CmdPal's search bar now accepts page up/down keyboard strokes. (#41886)

## Summary of the Pull Request The page up/down keys now function while the search box is focused.  ## PR Checklist - [ X ] Closes: #41877 - [ ] **Communication:** I've discussed this with core contributors already. If the work hasn't been agreed, this work might be rejected - [ ] **Tests:** Added/updated and all pass - [ ] **Localization:** All end-user-facing strings can be localized - [ ] **Dev docs:** Added/updated - [ ] **New binaries:** Added on the required places - [ ] [JSON for signing](https://github.com/microsoft/PowerToys/blob/main/.pipelines/ESRPSigning_core.json) for new binaries - [ ] [WXS for installer](https://github.com/microsoft/PowerToys/blob/main/installer/PowerToysSetup/Product.wxs) for new binaries and localization folder - [ ] [YML for CI pipeline](https://github.com/microsoft/PowerToys/blob/main/.pipelines/ci/templates/build-powertoys-steps.yml) for new test projects - [ ] [YML for signed pipeline](https://github.com/microsoft/PowerToys/blob/main/.pipelines/release.yml) - [ ] **Documentation updated:** If checked, please file a pull request on [our docs repo](https://github.com/MicrosoftDocs/windows-uwp/tree/docs/hub/powertoys) and link it here: #xxx  ## Detailed Description of the Pull Request / Additional comments Previously, the page up/down keys only performed any action while an item in the list was focused. The page up/down keys did not have any effect while the search box was focused, however the up/down arrows do have effect. This PR enables the page up/down keys while the search box is focused. There is a caveat here. The page up/down behavior is not consistent. I do not see a way to tell the ListView to perform its native page up/down function. Instead, I manually calculate roughly which item to scroll-to. Because of this, the amount of scroll between when the search box is focused and when an item in the ListView is focused is not consistent.  ## Validation Steps Performed ![pageupdown](https://github.com/user-attachments/assets/b30f6e4e-03de-45bd-8570-0b06850bef24) In this GIF: 1. CmdPal appears 2. SearchBar focused, down/up arrow keys. 3. SearchBar focused, page down/up keys. 4. Tab to item in ListView 5. ListView item focused down/up arrow keys. 6. ListView item focused page down/up keys. 7. SearchBar focused 8. Filter "abc" 9. SearchBar focused page down/up keys.
2025-12-16 03:37:59 +01:00 · 2025-10-28 13:56:17 -04:00
parent a4791cc493
commit d197af3da9
4 changed files with 183 additions and 6 deletions
--- a/src/modules/cmdpal/Microsoft.CmdPal.UI/ExtViews/ListPage.xaml.cs
+++ b/src/modules/cmdpal/Microsoft.CmdPal.UI/ExtViews/ListPage.xaml.cs
@@ -18,6 +18,7 @@ using Microsoft.UI.Xaml.Controls.Primitives;
 using Microsoft.UI.Xaml.Input;
 using Microsoft.UI.Xaml.Media;
 using Microsoft.UI.Xaml.Navigation;
+using Windows.Foundation;
 using Windows.System;

 namespace Microsoft.CmdPal.UI;
@@ -25,6 +26,8 @@ namespace Microsoft.CmdPal.UI;
 public sealed partial class ListPage : Page,
    IRecipient<NavigateNextCommand>,
    IRecipient<NavigatePreviousCommand>,
+    IRecipient<NavigatePageDownCommand>,
+    IRecipient<NavigatePageUpCommand>,
    IRecipient<ActivateSelectedListItemMessage>,
    IRecipient<ActivateSecondaryCommandMessage>
 {
@@ -82,6 +85,8 @@ public sealed partial class ListPage : Page,
        // RegisterAll isn't AOT compatible
        WeakReferenceMessenger.Default.Register<NavigateNextCommand>(this);
        WeakReferenceMessenger.Default.Register<NavigatePreviousCommand>(this);
+        WeakReferenceMessenger.Default.Register<NavigatePageDownCommand>(this);
+        WeakReferenceMessenger.Default.Register<NavigatePageUpCommand>(this);
        WeakReferenceMessenger.Default.Register<ActivateSelectedListItemMessage>(this);
        WeakReferenceMessenger.Default.Register<ActivateSecondaryCommandMessage>(this);

@@ -94,6 +99,8 @@ public sealed partial class ListPage : Page,

        WeakReferenceMessenger.Default.Unregister<NavigateNextCommand>(this);
        WeakReferenceMessenger.Default.Unregister<NavigatePreviousCommand>(this);
+        WeakReferenceMessenger.Default.Unregister<NavigatePageDownCommand>(this);
+        WeakReferenceMessenger.Default.Unregister<NavigatePageUpCommand>(this);
        WeakReferenceMessenger.Default.Unregister<ActivateSelectedListItemMessage>(this);
        WeakReferenceMessenger.Default.Unregister<ActivateSecondaryCommandMessage>(this);

@@ -181,9 +188,9 @@ public sealed partial class ListPage : Page,
                var notificationText = li.Title;

                UIHelper.AnnounceActionForAccessibility(
-                     ItemsList,
-                     notificationText,
-                     "CommandPaletteSelectedItemChanged");
+                    ItemsList,
+                    notificationText,
+                    "CommandPaletteSelectedItemChanged");
            }
        }
    }
@@ -296,6 +303,142 @@ public sealed partial class ListPage : Page,
        }
    }

+    public void Receive(NavigatePageDownCommand message)
+    {
+        var indexes = CalculateTargetIndexPageUpDownScrollTo(true);
+        if (indexes is null)
+        {
+            return;
+        }
+
+        if (indexes.Value.CurrentIndex != indexes.Value.TargetIndex)
+        {
+            ItemView.SelectedIndex = indexes.Value.TargetIndex;
+            ItemView.ScrollIntoView(ItemView.SelectedItem);
+        }
+    }
+
+    public void Receive(NavigatePageUpCommand message)
+    {
+        var indexes = CalculateTargetIndexPageUpDownScrollTo(false);
+        if (indexes is null)
+        {
+            return;
+        }
+
+        if (indexes.Value.CurrentIndex != indexes.Value.TargetIndex)
+        {
+            ItemView.SelectedIndex = indexes.Value.TargetIndex;
+            ItemView.ScrollIntoView(ItemView.SelectedItem);
+        }
+    }
+
+    /// <summary>
+    /// Calculates the item index to target when performing a page up or page down
+    /// navigation. The calculation attempts to estimate how many items fit into
+    /// the visible viewport by measuring actual container heights currently visible
+    /// within the internal ScrollViewer. If measurements are not available a
+    /// fallback estimate is used.
+    /// </summary>
+    /// <param name="isPageDown">True to calculate a page-down target, false for page-up.</param>
+    /// <returns>
+    /// A tuple containing the current index and the calculated target index, or null
+    /// if a valid calculation could not be performed (for example, missing ScrollViewer).
+    /// </returns>
+    private (int CurrentIndex, int TargetIndex)? CalculateTargetIndexPageUpDownScrollTo(bool isPageDown)
+    {
+        var scroll = FindScrollViewer(ItemView);
+        if (scroll is null)
+        {
+            return null;
+        }
+
+        var viewportHeight = scroll.ViewportHeight;
+        if (viewportHeight <= 0)
+        {
+            return null;
+        }
+
+        var currentIndex = ItemView.SelectedIndex < 0 ? 0 : ItemView.SelectedIndex;
+        var itemCount = ItemView.Items.Count;
+
+        // Compute visible item heights within the ScrollViewer viewport
+        const int firstVisibleIndexNotFound = -1;
+        var firstVisibleIndex = firstVisibleIndexNotFound;
+        var visibleHeights = new List<double>(itemCount);
+
+        for (var i = 0; i < itemCount; i++)
+        {
+            if (ItemView.ContainerFromIndex(i) is FrameworkElement container)
+            {
+                try
+                {
+                    var transform = container.TransformToVisual(scroll);
+                    var topLeft = transform.TransformPoint(new Point(0, 0));
+                    var bottom = topLeft.Y + container.ActualHeight;
+
+                    // If any part of the container is inside the viewport, consider it visible
+                    if (topLeft.Y >= 0 && bottom <= viewportHeight)
+                    {
+                        if (firstVisibleIndex == firstVisibleIndexNotFound)
+                        {
+                            firstVisibleIndex = i;
+                        }
+
+                        visibleHeights.Add(container.ActualHeight > 0 ? container.ActualHeight : 0);
+                    }
+                }
+                catch
+                {
+                    // ignore transform errors and continue
+                }
+            }
+        }
+
+        var itemsPerPage = 0;
+
+        // Calculate how many items fit in the viewport based on their actual heights
+        if (visibleHeights.Count > 0)
+        {
+            double accumulated = 0;
+            for (var i = 0; i < visibleHeights.Count; i++)
+            {
+                accumulated += visibleHeights[i] <= 0 ? 1 : visibleHeights[i];
+                itemsPerPage++;
+                if (accumulated >= viewportHeight)
+                {
+                    break;
+                }
+            }
+        }
+        else
+        {
+            // fallback: estimate using first measured container height
+            double itemHeight = 0;
+            for (var i = currentIndex; i < itemCount; i++)
+            {
+                if (ItemView.ContainerFromIndex(i) is FrameworkElement { ActualHeight: > 0 } c)
+                {
+                    itemHeight = c.ActualHeight;
+                    break;
+                }
+            }
+
+            if (itemHeight <= 0)
+            {
+                itemHeight = 1;
+            }
+
+            itemsPerPage = Math.Max(1, (int)Math.Floor(viewportHeight / itemHeight));
+        }
+
+        var targetIndex = isPageDown
+                              ? Math.Min(itemCount - 1, currentIndex + Math.Max(1, itemsPerPage))
+                              : Math.Max(0, currentIndex - Math.Max(1, itemsPerPage));
+
+        return (currentIndex, targetIndex);
+    }
+
    private static void OnViewModelChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
    {
        if (d is ListPage @this)
@@ -351,11 +494,11 @@ public sealed partial class ListPage : Page,
        }
    }

-    private ScrollViewer? FindScrollViewer(DependencyObject parent)
+    private static ScrollViewer? FindScrollViewer(DependencyObject parent)
    {
-        if (parent is ScrollViewer)
+        if (parent is ScrollViewer viewer)
        {
-            return (ScrollViewer)parent;
+            return viewer;
        }

        for (var i = 0; i < VisualTreeHelper.GetChildrenCount(parent); i++)