//// "$Id: Fl_add_idle.cxx,v 1.1.1.1 2003/08/07 21:18:40 jasonk Exp $"//// Idle routine support for the Fast Light Tool Kit (FLTK).//// Copyright 1998-1999 by Bill Spitzak and others.//// This library is free software; you can redistribute it and/or// modify it under the terms of the GNU Library General Public// License as published by the Free Software Foundation; either// version 2 of the License, or (at your option) any later version.//// This library is distributed in the hope that it will be useful,// but WITHOUT ANY WARRANTY; without even the implied warranty of// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU// Library General Public License for more details.//// You should have received a copy of the GNU Library General Public// License along with this library; if not, write to the Free Software// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307// USA.//// Please report all bugs and problems to "fltk-bugs@easysw.com".//// Allows you to manage an arbitrary set of idle() callbacks.// Replaces the older set_idle() call (which is used to implement this)#include <FL/Fl.H>struct idle_cb {  void (*cb)(void*);  void* data;  idle_cb *next;};// the callbacks are stored linked in a ring.  last points at the one// just called, first at the next to call.  last->next == first.static idle_cb* first;static idle_cb* last;static idle_cb* freelist;static void call_idle() {  idle_cb* p = first;  last = p; first = p->next;  p->cb(p->data); // this may call add_idle() or remove_idle()!}void Fl::add_idle(void (*cb)(void*), void* data) {  idle_cb* p = freelist;  if (p) freelist = p->next;  else p = new idle_cb;  p->cb = cb;  p->data = data;  if (first) {    last->next = p;    p->next = first;    first = p;  } else {    first = last = p;    p->next = p;    set_idle(call_idle);  }}void Fl::remove_idle(void (*cb)(void*), void* data) {  idle_cb* p = first;  if (!p) return;  idle_cb* l = last;  for (;; p = p->next) {    if (p->cb == cb && p->data == data) break;    if (p==last) return; // not found    l = p;  }  if (l == p) { // only one    first = last = 0;    set_idle(0);  } else {    last = l;    first = l->next = p->next;  }  p->next = freelist;  freelist = p;}//// End of "$Id: Fl_add_idle.cxx,v 1.1.1.1 2003/08/07 21:18:40 jasonk Exp $".//