Explain and fix a Filee that Explorer can't reach (#99)

src/Filee.App/App.axaml.cs

@@ -5,6 +5,7 @@
 using Avalonia.Controls.ApplicationLifetimes;
 using Avalonia.Markup.Xaml;
 using Avalonia.Threading;
+using Filee.App.Controls;
 using Filee.App.Services;
 using Filee.App.Services.Triggers;
 using Filee.Core.Conversion;
@@ -22,7 +23,14 @@ public partial class App : Application
     private IDisposable? _convertDebounce;
     private bool _selectionPending;
 
-    public override void Initialize() => AvaloniaXamlLoader.Load(this);
+    /// <summary>Forwarded launches and empty selections can come in bursts: a few lines a minute are enough.</summary>
+    private static readonly LogThrottle Throttle = new(TimeSpan.FromSeconds(30));
+
+    public override void Initialize()
+    {
+        AvaloniaXamlLoader.Load(this);
+        SingleSelectionGuard.Register();
+    }
 
     public override void OnFrameworkInitializationCompleted()
     {
@@ -34,6 +42,9 @@ public override void OnFrameworkInitializationCompleted()
         base.OnFrameworkInitializationCompleted();
     }
 
+    /// <summary>Ends Filee as the tray's Quit does.</summary>
+    public static void Quit() => (Current?.ApplicationLifetime as IClassicDesktopStyleApplicationLifetime)?.Shutdown();
+
     private void Start(IClassicDesktopStyleApplicationLifetime desktop)
     {
         // macOS: "Convert with Filee" in Finder's right-click menu. Registered first, so a service picked while
@@ -42,12 +53,20 @@ private void Start(IClassicDesktopStyleApplicationLifetime desktop)
             Filee.Platform.MacOS.MacOSServicesProvider.Register(files =>
                 Dispatcher.UIThread.Post(() => HandleCommandLine(CommandLine.Parse(["--convert", .. files]))));
         var log = AppHost.Get<ILogger<App>>();
+        // Exceptions in UI event handlers end Filee; write them down first (they are not marked handled).
+        Dispatcher.UIThread.UnhandledException += (_, e) =>
+            log.LogCritical(e.Exception, "Unhandled exception on the UI thread");
+        var watchdog = new UiWatchdog(action => Dispatcher.UIThread.Post(action), AppHost.Get<ILogger<UiWatchdog>>());
+        watchdog.Start();
         var store = AppHost.Get<UserDataStore>();
         store.Load();
 
         var loc = AppHost.Get<LocalizationService>();
         loc.Attach(this);
         ApplySettings(store.Settings);
+        // Every engine's availability, checked once off the UI thread: the first donut or drop otherwise starts
+        // every engine's check (FFmpeg -version, folder searches) on the UI thread and freezes it meanwhile.
+        _ = AppHost.Get<ConverterCatalog>().CheckInBackgroundAsync();
 
         // Global gestures → donut toolbar
         var triggers = AppHost.Get<TriggerService>();
@@ -66,6 +85,11 @@ private void Start(IClassicDesktopStyleApplicationLifetime desktop)
                     ? await Task.Run(platform.GetFileManagerSelection) : platform.GetFileManagerSelection();
                 if (files.Count > 0 && !store.Settings.Paused)
                     radial.ShowForFiles(e.X, e.Y, files);
+                else if (files.Count == 0 && Throttle.TryEnter("empty-selection", out var held))
+                    log.LogInformation("The selection shortcut found no selected files in {Window}{Elevation}{Held}",
+                        platform.DescribeForegroundWindow() is { Length: > 0 } window ? window : "the foreground window",
+                        Program.Elevation.ShellCannotReachFilee ? " (Filee runs as administrator and can't read Explorer)" : "",
+                        LogThrottle.HeldText(held));
             }
             catch (Exception ex) when (ex is not OutOfMemoryException)
             {
@@ -104,20 +128,34 @@ private void Start(IClassicDesktopStyleApplicationLifetime desktop)
 
         // Later launches (context menu, Send To, double-clicking the exe) forward their arguments here.
         if (Program.Instance is { } instance)
-        {
-            instance.ArgumentsReceived += args => Dispatcher.UIThread.Post(() => HandleCommandLine(CommandLine.Parse(args)));
-            instance.StartListening();
-        }
+            ListenForLaterLaunches(instance, log);
+        Program.InstanceAcquired += again => ListenForLaterLaunches(again, log);
 
         desktop.Exit += (_, _) =>
         {
+            watchdog.Dispose();
             AppHost.Get<TriggerService>().Dispose();
             AppHost.Get<TrayService>().Dispose();
             AppHost.Get<WatchFolderService>().DisposeAsync().AsTask().Wait(TimeSpan.FromSeconds(5));
         };
 
         HandleCommandLine(Program.Options, firstLaunch: true);
         WatchForUpdates(store);
+        // Filee runs as administrator while Explorer doesn't (an installer started "as administrator" started it):
+        // say so once, next to the tray, and on the Home page for as long as it lasts.
+        if (AppHost.Get<ElevationService>().ShellCannotReachFilee)
+            DispatcherTimer.RunOnce(() => AppHost.Get<WindowService>().ShowElevationNotice(), TimeSpan.FromSeconds(2));
+    }
+
+    private void ListenForLaterLaunches(SingleInstance instance, ILogger log)
+    {
+        instance.ArgumentsReceived += args =>
+        {
+            if (Throttle.TryEnter("forwarded", out var held))
+                log.LogInformation("A later launch handed over {Count} argument(s){Held}", args.Length, LogThrottle.HeldText(held));
+            Dispatcher.UIThread.Post(() => HandleCommandLine(CommandLine.Parse(args), forwarded: true));
+        };
+        instance.StartListening();
     }
 
     /// <summary>
@@ -193,8 +231,13 @@ private static void ApplySettings(AppSettings settings)
         AppHost.Get<SystemIntegrationService>().Apply(settings);
     }
 
-    private void HandleCommandLine(CommandLine options, bool firstLaunch = false)
+    private void HandleCommandLine(CommandLine options, bool firstLaunch = false, bool forwarded = false)
     {
+        // Pairs with "A later launch handed over …": the request reached the UI thread too.
+        if (forwarded && Throttle.TryEnter("forwarded-handled", out var held))
+            AppHost.Get<ILogger<App>>().LogInformation("Handling a later launch: {Request}{Held}",
+                options.Quit ? "quit" : options.ConvertFiles.Count > 0 ? $"convert {options.ConvertFiles.Count} file(s)" : "show Filee",
+                LogThrottle.HeldText(held));
         if (options.Quit)
         {
             // The installer is about to replace or remove Filee's files (Program.RunInstallerCommand waits for this).

src/Filee.App/Assets/i18n/en.json

@@ -25,6 +25,13 @@
   "home.drop_hint_macos": "Or hold {0} while dragging files in Finder. The donut toolbar opens at your cursor.",
   "home.drop_hint_linux": "Or hold {0} while dragging files in your file manager. The donut toolbar opens at your cursor.",
   "home.accessibility_needed": "To open the donut by dragging with ⌥ Option, allow Filee under Accessibility.\nIt works as soon as you switch it on.",
+  "home.elevated": "Filee is running as administrator, so Explorer can't drop files on it or use its menu.\nThe shortcut can't read Explorer's selection either.\nRestart Filee without administrator rights to fix this.",
+  "home.elevated_restart": "Restart without administrator rights",
+  "home.elevated_restart_failed": "Filee couldn't restart itself.\nQuit Filee from the tray, then start it again.",
+  "elevation.notice_title": "Filee is running as administrator",
+  "elevation.notice_text": "Explorer can't drop files on Filee or use its menu while it runs this way.\nRestart it without administrator rights.",
+  "startup.elevated_other": "Another Filee is running as administrator.\nExplorer can't hand files to it.\nQuit Filee from the tray, then start it again.",
+  "startup.no_answer": "Filee is running but didn't answer.\nIf it runs as administrator, quit it from the tray and start it again.",
   "home.recent": "Recent conversions",
   "home.recent_empty": "Your converted files will show up here.",
   "home.open_folder": "Open folder",

src/Filee.App/Assets/i18n/ko.json

@@ -25,6 +25,13 @@
   "home.drop_hint_macos": "또는 Finder에서 {0} 키를 누른 채 파일을 드래그하면 커서 위치에 원형 툴바가 열려요.",
   "home.drop_hint_linux": "또는 파일 관리자에서 {0} 키를 누른 채 파일을 드래그하면 커서 위치에 원형 툴바가 열려요.",
   "home.accessibility_needed": "⌥ Option 드래그로 원형 툴바를 열려면 손쉬운 사용에서 Filee를 허용해 주세요.\n켜는 즉시 동작해요.",
+  "home.elevated": "Filee가 관리자 권한으로 실행 중이에요.\n그래서 탐색기에서 파일을 끌어 놓거나 메뉴를 쓸 수 없어요.\n단축키도 탐색기에서 선택한 파일을 읽지 못해요.\n관리자 권한 없이 다시 시작해 주세요.",
+  "home.elevated_restart": "관리자 권한 없이 다시 시작",
+  "home.elevated_restart_failed": "Filee를 다시 시작하지 못했어요.\n트레이에서 Filee를 종료한 뒤 다시 실행해 주세요.",
+  "elevation.notice_title": "Filee가 관리자 권한으로 실행 중이에요",
+  "elevation.notice_text": "이 상태에서는 탐색기에서 파일을 끌어 놓거나 메뉴를 쓸 수 없어요.\n관리자 권한 없이 다시 시작해 주세요.",
+  "startup.elevated_other": "다른 Filee가 관리자 권한으로 실행 중이에요.\n그래서 탐색기가 파일을 넘겨줄 수 없어요.\n트레이에서 Filee를 종료한 뒤 다시 실행해 주세요.",
+  "startup.no_answer": "Filee가 실행 중이지만 응답하지 않아요.\n관리자 권한으로 실행 중이라면 트레이에서 종료한 뒤 다시 실행해 주세요.",
   "home.recent": "최근 변환",
   "home.recent_empty": "변환한 파일이 여기에 표시됩니다.",
   "home.open_folder": "폴더 열기",

src/Filee.App/Assets/i18n/zh-CN.json

@@ -25,6 +25,13 @@
   "home.drop_hint_macos": "或在访达中按住 {0} 拖动文件，环形工具栏会在光标处打开。",
   "home.drop_hint_linux": "或在文件管理器中按住 {0} 拖动文件，环形工具栏会在光标处打开。",
   "home.accessibility_needed": "要按住 ⌥ Option 拖动打开环形工具栏，请在“辅助功能”中允许 Filee。\n打开后立即生效。",
+  "home.elevated": "Filee 正以管理员身份运行。\n因此无法从资源管理器拖放文件，也无法使用右键菜单。\n快捷键也无法读取资源管理器中选中的文件。\n请以非管理员身份重新启动 Filee。",
+  "home.elevated_restart": "以非管理员身份重新启动",
+  "home.elevated_restart_failed": "Filee 无法自行重新启动。\n请从托盘退出 Filee，然后再次启动。",
+  "elevation.notice_title": "Filee 正以管理员身份运行",
+  "elevation.notice_text": "此时无法从资源管理器拖放文件，也无法使用右键菜单。\n请以非管理员身份重新启动。",
+  "startup.elevated_other": "另一个 Filee 正以管理员身份运行。\n资源管理器无法把文件交给它。\n请从托盘退出 Filee，然后再次启动。",
+  "startup.no_answer": "Filee 正在运行，但没有响应。\n如果它以管理员身份运行，请从托盘退出，然后再次启动。",
   "home.recent": "最近的转换",
   "home.recent_empty": "转换后的文件会显示在这里。",
   "home.open_folder": "打开文件夹",

src/Filee.App/Controls/SingleSelectionGuard.cs

@@ -0,0 +1,76 @@
+// Keeps combo boxes and single-selection lists from losing their selection to the toggle modifier. Avalonia treats
+// Ctrl+Space, Ctrl+Enter and Ctrl+click (Cmd on macOS) on the selected item as "toggle", which leaves a combo box
+// empty and pushes null into a setting that always has a value (#107). Multi-selection lists keep the toggle.
+//
+// A selection cleared some other way is refused by the view models (Choices.Restore); the control then shows the
+// bound value again.
+
+using Avalonia;
+using Avalonia.Controls;
+using Avalonia.Controls.Primitives;
+using Avalonia.Data;
+using Avalonia.Input;
+using Avalonia.Interactivity;
+using Avalonia.Threading;
+
+namespace Filee.App.Controls;
+
+public static class SingleSelectionGuard
+{
+    private static bool _registered;
+
+    /// <summary>Installs the class handlers once for every combo box and list box of the application.</summary>
+    public static void Register()
+    {
+        if (_registered)
+            return;
+        _registered = true;
+        // Tunnel: the item's own handlers (which toggle) run in the bubble phase.
+        InputElement.KeyDownEvent.AddClassHandler<ListBoxItem>(OnKeyDown, RoutingStrategies.Tunnel);
+        InputElement.PointerPressedEvent.AddClassHandler<ListBoxItem>(OnPointer, RoutingStrategies.Tunnel);
+        InputElement.PointerReleasedEvent.AddClassHandler<ListBoxItem>(OnPointer, RoutingStrategies.Tunnel);
+        SelectingItemsControl.SelectedItemProperty.Changed.AddClassHandler<SelectingItemsControl>(OnSelectedItemChanged);
+    }
+
+    /// <summary>
+    /// The view model puts its value back while the control is still clearing its selection, which the control misses:
+    /// once it is done, it reads the bound value again (still null when the view model took the null).
+    /// </summary>
+    private static void OnSelectedItemChanged(SelectingItemsControl control, AvaloniaPropertyChangedEventArgs e)
+    {
+        if (e.NewValue is null && e.OldValue is not null && control is ComboBox or ListBox
+            && BindingOperations.GetBindingExpressionBase(control, SelectingItemsControl.SelectedItemProperty) is { } binding)
+            Dispatcher.UIThread.Post(binding.UpdateTarget);
+    }
+
+    private static void OnKeyDown(ListBoxItem item, KeyEventArgs e)
+    {
+        if (ItemSelectionEventTriggers.ShouldTriggerSelection(item, e) && WouldDeselect(item, e))
+            Keep(item, e);
+    }
+
+    private static void OnPointer(ListBoxItem item, PointerEventArgs e)
+    {
+        if (e.GetCurrentPoint(item).Properties.PointerUpdateKind is PointerUpdateKind.LeftButtonPressed or PointerUpdateKind.LeftButtonReleased
+            && WouldDeselect(item, e))
+            Keep(item, e);
+    }
+
+    /// <summary>The selected item of a single-selection control, picked again with the toggle modifier held.</summary>
+    private static bool WouldDeselect(ListBoxItem item, RoutedEventArgs e) =>
+        !e.Handled && item.IsSelected && ItemSelectionEventTriggers.HasToggleSelectionModifier(item, e)
+        && ItemsControl.ItemsControlFromItemContainer(item) switch
+        {
+            ComboBox => true,
+            ListBox list => (list.SelectionMode & (SelectionMode.Multiple | SelectionMode.Toggle)) == 0,
+            _ => false,
+        };
+
+    /// <summary>Picking the item that is already selected: nothing changes, an open combo box closes as after any pick.</summary>
+    private static void Keep(ListBoxItem item, RoutedEventArgs e)
+    {
+        e.Handled = true;
+        if (e.RoutedEvent != InputElement.PointerPressedEvent && ItemsControl.ItemsControlFromItemContainer(item) is ComboBox combo)
+            combo.SetCurrentValue(ComboBox.IsDropDownOpenProperty, false);
+    }
+}