#define MSP_GL_VIEW_H_
#include <list>
+#include <sigc++/trackable.h>
#include <msp/graphics/glcontext.h>
#include <msp/graphics/window.h>
/**
Manages the presentation of rendering results on the screen.
*/
-class View
+class View: public sigc::trackable
{
private:
Graphics::Window &window;