UI/MainWindow.xaml

<Window x:Class="FastPrint.UI.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="FastPrint 3D Slicer" Height="600" Width="900">
    <DockPanel>
        <ToolBar DockPanel.Dock="Top">
            <Button Content="Open STL" Click="OpenSTL_Click"/>
            <Button Content="Slice" Click="Slice_Click"/>
            <ComboBox x:Name="PortSelector" Width="120"/>
            <Button Content="Connect" Click="Connect_Click"/>
        </ToolBar>
        <Grid>
            <Viewport3D x:Name="viewport"/>
        </Grid>
    </DockPanel>
</Window>