Enable keyboard accessibility for template and custom layout items (#7977)

src/modules/fancyzones/editor/FancyZonesEditor/MainWindow.xaml

@@ -211,7 +211,10 @@
                                 <Border Margin="8" 
                                         BorderBrush="{Binding Path=IsSelected, Converter={StaticResource BooleanToBrushConverter}}"
                                         Style="{StaticResource templateBackground}" 
-                                        MouseDown="LayoutItem_Click">
+                                        MouseDown="LayoutItem_Click"
+                                        Focusable="True"
+                                        FocusManager.GotFocus="LayoutItem_Focused"
+                                        KeyDown="LayoutItem_Apply">
                                     <DockPanel Margin="0,20,0,0" 
                                                VerticalAlignment="Stretch" 
                                                HorizontalAlignment="Stretch" 
@@ -244,7 +247,10 @@
                                 <Border Margin="8"
                                         BorderBrush="{Binding Path=IsSelected, Converter={StaticResource BooleanToBrushConverter}}" 
                                         Style="{StaticResource templateBackground}" 
-                                        MouseDown="LayoutItem_Click">
+                                        MouseDown="LayoutItem_Click"
+                                        Focusable="True"
+                                        FocusManager.GotFocus="LayoutItem_Focused"
+                                        KeyDown="LayoutItem_Apply">
                                     <DockPanel Margin="0,20,0,0" 
                                                VerticalAlignment="Stretch" 
                                                HorizontalAlignment="Stretch" 

src/modules/fancyzones/editor/FancyZonesEditor/MainWindow.xaml.cs

@@ -84,6 +84,21 @@ namespace FancyZonesEditor
             Select(((Border)sender).DataContext as LayoutModel);
         }
 
+        private void LayoutItem_Focused(object sender, RoutedEventArgs e)
+        {
+            Select(((Border)sender).DataContext as LayoutModel);
+        }
+
+        private void LayoutItem_Apply(object sender, KeyEventArgs e)
+        {
+            if (e.Key == Key.Return || e.Key == Key.Space)
+            {
+                // When certain layout item (template or custom) is focused through keyboard and user
+                // presses Enter or Space key, layout will be applied.
+                Apply();
+            }
+        }
+
         private void Select(LayoutModel newSelection)
         {
             if (EditorOverlay.Current.DataContext is LayoutModel currentSelection)
@@ -154,6 +169,11 @@ namespace FancyZonesEditor
         }
 
         private void Apply_Click(object sender, RoutedEventArgs e)
+        {
+            Apply();
+        }
+
+        private void Apply()
         {
             EditorOverlay mainEditor = EditorOverlay.Current;