MainWindow.xaml

<Window x:Class="QuadTreeSample.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        mc:Ignorable="d"
        x:Name="Window"
        Title="QuadTree Sample" Height="700" Width="900" WindowStartupLocation="CenterScreen">
    <Grid Background="Beige">
        <!-- Canvas for adding points and quads rectangles -->
        <Canvas
            x:Name="CanvasControl"
            HorizontalAlignment="Center"
            VerticalAlignment="Center"
            Background="White">
            <Canvas.LayoutTransform>
                <ScaleTransform
                    ScaleX="{Binding CanvasScale, ElementName=Window}"
                    ScaleY="{Binding CanvasScale, ElementName=Window}" />
            </Canvas.LayoutTransform>
        </Canvas>

        <!-- Stats -->
        <Border Background="#FFCCCCCC" HorizontalAlignment="Left" VerticalAlignment="Top" IsHitTestVisible="False"
                Padding="5" Margin="5" CornerRadius="3">
            <StackPanel Orientation="Vertical" MinWidth="60" MinHeight="20">
                <StackPanel Orientation="Horizontal">
                    <TextBlock Text="Brush size: " />
                    <TextBlock Text="{Binding BrushSize, ElementName=Window}" />
                </StackPanel>
                <TextBlock Text="Use +/- keys to change the brush size" />
                <TextBlock Text="Use left mouse button to draw the area" />
                <TextBlock Text="Use right mouse button to clear the area" />
                <TextBlock Text="Press S to Save the quadtree" />
                <TextBlock Text="Press L to Load the quadtree" />
                <TextBlock Text="Press Escape to clear the screen" />

                <StackPanel Orientation="Horizontal" Margin="0,5,0,0">
                    <TextBlock Text="Points: " />
                    <TextBlock Text="{Binding StatsPointsCount, ElementName=Window}" />
                </StackPanel>
                <StackPanel Orientation="Horizontal">
                    <TextBlock Text="QuadTree nodes: " />
                    <TextBlock Text="{Binding StatsQuadTreeNodesCount, ElementName=Window}" />
                </StackPanel>
            </StackPanel>
        </Border>
    </Grid>

</Window>