PowerToys/src/modules/registrypreview/RegistryPreviewUILib/MonacoEditorControl.xaml

<UserControl
    x:Class="RegistryPreviewUILib.MonacoEditorControl"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:controls="using:Microsoft.UI.Xaml.Controls"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:local="using:RegistryPreviewUILib"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    xmlns:tkconverters="using:CommunityToolkit.WinUI.Converters"
    mc:Ignorable="d">

    <UserControl.Resources>
        <tkconverters:BoolToVisibilityConverter
            x:Key="BoolToInvertedVisibilityConverter"
            FalseValue="Visible"
            TrueValue="Collapsed" />
    </UserControl.Resources>

    <Grid>
        <ProgressRing
            Width="48"
            Height="48"
            Visibility="{x:Bind IsLoading, Mode=OneWay}" />
        <Border
            BorderBrush="{ThemeResource SurfaceStrokeColorDefaultBrush}"
            BorderThickness="1"
            Visibility="{x:Bind IsLoading, Mode=OneWay, Converter={StaticResource BoolToInvertedVisibilityConverter}}">
            <controls:WebView2
                x:Name="Browser"
                HorizontalAlignment="Stretch"
                VerticalAlignment="Stretch"
                Loaded="Browser_Loaded" />
        </Border>
    </Grid>
</UserControl>