Automate view initialization

Author: Tyrrrz

YoutubeDownloader/App.axaml.cs

@@ -15,17 +15,13 @@
 using YoutubeDownloader.ViewModels;
 using YoutubeDownloader.ViewModels.Components;
 using YoutubeDownloader.ViewModels.Dialogs;
-using YoutubeDownloader.Views;
 
 namespace YoutubeDownloader;
 
 public class App : Application, IDisposable
 {
-    private readonly DisposableCollector _eventRoot = new();
-
     private readonly ServiceProvider _services;
-    private readonly SettingsService _settingsService;
-    private readonly MainViewModel _mainViewModel;
+    private readonly DisposableCollector _eventRoot = new();
 
     private bool _isDisposed;
 
@@ -57,42 +53,30 @@ public App()
         services.AddTransient<SettingsViewModel>();
 
         _services = services.BuildServiceProvider(true);
-        _settingsService = _services.GetRequiredService<SettingsService>();
-        _mainViewModel = _services.GetRequiredService<ViewModelManager>().CreateMainViewModel();
 
         // Re-initialize the theme when the user changes it
         _eventRoot.Add(
-            _settingsService.WatchProperty(
-                o => o.Theme,
-                () =>
-                {
-                    RequestedThemeVariant = _settingsService.Theme switch
+            _services
+                .GetRequiredService<SettingsService>()
+                .WatchProperty(
+                    o => o.Theme,
+                    () =>
                     {
-                        ThemeVariant.Light => Avalonia.Styling.ThemeVariant.Light,
-                        ThemeVariant.Dark => Avalonia.Styling.ThemeVariant.Dark,
-                        _ => Avalonia.Styling.ThemeVariant.Default,
-                    };
-
-                    InitializeTheme();
-                }
-            )
+                        RequestedThemeVariant = _services
+                            .GetRequiredService<SettingsService>()
+                            .Theme switch
+                        {
+                            ThemeVariant.Light => Avalonia.Styling.ThemeVariant.Light,
+                            ThemeVariant.Dark => Avalonia.Styling.ThemeVariant.Dark,
+                            _ => Avalonia.Styling.ThemeVariant.Default,
+                        };
+
+                        InitializeTheme();
+                    }
+                )
         );
     }
 
-    public override void Initialize()
-    {
-        base.Initialize();
-
-        AvaloniaXamlLoader.Load(this);
-    }
-
-    public override void RegisterServices()
-    {
-        base.RegisterServices();
-
-        AvaloniaWebViewBuilder.Initialize(config => config.IsInPrivateModeEnabled = true);
-    }
-
     private void InitializeTheme()
     {
         var actualTheme = RequestedThemeVariant?.Key switch
@@ -108,25 +92,35 @@ private void InitializeTheme()
                 : Theme.Create(Theme.Dark, Color.Parse("#E8E8E8"), Color.Parse("#F9A825"));
     }
 
+    public override void Initialize()
+    {
+        base.Initialize();
+
+        AvaloniaXamlLoader.Load(this);
+    }
+
+    public override void RegisterServices()
+    {
+        base.RegisterServices();
+
+        AvaloniaWebViewBuilder.Initialize(config => config.IsInPrivateModeEnabled = true);
+    }
+
     public override void OnFrameworkInitializationCompleted()
     {
         if (ApplicationLifetime is IClassicDesktopStyleApplicationLifetime desktop)
         {
-            desktop.MainWindow = new MainView { DataContext = _mainViewModel };
-
-            void OnExit(object? sender, ControlledApplicationLifetimeExitEventArgs args)
-            {
-                if (sender is IControlledApplicationLifetime lifetime)
-                    lifetime.Exit -= OnExit;
-
-                Dispose();
-            }
+            desktop.MainWindow = _services
+                .GetRequiredService<ViewManager>()
+                .TryBindWindow(
+                    _services.GetRequiredService<ViewModelManager>().CreateMainViewModel()
+                );
 
             // Although `App.Dispose()` is invoked from `Program.Main(...)`, on some platforms
             // it may be called too late in the shutdown lifecycle. Attach an exit
             // handler to ensure timely disposal as a safeguard.
             // https://github.com/Tyrrrz/YoutubeDownloader/issues/795
-            desktop.Exit += OnExit;
+            desktop.Exit += (_, _) => Dispose();
         }
 
         base.OnFrameworkInitializationCompleted();
@@ -135,7 +129,7 @@ void OnExit(object? sender, ControlledApplicationLifetimeExitEventArgs args)
         InitializeTheme();
 
         // Load settings
-        _settingsService.Load();
+        _services.GetRequiredService<SettingsService>().Load();
     }
 
     private void Application_OnActualThemeVariantChanged(object? sender, EventArgs args) =>

YoutubeDownloader/Framework/ViewManager.cs

@@ -32,8 +32,23 @@ public partial class ViewManager
 
         view.DataContext ??= viewModel;
 
+        if (view.IsInitialized)
+        {
+            _ = viewModel.InitializeAsync();
+        }
+        else
+        {
+            view.Initialized += async (_, _) => await viewModel.InitializeAsync();
+        }
+
         return view;
     }
+
+    public UserControl<T>? TryBindUserControl<T>(T viewModel)
+        where T : ViewModelBase => TryBindView(viewModel) as UserControl<T>;
+
+    public Window<T>? TryBindWindow<T>(T viewModel)
+        where T : ViewModelBase => TryBindView(viewModel) as Window<T>;
 }
 
 public partial class ViewManager : IDataTemplate

YoutubeDownloader/Framework/ViewModelBase.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Threading.Tasks;
 using CommunityToolkit.Mvvm.ComponentModel;
 
 namespace YoutubeDownloader.Framework;
@@ -9,6 +10,8 @@ public abstract class ViewModelBase : ObservableObject, IDisposable
 
     protected void OnAllPropertiesChanged() => OnPropertyChanged(string.Empty);
 
+    public virtual Task InitializeAsync() => Task.CompletedTask;
+
     protected virtual void Dispose(bool disposing) { }
 
     public void Dispose()

YoutubeDownloader/ViewModels/Components/DashboardViewModel.cs

@@ -137,8 +137,7 @@ await _dialogManager.ShowDialogAsync(
         }
     }
 
-    [RelayCommand]
-    private async Task InitializeAsync() => await EnsureFFmpegAsync();
+    public override async Task InitializeAsync() => await EnsureFFmpegAsync();
 
     private bool CanShowAuthSetup() => !IsBusy;
 

YoutubeDownloader/ViewModels/Dialogs/DownloadMultipleSetupViewModel.cs

@@ -49,12 +49,13 @@ SettingsService settingsService
         // Without .AsEnumerable(), the below line throws a compile-time error starting with .NET SDK v9.0.200
         Enum.GetValues<VideoQualityPreference>().AsEnumerable().Reverse().ToArray();
 
-    [RelayCommand]
-    private void Initialize()
+    public override Task InitializeAsync()
     {
         SelectedContainer = settingsService.LastContainer;
         SelectedVideoQualityPreference = settingsService.LastVideoQualityPreference;
         SelectedVideos.CollectionChanged += (_, _) => ConfirmCommand.NotifyCanExecuteChanged();
+
+        return Task.CompletedTask;
     }
 
     [RelayCommand]

YoutubeDownloader/ViewModels/Dialogs/DownloadSingleSetupViewModel.cs

@@ -34,12 +34,13 @@ SettingsService settingsService
     [ObservableProperty]
     public partial VideoDownloadOption? SelectedDownloadOption { get; set; }
 
-    [RelayCommand]
-    private void Initialize()
+    public override Task InitializeAsync()
     {
         SelectedDownloadOption = AvailableDownloadOptions?.FirstOrDefault(o =>
             o.Container == settingsService.LastContainer
         );
+
+        return Task.CompletedTask;
     }
 
     [RelayCommand]

YoutubeDownloader/ViewModels/MainViewModel.cs

@@ -2,7 +2,6 @@
 using System.Diagnostics;
 using System.Threading.Tasks;
 using Avalonia;
-using CommunityToolkit.Mvvm.Input;
 using YoutubeDownloader.Framework;
 using YoutubeDownloader.Localization;
 using YoutubeDownloader.Services;
@@ -100,8 +99,7 @@ private async Task CheckForUpdatesAsync()
         }
     }
 
-    [RelayCommand]
-    private async Task InitializeAsync()
+    public override async Task InitializeAsync()
     {
         await ShowUkraineSupportMessageAsync();
         await ShowDevelopmentBuildMessageAsync();

YoutubeDownloader/Views/Components/DashboardView.axaml.cs

@@ -16,11 +16,7 @@ public DashboardView()
         QueryTextBox.AddHandler(KeyDownEvent, QueryTextBox_OnKeyDown, RoutingStrategies.Tunnel);
     }
 
-    private void UserControl_OnLoaded(object? sender, RoutedEventArgs args)
-    {
-        DataContext.InitializeCommand.Execute(null);
-        QueryTextBox.Focus();
-    }
+    private void UserControl_OnLoaded(object? sender, RoutedEventArgs args) => QueryTextBox.Focus();
 
     private void QueryTextBox_OnKeyDown(object? sender, KeyEventArgs args)
     {

YoutubeDownloader/Views/Dialogs/DownloadMultipleSetupView.axaml

@@ -9,8 +9,7 @@
     xmlns:materialIcons="clr-namespace:Material.Icons.Avalonia;assembly=Material.Icons.Avalonia"
     x:Name="UserControl"
     Width="500"
-    x:DataType="dialogs:DownloadMultipleSetupViewModel"
-    Loaded="UserControl_OnLoaded">
+    x:DataType="dialogs:DownloadMultipleSetupViewModel">
     <Grid RowDefinitions="Auto,*,Auto,Auto">
         <!--  Title  -->
         <TextBlock

YoutubeDownloader/Views/Dialogs/DownloadMultipleSetupView.axaml.cs

@@ -1,4 +1,3 @@
-using Avalonia.Interactivity;
 using YoutubeDownloader.Framework;
 using YoutubeDownloader.ViewModels.Dialogs;
 
@@ -7,7 +6,4 @@ namespace YoutubeDownloader.Views.Dialogs;
 public partial class DownloadMultipleSetupView : UserControl<DownloadMultipleSetupViewModel>
 {
     public DownloadMultipleSetupView() => InitializeComponent();
-
-    private void UserControl_OnLoaded(object? sender, RoutedEventArgs args) =>
-        DataContext.InitializeCommand.Execute(null);
 }