mod/maxgui.mod/fltkmaxgui.mod/src/Fl.cxx
void Fl::add_handler(Fl_Event_Handler ha) {
  handler_link *l = new handler_link;
  l->handle = ha;
  l->next = handlers;
  handlers = l;
}
/**
  Install a function to parse unrecognized events.  If FLTK cannot
  figure out what to do with an event, it calls each of these functions
  (most recent first) until one of them returns non-zero.  If none of
  them returns non zero then the event is ignored.  Events that cause
  this to be called are:
  
  - FL_SHORTCUT events that are not recognized by any  widget.
    This lets you provide global shortcut keys.
  - System events that FLTK does not recognize.  See fl_xevent.
  - \e Some other events when the widget FLTK selected  returns
    zero from its handle() method.  Exactly which  ones may change
    in future versions, however.
*/
Install a function to parse unrecognized events.  If FLTK cannot
figure out what to do with an event, it calls each of these functions
(most recent first) until one of them returns non-zero.  If none of
them returns non zero then the event is ignored.  Events that cause
this to be called are.

FL_SHORTCUT events that are not recognized by any  widget.
This lets you provide global shortcut keys.
System events that FLTK does not recognize.
Install a function to parse unrecognized events . If FLTK cannot figure out what to do with an event it calls each of these functions ( most recent first ) until one of them returns non - zero . If none of them returns non zero then the event is ignored . Events that cause this to be called are . FL_SHORTCUT events that are not recognized by any widget . This lets you provide global shortcut keys . System events that FLTK does not recognize .
void Fl::add_handler(Fl_Event_Handler ha) {
  handler_link *l = new handler_link;
  l->handle = ha;
  l->next = handlers;
  handlers = l;
}
void Fl :: add_handler ( Fl_Event_Handler ha ) { handler_link * l = new handler_link ; l -> handle = ha ; l -> next = handlers ; handlers = l ; }
Install a function to parse unrecognized events.
Install a function to parse unrecognized events .