--- /dev/null
+## Copyright (C) 2007-2012 John W. Eaton
+##
+## 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{rgb} =} __next_line_color__ (@var{reset})
+## Undocumented internal function.
+## @end deftypefn
+
+## Return the next line color in the rotation.
+
+## Author: jwe
+
+function rgb = __next_line_color__ (reset)
+
+ persistent color_rotation;
+ persistent num_colors;
+ persistent color_index;
+
+ if (nargin < 2)
+ if (nargin == 1)
+ if (reset || isempty (color_rotation))
+ color_rotation = get (gca (), "colororder");
+ num_colors = rows (color_rotation);
+ color_index = 1;
+ endif
+ elseif (! isempty (color_rotation))
+ rgb = color_rotation(color_index,:);
+ if (++color_index > num_colors)
+ color_index = 1;
+ __next_line_style__ ("incr");
+ endif
+ else
+ error ("__next_line_color__: color_rotation not initialized");
+ endif
+ else
+ print_usage ();
+ endif
+
+endfunction