Using the WPF FocusScope

<Window x:Class="TestApp.Window1" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:t="clr-namespace:TestApp" Title="EnhancedFocusScope" Height="400" Width="500">
	<Window.Resources>
		<Style TargetType="GroupBox">
			<Setter Property="Background" Value="Transparent"/>
			<Setter Property="KeyboardNavigation.TabNavigation" Value="Cycle"/>
			<Setter Property="KeyboardNavigation.ControlTabNavigation" Value="Once"/>
		</Style>
	</Window.Resources>
	<Grid>
		<Grid.RowDefinitions>
			<RowDefinition Height="Auto" />
			<RowDefinition Height="100" />
			<RowDefinition />
		</Grid.RowDefinitions>
		<Grid.ColumnDefinitions>
			<ColumnDefinition />
			<ColumnDefinition />
			<ColumnDefinition />
		</Grid.ColumnDefinitions>
		<ToolBar Grid.Row="0" Grid.Column="0" Grid.ColumnSpan="3">
			<Button Command="Copy">Copy</Button>
			<Button Command="Cut">Cut</Button>
			<Button Command="Paste">Paste</Button>
		</ToolBar>
		<TextBox Grid.Row="1" Grid.ColumnSpan="3" AcceptsReturn="True">A free text area</TextBox>
		<GroupBox Name="box1" Header="No focus scope" Grid.Row="2" MouseDown="Box1_MouseDown">
			<StackPanel Margin="4">
				<Button>a</Button>
				<Button>b</Button>
				<Button>c</Button>
				<TextBox />
				<CheckBox>CheckBox</CheckBox>
			</StackPanel>
		</GroupBox>
		<GroupBox Name="box2" Header="WPF focus scope" FocusManager.IsFocusScope="True" Grid.Column="1" Grid.Row="2" MouseDown="Box2_MouseDown">
			<StackPanel Margin="4">
				<Button>a</Button>
				<Button>b</Button>
				<Button>c</Button>
				<TextBox />
				<CheckBox>CheckBox</CheckBox>
			</StackPanel>
		</GroupBox>
		<GroupBox Name="box3" Header="My Focus Scope" t:EnhancedFocusScope.IsEnhancedFocusScope="True" Grid.Column="2" Grid.Row="2" MouseDown="Box3_MouseDown">
			<StackPanel Margin="4">
				<Button>a</Button>
				<Button>b</Button>
				<Button>c</Button>
				<TextBox />
				<CheckBox>CheckBox</CheckBox>
			</StackPanel>
		</GroupBox>
	</Grid>
</Window>