update packages

[CreaPhase.git] / octave_packages / m / plot / ishold.m

diff --git a/octave_packages/m/plot/ishold.m b/octave_packages/m/plot/ishold.m
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+++ b/octave_packages/m/plot/ishold.m
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+## 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  {Command} {} ishold
+## @deftypefnx {Function File} {} ishold (@var{h})
+## Return true if the next plot will be added to the current plot, or
+## false if the plot device will be cleared before drawing the next plot.
+##
+## Optionally, operate on the graphics handle @var{h} rather than the current
+## plot.
+## @seealso{hold}
+## @end deftypefn
+
+function retval = ishold (h)
+
+  if (nargin == 0)
+    fig = gcf ();
+    ax = get (fig, "currentaxes");
+  elseif (nargin == 1)
+    if (ishandle (h))
+      if (isfigure (h))
+        ax = get (h, "currentaxes");
+        fig = h;
+      elseif (strcmpi (get (h, "type"), "axes"))
+        ax = h;
+        fig = get (h, "parent");
+      else
+        error ("ishold: expecting argument to be axes or figure graphics handle");
+      endif
+    else
+      error ("ishold: expecting argument to be axes or figure graphics handle");
+    endif
+  else
+    print_usage ();
+  endif
+
+  retval = (strcmpi (get (fig, "nextplot"), "add")
+            && ! isempty (ax) && strcmpi (get (ax, "nextplot"), "add"));
+
+endfunction
+
+%!test
+%! hf = figure ("visible", "off");
+%! unwind_protect
+%!   assert (!ishold);
+%!   assert (isempty (get (hf, "currentaxes")));
+%!   assert (get (hf, "NextPlot"), "add");
+%!   l = plot ([0 1]);
+%!   assert (!ishold);
+%!   assert (!ishold (gca));
+%!   assert (get (gca, "NextPlot"), "replace");
+%!   assert (get (hf, "NextPlot"), "add");
+%!   hold;
+%!   assert (ishold);
+%!   assert (ishold (gca));
+%!   assert (get (gca, "NextPlot"), "add");
+%!   assert (get (hf, "NextPlot"), "add");
+%!   p = fill ([0 1 1], [0 0 1],"black");
+%!   assert (length (get (hf, "children")), 1);
+%!   assert (length (get (gca, "children")), 2);
+%! unwind_protect_cleanup
+%!   close (hf);
+%! end_unwind_protect