Added some runtime protections. Fixed minor things.

Widgets/WidgetRect.h

@@ -31,7 +31,7 @@ public:
 
 	static std::unique_ptr<Widget> builder(const nlohmann::json& j);
 
-private:
+protected:
 	// x, y - center of circle
 	// quadrant - 1--4
 	void draw_circle_corner(int x, int y, int quadrant);