public MainPage()
{
InitializeComponent();
layerStack = LayerStack.DataContext as LayerStack;
lessonPage = LessonPage.DataContext as Lesson;
appBar = AppBar.DataContext as AppBarState;
lessonPage.SetComponents(LessonPage, LessonSidebar.ThumbsContainer);
layerStack.Viewport.SetComponents(LessonContainer, LessonContent, DrawingAreaBound, RadialMenu);
}