sigc::signal<void, int, int> signal_pointer_motion;
sigc::signal<void, unsigned, unsigned, unsigned> signal_key_press;
sigc::signal<void, unsigned, unsigned> signal_key_release;
sigc::signal<void, int, int> signal_pointer_motion;
sigc::signal<void, unsigned, unsigned, unsigned> signal_key_press;
sigc::signal<void, unsigned, unsigned> signal_key_release;