Add MIDI uninstall, HidHide/MIDI uninstall guards, settings auto-save

hifihedgehog · claude · hifihedgehog · commit 40cfb21ee412 · 2026-03-07T21:59:44.000-05:00
- MIDI Services uninstall via registry-cached WiX bootstrapper (silent)
- Registry-based MIDI detection (no SDK loading) to prevent native crashes
- HidHide uninstall guard: disabled when any device has HidHide enabled
- MIDI uninstall guard: disabled when any MIDI slots exist
- Settings auto-save: theme, polling, checkboxes trigger MarkDirty()
- InputService double-stop protection via _stopped flag

Co-Authored-By: Claude Opus 4.6 &lt;noreply@anthropic.com&gt;
diff --git a/PadForge.App/Common/DriverInstaller.cs b/PadForge.App/Common/DriverInstaller.cs
@@ -655,11 +655,90 @@ private static async Task<string> FindMidiServicesDownloadUrl(HttpClient http)
         }
 
         /// <summary>
-        /// Checks whether Windows MIDI Services is available on this system.
+        /// Uninstalls Windows MIDI Services by finding the cached WiX Burn bootstrapper
+        /// via the registry UninstallString and launching it with /uninstall /quiet.
+        /// The uninstaller is launched fire-and-forget because the MIDI Services SDK
+        /// DLLs are loaded in-process — waiting for the uninstaller to finish would
+        /// cause a native crash when the backing service is removed mid-session.
+        /// </summary>
+        public static void UninstallMidiServices()
+        {
+            string uninstallCmd = FindMidiServicesUninstallString();
+            if (string.IsNullOrEmpty(uninstallCmd))
+                throw new InvalidOperationException("Could not find Windows MIDI Services uninstall entry in registry.");
+
+            // UninstallString is e.g.: "C:\...\Setup.exe"  /uninstall
+            // Parse the quoted exe path and any existing arguments, then append /quiet.
+            string exePath;
+            string existingArgs = "";
+            if (uninstallCmd.StartsWith('"'))
+            {
+                int closeQuote = uninstallCmd.IndexOf('"', 1);
+                exePath = uninstallCmd.Substring(1, closeQuote - 1);
+                existingArgs = uninstallCmd.Substring(closeQuote + 1).Trim();
+            }
+            else
+            {
+                int space = uninstallCmd.IndexOf(' ');
+                exePath = space > 0 ? uninstallCmd.Substring(0, space) : uninstallCmd;
+                if (space > 0) existingArgs = uninstallCmd.Substring(space + 1).Trim();
+            }
+
+            var psi = new ProcessStartInfo
+            {
+                FileName = exePath,
+                Arguments = $"{existingArgs} /quiet /norestart".Trim(),
+                UseShellExecute = false,
+                CreateNoWindow = true
+            };
+            using var proc = Process.Start(psi);
+            proc?.WaitForExit(300_000);
+        }
+
+        /// <summary>
+        /// Searches the registry Uninstall keys for the Windows MIDI Services entry
+        /// and returns its UninstallString value.
+        /// </summary>
+        private static string FindMidiServicesUninstallString()
+        {
+            var views = new[] { RegistryView.Registry64, RegistryView.Registry32 };
+
+            foreach (var view in views)
+            {
+                try
+                {
+                    using var baseKey = RegistryKey.OpenBaseKey(RegistryHive.LocalMachine, view);
+                    using var uninstallKey = baseKey.OpenSubKey(
+                        @"SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall", false);
+                    if (uninstallKey == null) continue;
+
+                    foreach (var subName in uninstallKey.GetSubKeyNames())
+                    {
+                        using var sub = uninstallKey.OpenSubKey(subName, false);
+                        var name = sub?.GetValue("DisplayName") as string;
+                        if (string.IsNullOrEmpty(name)) continue;
+
+                        // Match the WiX Burn bootstrapper bundle entry, not the individual MSI components.
+                        if (name.Equals("Windows MIDI Services Runtime and Tools", StringComparison.OrdinalIgnoreCase))
+                        {
+                            return sub.GetValue("UninstallString") as string;
+                        }
+                    }
+                }
+                catch { }
+            }
+
+            return null;
+        }
+
+        /// <summary>
+        /// Checks whether Windows MIDI Services is installed by looking for the
+        /// registry uninstall entry. Does NOT load the SDK runtime — that would
+        /// lock native DLLs in-process and prevent clean uninstallation.
         /// </summary>
         public static bool IsMidiServicesInstalled()
         {
-            return MidiVirtualController.IsAvailable();
+            return FindMidiServicesUninstallString() != null;
         }
 
         // ─────────────────────────────────────────────
diff --git a/PadForge.App/Common/Input/MidiVirtualController.cs b/PadForge.App/Common/Input/MidiVirtualController.cs
@@ -329,13 +329,20 @@ public static void ResetAvailability()
         /// <summary>
         /// Shuts down the MIDI Services SDK initializer. Call on app exit.
         /// </summary>
-        public static void Shutdown()
+        /// <param name="skipDispose">
+        /// When true, abandons the initializer without calling Dispose().
+        /// Use before uninstalling MIDI Services — Dispose() calls into the
+        /// runtime which triggers a native crash if the service is being removed.
+        /// </param>
+        public static void Shutdown(bool skipDispose = false)
         {
             if (_initializer != null)
             {
-                _initializer.Dispose();
+                if (!skipDispose)
+                    try { _initializer.Dispose(); } catch { }
                 _initializer = null;
             }
+            lock (_availLock) { _isAvailable = null; }
         }
     }
 }
diff --git a/PadForge.App/MainWindow.xaml.cs b/PadForge.App/MainWindow.xaml.cs
@@ -83,6 +83,25 @@ public MainWindow()
                         return true;
                 return false;
             };
+            _viewModel.Settings.HasAnyMidiSlots = () =>
+            {
+                for (int i = 0; i < InputManager.MaxPads; i++)
+                    if (SettingsManager.SlotCreated[i] &&
+                        _viewModel.Pads[i].OutputType == VirtualControllerType.Midi)
+                        return true;
+                return false;
+            };
+            _viewModel.Settings.HasAnyHidHideDevices = () =>
+            {
+                var devices = SettingsManager.UserDevices;
+                if (devices == null) return false;
+                lock (devices.SyncRoot)
+                {
+                    foreach (var ud in devices.Items)
+                        if (ud.HidHideEnabled) return true;
+                }
+                return false;
+            };
 
             // Wire engine start/stop commands.
             _viewModel.StartEngineRequested += (s, e) => _inputService.Start();
@@ -116,11 +135,23 @@ public MainWindow()
             _viewModel.Settings.LoadProfileRequested += OnLoadProfile;
             _viewModel.Settings.RevertToDefaultRequested += OnRevertToDefault;
 
-            // Apply registry Run key when Start at Login is toggled.
+            // Persist Settings VM changes (theme, polling, checkboxes) and handle login toggle.
             _viewModel.Settings.PropertyChanged += (s, e) =>
             {
                 if (e.PropertyName == nameof(SettingsViewModel.StartAtLogin))
                     Common.StartupHelper.SetStartupEnabled(_viewModel.Settings.StartAtLogin);
+
+                if (e.PropertyName is nameof(SettingsViewModel.SelectedThemeIndex)
+                     or nameof(SettingsViewModel.AutoStartEngine)
+                     or nameof(SettingsViewModel.MinimizeToTray)
+                     or nameof(SettingsViewModel.StartMinimized)
+                     or nameof(SettingsViewModel.StartAtLogin)
+                     or nameof(SettingsViewModel.EnablePollingOnFocusLoss)
+                     or nameof(SettingsViewModel.PollingRateMs)
+                     or nameof(SettingsViewModel.EnableInputHiding)
+                     or nameof(SettingsViewModel.Use2DControllerView)
+                     or nameof(SettingsViewModel.EnableAutoProfileSwitching))
+                    _settingsService.MarkDirty();
             };
 
             // Persist DSU / web controller server settings on change (Dashboard VM).
@@ -151,7 +182,7 @@ or nameof(DashboardViewModel.WebControllerPort))
             _viewModel.Settings.UninstallVJoyRequested += async (s, e) => await RunDriverOperationAsync(
                 "Uninstalling vJoy…", DriverInstaller.UninstallVJoy, OnVJoyDriverChanged);
 
-            // Wire MIDI Services install command.
+            // Wire MIDI Services install/uninstall commands.
             _viewModel.Settings.InstallMidiServicesRequested += async (s, e) =>
             {
                 _viewModel.StatusText = "Downloading Windows MIDI Services…";
@@ -176,6 +207,15 @@ or nameof(DashboardViewModel.WebControllerPort))
                     RefreshMidiServicesStatus();
                 }
             };
+            _viewModel.Settings.UninstallMidiServicesRequested += async (s, e) =>
+            {
+                // The uninstall guard prevents this when MIDI slots are active, so the
+                // SDK runtime won't be loaded in-process. Safe to wait for the uninstaller.
+                // Abandon the initializer just in case (e.g. IsAvailable was called elsewhere).
+                Common.Input.MidiVirtualController.Shutdown(skipDispose: true);
+                await RunDriverOperationAsync(
+                    "Uninstalling Windows MIDI Services…", DriverInstaller.UninstallMidiServices, RefreshMidiServicesStatus);
+            };
 
             // Wire device service events (assign to slot, hide, etc.).
             _deviceService.WireEvents();
@@ -191,6 +231,7 @@ or nameof(DashboardViewModel.WebControllerPort))
             _deviceService.DeviceHidingStateChanged += (s, e) =>
             {
                 _inputService.ApplyDeviceHiding();
+                _viewModel.Settings.RefreshDriverGuards();
             };
 
             // After assigning a device to a slot, navigate to that controller page.
@@ -1873,7 +1914,7 @@ private bool HasAnyControllerTypeCapacity()
             return xboxCount < SettingsManager.MaxXbox360Slots
                 || ds4Count < SettingsManager.MaxDS4Slots
                 || vjoyCount < SettingsManager.MaxVJoySlots
-                || (Common.Input.MidiVirtualController.IsAvailable() && midiCount < SettingsManager.MaxMidiSlots);
+                || (DriverInstaller.IsMidiServicesInstalled() && midiCount < SettingsManager.MaxMidiSlots);
         }
 
         private void ShowControllerTypePopup(UIElement anchor, PlacementMode placement = PlacementMode.Right)
@@ -2078,7 +2119,7 @@ private void ShowControllerTypePopup(UIElement anchor, PlacementMode placement =
                 Stretch = System.Windows.Media.Stretch.Uniform
             };
             midiPopupPath.SetResourceReference(System.Windows.Shapes.Shape.FillProperty, "SystemControlForegroundBaseHighBrush");
-            bool midiAvailable = Common.Input.MidiVirtualController.IsAvailable();
+            bool midiAvailable = DriverInstaller.IsMidiServicesInstalled();
             bool midiAtCapacity = midiCount >= SettingsManager.MaxMidiSlots;
             bool midiDisabled = !midiAvailable || midiAtCapacity;
             string midiTooltip = !midiAvailable ? "MIDI (requires Windows MIDI Services)"
diff --git a/PadForge.App/Services/InputService.cs b/PadForge.App/Services/InputService.cs
@@ -122,6 +122,8 @@ public void Start()
             if (_inputManager != null)
                 return; // Already running.
 
+            _stopped = false;
+
             // Remove stale ViGEm USB device nodes left over from previous sessions
             // (e.g., app crash without Dispose, or old builds that didn't call Dispose).
             // Must run BEFORE SDL initialization so stale nodes aren't enumerated.
@@ -213,8 +215,13 @@ public void Start()
         /// <summary>
         /// Stops the UI timer and engine, releases resources.
         /// </summary>
+        private bool _stopped;
+
         public void Stop(bool preserveVJoyNodes = false)
         {
+            if (_stopped) return;
+            _stopped = true;
+
             // Stop UI timer.
             if (_uiTimer != null)
             {
@@ -2772,7 +2779,7 @@ public void Dispose()
             if (_disposed)
                 return;
 
-            Stop();
+            try { Stop(); } catch { /* Best effort on shutdown */ }
             _disposed = true;
         }
     }
diff --git a/PadForge.App/ViewModels/SettingsViewModel.cs b/PadForge.App/ViewModels/SettingsViewModel.cs
@@ -141,7 +141,7 @@ public string HidHideVersion
         public RelayCommand UninstallHidHideCommand =>
             _uninstallHidHideCommand ??= new RelayCommand(
                 () => UninstallHidHideRequested?.Invoke(this, EventArgs.Empty),
-                () => _isHidHideInstalled);
+                () => _isHidHideInstalled && !HasAnyHidHideDevices());
 
         /// <summary>Raised when the user requests HidHide installation.</summary>
         public event EventHandler InstallHidHideRequested;
@@ -220,6 +220,7 @@ public bool IsMidiServicesInstalled
                 {
                     OnPropertyChanged(nameof(MidiServicesStatusText));
                     _installMidiServicesCommand?.NotifyCanExecuteChanged();
+                    _uninstallMidiServicesCommand?.NotifyCanExecuteChanged();
                 }
             }
         }
@@ -244,9 +245,20 @@ public string MidiServicesVersion
                 () => InstallMidiServicesRequested?.Invoke(this, EventArgs.Empty),
                 () => !_isMidiServicesInstalled);
 
+        private RelayCommand _uninstallMidiServicesCommand;
+
+        /// <summary>Command to uninstall Windows MIDI Services.</summary>
+        public RelayCommand UninstallMidiServicesCommand =>
+            _uninstallMidiServicesCommand ??= new RelayCommand(
+                () => UninstallMidiServicesRequested?.Invoke(this, EventArgs.Empty),
+                () => _isMidiServicesInstalled && !HasAnyMidiSlots());
+
         /// <summary>Raised when the user requests MIDI Services installation.</summary>
         public event EventHandler InstallMidiServicesRequested;
 
+        /// <summary>Raised when the user requests MIDI Services uninstallation.</summary>
+        public event EventHandler UninstallMidiServicesRequested;
+
         // ─────────────────────────────────────────────
         //  Driver uninstall guards
         // ─────────────────────────────────────────────
@@ -263,6 +275,18 @@ public string MidiServicesVersion
         /// </summary>
         internal Func<bool> HasAnyVJoySlots { get; set; } = () => false;
 
+        /// <summary>
+        /// Set by MainWindow to provide slot-type queries for uninstall guards.
+        /// Returns true if any created slot uses MIDI.
+        /// </summary>
+        internal Func<bool> HasAnyMidiSlots { get; set; } = () => false;
+
+        /// <summary>
+        /// Set by MainWindow to provide device-state queries for uninstall guards.
+        /// Returns true if any device has HidHide enabled.
+        /// </summary>
+        internal Func<bool> HasAnyHidHideDevices { get; set; } = () => false;
+
         /// <summary>
         /// Re-evaluates uninstall button CanExecute state.
         /// Call after slot creation/deletion/type changes.
@@ -271,6 +295,8 @@ public void RefreshDriverGuards()
         {
             _uninstallViGEmCommand?.NotifyCanExecuteChanged();
             _uninstallVJoyCommand?.NotifyCanExecuteChanged();
+            _uninstallHidHideCommand?.NotifyCanExecuteChanged();
+            _uninstallMidiServicesCommand?.NotifyCanExecuteChanged();
         }
 
         // ─────────────────────────────────────────────
diff --git a/PadForge.App/Views/SettingsPage.xaml b/PadForge.App/Views/SettingsPage.xaml
@@ -235,7 +235,11 @@
                                     VerticalAlignment="Center">
                             <Button Content="Install"
                                     Command="{Binding InstallMidiServicesCommand}"
-                                    Visibility="{Binding IsMidiServicesInstalled, Converter={StaticResource BoolToVisibilityConverter}, ConverterParameter=Invert}"/>
+                                    Visibility="{Binding IsMidiServicesInstalled, Converter={StaticResource BoolToVisibilityConverter}, ConverterParameter=Invert}"
+                                    Margin="0,0,8,0"/>
+                            <Button Content="Uninstall"
+                                    Command="{Binding UninstallMidiServicesCommand}"
+                                    Visibility="{Binding IsMidiServicesInstalled, Converter={StaticResource BoolToVisibilityConverter}}"/>
                         </StackPanel>
                     </Grid>
                 </StackPanel>

Original file line number	Diff line number	Diff line change
`@@ -329,13 +329,20 @@ public static void ResetAvailability()`
`329`	`329`	`/// <summary>`
`330`	`330`	`/// Shuts down the MIDI Services SDK initializer. Call on app exit.`
`331`	`331`	`/// </summary>`
`332`		`- public static void Shutdown()`
	`332`	`+ /// <param name="skipDispose">`
	`333`	`+ /// When true, abandons the initializer without calling Dispose().`
	`334`	`+ /// Use before uninstalling MIDI Services — Dispose() calls into the`
	`335`	`+ /// runtime which triggers a native crash if the service is being removed.`
	`336`	`+ /// </param>`
	`337`	`+ public static void Shutdown(bool skipDispose = false)`
`333`	`338`	`{`
`334`	`339`	`if (_initializer != null)`
`335`	`340`	`{`
`336`		`- _initializer.Dispose();`
	`341`	`+ if (!skipDispose)`
	`342`	`+ try { _initializer.Dispose(); } catch { }`
`337`	`343`	`_initializer = null;`
`338`	`344`	`}`
	`345`	`+ lock (_availLock) { _isAvailable = null; }`
`339`	`346`	`}`
`340`	`347`	`}`
`341`	`348`	`}`