void update_vca_display ();
void vca_menu_toggle (Gtk::CheckMenuItem*, uint32_t n);
bool specific_vca_button_release (GdkEventButton* ev, uint32_t n);
void update_vca_display ();
void vca_menu_toggle (Gtk::CheckMenuItem*, uint32_t n);
bool specific_vca_button_release (GdkEventButton* ev, uint32_t n);