about_sighandler(ek_signal_t s, ek_data_t data)
static DISPATCHER_SIGHANDLER(about_sighandler, s, data)
about_sighandler(ek_signal_t s, ek_data_t data){  if(s == ctk_signal_button_activate) {    if(data == (ek_data_t)&aboutclose) {      about_quit();    }  } else if(s == ctk_signal_hyperlink_activate) {    if((struct ctk_widget *)data == (struct ctk_widget *)&abouturl) {      about_quit();    }  }}