+class Label;
+
+/**
+A Root is a special type of Panel that covers and entire Window and accepts
+input from it. When created, a Root widget will take its size from the window
+it is created for. The size can be changed, but a Root should always be
+rendered to fill the window in order to get coordinates mapped correctly.
+*/
+class Root: public Panel, public Graphics::EventSource, public sigc::trackable