# HG changeset patch
# User Ben Abbott <bpabbott@mac.com>
# Date 1239583253 14400
# Node ID 4bb94a71913b97b802634e7b5fc77fcdd8ae882a
# Parent  f5b51f54f44ee22d3638a2212ddf520ad47c0e25
__gnuplot_open_stream__.m: New function and its application.

diff --git a/scripts/ChangeLog b/scripts/ChangeLog
--- a/scripts/ChangeLog
+++ b/scripts/ChangeLog
@@ -1,3 +1,10 @@
+2009-04-12  Ben Abbott <bpabbott@mac.com>
+
+	* plot/__gnuplot_open_stream__.m: New function.
+	* plot/__gnuplot_get_var__.m: If not open, open the gnuplot plot stream.
+	* plot/gnuplot_drawnow.m: Replace internal function open_gnuplot_stream
+	with new __gnuplot_open_stream__.
+
 2009-04-11  David Bateman  <dbateman@free.fr>
 
 	* geometry/trisurf.m: New file.
diff --git a/scripts/plot/Makefile.in b/scripts/plot/Makefile.in
--- a/scripts/plot/Makefile.in
+++ b/scripts/plot/Makefile.in
@@ -49,6 +49,7 @@
   __ezplot__.m \
   __gnuplot_get_var__.m \
   __gnuplot_has_feature__.m \
+  __gnuplot_open_stream__.m \
   __go_close_all__.m \
   __go_draw_axes__.m \
   __go_draw_figure__.m \
diff --git a/scripts/plot/__gnuplot_get_var__.m b/scripts/plot/__gnuplot_get_var__.m
--- a/scripts/plot/__gnuplot_get_var__.m
+++ b/scripts/plot/__gnuplot_get_var__.m
@@ -37,7 +37,11 @@
   endif
 
   if (numel (h) == 1 && isfigure (h))
-    ostream = get (h, "__plot_stream__");
+    if (isempty (get (gcf, "__plot_stream__")))
+      ostream = __gnuplot_open_stream__ (2, h);
+    else
+      ostream = get (h, "__plot_stream__");
+    endif
   else
     ostream = h;
   endif
diff --git a/scripts/plot/__gnuplot_open_stream__.m b/scripts/plot/__gnuplot_open_stream__.m
new file mode 100644
--- /dev/null
+++ b/scripts/plot/__gnuplot_open_stream__.m
@@ -0,0 +1,41 @@
+## Copyright (C) 2009 Ben Abbott
+## 
+## This program 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 2 of the License, or
+## (at your option) any later version.
+## 
+## This program 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{stream}} __gnuplot_open_stream__ (@var{npipes}, @var{h})
+## Undocumented internal function.
+## @end deftypefn
+
+## Author: Ben Abbott <bpabbott@mac.com>
+## Created: 2009-04-11
+
+function plot_stream = __gnuplot_open_stream__ (npipes, h)
+  cmd = gnuplot_binary ();
+  if (npipes > 1)
+    [plot_stream(1), plot_stream(2), pid] = popen2 (cmd);
+    if (pid < 0)
+      error ("__gnuplot_open_stream__: failed to open connection to gnuplot.");
+    endif
+  else
+    plot_stream = popen (cmd, "w");
+    if (plot_stream < 0)
+      error ("__gnuplot_open_stream__: failed to open connection to gnuplot.");
+    endif
+  endif
+  if (nargin > 1)
+    set (h, "__plot_stream__", plot_stream);
+  endif
+endfunction
diff --git a/scripts/plot/gnuplot_drawnow.m b/scripts/plot/gnuplot_drawnow.m
--- a/scripts/plot/gnuplot_drawnow.m
+++ b/scripts/plot/gnuplot_drawnow.m
@@ -41,7 +41,7 @@
     printing = ! output_to_screen (gnuplot_trim_term (term));
     default_plot_stream = get (h, "__plot_stream__");
     unwind_protect
-      plot_stream = open_gnuplot_stream (2, h);
+      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");
@@ -79,7 +79,7 @@
     ##  Graphics terminal for display.
     plot_stream = get (h, "__plot_stream__");
     if (isempty (plot_stream))
-      plot_stream = open_gnuplot_stream (2, h);
+      plot_stream = __gnuplot_open_stream__ (2, h);
       new_stream = true;
     else
       new_stream = false;
@@ -108,24 +108,6 @@
   endif
 endfunction
 
-function plot_stream = open_gnuplot_stream (npipes, h)
-  cmd = gnuplot_binary ();
-  if (npipes > 1)
-    [plot_stream(1), plot_stream(2), pid] = popen2 (cmd);
-    if (pid < 0)
-      error ("drawnow: failed to open connection to gnuplot");
-    endif
-  else
-    plot_stream = popen (cmd, "w");
-    if (plot_stream < 0)
-      error ("drawnow: failed to open connection to gnuplot");
-    endif
-  endif
-  if (! isempty (h))
-    set (h, "__plot_stream__", plot_stream);
-  endif
-endfunction
-
 function [enhanced, implicit_margin] = gnuplot_set_term (plot_stream, new_stream, h, term, file)
   ## Generate the gnuplot "set terminal <term> ..." command.  Include
   ## the subset of properties "position", "units", "paperposition",