GtkSpinButton::set_wrap
void set_wrap(bool wrap); 
    
     Where set_wrap()  is set to
     true, the spinbutton having displayed the upper
     bound of its value range will return to the lower bound on the next
     step increment.  In other words, if the range is 1 to 10, 1 will follow
     10 in the display area when the up arrow is pressed.
    
    
     The default setting is false, which greys out the
     appropriate arrow when the lower or upper bound of the range is reached.