Tabs: open, close

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

@@ -1,6 +1,7 @@
 using System.Collections.ObjectModel;
 using System.Reactive.Linq;
 using System.Reactive.Subjects;
+using DynamicData;
 using FileTime.App.Core.Models.Enums;
 using MvvmGen;
 using MoreLinq;
@@ -12,15 +13,16 @@ public abstract partial class AppStateBase : IAppState
 {
     private readonly BehaviorSubject<string?> _searchText = new(null);
     private readonly BehaviorSubject<ITabViewModel?> _selectedTab = new(null);
-    private readonly BehaviorSubject<IEnumerable<ITabViewModel>> _tabs = new(Enumerable.Empty<ITabViewModel>());
     private readonly BehaviorSubject<ViewMode> _viewMode = new(Models.Enums.ViewMode.Default);
+    private readonly SourceList<ITabViewModel> _tabs = new();
 
     public IObservable<ViewMode> ViewMode { get; private set; }
 
-    public ObservableCollection<ITabViewModel> Tabs { get; } = new();
+    public ReadOnlyObservableCollection<ITabViewModel> Tabs { get; private set; }
     public IObservable<string?> SearchText { get; private set; }
 
     public IObservable<ITabViewModel?> SelectedTab { get; private set; }
+    public ITabViewModel? CurrentSelectedTab { get; private set; }
 
     [Property] private string _rapidTravelText = "";
 
@@ -28,21 +30,39 @@ public abstract partial class AppStateBase : IAppState
     {
         ViewMode = _viewMode.AsObservable();
 
-        Tabs.CollectionChanged += (_, _) => _tabs.OnNext(Tabs);
+        var tabsObservable = _tabs.Connect();
+
         SearchText = _searchText.AsObservable();
-        SelectedTab = Observable.CombineLatest(_tabs, _selectedTab, GetSelectedTab);
+        SelectedTab = Observable.CombineLatest(tabsObservable.ToCollection(), _selectedTab.DistinctUntilChanged(), GetSelectedTab);
+
+        SelectedTab.Subscribe(t =>
+        {
+            _selectedTab.OnNext(t);
+            CurrentSelectedTab = t;
+        });
+
+        tabsObservable
+            .Bind(out var collection)
+            .DisposeMany()
+            .Subscribe();
+
+        Tabs = collection;
     }
 
     public void AddTab(ITabViewModel tabViewModel)
     {
-        Tabs.Add(tabViewModel);
+        if (_tabs.Items.Any(t => t.TabNumber == tabViewModel.TabNumber))
+            throw new ArgumentException($"There is a tab with the same tab number {tabViewModel.TabNumber}.", nameof(tabViewModel));
+
+        var index = _tabs.Items.Count(t => t.TabNumber < tabViewModel.TabNumber);
+        _tabs.Insert(index, tabViewModel);
     }
 
     public void RemoveTab(ITabViewModel tabViewModel)
     {
-        if (!Tabs.Contains(tabViewModel)) return;
+        if (!_tabs.Items.Contains(tabViewModel)) return;
 
-        Tabs.Remove(tabViewModel);
+        _tabs.Remove(tabViewModel);
     }
 
     public void SetSearchText(string? searchText) => _searchText.OnNext(searchText);
@@ -56,7 +76,7 @@ public abstract partial class AppStateBase : IAppState
 
     private ITabViewModel? GetSelectedTab(IEnumerable<ITabViewModel> tabs, ITabViewModel? expectedSelectedTab)
     {
-        var (prefered, others) = tabs.OrderBy(t => t.TabNumber).Partition(t => t.TabNumber >= (expectedSelectedTab?.TabNumber ?? 0));
-        return prefered.Concat(others).FirstOrDefault();
+        var (preferred, others) = tabs.OrderBy(t => t.TabNumber).Partition(t => t.TabNumber >= (expectedSelectedTab?.TabNumber ?? 0));
+        return preferred.Concat(others).FirstOrDefault();
     }
 }