use is not, moved navigation pane open/close strings to resources

Quality of life improvement for the dev loop: removing the dialog in
Settings, since we have a DEBUG header in the titlebar anyways.

src/modules/cmdpal/Microsoft.CmdPal.Core.ViewModels/ListViewModel.cs

@@ -63,6 +63,7 @@ public partial class ListViewModel : PageViewModel, IDisposable
 
     private Task? _initializeItemsTask;
     private CancellationTokenSource? _cancellationTokenSource;
+    private CancellationTokenSource? _fetchItemsCancellationTokenSource;
 
     private ListItemViewModel? _lastSelectedItem;
 
@@ -129,14 +130,27 @@ public partial class ListViewModel : PageViewModel, IDisposable
     //// Run on background thread, from InitializeAsync or Model_ItemsChanged
     private void FetchItems()
     {
+        // Cancel any previous FetchItems operation
+        _fetchItemsCancellationTokenSource?.Cancel();
+        _fetchItemsCancellationTokenSource?.Dispose();
+        _fetchItemsCancellationTokenSource = new CancellationTokenSource();
+
+        var cancellationToken = _fetchItemsCancellationTokenSource.Token;
+
         // TEMPORARY: just plop all the items into a single group
         // see 9806fe5d8 for the last commit that had this with sections
         _isFetching = true;
 
         try
         {
+            // Check for cancellation before starting expensive operations
+            cancellationToken.ThrowIfCancellationRequested();
+
             var newItems = _model.Unsafe!.GetItems();
 
+            // Check for cancellation after getting items from extension
+            cancellationToken.ThrowIfCancellationRequested();
+
             // Collect all the items into new viewmodels
             Collection<ListItemViewModel> newViewModels = [];
 
@@ -145,6 +159,9 @@ public partial class ListViewModel : PageViewModel, IDisposable
             // building new viewmodels for the ones we haven't already built.
             foreach (var item in newItems)
             {
+                // Check for cancellation during item processing
+                cancellationToken.ThrowIfCancellationRequested();
+
                 ListItemViewModel viewModel = new(item, new(this));
 
                 // If an item fails to load, silently ignore it.
@@ -154,15 +171,22 @@ public partial class ListViewModel : PageViewModel, IDisposable
                 }
             }
 
+            // Check for cancellation before initializing first twenty items
+            cancellationToken.ThrowIfCancellationRequested();
+
             var firstTwenty = newViewModels.Take(20);
             foreach (var item in firstTwenty)
             {
+                cancellationToken.ThrowIfCancellationRequested();
                 item?.SafeInitializeProperties();
             }
 
             // Cancel any ongoing search
             _cancellationTokenSource?.Cancel();
 
+            // Check for cancellation before updating the list
+            cancellationToken.ThrowIfCancellationRequested();
+
             lock (_listLock)
             {
                 // Now that we have new ViewModels for everything from the
@@ -173,6 +197,11 @@ public partial class ListViewModel : PageViewModel, IDisposable
             // TODO: Iterate over everything in Items, and prune items from the
             // cache if we don't need them anymore
         }
+        catch (OperationCanceledException)
+        {
+            // Cancellation is expected, don't treat as error
+            return;
+        }
         catch (Exception ex)
         {
             // TODO: Move this within the for loop, so we can catch issues with individual items
@@ -560,6 +589,10 @@ public partial class ListViewModel : PageViewModel, IDisposable
         _cancellationTokenSource?.Cancel();
         _cancellationTokenSource?.Dispose();
         _cancellationTokenSource = null;
+
+        _fetchItemsCancellationTokenSource?.Cancel();
+        _fetchItemsCancellationTokenSource?.Dispose();
+        _fetchItemsCancellationTokenSource = null;
     }
 
     protected override void UnsafeCleanup()
@@ -570,6 +603,7 @@ public partial class ListViewModel : PageViewModel, IDisposable
         EmptyContent = new(new(null), PageContext); // necessary?
 
         _cancellationTokenSource?.Cancel();
+        _fetchItemsCancellationTokenSource?.Cancel();
 
         lock (_listLock)
         {

src/modules/cmdpal/Microsoft.CmdPal.UI/ExtViews/ListPage.xaml.cs

@@ -7,6 +7,7 @@ using CommunityToolkit.Mvvm.Messaging;
 using ManagedCommon;
 using Microsoft.CmdPal.Core.ViewModels;
 using Microsoft.CmdPal.Core.ViewModels.Messages;
+using Microsoft.CmdPal.UI.Helpers;
 using Microsoft.CmdPal.UI.Messages;
 using Microsoft.CmdPal.UI.ViewModels;
 using Microsoft.Extensions.DependencyInjection;
@@ -162,11 +163,11 @@ public sealed partial class ListPage : Page,
             if (listViewPeer is not null && li is not null)
             {
                 var notificationText = li.Title;
-                listViewPeer.RaiseNotificationEvent(
-                    Microsoft.UI.Xaml.Automation.Peers.AutomationNotificationKind.Other,
-                    Microsoft.UI.Xaml.Automation.Peers.AutomationNotificationProcessing.MostRecent,
-                    notificationText,
-                    "CommandPaletteSelectedItemChanged");
+
+                UIHelper.AnnounceActionForAccessibility(
+                     ItemsList,
+                     notificationText,
+                     "CommandPaletteSelectedItemChanged");
             }
         }
     }

src/modules/cmdpal/Microsoft.CmdPal.UI/Helpers/UIHelper.cs

@@ -0,0 +1,32 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using Microsoft.UI.Xaml;
+using Microsoft.UI.Xaml.Automation.Peers;
+
+namespace Microsoft.CmdPal.UI.Helpers;
+
+public static partial class UIHelper
+{
+    static UIHelper()
+    {
+    }
+
+    public static void AnnounceActionForAccessibility(UIElement ue, string announcement, string activityID)
+    {
+        if (FrameworkElementAutomationPeer.FromElement(ue) is AutomationPeer peer)
+        {
+            peer.RaiseNotificationEvent(
+                AutomationNotificationKind.ActionCompleted,
+                AutomationNotificationProcessing.ImportantMostRecent,
+                announcement,
+                activityID);
+        }
+    }
+}

src/modules/cmdpal/Microsoft.CmdPal.UI/Settings/SettingsWindow.xaml

@@ -25,17 +25,11 @@
             <RowDefinition Height="*" />
         </Grid.RowDefinitions>
         <!--  TO DO: Replace this with WinUI TitleBar once that ships.  -->
-        <Button
-            x:Name="PaneToggleBtn"
-            Width="48"
-            HorizontalAlignment="Left"
-            VerticalAlignment="Center"
-            Click="PaneToggleBtn_Click"
-            Style="{StaticResource PaneToggleButtonStyle}" />
         <StackPanel
             x:Name="AppTitleBar"
             Grid.Row="0"
             Height="48"
+            Margin="16,0,0,0"
             Orientation="Horizontal">
             <Image
                 Width="16"

src/modules/cmdpal/Microsoft.CmdPal.UI/Settings/SettingsWindow.xaml.cs

@@ -10,6 +10,7 @@ using Microsoft.CmdPal.UI.ViewModels;
 using Microsoft.CmdPal.UI.ViewModels.Messages;
 using Microsoft.UI.Windowing;
 using Microsoft.UI.Xaml;
+using Microsoft.UI.Xaml.Automation.Peers;
 using Microsoft.UI.Xaml.Controls;
 using WinUIEx;
 using RS_ = Microsoft.CmdPal.UI.Helpers.ResourceLoaderInstance;
@@ -22,6 +23,9 @@ public sealed partial class SettingsWindow : WindowEx,
 {
     public ObservableCollection<Crumb> BreadCrumbs { get; } = [];
 
+    // Gets or sets optional action invoked after NavigationView is loaded.
+    public Action NavigationViewLoaded { get; set; } = () => { };
+
     public SettingsWindow()
     {
         this.InitializeComponent();
@@ -35,10 +39,33 @@ public sealed partial class SettingsWindow : WindowEx,
         WeakReferenceMessenger.Default.Register<QuitMessage>(this);
     }
 
+    // Handles NavigationView loaded event.
+    // Sets up initial navigation and accessibility notifications.
     private void NavView_Loaded(object sender, RoutedEventArgs e)
     {
+        // Delay necessary to ensure NavigationView visual state can match navigation
+        Task.Delay(500).ContinueWith(_ => this.NavigationViewLoaded?.Invoke(), TaskScheduler.FromCurrentSynchronizationContext());
+
         NavView.SelectedItem = NavView.MenuItems[0];
         Navigate("General");
+
+        if (sender is NavigationView navigationView)
+        {
+            // Register for pane open/close changes to announce to screen readers
+            navigationView.RegisterPropertyChangedCallback(NavigationView.IsPaneOpenProperty, AnnounceNavigationPaneStateChanged);
+        }
+    }
+
+    // Announces navigation pane open/close state to screen readers for accessibility.
+    private void AnnounceNavigationPaneStateChanged(DependencyObject sender, DependencyProperty dp)
+    {
+        if (sender is NavigationView navigationView)
+        {
+            UIHelper.AnnounceActionForAccessibility(
+            ue: (UIElement)sender,
+            (sender as NavigationView)?.IsPaneOpen == true ? RS_.GetString("NavigationPaneOpened") : RS_.GetString("NavigationPaneClosed"),
+            "NavigationViewPaneIsOpenChangeNotificationId");
+        }
     }
 
     private void NavView_ItemInvoked(NavigationView sender, NavigationViewItemInvokedEventArgs args)
@@ -109,24 +136,15 @@ public sealed partial class SettingsWindow : WindowEx,
         WeakReferenceMessenger.Default.UnregisterAll(this);
     }
 
-    private void PaneToggleBtn_Click(object sender, RoutedEventArgs e)
-    {
-        NavView.IsPaneOpen = !NavView.IsPaneOpen;
-    }
-
     private void NavView_DisplayModeChanged(NavigationView sender, NavigationViewDisplayModeChangedEventArgs args)
     {
         if (args.DisplayMode == NavigationViewDisplayMode.Compact || args.DisplayMode == NavigationViewDisplayMode.Minimal)
         {
-            PaneToggleBtn.Visibility = Visibility.Visible;
             NavView.IsPaneToggleButtonVisible = false;
-            AppTitleBar.Margin = new Thickness(48, 0, 0, 0);
         }
         else
         {
-            PaneToggleBtn.Visibility = Visibility.Collapsed;
             NavView.IsPaneToggleButtonVisible = true;
-            AppTitleBar.Margin = new Thickness(16, 0, 0, 0);
         }
     }
 

src/modules/cmdpal/Microsoft.CmdPal.UI/Strings/en-us/Resources.resw

@@ -434,4 +434,10 @@ Right-click to remove the key combination, thereby deactivating the shortcut.</v
   <data name="StatusMessagesButton.[using:Microsoft.UI.Xaml.Controls]ToolTipService.ToolTip" xml:space="preserve">
     <value>Show status messages</value>
   </data>
+  <data name="NavigationPaneClosed" xml:space="preserve">
+    <value>Navigation pane closed</value>
+  </data>
+  <data name="NavigationPageOpened" xml:space="preserve">
+    <value>Navigation page opened</value>
+  </data>
 </root>

src/settings-ui/Settings.UI/SettingsXAML/App.xaml.cs

@@ -320,7 +320,6 @@ namespace Microsoft.PowerToys.Settings.UI
                 WindowHelpers.ForceTopBorder1PixelInsetOnWindows10(WindowNative.GetWindowHandle(settingsWindow));
                 settingsWindow.Activate();
                 settingsWindow.NavigateToSection(StartupPage);
-                ShowMessageDialog("The application is running in Debug mode.", "DEBUG");
 #else
                 /* If we try to run Settings as a standalone app, it will start PowerToys.exe if not running and open Settings again through it in the Dashboard page. */
                 Common.UI.SettingsDeepLink.OpenSettings(Common.UI.SettingsDeepLink.SettingsWindow.Dashboard, true);
@@ -329,31 +328,6 @@ namespace Microsoft.PowerToys.Settings.UI
             }
         }
 
-#if !DEBUG
-        private async void ShowMessageDialogAndExit(string content, string title = null)
-#else
-        private async void ShowMessageDialog(string content, string title = null)
-#endif
-        {
-            await ShowDialogAsync(content, title);
-#if !DEBUG
-            this.Exit();
-#endif
-        }
-
-        public static Task<IUICommand> ShowDialogAsync(string content, string title = null)
-        {
-            var dialog = new MessageDialog(content, title ?? string.Empty);
-            var handle = NativeMethods.GetActiveWindow();
-            if (handle == IntPtr.Zero)
-            {
-                throw new InvalidOperationException();
-            }
-
-            InitializeWithWindow.Initialize(dialog, handle);
-            return dialog.ShowAsync().AsTask<IUICommand>();
-        }
-
         public static TwoWayPipeMessageIPCManaged GetTwoWayIPCManager()
         {
             return ipcmanager;