Startup error handling

src/GuiApp/Avalonia/FileTime.GuiApp/ViewModels/IMainWindowViewModel.cs

@@ -9,7 +9,6 @@ namespace FileTime.GuiApp.ViewModels;
 
 public interface IMainWindowViewModel : IMainWindowViewModelBase
 {
-    string Title { get; }
     IGuiAppState AppState { get; }
     IItemPreviewService ItemPreviewService { get; }
     IDialogService DialogService { get; }

src/GuiApp/Avalonia/FileTime.GuiApp/ViewModels/IMainWindowViewModelBase.cs

@@ -1,7 +1,11 @@
+using DeclarativeProperty;
+
 namespace FileTime.GuiApp.ViewModels;
 
 public interface IMainWindowViewModelBase
 {
+    DeclarativeProperty<string> Title { get; }
     bool Loading { get; }
     IObservable<string?> MainFont { get; } 
+    DeclarativeProperty<string> FatalError { get; }
 }

src/GuiApp/Avalonia/FileTime.GuiApp/ViewModels/MainWindowLoadingViewModel.cs

@@ -1,4 +1,5 @@
 using System.Reactive.Subjects;
+using DeclarativeProperty;
 
 namespace FileTime.GuiApp.ViewModels;
 
@@ -6,4 +7,6 @@ public class MainWindowLoadingViewModel : IMainWindowViewModelBase
 {
     public bool Loading => true;
     public IObservable<string?> MainFont { get; } = new BehaviorSubject<string?>("");
+    public DeclarativeProperty<string> Title { get; } = new("Loading...");
+    public DeclarativeProperty<string> FatalError { get; } = new();
 }

src/GuiApp/Avalonia/FileTime.GuiApp/ViewModels/MainWindowViewModel.cs

@@ -1,6 +1,7 @@
 using System.Reactive.Linq;
 using System.Reflection;
 using Avalonia.Input;
+using DeclarativeProperty;
 using FileTime.App.CommandPalette.Services;
 using FileTime.App.Core.Services;
 using FileTime.App.Core.UserCommand;
@@ -38,8 +39,9 @@ public partial class MainWindowViewModel : IMainWindowViewModel
 {
     public bool Loading => false;
     public IObservable<string?> MainFont => _fontService.MainFont.Select(x => x ?? "");
+    public DeclarativeProperty<string> FatalError { get; } = new();
     public IGuiAppState AppState => _appState;
-    public string Title { get; private set; }
+    public DeclarativeProperty<string> Title { get; } = new();
     public Action? FocusDefaultElement { get; set; }
 
     partial void OnInitialize()
@@ -57,11 +59,13 @@ public partial class MainWindowViewModel : IMainWindowViewModel
             }
         }
 
-        Title = "FileTime " + versionString;
+        var title = "FileTime " + versionString;
 #if DEBUG
-        Title += " (Debug)";
+        title += " (Debug)";
 #endif
         
+        Title.SetValueSafe(title);
+
         _modalService.AllModalClosed += (_, _) => FocusDefaultElement?.Invoke();
 
         Task.Run(async () => await _lifecycleService.InitStartupHandlersAsync()).Wait();

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

@@ -53,7 +53,7 @@
 
                 <Grid PointerPressed="HeaderPointerPressed">
                     <Rectangle Fill="#01000000" />
-                    <TextBlock Margin="15,10" Text="{Binding Title}" />
+                    <TextBlock Margin="15,10" Text="{Binding Title.Value}" />
                 </Grid>
 
                 <Grid Grid.Column="1" PointerPressed="HeaderPointerPressed">
@@ -998,7 +998,12 @@
                 <TextBlock
                     HorizontalAlignment="Center"
                     Margin="50"
-                    Text="Loading..." />
+                    Text="{Binding Title.Value}" />
+                <TextBlock
+                    Foreground="Red"
+                    HorizontalAlignment="Center"
+                    Margin="50"
+                    Text="{Binding FatalError.Value}" />
             </StackPanel>
         </Grid>
     </Grid>

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

@@ -75,10 +75,23 @@ public partial class MainWindow : Window, IUiAccessor
             _logger?.LogInformation(
                 $"{nameof(MainWindow)} opened, starting {nameof(MainWindowViewModel)} initialization...");
 
+            try
+            {
                 var viewModel = DI.ServiceProvider.GetRequiredService<MainWindowViewModel>();
                 viewModel.FocusDefaultElement = () => Focus();
                 ViewModel = viewModel;
             }
+            catch (Exception ex)
+            {
+                _logger?.LogError(ex, "Error initializing {ViewModel}", nameof(MainWindowViewModel));
+                if (DataContext is IMainWindowViewModelBase mainWindowViewModelBase)
+                {
+                    mainWindowViewModelBase.FatalError.SetValueSafe(
+                        $"Error initializing {nameof(MainWindowViewModel)}: " + ex.Message
+                    );
+                }
+            }
+        }
     }
 
     private void OnKeyDown(object sender, KeyEventArgs e)