## Copyright (C) 2005-2012 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} {} __go_draw_figure__ (@var{h}, @var{plot_stream}, @var{enhanced}, @var{mono})
## Undocumented internal function.
## @end deftypefn

## Author: jwe

function __go_draw_figure__ (h, plot_stream, enhanced, mono)

  if (nargin == 4)
    htype = get (h, "type");
    if (strcmp (htype, "figure"))
      ## Get complete list of children.
      kids = allchild (h);
      nkids = length (kids);

      if (nkids > 0)
        fputs (plot_stream, "\nreset;\n");
        fputs (plot_stream, "set autoscale keepfix;\n");
        fputs (plot_stream, "set origin 0, 0\n");
        fputs (plot_stream, "set size 1, 1\n");
        bg = get (h, "color");
        if (isnumeric (bg))
          fprintf (plot_stream, "set obj 1 rectangle from screen 0,0 to screen 1,1 behind fc rgb \"#%02x%02x%02x\"\n", 255 * bg);
          bg_is_set = true;
        else
          bg_is_set = false;
        endif

        for i = nkids:-1:1
          type = get (kids(i), "type");
          switch (type)
            case "axes"
              if (strcmpi (get (kids (i), "tag"), "legend"))
                ## This is so ugly. If there was a way of getting
                ## gnuplot to give us the text extents of strings
                ## then we could get rid of this mess.
                lh = getfield (get (kids(i), "userdata"), "handle");
                if (isscalar (lh))
                  ## We have a legend with a single parent. It'll be handled
                  ## below as a gnuplot key to the axis it corresponds to
                  continue;
                else
                  ca = lh(1);
                  ## Rely upon listener to convert axes position
                  ## to "normalized" units.
                  legend_axes_units = get (kids(i), "units");
                  legend_axes_position = get (kids(i), "position");
                  legend_axes_outerposition = get (kids(i), "outerposition");
                  legend_axes_box = get (kids(i), "box");
                  legend_axes_ylim = get (kids(i), "ylim");
                  orig_axes_units = get (ca, "units");
                  hlgnd = get (kids(i));

                  unwind_protect
                    set (ca, "units", "normalized");
                    set (kids(i), "units", "normalized", "box", "off",
                         "ylim", [-2, -1], "position", get (ca(1), "position"),
                         "outerposition", get (ca(1), "outerposition"));

                    ## Create a new set of lines with the appropriate
                    ## displaynames, etc
                    toberm = [];
                    hobj = get (kids(i), "children");
                    for j = numel (hobj) : -1 : 1
                      if (! strcmp (get (hobj(j), "type"), "text"))
                        continue;
                      endif
                      displayname = get (hobj(j), "string");
                      ll = [];
                      lm = [];
                      for k = numel (hobj) : -1 : 1
                        if (! strcmp (get (hobj(k), "type"), "line"))
                          continue;
                        endif
                        if (get (hobj(j), "userdata")
                            != get (hobj(k), "userdata"))
                          continue;
                        endif
                        if (! strcmp (get (hobj(k), "linestyle"), "none"))
                          ll = hobj(k);
                        endif
                        if (! strcmp (get (hobj(k), "marker"), "none"))
                          lm = hobj(k);
                        endif
                      endfor

                      if (! isempty (ll))
                        if (!isempty (lm))
                          toberm = [toberm, line("xdata",[0,0],"ydata",[0,0], "color", get(lm,"color"), "linestyle", get(ll,"linestyle"), "marker", get(lm,"marker"), "markeredgecolor", get(lm,"markeredgecolor"), "markerfacecolor", get(lm,"markerfacecolor"), "markersize", get (lm, "markersize"), "displayname", displayname, "parent", kids(i))];
                        else
                          toberm = [toberm, line("xdata",[0,0],"ydata",[0,0], "color", get(ll,"color"), "linestyle", get(ll,"linestyle"), "marker", "none", "displayname", displayname, "parent", kids(i))];
                        endif
                      elseif (! isempty (lm))
                        toberm = [toberm, line("xdata",[0,0],"ydata",[0,0], "color", get(lm,"color"), "linestyle", "none", "marker", get(lm,"marker"), "markeredgecolor", get(lm,"markeredgecolor"), "markerfacecolor", get(lm,"markerfacecolor"), "markersize", get (lm, "markersize"), "displayname", displayname, "parent", kids(i))];
                      endif
                    endfor
                    if (bg_is_set)
                      fprintf (plot_stream, "set border linecolor rgb \"#%02x%02x%02x\"\n", 255 * (1 - bg));
                    endif
                    __go_draw_axes__ (kids(i), plot_stream, enhanced, mono,
                                      bg_is_set, false, hlgnd);
                  unwind_protect_cleanup
                    ## Return axes "units" and "position" back to
                    ## their original values.
                    set (ca, "units", orig_axes_units);
                    set (kids(i), "units", legend_axes_units,
                         "box", legend_axes_box,
                         "ylim", legend_axes_ylim,
                         "position", legend_axes_position,
                         "outerposition", legend_axes_outerposition);
                    delete (toberm);
                    bg_is_set = false;
                  end_unwind_protect
                endif
              else
                ## Rely upon listener to convert axes position
                ## to "normalized" units.
                orig_axes_units = get (kids(i), "units");
                orig_axes_position = get (kids(i), "position");
                unwind_protect
                  set (kids(i), "units", "normalized");
                  fg = get (kids(i), "color");
                  if (isnumeric (fg) && strcmp (get (kids(i), "visible"), "on"))
                    fprintf (plot_stream, "set obj 2 rectangle from graph 0,0 to graph 1,1 behind fc rgb \"#%02x%02x%02x\"\n", 255 * fg);
                    fg_is_set = true;
                  else
                    fg_is_set = false;
                  endif
                  if (bg_is_set)
                    fprintf (plot_stream, "set border linecolor rgb \"#%02x%02x%02x\"\n", 255 * (1 - bg));
                  endif
                  ## Find if this axes has an associated legend axes and pass it
                  ## to __go_draw_axes__
                  hlegend = [];
                  fkids = get (h, "children");
                  for j = 1 : numel(fkids)
                    if (ishandle (fkids (j))
                        && strcmp (get (fkids (j), "type"), "axes")
                        && (strcmp (get (fkids (j), "tag"), "legend")))
                      udata = get (fkids (j), "userdata");
                      if (isscalar(udata.handle)
                          && ! isempty (intersect (udata.handle, kids (i))))
                        hlegend = get (fkids (j));
                        break;
                      endif
                    endif
                  endfor
                  __go_draw_axes__ (kids(i), plot_stream, enhanced, mono,
                                    bg_is_set, fg_is_set, hlegend);
                unwind_protect_cleanup
                  ## Return axes "units" and "position" back to
                  ## their original values.
                  set (kids(i), "units", orig_axes_units);
                  set (kids(i), "position", orig_axes_position);
                  bg_is_set = false;
                  fg_is_set = false;
                end_unwind_protect
              endif
            case "uimenu"
              ## ignore uimenu objects
            otherwise
              error ("__go_draw_figure__: unknown object class, %s", type);
          endswitch
        endfor
        fputs (plot_stream, "\nunset multiplot;\n");
      else
        fputs (plot_stream, "\nreset; clear;\n");
        fflush (plot_stream);
      endif
    else
      error ("__go_draw_figure__: expecting figure object, found `%s'",
             htype);
    endif
  else
    print_usage ();
  endif

endfunction