bool on_button_press_event (GdkEventButton*);
bool on_button_release_event(GdkEventButton*);
bool on_scroll_event (GdkEventScroll*);
bool on_motion_notify_event(GdkEventMotion*);
bool on_button_press_event (GdkEventButton*);
bool on_button_release_event(GdkEventButton*);
bool on_scroll_event (GdkEventScroll*);
bool on_motion_notify_event(GdkEventMotion*);