## Copyright (C) 2005, 2006, 2007, 2008, 2009 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} {} drawnow ()

 ## Update and display the current graphics.

 ##

 ## Octave automatically calls drawnow just before printing a prompt,

 ## when @code{sleep} or @code{pause} is called, or while waiting for

 ## command-line input.

 ## @end deftypefn

 ## Author: jwe

 function gnuplot_drawnow (h, term, file, mono, debug_file)

   if (nargin < 4)

     mono = false;

   endif

   if (nargin >= 3 && nargin <= 5)

     ## Produce various output formats, or redirect gnuplot stream to a

     ## debug file.

     plot_stream = [];

     fid = [];

     printing = ! output_to_screen (gnuplot_trim_term (term));

     default_plot_stream = get (h, "__plot_stream__");

     unwind_protect

       plot_stream = __gnuplot_open_stream__ (2, h);

       if (__gnuplot_has_feature__ ("variable_GPVAL_TERMINALS"))

         available_terminals = __gnuplot_get_var__ (plot_stream, "GPVAL_TERMINALS");

         available_terminals = regexp (available_terminals, "\\b\\w+\\b", "match");

         gnuplot_supports_term = any (strcmpi (available_terminals,

                                               gnuplot_trim_term (term)));

       else

         gnuplot_supports_term = true;

       endif

       if (gnuplot_supports_term)

         [enhanced, implicit_margin] = gnuplot_set_term (plot_stream (1), true,

                                                         h, term, file);

         __go_draw_figure__ (h, plot_stream(1), enhanced, mono, printing, implicit_margin);

         if (nargin == 5)

           fid = fopen (debug_file, "wb");

           [enhanced, implicit_margin] = gnuplot_set_term (fid, true, h, term, file);

           __go_draw_figure__ (h, fid, enhanced, mono, printing, implicit_margin);

         endif

       else

         error ("gnuplot_drawnow: the gnuplot terminal, \"%s\", is not available.",

                gnuplot_trim_term (term))

       endif

     unwind_protect_cleanup

       set (h, "__plot_stream__", default_plot_stream);

       if (! isempty (plot_stream))

         pclose (plot_stream(1));

         if (numel (plot_stream) == 2)

           pclose (plot_stream(2));

         endif

       endif

       if (! isempty (fid))

         fclose (fid);

       endif

     end_unwind_protect

   elseif (nargin == 1)

     ##  Graphics terminal for display.

     plot_stream = get (h, "__plot_stream__");

     if (isempty (plot_stream))

       plot_stream = __gnuplot_open_stream__ (2, h);

       new_stream = true;

     else

       new_stream = false;

     endif

     enhanced = gnuplot_set_term (plot_stream (1), new_stream, h);

     __go_draw_figure__ (h, plot_stream (1), enhanced, mono, 0);

     fflush (plot_stream (1));

   else

     print_usage ();

   endif

 endfunction

 function implicit_margin = gnuplot_implicit_margin (term, opts_str)

   ## gnuplot has an implicit margin of 50pts for PS output.

   if (strcmpi (term, "postscript"))

     if (isempty (strfind (opts_str, " eps"))

         && isempty (strfind (opts_str, "eps ")))

       implicit_margin = 50/72;

     else

       ## When zero, the behavior of gnuplot changes.

       implicit_margin = 1/72;

     endif

   else

     implicit_margin = 0.0;

   endif

 endfunction

 function [enhanced, implicit_margin] = gnuplot_set_term (plot_stream, new_stream, h, term, file)

   ## Generate the gnuplot "set terminal <term> ..." command.

   ## When "term" originates from print.m, it may include other options.

   if (nargin < 4)

     ## This supports the gnuplot backend.

     term = gnuplot_default_term ();

     opts_str = "";

   else

     ## Get the one word terminal id and save the remaining as options to

     ## be passed on to gnuplot.  The terminal may respect the backend.

     [term, opts_str] = gnuplot_trim_term (term);

     if (strcmpi (term, "pdf") && strcmpi (opts_str, "color"))

       ## FIXME -- "color" for the pdf terminal produces a gnuplot error.

       opts_str = "";

     endif

   endif

   implicit_margin = gnuplot_implicit_margin (term, opts_str);

   enhanced = gnuplot_is_enhanced_term (term);

   ## Set the terminal.

   if (! isempty (term))

     if (enhanced)

       enh_str = "enhanced";

     else

       enh_str = "";

     endif

     if (! isempty (h) && isfigure (h))

       ## Generate gnuoplot title string for backend plot windows.

       if (output_to_screen (term))

         fig.numbertitle = get (h, "numbertitle");

         fig.name = get (h, "name");

         if (strcmpi (get (h, "numbertitle"), "on"))

           title_str = sprintf ("Figure %d", h);

         else

           title_str = "";

         endif

         if (! isempty (fig.name) && ! isempty (title_str))

           title_str = sprintf ("%s: %s", title_str, fig.name);

         elseif (! isempty (fig.name) && isempty (title_str))

           title_str = fig.name;

         endif

         if (! isempty (title_str))

           title_str = sprintf ("title \"%s\"", title_str);

         endif

       else

         title_str = "";

       endif

       if (! (any (strfind (opts_str, " size ") > 0) 

 	  || any (strfind (opts_str, "size ") == 1)))

         ## Convert position to units used by gnuplot.

         if (output_to_screen (term))

           ## Get figure size in pixels.  Rely on listener

 	  ## to handle coversion of position property.

 	  units = get (h, "units");

 	  unwind_protect

 	    set (h, "units", "pixels");

 	    position_in_pixesl = get (h, "position");

 	  unwind_protect_cleanup

 	    set (h, "units", units);

 	  end_unwind_protect

 	  gnuplot_pos = position_in_pixesl(1:2);

 	  gnuplot_size = position_in_pixesl(3:4);

         else

           ## Get size of the printed plot in inches. Rely on listener

 	  ## to handle coversion of papersize property.

 	  paperunits = get (h, "paperunits");

 	  unwind_protect

 	    set (h, "paperunits", "inches");

             gnuplot_size = get (h, "papersize");

 	  unwind_protect_cleanup

 	    set (h, "paperunits", paperunits);

 	  end_unwind_protect

           if (term_units_are_pixels (term))

 	    ## Convert to inches using the property set by print().

 	    gnuplot_size = gnuplot_size * get (h, "__pixels_per_inch__");

 	  else

 	    ## Implicit margins are in units of "inches"

 	    gnuplot_size = gnuplot_size - implicit_margin;

           endif

         endif

 	[begin_match, end_match, te, match] = regexp (opts_str, "(\\s-r\\d+)|(^-r\\d+)");

 	if (! isempty (begin_match))

 	  error ("gnuplot_drawnow.m: specifying resultion, '%s', not supported for terminal '%s'",

 	         strtrim (match{1}), term)

 	endif

         if (all (gnuplot_size > 0))

           ## Set terminal size.

           terminals_with_size = {"emf", "gif", "jpeg", "latex", "pbm", ...

                                  "pdf", "png", "postscript", "svg", ...

                                  "epslatex", "pstex", "pslatex"};

           if (__gnuplot_has_feature__ ("x11_figure_position"))

             terminals_with_size{end+1} = "x11";

           endif

           if (__gnuplot_has_feature__ ("wxt_figure_size"))

             terminals_with_size{end+1} = "wxt";

           endif

           if (any (strncmpi (term, terminals_with_size, 3)))

 	    if (term_units_are_pixels (term))

               size_str = sprintf ("size %d,%d", gnuplot_size);

 	    else

               size_str = sprintf ("size %.15g,%.15g", gnuplot_size);

 	    endif

             if (strncmpi (term, "X11", 3) && __gnuplot_has_feature__ ("x11_figure_position"))

 	      ## X11 allows the window to be positioned as well.

 	      units = get (0, "units");

 	      unwind_protect

 	        set (0, "units", "pixels");

 	        screen_size = get (0, "screensize")(3:4);

 	      unwind_protect_cleanup

 	        set (0, "units", units);

 	      end_unwind_protect

               if (all (screen_size > 0))

                 ## For X11, set the figure positon as well as the size

                 ## gnuplot position is UL, Octave's is LL (same for screen/window)

                 gnuplot_pos(2) = screen_size(2) - gnuplot_pos(2) - gnuplot_size(2);

                 gnuplot_pos = max (gnuplot_pos, 1);

                 size_str = sprintf ("%s position %d,%d", size_str, 

                                     gnuplot_pos(1), gnuplot_pos(2));

               endif

             endif

           elseif (strncmpi (term, "aqua", 3))

             ## Aqua has size, but the format is different.

             size_str = sprintf ("size %d %d", gnuplot_size);

           elseif (strncmpi (term, "fig", 3))

             ## Fig also has size, but the format is different.

             size_str = sprintf ("size %.15g %.15g", gnuplot_size);

           elseif (any (strncmpi (term, {"corel", "hpgl"}, 3)))

             ## The size for corel and hpgl are goes at the end (implicit).

             size_str = sprintf ("%.15g %.15g", gnuplot_size);

           elseif (any (strncmpi (term, {"dxf"}, 3)))

             ## DXF uses autocad units.

             size_str = "";

           else

             size_str = "";

           endif

         else

           size_str = "";

 	  warning ("gnuplot_set_term: size is zero")

         endif

       else

         ## A specified size take priority over the figure properies.

         size_str = "";

       endif

     else

       if isempty (h)

         disp ("gnuplot_set_term: figure handle is empty")

       elseif !isfigure(h)

         disp ("gnuplot_set_term: not a figure handle")

       endif

       title_str = "";

       size_str = "";

     endif

     ## Set the gnuplot terminal (type, enhanced, title, options & size).

     term_str = sprintf ("set terminal %s", term);

     if (! isempty (enh_str))

       term_str = sprintf ("%s %s", term_str, enh_str);

     endif

     if (! isempty (title_str))

       term_str = sprintf ("%s %s", term_str, title_str);

     endif

     if (nargin > 3 && ischar (opts_str))

       ## Options must go last.

       term_str = sprintf ("%s %s", term_str, opts_str);

     endif

     if (! isempty (size_str) && new_stream)

       ## size_str comes after other options to permit specification of

       ## the canvas size for terminals cdr/corel.

       term_str = sprintf ("%s %s", term_str, size_str);

     endif

     ## Work around the gnuplot feature of growing the x11 window when

     ## the mouse and multiplot are set.

     fputs (plot_stream, "unset multiplot;\n");

     if (! strcmp (term, "x11")

         || numel (findall (h, "type", "axes")) > 1

         || numel (findall (h, "type", "image")) > 0)

       fprintf (plot_stream, "%s\n", term_str);

       if (nargin == 5)

         if (! isempty (file))

           fprintf (plot_stream, "set output '%s';\n", file);

         endif

       endif

       fputs (plot_stream, "set multiplot;\n");

     elseif (strcmp (term, "x11"))

       fprintf (plot_stream, "%s\n", term_str);

       if (nargin == 5)

         if (! isempty (file))

           fprintf (plot_stream, "set output '%s';\n", file);

         endif

       endif

     endif

   else

     ## gnuplot will pick up the GNUTERM environment variable itself

     ## so no need to set the terminal type if not also setting the

     ## figure title, enhanced mode, or position.

   endif

 endfunction

 function term = gnuplot_default_term ()

   term = getenv ("GNUTERM");

   ## If not specified, guess the terminal type.

   if (isempty (term))

     if (ismac ())

       term = "aqua";

     elseif (! isunix ())

       term = "windows";

     else

       term = "x11";

     endif

   endif

 endfunction

 function [term, opts] = gnuplot_trim_term (string)

   ## Extract the terminal type and terminal options (from print.m)

   string = deblank (string);

   n = strfind (string, ' ');

   if (isempty (n))

     term = string;

     opts = "";

   else

     term = string(1:(n-1));

     opts = string((n+1):end);

   endif

 endfunction

 function have_enhanced = gnuplot_is_enhanced_term (term)

   persistent enhanced_terminals;

   if (isempty (enhanced_terminals))

     ## Don't include pstex, pslatex or epslatex here as the TeX commands

     ## should not be interpreted in that case.

     enhanced_terminals = {"aqua", "dumb", "png", "jpeg", "gif", "pm", ...

                           "windows", "wxt", "svg", "postscript", "x11", "pdf"};

   endif

   if (nargin < 1)

     ## Determine the default gnuplot terminal.

     term = gnuplot_default_term ();

   endif

   have_enhanced = any (strncmp (enhanced_terminals, term, min (numel (term), 3)));

 endfunction

 function ret = output_to_screen (term)

   ret = any (strcmpi ({"aqua", "wxt", "x11", "windows", "pm"}, term));

 endfunction

 function ret = term_units_are_pixels (term)

   ret = any (strncmpi ({"emf", "gif", "jpeg", "pbm", "png", "svg"}, term, 3));

 endfunction