ItemsCollection on Container

src/AppCommon/FileTime.App.Core/Services/UserCommandHandler/ItemManipulationUserCommandHandlerService.cs

@@ -195,8 +195,7 @@ public class ItemManipulationUserCommandHandlerService : UserCommandHandlerServi
             var resolvedOnlyItem = await _timelessContentProvider.GetItemByFullNameAsync(itemsToDelete[0], PointInTime.Present);
 
             if (resolvedOnlyItem is IContainer {AllowRecursiveDeletion: true} onlyContainer
-                && await onlyContainer.Items.GetItemsAsync() is { } children
+                && onlyContainer.ItemsCollection.Any())
-                && children.Any())
             {
                 questionText = $"The container '{onlyContainer.DisplayName}' is not empty. Proceed with delete?";
             }
@@ -206,7 +205,7 @@ public class ItemManipulationUserCommandHandlerService : UserCommandHandlerServi
             }
         }
 
-        if (itemsToDelete?.Count == 0) return;
+        if (itemsToDelete.Count == 0) return;
 
         if (questionText is { })
         {

src/AppCommon/FileTime.App.Search/SearchTask.cs

@@ -80,8 +80,7 @@ public class SearchTask : ISearchTask
 
     private async Task TraverseTree(IContainer container)
     {
-        var items = (await container.Items.GetItemsAsync())?.ToList();
+        var items = container.ItemsCollection.ToList();
-        if (items is null) return;
 
         var childContainers = new List<IContainer>();
 

src/Core/FileTime.Core.Abstraction/Extensions/DynamicDataExtensions.cs

@@ -1,87 +0,0 @@
-using System.Reactive.Linq;
-using DynamicData;
-using FileTime.Core.Models;
-
-namespace FileTime.Core.Extensions;
-
-public static class DynamicDataExtensions
-{
-    private class DisposableContext<TParam, TTaskResult>
-    {
-        private readonly SemaphoreSlim _semaphore = new(1, 1);
-        private readonly Func<TParam, TTaskResult> _transformResult;
-        private readonly TaskCompletionSource<TTaskResult?> _taskCompletionSource;
-        private bool _isFinished;
-        public IDisposable? Disposable { get; set; }
-
-        public DisposableContext(Func<TParam, TTaskResult> transformResult,
-            TaskCompletionSource<TTaskResult?> taskCompletionSource, IDisposable? disposable = null)
-        {
-            _transformResult = transformResult;
-            _taskCompletionSource = taskCompletionSource;
-            Disposable = disposable;
-        }
-
-        public void OnNext(TParam param)
-        {
-            if (IsFinished()) return;
-            Disposable?.Dispose();
-            var result = _transformResult(param);
-            _taskCompletionSource.SetResult(result);
-        }
-
-        public void OnError(Exception ex)
-        {
-            if (IsFinished()) return;
-            Disposable?.Dispose();
-            _taskCompletionSource.SetException(ex);
-        }
-
-        public void OnCompleted()
-        {
-            if (IsFinished()) return;
-            Disposable?.Dispose();
-            _taskCompletionSource.SetResult(default);
-        }
-
-        private bool IsFinished()
-        {
-            _semaphore.Wait();
-            var finished = _isFinished;
-            _isFinished = true;
-            _semaphore.Release();
-
-            return finished;
-        }
-    }
-
-    public static async Task<IEnumerable<AbsolutePath>?> GetItemsAsync(
-        this IObservable<IObservable<IChangeSet<AbsolutePath, string>>?> stream)
-        => await GetItemsAsync(stream
-            .Select(s =>
-                s is null
-                    ? new SourceList<AbsolutePath>().Connect().StartWithEmpty().ToCollection()
-                    : s.StartWithEmpty().ToCollection())
-            .Switch());
-
-    public static async Task<IEnumerable<AbsolutePath>?> GetItemsAsync(
-        this IObservable<IChangeSet<AbsolutePath, string>> stream)
-        => await GetItemsAsync(stream.StartWithEmpty().ToCollection());
-
-    public static Task<IEnumerable<AbsolutePath>?> GetItemsAsync(
-        this IObservable<IReadOnlyCollection<AbsolutePath>> stream)
-    {
-        var taskCompletionSource = new TaskCompletionSource<IEnumerable<AbsolutePath>?>();
-        var context = new DisposableContext<IReadOnlyCollection<AbsolutePath>, IEnumerable<AbsolutePath>?>(r => r,
-            taskCompletionSource);
-
-        context.Disposable = stream
-            .Subscribe(
-                context.OnNext,
-                context.OnError,
-                context.OnCompleted
-            );
-
-        return taskCompletionSource.Task;
-    }
-}

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

@@ -1,3 +1,4 @@
+using System.Collections.ObjectModel;
 using DynamicData;
 
 namespace FileTime.Core.Models;
@@ -5,6 +6,7 @@ namespace FileTime.Core.Models;
 public interface IContainer : IItem
 {
     IObservable<IChangeSet<AbsolutePath, string>> Items { get; }
+    ReadOnlyObservableCollection<AbsolutePath> ItemsCollection { get; }
     IObservable<bool> IsLoading { get; }
     bool AllowRecursiveDeletion { get; }
 }

src/Core/FileTime.Core.Command/Copy/CopyCommand.cs

@@ -111,13 +111,12 @@ public class CopyCommand : CommandBase, ITransportationCommand
 
             if (item is IContainer container)
             {
-                if (!((await resolvedTarget.Items.GetItemsAsync())?.Any(i => i.Path.GetName() == item.Name) ?? false))
+                if (resolvedTarget.ItemsCollection.All(i => i.Path.GetName() != item.Name))
                 {
                     await copyOperation.CreateContainerAsync(resolvedTarget, container.Name, container.PointInTime);
                 }
 
-                var children = await container.Items.GetItemsAsync();
+                var children = container.ItemsCollection;
-                if (children is null) continue;
 
                 await TraverseTree(currentTime, children.Select(c => c.Path).ToList(), target.GetChild(item.Name, AbsolutePathType.Container), transportMode, copyOperation);
                 await copyOperation.ContainerCopyDoneAsync(new AbsolutePath(_timelessContentProvider, container));

src/Core/FileTime.Core.Command/Create/CreateItemBase.cs

@@ -42,9 +42,7 @@ public abstract class CreateItemBase : CommandBase, IExecutableCommand, IInitabl
             var parent = await ResolveParentAsync();
             if (parent is not IContainer parentContainer) return CanCommandRun.False;
 
-            var items = await parentContainer.Items.GetItemsAsync().AwaitWithTimeout(10, Enumerable.Empty<AbsolutePath>());
+            var items = parentContainer.ItemsCollection;
-            if (items is null) return CanCommandRun.Forcable;
-
             var existingItem = items.FirstOrDefault(i => i.Path.GetName() == NewItemName);
 
             return existingItem switch

src/Core/FileTime.Core.Command/Delete/DeleteCommand.cs

@@ -71,7 +71,7 @@ public class DeleteCommand : CommandBase, IExecutableCommand
             {
                 await TraverseTree(
                     currentTime,
-                    (await container.Items.GetItemsAsync())?.Select(i => i.Path) ?? Enumerable.Empty<FullName>(),
+                    container.ItemsCollection.Select(i => i.Path),
                     itemDeleters,
                     deleteStrategy
                 );

src/Core/FileTime.Core.Command/Helper.cs

@@ -7,7 +7,7 @@ public static class Helper
 {
     public static async Task<string?> GetNewNameAsync(IContainer resolvedTarget, string name, TransportMode transportMode)
     {
-        var items = (await resolvedTarget.Items.GetItemsAsync() ?? throw new NullReferenceException()).ToList();
+        var items = resolvedTarget.ItemsCollection.ToList();
         var newName = name;
         var targetNameExists = items.Any(i => i.Path.GetName() == newName);
         if (transportMode == TransportMode.Merge)

src/Core/FileTime.Core.CommandHandlers/StreamCopyCommandHandler.cs

@@ -53,8 +53,8 @@ public class StreamCopyCommandHandler : ICommandHandler
     {
         var parent = (IContainer?) (await targetPath.GetParent()!.ResolveAsync())!;
         var elementName = targetPath.Path;
-        var parentChildren = await parent.Items.GetItemsAsync();
+        var parentChildren = parent.ItemsCollection.ToList();
-        if (parentChildren!.All(e => e.Path.GetName() != elementName.GetName()))
+        if (parentChildren.All(e => e.Path.GetName() != elementName.GetName()))
         {
             var itemCreator = _contentAccessorFactory.GetItemCreator(parent.Provider);
             await itemCreator.CreateElementAsync(parent.Provider, elementName);

src/Core/FileTime.Core.ContentAccess/ContentProviderBase.cs

@@ -1,3 +1,4 @@
+using System.Collections.ObjectModel;
 using System.Reactive.Linq;
 using System.Reactive.Subjects;
 using DynamicData;
@@ -13,6 +14,7 @@ public abstract class ContentProviderBase : IContentProvider
     private readonly IObservable<IChangeSet<AbsolutePath, string>> _items;
 
     protected SourceCache<AbsolutePath, string> Items { get; } = new(p => p.Path.Path);
+    public ReadOnlyObservableCollection<AbsolutePath> ItemsCollection { get; }
     protected ExtensionCollection Extensions { get; }
 
     IObservable<IChangeSet<AbsolutePath, string>> IContainer.Items => _items;
@@ -61,6 +63,8 @@ public abstract class ContentProviderBase : IContentProvider
         Extensions = new ExtensionCollection();
         _extensions = Extensions.AsReadOnly();
         _items = Items.Connect().StartWithEmpty();
+        _items.Bind(out var items).Subscribe();
+        ItemsCollection = items;
     }
 
     public virtual Task OnEnter() => Task.CompletedTask;

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

@@ -1,3 +1,4 @@
+using System.Collections.ObjectModel;
 using System.Reactive.Linq;
 using System.Reactive.Subjects;
 using DynamicData;
@@ -26,11 +27,19 @@ public record Container(
     ReadOnlyExtensionCollection Extensions,
     IObservable<IChangeSet<AbsolutePath, string>> Items) : IContainer
 {
+    private readonly Lazy<ReadOnlyObservableCollection<AbsolutePath>> _itemsCollectionLazy =
+        new (() =>
+        {
+            Items.Bind(out var items).Subscribe();
+            return items;
+        });
     private readonly CancellationTokenSource _loadingCancellationTokenSource = new();
     public CancellationToken LoadingCancellationToken => _loadingCancellationTokenSource.Token;
     public BehaviorSubject<bool> IsLoading { get; } = new(false);
     IObservable<bool> IContainer.IsLoading => IsLoading.AsObservable();
     public AbsolutePathType Type => AbsolutePathType.Container;
 
+    public ReadOnlyObservableCollection<AbsolutePath> ItemsCollection => _itemsCollectionLazy.Value;
+
     public void CancelLoading() => _loadingCancellationTokenSource.Cancel();
 }