FastWPF is basically divided into two areas. On the one hand, the current XAML content, which is visually displayed on the left side, and the settings on the right side.
In the preview, you can interact with the view directly. In doing so, you can interactively resize the application using the arrows in the corner.
Thereby you are able to analyze how your mask, form or control behaves under certain size conditions. If desired, you can also change the zoom factor at any time using the selection box or CTRL+mouse wheel.