/* Primitives for work of the "widget" library.
   Copyright (C) 1997 Free Software Foundation, Inc.

This file is part of XEmacs.

XEmacs is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation; either version 2, or (at your option) any
later version.

XEmacs 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 General Public License
for more details.

You should have received a copy of the GNU General Public License
along with XEmacs; see the file COPYING.  If not, write to
the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.  */

/* Synched up with: Not in FSF. */

/* In an ideal world, this file would not have been necessary.
   However, elisp function calls being as slow as they are, it turns
   out that some functions in the widget library (wid-edit.el) are the
   bottleneck of Widget operation.  Here is their translation to C,
   for the sole reason of efficiency.  */

#include <config.h>
#include "lisp.h"
#include "buffer.h"


Lisp_Object Qwidget_type;


DEFUN ("widget-plist-member", Fwidget_plist_member, 2, 2, 0, /*
Like `plist-get', but returns the tail of PLIST whose car is PROP.
*/
       (plist, prop))
{
  while (!NILP (plist) && !EQ (Fcar (plist), prop))
    {
      /* Check for QUIT, so a circular plist doesn't lock up the
         editor. */
      QUIT;
      plist = Fcdr (Fcdr (plist));
    }
  return plist;
}

DEFUN ("widget-put", Fwidget_put, 3, 3, 0, /*
In WIDGET set PROPERTY to VALUE.
The value can later be retrieved with `widget-get'.
*/
       (widget, property, value))
{
  CHECK_CONS (widget);
  XCDR (widget) = Fplist_put (XCDR (widget), property, value);
  return widget;
}

DEFUN ("widget-get", Fwidget_get, 2, 2, 0, /*
  In WIDGET, get the value of PROPERTY.
The value could either be specified when the widget was created, or
later with `widget-put'.
*/
       (widget, property))
{
  Lisp_Object value = Qnil;

  while (1)
    {
      Lisp_Object tmp = Fwidget_plist_member (Fcdr (widget), property);
      if (!NILP (tmp))
	{
	  value = Fcar (Fcdr (tmp));
	  break;
	}
      tmp = Fcar (widget);
      if (!NILP (tmp))
	{
	  widget = Fget (tmp, Qwidget_type, Qnil);
	  continue;
	}
      break;
    }
  return value;
}

DEFUN ("widget-apply", Fwidget_apply, 2, MANY, 0, /*
Apply the value of WIDGET's PROPERTY to the widget itself.
ARGS are passed as extra arguments to the function.
*/
       (int nargs, Lisp_Object *args))
{
  /* This function can GC */
  Lisp_Object newargs[3];
  struct gcpro gcpro1;

  newargs[0] = Fwidget_get (args[0], args[1]);
  newargs[1] = args[0];
  newargs[2] = Flist (nargs - 2, args + 2);
  GCPRO1 (newargs[2]);
  RETURN_UNGCPRO (Fapply (3, newargs));
}

void
syms_of_widget (void)
{
  DEFSYMBOL (Qwidget_type);

  DEFSUBR (Fwidget_plist_member);
  DEFSUBR (Fwidget_put);
  DEFSUBR (Fwidget_get);
  DEFSUBR (Fwidget_apply);
}