void on_size_request (Gtk::Requisition *);
bool on_button_press_event (GdkEventButton *);
bool on_button_release_event (GdkEventButton *);
void on_size_request (Gtk::Requisition *);
bool on_button_press_event (GdkEventButton *);
bool on_button_release_event (GdkEventButton *);
bool on_scroll_event (GdkEventScroll *);
bool on_key_press_event (GdkEventKey*);
bool on_key_release_event (GdkEventKey*);
bool on_scroll_event (GdkEventScroll *);
bool on_key_press_event (GdkEventKey*);
bool on_key_release_event (GdkEventKey*);
void centre_on_click (GdkEventButton *);
void render (cairo_t *, cairo_rectangle_t*);
void centre_on_click (GdkEventButton *);
void render (cairo_t *, cairo_rectangle_t*);