/*

Copyright (C) 2009-2020 The Octave Project Developers

See the file COPYRIGHT.md in the top-level directory of this distribution
or <https://octave.org/COPYRIGHT.html/>.


This file is part of Octave.

Octave 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 3 of the License, or
(at your option) any later version.

Octave 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 Octave; see the file COPYING.  If not, see
<https://www.gnu.org/licenses/>.

*/

#if defined (HAVE_CONFIG_H)
#  include "config.h"
#endif

#include "singleton-cleanup.h"

#include "cdisplay.h"
#include "defun.h"
#include "display.h"
#include "error.h"
#include "interpreter.h"
#include "ov.h"
#include "ovl.h"

namespace octave
{
  void display_info::initialize (void)
  {
    int avail = 0;

    const char *msg
      = octave_get_display_info (nullptr, &m_ht, &m_wd, &m_dp,
                                 &m_rx, &m_ry, &avail);

    m_dpy_avail = avail;

    if (msg)
      m_msg = msg;
  }
}

DEFMETHOD (have_window_system, interp, , ,
           doc: /* -*- texinfo -*-
@deftypefn {} {} have_window_system ()
Return true if a window system is available (X11, Windows, or Apple OS X)
and false otherwise.
@seealso{isguirunning}
@end deftypefn */)
{
  octave::display_info& dpy_info = interp.get_display_info ();

  return ovl (dpy_info.display_available ());
}