Added Keydown adjustments to GradientSlider

Author: Avid29

components/GradientSlider/src/GradientSlider.Input.cs

@@ -8,6 +8,7 @@
 using Microsoft.UI;
 using Microsoft.UI.Xaml.Controls.Primitives;
 #endif
+using Windows.System;
 
 namespace CommunityToolkit.WinUI.Controls;
 
@@ -48,6 +49,32 @@ private void Thumb_DragCompleted(object sender, DragCompletedEventArgs e)
         OnValueChanged();
     }
 
+    private void Thumb_KeyDown(object sender, KeyRoutedEventArgs e)
+    {
+        if (sender is not GradientSliderThumb thumb)
+            return;
+
+        var change = e.Key switch
+        {
+#if !HAS_UNO
+            VirtualKey.Left when FlowDirection is FlowDirection.RightToLeft => 0.05,
+            VirtualKey.Right when FlowDirection is FlowDirection.RightToLeft => -0.05,
+#endif
+
+            VirtualKey.Left => -0.01,
+            VirtualKey.Right => 0.01,
+
+            _ => 0,
+        };
+
+        if (change is not 0)
+        {
+            thumb.GradientStop.Offset = Math.Clamp(change + thumb.GradientStop.Offset, 0, 1);
+            UpdateThumbPosition(thumb);
+            e.Handled = true;
+        }
+    }
+
     private void ContainerCanvas_PointerEntered(object sender, PointerRoutedEventArgs e)
     {
         if (_placeholderThumb is null)

components/GradientSlider/src/GradientSlider.cs

@@ -107,6 +107,7 @@ private void ContainerCanvas_SizeChanged(object sender, SizeChangedEventArgs e)
         thumb.DragStarted += Thumb_DragStarted;
         thumb.DragDelta += Thumb_DragDelta;
         thumb.DragCompleted += Thumb_DragCompleted;
+        thumb.KeyDown += Thumb_KeyDown;
         thumb.Loaded += Thumb_Loaded;
         var callback = stop.RegisterPropertyChangedCallback(GradientStop.OffsetProperty, OnGradientStopOffsetChanged);
         _stopCallbacks.Add(stop, callback);
@@ -131,6 +132,7 @@ private void RemoveStop(GradientStop stop)
         thumb.DragStarted -= Thumb_DragStarted;
         thumb.DragDelta -= Thumb_DragDelta;
         thumb.DragCompleted -= Thumb_DragCompleted;
+        thumb.KeyDown -= Thumb_KeyDown;
         thumb.Loaded -= Thumb_Loaded;
         stop.UnregisterPropertyChangedCallback(GradientStop.OffsetProperty, _stopCallbacks[stop]);
         _stopCallbacks.Remove(stop);