## Copyright (C) 2010-2012 Ben Abbott
##
## 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
## <http://www.gnu.org/licenses/>.

## -*- texinfo -*-
## @deftypefn {Function File} {@var{has_terminal} =} __gnuplot_has_terminal__ (@var{terminal})
## Undocumented internal function.
## @end deftypefn

## Author: Ben Abbott <bpabbott@mac.com>
## Created: 2010-09-13

function gnuplot_supports_term = __gnuplot_has_terminal__ (term, plot_stream)
  term = deblank (term);
  n = find (term == " ", 1);
  if (! isempty (n))
    term = term(1:n-1);
  endif
  if (__gnuplot_has_feature__ ("variable_GPVAL_TERMINALS"))
    if (nargin < 2)
      plot_stream = __gnuplot_open_stream__ (2);
    endif
    available_terminals = __gnuplot_get_var__ (plot_stream, "GPVAL_TERMINALS");
    available_terminals = regexp (available_terminals, '\w+', "match");
    if (nargin < 2 && ! isempty (plot_stream))
      pclose (plot_stream(1));
      if (numel (plot_stream) > 1)
        pclose (plot_stream(2));
      endif
      if (numel (plot_stream) > 2)
        waitpid (plot_stream(3));
      endif
    endif
  else
    ## Gnuplot 4.0 terminals. No new terminals were added until 4.4 which
    ## allows the list of terminals to be obtained from GPVAL_TERMINALS.
    available_terminals = {"aifm", "aqua", "canvas", "cgm", "corel", ...
                           "dumb", "dxf", "eepic", "emf", "epslatex", ...
                           "epson_180dpi", "fig", "gif", "gnugraph", ...
                           "gpic", "hp2623A", "hp2648", "hp500c", ...
                           "hpgl", "hpljii", "hppj", "imagen", "jpeg", ...
                           "latex", "mf", "mif", "mp", "pbm", "pdf", ...
                           "pm", "png", "postscript", "pslatex", ...
                           "pstex", "pstricks", "qms", "regis", "rgip", ...
                           "svg", "texdraw", "tgif", "tkcanvas", ...
                           "tpic", "windows", "x11", "xlib", "xterm"};
  endif
  gnuplot_supports_term = any (strcmpi (available_terminals, term));
endfunction