.Subscribe(children =>
-            )
+            {
-            .ObserveOn(_rxSchedulerService.GetWorkerScheduler())
+                SelectedsChildrenCollection?.Dispose();
-            .SubscribeOn(_rxSchedulerService.GetUIScheduler())
+                SelectedsChildrenCollection = children.MapNull(c => new BindedCollection<IItemViewModel>(c!));
-            .Publish(null)
+            });
-            .RefCount();
 
             tab.CurrentLocation.Subscribe((_) => _markedItems.OnNext(Enumerable.Empty<FullName>()));
 
-            static async Task<List<IItem>?> Map(IEnumerable<IAbsolutePath>? items)
+            IObservable<IObservable<IChangeSet<IItemViewModel>>?> InitSelectedsChildren()
             {
-                if (items == null) return null;
+                var currentSelectedItemThrottled = CurrentSelectedItem.Throttle(TimeSpan.FromMilliseconds(250)).Publish(null).RefCount();
+                return Observable.Merge(
+                    currentSelectedItemThrottled
+                        .WhereNotNull()
+                        .OfType<IContainerViewModel>()
+                        .Where(c => c?.Container is not null)
+                        .Select(c => c.Container!.Items)
+                        .Switch()
+                        .Select(i => i?.TransformAsync(MapItem).Transform(MapItemToViewModel)),
+                    currentSelectedItemThrottled
+                        .Where(c => c is null || c is not IContainerViewModel)
+                        .Select(_ => (IObservable<IChangeSet<IItemViewModel>>?)null)
+                )
+                .ObserveOn(_rxSchedulerService.GetWorkerScheduler())
+                .SubscribeOn(_rxSchedulerService.GetUIScheduler())
+                .Publish(null)
+                .RefCount();
+            }
 
-                return await items
+            IObservable<IObservable<IChangeSet<IItemViewModel>>?> InitParentsChildren()
-                    .ToAsyncEnumerable()
+            {
-                    .SelectAwait(async i => await i.ResolveAsync(forceResolve: true, itemInitializationSettings: new ItemInitializationSettings(true)))
+                var parentThrottled = CurrentLocation
-                    .ToListAsync();
+                    .Select(l => l?.Parent)
+                    .DistinctUntilChanged()
+                    .Publish(null)
+                    .RefCount();
+
+                return Observable.Merge(
+                    parentThrottled
+                        .Where(p => p is not null)
+                        .Select(p => Observable.FromAsync(async () => (IContainer)await p!.ResolveAsync()))
+                        .Switch()
+                        .Select(p => p.Items)
+                        .Switch()
+                        .Select(items => items?.TransformAsync(MapItem).Transform(MapItemToViewModel)),
+                    parentThrottled
+                        .Where(p => p is null)
+                        .Select(_ => (IObservable<IChangeSet<IItemViewModel>>?)null)
+                )
+                .ObserveOn(_rxSchedulerService.GetWorkerScheduler())
+                .SubscribeOn(_rxSchedulerService.GetUIScheduler())
+                .Publish(null)
+                .RefCount();
             }
         }
 
-        private IItemViewModel MapItemToViewModel(IItem item, int index)
+        private static async Task<IItem> MapItem(IAbsolutePath item)
+            => await item.ResolveAsync(forceResolve: true, itemInitializationSettings: new ItemInitializationSettings(true));
+
+        private IItemViewModel MapItemToViewModel(IItem item)
         {
             if (item is IContainer container)
             {
-                var containerViewModel = _serviceProvider.GetInitableResolver<IContainer, ITabViewModel, int>(container, this, index).GetRequiredService<IContainerViewModel>();
+                var containerViewModel = _serviceProvider.GetInitableResolver<IContainer, ITabViewModel>(container, this).GetRequiredService<IContainerViewModel>();
 
                 return containerViewModel;
             }
             else if (item is IFileElement fileElement)
             {
-                var fileViewModel = _serviceProvider.GetInitableResolver<IFileElement, ITabViewModel, int>(fileElement, this, index).GetRequiredService<IFileViewModel>();
+                var fileViewModel = _serviceProvider.GetInitableResolver<IFileElement, ITabViewModel>(fileElement, this).GetRequiredService<IFileViewModel>();
                 fileViewModel.Size = fileElement.Size;
 
                 return fileViewModel;
             }
             else if (item is IElement element)
             {
-                var elementViewModel = _serviceProvider.GetInitableResolver<IElement, ITabViewModel, int>(element, this, index).GetRequiredService<IElementViewModel>();
+                var elementViewModel = _serviceProvider.GetInitableResolver<IElement, ITabViewModel>(element, this).GetRequiredService<IElementViewModel>();
 
                 return elementViewModel;
             }

src/Core/FileTime.Core.Abstraction/FileTime.Core.Abstraction.csproj

@@ -7,6 +7,7 @@
   </PropertyGroup>
 
   <ItemGroup>
+    <PackageReference Include="DynamicData" Version="7.6.7" />
     <PackageReference Include="System.Reactive" Version="5.0.0" />
   </ItemGroup>
 

src/Core/FileTime.Core.Abstraction/Models/IContainer.cs

@@ -1,8 +1,10 @@
+using DynamicData;
+
 namespace FileTime.Core.Models
 {
     public interface IContainer : IItem
     {
-        IObservable<IEnumerable<IAbsolutePath>?> Items { get; }
+        IObservable<IObservable<IChangeSet<IAbsolutePath>>?> Items { get; }
         IObservable<bool> IsLoading { get; }
     }
 }

src/Core/FileTime.Core.Abstraction/Services/ITab.cs

@@ -1,3 +1,4 @@
+using DynamicData;
 using FileTime.Core.Models;
 using InitableService;
 
@@ -7,7 +8,7 @@ namespace FileTime.Core.Services
     {
         IObservable<IContainer?> CurrentLocation { get; }
         IObservable<IAbsolutePath?> CurrentSelectedItem { get; }
-        IObservable<IEnumerable<IItem>?> CurrentItems { get; }
+        IObservable<IObservable<IChangeSet<IItem>>?> CurrentItems { get; }
 
         void SetCurrentLocation(IContainer newLocation);
         void AddSelectedItemsTransformator(ItemsTransformator transformator);

src/Core/FileTime.Core.Models/AbsolutePath.cs

@@ -19,6 +19,14 @@ namespace FileTime.Core.Models
             Type = type;
         }
 
+        public AbsolutePath(IItem item, IContentProvider? virtualContentProvider = null)
+        {
+            ContentProvider = item.Provider;
+            Path = item.FullName ?? throw new ArgumentException($"{nameof(item.FullName)} can not be null.", nameof(item));
+            VirtualContentProvider = virtualContentProvider;
+            Type = item.Type;
+        }
+
         public async Task<IItem> ResolveAsync(bool forceResolve = false, ItemInitializationSettings itemInitializationSettings = default)
         {
             var provider = VirtualContentProvider ?? ContentProvider;

src/Core/FileTime.Core.Models/Container.cs

@@ -1,5 +1,6 @@
 using System.Reactive.Linq;
 using System.Reactive.Subjects;
+using DynamicData;
 using FileTime.Core.Enums;
 using FileTime.Core.Services;
 
@@ -19,7 +20,7 @@ namespace FileTime.Core.Models
         string? Attributes,
         IContentProvider Provider,
         IObservable<IEnumerable<Exception>> Exceptions,
-        IObservable<IEnumerable<IAbsolutePath>?> Items) : IContainer
+        IObservable<IObservable<IChangeSet<IAbsolutePath>>?> Items) : IContainer
     {
         BehaviorSubject<bool> IsLoading { get; } = new BehaviorSubject<bool>(false);
         IObservable<bool> IContainer.IsLoading => IsLoading.AsObservable();

src/Core/FileTime.Core.Services/ContentProviderBase.cs

@@ -1,5 +1,6 @@
 using System.Reactive.Linq;
 using System.Reactive.Subjects;
+using DynamicData;
 using FileTime.Core.Enums;
 using FileTime.Core.Models;
 
@@ -7,9 +8,9 @@ namespace FileTime.Core.Services
 {
     public abstract class ContentProviderBase : IContentProvider
     {
-        protected BehaviorSubject<IReadOnlyList<IAbsolutePath>> Items { get; } = new BehaviorSubject<IReadOnlyList<IAbsolutePath>>(new List<IAbsolutePath>());
+        protected BehaviorSubject<IObservable<IChangeSet<IAbsolutePath>>?> Items { get; } = new (null);
 
-        IObservable<IEnumerable<IAbsolutePath>> IContainer.Items => Items;
+        IObservable<IObservable<IChangeSet<IAbsolutePath>>?> IContainer.Items => Items;
 
         public string Name { get; }
 

src/Core/FileTime.Core.Services/FileTime.Core.Services.csproj

@@ -13,6 +13,7 @@
   </ItemGroup>
 
   <ItemGroup>
+    <ProjectReference Include="..\..\Tools\FileTime.Tools\FileTime.Tools.csproj" />
     <ProjectReference Include="..\FileTime.Core.Abstraction\FileTime.Core.Abstraction.csproj" />
     <ProjectReference Include="..\FileTime.Core.Models\FileTime.Core.Models.csproj" />
   </ItemGroup>

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

@@ -1,5 +1,6 @@
 using System.Reactive.Linq;
 using System.Reactive.Subjects;
+using DynamicData;
 using FileTime.Core.Models;
 
 namespace FileTime.Core.Services
@@ -10,8 +11,9 @@ namespace FileTime.Core.Services
         private readonly BehaviorSubject<IAbsolutePath?> _currentSelectedItem = new(null);
         private readonly List<ItemsTransformator> _transformators = new();
         private IAbsolutePath? _currentSelectedItemCached;
+
         public IObservable<IContainer?> CurrentLocation { get; }
-        public IObservable<IEnumerable<IItem>?> CurrentItems { get; }
+        public IObservable<IObservable<IChangeSet<IItem>>?> CurrentItems { get; }
         public IObservable<IAbsolutePath?> CurrentSelectedItem { get; }
 
         public Tab()
@@ -23,53 +25,54 @@ namespace FileTime.Core.Services
                         .Where(c => c is not null)
                         .Select(c => c!.Items)
                         .Switch()
-                        .Select(i => i == null ? Observable.Return<IEnumerable<IItem>?>(null) : Observable.FromAsync(async () => await MapItems(i)))
+                        .Select(items => items?.TransformAsync(MapItem)),
-                        .Switch(),
                     CurrentLocation
                         .Where(c => c is null)
-                        .Select(_ => Enumerable.Empty<IItem>())
+                        .Select(_ => (IObservable<IChangeSet<IItem>>?)null)
                 )
-                .Publish(Enumerable.Empty<IItem>())
+                .Publish((IObservable<IChangeSet<IItem>>?)null)
                 .RefCount();
 
-            CurrentSelectedItem = CurrentLocation
+            CurrentSelectedItem =
-                .Select(GetSelectedItemByLocation)
+                Observable.CombineLatest(
-                .Switch()
+                    CurrentItems
-                .Merge(_currentSelectedItem)
+                        .Select(c =>
+                            c == null
+                            ? Observable.Return<IReadOnlyCollection<IItem>?>(null)
+                            : c.ToCollection()
+                        )
+                        .Switch(),
+                    _currentSelectedItem,
+                    (items, selected) =>
+                    {
+                        if (selected != null && (items?.Any(i => i.FullName == selected.Path) ?? true)) return selected;
+                        if (items == null || items.Count == 0) return null;
+
+                        return GetSelectedItemByItems(items);
+                    }
+                )
                 .DistinctUntilChanged()
                 .Publish(null)
                 .RefCount();
 
-            CurrentSelectedItem.Subscribe(s => _currentSelectedItemCached = s);
+            CurrentSelectedItem.Subscribe(s =>
+            {
+                _currentSelectedItemCached = s;
+                _currentSelectedItem.OnNext(s);
+            });
         }
 
-        private async Task<IEnumerable<IItem>> MapItems(IEnumerable<IAbsolutePath> items)
+        private async Task<IItem> MapItem(IAbsolutePath item) => await item.ResolveAsync(true);
-        {
-            IEnumerable<IItem> resolvedItems = await items
-                .ToAsyncEnumerable()
-                .SelectAwait(async i => await i.ResolveAsync(true))
-                .Where(i => i != null)
-                .ToListAsync();
-
-            return _transformators.Count == 0
-                ? resolvedItems
-                : (await _transformators
-                        .ToAsyncEnumerable()
-                        .Scan(resolvedItems, (acc, t) => new ValueTask<IEnumerable<IItem>>(t.Transformator(acc)))
-                        .ToListAsync()
-                    )
-                    .SelectMany(t => t);
-        }
 
         public void Init(IContainer currentLocation)
         {
             _currentLocation.OnNext(currentLocation);
         }
 
-        private IObservable<IAbsolutePath?> GetSelectedItemByLocation(IContainer? currentLocation)
+        private static IAbsolutePath? GetSelectedItemByItems(IEnumerable<IItem> items)
         {
             //TODO: 
-            return currentLocation?.Items?.Select(i => i?.FirstOrDefault()) ?? Observable.Return((IAbsolutePath?)null);
+            return new AbsolutePath(items.First());
         }
 
         public void SetCurrentLocation(IContainer newLocation) => _currentLocation.OnNext(newLocation);

src/FileTime.sln

@@ -47,6 +47,10 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "FileTime.Providers.Local.Ab
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "FileTime.GuiApp.Abstractions", "GuiApp\Avalonia\FileTime.GuiApp.Abstractions\FileTime.GuiApp.Abstractions.csproj", "{D7D1C76A-05B0-49BC-BCFF-06340E264EC1}"
 EndProject
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Tools", "Tools", "{8C3CFEFE-78A5-4940-B388-D15FCE02ECE9}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "FileTime.Tools", "Tools\FileTime.Tools\FileTime.Tools.csproj", "{B7A45654-E56C-43C8-998E-0F4661395540}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -113,6 +117,10 @@ Global
 		{D7D1C76A-05B0-49BC-BCFF-06340E264EC1}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{D7D1C76A-05B0-49BC-BCFF-06340E264EC1}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{D7D1C76A-05B0-49BC-BCFF-06340E264EC1}.Release|Any CPU.Build.0 = Release|Any CPU
+		{B7A45654-E56C-43C8-998E-0F4661395540}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{B7A45654-E56C-43C8-998E-0F4661395540}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{B7A45654-E56C-43C8-998E-0F4661395540}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{B7A45654-E56C-43C8-998E-0F4661395540}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
@@ -134,6 +142,7 @@ Global
 		{4B742649-225F-4C73-B118-1B29FE2A5774} = {01F231DE-4A65-435F-B4BB-77EE5221890C}
 		{1500A537-2116-4111-B216-7632040619B0} = {2FC40FE1-4446-44AB-BF77-00F94D995FA3}
 		{D7D1C76A-05B0-49BC-BCFF-06340E264EC1} = {01F231DE-4A65-435F-B4BB-77EE5221890C}
+		{B7A45654-E56C-43C8-998E-0F4661395540} = {8C3CFEFE-78A5-4940-B388-D15FCE02ECE9}
 	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution
 		SolutionGuid = {859FB3DF-C60A-46B1-82E5-90274905D1EF}

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

@@ -108,7 +108,7 @@
                                 AutoScrollToSelectedItem="True"
                                 Classes="ContentListView"
                                 IsTabStop="True"
-                                Items="{Binding AppState.SelectedTab^.ParentsChildren^}"
+                                Items="{Binding AppState.SelectedTab^.ParentsChildrenCollection.Collection}"
                                 ScrollViewer.HorizontalScrollBarVisibility="Hidden"
                                 ScrollViewer.VerticalScrollBarVisibility="Visible">
                                 <ListBox.ItemTemplate>
@@ -146,7 +146,7 @@
                                     AutoScrollToSelectedItem="True"
                                     Classes="ContentListView"
                                     IsTabStop="True"
-                                    Items="{Binding AppState.SelectedTab^.CurrentItems^}"
+                                    Items="{Binding AppState.SelectedTab^.CurrentItemsCollection.Collection}"
                                     ScrollViewer.HorizontalScrollBarVisibility="Hidden"
                                     ScrollViewer.VerticalScrollBarVisibility="Visible">
                                     <ListBox.ItemTemplate>
@@ -166,7 +166,7 @@
                                     x:CompileBindings="False"
                                     FontWeight="Bold"
                                     Foreground="{DynamicResource ErrorBrush}"
-                                    IsVisible="{Binding AppState.SelectedTab^.CurrentLocation^.Items^.Count, Converter={StaticResource EqualityConverter}, ConverterParameter=0}">
+                                    IsVisible="{Binding AppState.SelectedTab^.CurrentItemsCollection.Collection.Count, Converter={StaticResource EqualityConverter}, ConverterParameter=0}">
                                     Empty
                                 </TextBlock>
                             </Grid>
@@ -180,14 +180,14 @@
                                 Fill="{DynamicResource ContentSeparatorBrush}" />
 
                             <Grid Grid.Column="4">
-                                <Grid IsVisible="{Binding AppState.SelectedTab^.SelectedsChildren^, Converter={x:Static ObjectConverters.IsNotNull}}">
+                                <Grid IsVisible="{Binding AppState.SelectedTab^.SelectedsChildrenCollection.Collection, Converter={x:Static ObjectConverters.IsNotNull}}">
                                     <ListBox
                                         x:Name="ChildItems"
                                         x:CompileBindings="False"
                                         AutoScrollToSelectedItem="True"
                                         Classes="ContentListView"
-                                        IsVisible="{Binding AppState.SelectedTab^.SelectedsChildren^.Count, Converter={StaticResource NotEqualsConverter}, ConverterParameter=0}"
+                                        IsVisible="{Binding AppState.SelectedTab^.SelectedsChildrenCollection.Collection.Count, Converter={StaticResource NotEqualsConverter}, ConverterParameter=0}"
-                                        Items="{Binding AppState.SelectedTab^.SelectedsChildren^}">
+                                        Items="{Binding AppState.SelectedTab^.SelectedsChildrenCollection.Collection}">
                                         <ListBox.ItemTemplate>
                                             <DataTemplate x:DataType="corevm:IItemViewModel">
                                                 <local:ItemView />
@@ -202,13 +202,13 @@
                                         x:CompileBindings="False"
                                         FontWeight="Bold"
                                         Foreground="{DynamicResource ErrorBrush}"
-                                        IsVisible="{Binding AppState.SelectedTab^.SelectedsChildren^.Count, Converter={StaticResource EqualityConverter}, ConverterParameter=0}">
+                                        IsVisible="{Binding AppState.SelectedTab^.SelectedsChildrenCollection.Collection.Count, Converter={StaticResource EqualityConverter}, ConverterParameter=0}">
                                         Empty
                                     </TextBlock>
                                 </Grid>
 
                                 <Grid
-                                    IsVisible="{Binding AppState.SelectedTab^.SelectedsChildren^, Converter={x:Static ObjectConverters.IsNull}, ConverterParameter=0}"
+                                    IsVisible="{Binding AppState.SelectedTab^.SelectedsChildrenCollection, Converter={x:Static ObjectConverters.IsNull}, ConverterParameter=0}"
                                     RowDefinitions="Auto, Auto">
                                     <TextBlock
                                         Margin="0,0,0,10"

src/Providers/FileTime.Providers.Local/FileTime.Providers.Local.csproj

@@ -7,6 +7,7 @@
   </PropertyGroup>
 
   <ItemGroup>
+    <PackageReference Include="DynamicData" Version="7.6.7" />
     <PackageReference Include="Microsoft.Extensions.DependencyInjection.Abstractions" Version="6.0.0" />
   </ItemGroup>
 

src/Providers/FileTime.Providers.Local/LocalContentProvider.cs

@@ -1,19 +1,24 @@
 using System.Reactive.Linq;
 using System.Reactive.Subjects;
 using System.Runtime.InteropServices;
+using DynamicData;
 using FileTime.Core.Enums;
 using FileTime.Core.Models;
 using FileTime.Core.Services;
 
 namespace FileTime.Providers.Local
 {
-    public partial class LocalContentProvider : ContentProviderBase, ILocalContentProvider
+    public sealed partial class LocalContentProvider : ContentProviderBase, ILocalContentProvider
     {
-        protected bool IsCaseInsensitive { get; init; }
+        private readonly SourceList<IAbsolutePath> _rootDirectories = new();
+        private readonly bool _isCaseInsensitive;
         public LocalContentProvider() : base("local")
         {
-            IsCaseInsensitive = RuntimeInformation.IsOSPlatform(OSPlatform.Windows);
+            _isCaseInsensitive = RuntimeInformation.IsOSPlatform(OSPlatform.Windows);
+
             RefreshRootDirectories();
+
+            Items.OnNext(_rootDirectories.Connect());
         }
 
         public override Task OnEnter()
@@ -29,7 +34,11 @@ namespace FileTime.Providers.Local
                 ? new DirectoryInfo("/").GetDirectories()
                 : Environment.GetLogicalDrives().Select(d => new DirectoryInfo(d));
 
-            Items.OnNext(rootDirectories.Select(DirectoryToAbsolutePath).ToList());
+            _rootDirectories.Edit(actions =>
+            {
+                actions.Clear();
+                actions.AddRange(rootDirectories.Select(DirectoryToAbsolutePath));
+            });
         }
 
         public override Task<IItem> GetItemByNativePathAsync(
@@ -108,7 +117,7 @@ namespace FileTime.Providers.Local
                 "???",
                 this,
                 nonNullExceptions,
-                Observable.Return<IEnumerable<IAbsolutePath>?>(null)
+                Observable.Return<IObservable<IChangeSet<IAbsolutePath>>?>(null)
             );
         }
 
@@ -160,19 +169,24 @@ namespace FileTime.Providers.Local
                 Observable.FromAsync(async () => await Task.Run(InitChildren))
             );
 
-            Task<List<IAbsolutePath>?> InitChildren()
+            Task<IObservable<IChangeSet<IAbsolutePath>>?> InitChildren()
             {
-                List<IAbsolutePath>? result = null;
+                SourceList<IAbsolutePath>? result = null;
                 try
                 {
-                    result = initializeChildren ? (List<IAbsolutePath>?)GetItemsByContainer(directoryInfo) : null;
+                    var items = initializeChildren ? (List<IAbsolutePath>?)GetItemsByContainer(directoryInfo) : null;
+                    if (items != null)
+                    {
+                        result = new SourceList<IAbsolutePath>();
+                        result.AddRange(items);
+                    }
                 }
                 catch (Exception e)
                 {
                     exceptions.OnNext(new List<Exception>() { e });
                 }
 
-                return Task.FromResult(result);
+                return Task.FromResult(result?.Connect());
             }
         }
 

src/Tools/FileTime.Tools/Extensions/ObjectExtensions.cs

@@ -0,0 +1,11 @@
+namespace FileTime.Tools.Extensions
+{
+    public static class ObjectExtensions
+    {
+        public static TResult? MapNull<T, TResult>(this T obj, Func<TResult?> nullHandler, Func<T, TResult?> valueHandler)
+            => obj == null ? nullHandler() : valueHandler(obj);
+
+        public static TResult? MapNull<T, TResult>(this T obj, Func<T, TResult?> valueHandler)
+            => obj == null ? default : valueHandler(obj);
+    }
+}

src/Tools/FileTime.Tools/FileTime.Tools.csproj

@@ -0,0 +1,9 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net6.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+</Project>