printf("click event!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!\n");
clicked(GtkMathView* math_view, gpointer user_data){  printf("click event!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!\n");  if (gtk_math_view_get_action(math_view) != NULL)    gtk_math_view_action_toggle(math_view);  else     printf("no action!\n");}