update packages

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

diff --git a/octave_packages/m/plot/linkprop.m b/octave_packages/m/plot/linkprop.m
new file mode 100644 (file)
index 0000000..facda4d
--- /dev/null
+++ b/octave_packages/m/plot/linkprop.m
@@ -0,0 +1,98 @@
+## Copyright (C) 2008-2012 David Bateman
+##
+## 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{hlink} =} linkprop (@var{h}, @var{prop})
+## Link graphics object properties, such that a change in one is
+## propagated to the others.  The properties to link are given as a
+## string of cell string array by @var{prop} and the objects containing
+## these properties by the handle array @var{h}.
+##
+## An example of the use of linkprop is
+##
+## @example
+## @group
+## x = 0:0.1:10;
+## subplot (1,2,1);
+## h1 = plot (x, sin (x));
+## subplot (1,2,2);
+## h2 = plot (x, cos (x));
+## hlink = linkprop ([h1, h2], @{"color","linestyle"@});
+## set (h1, "color", "green");
+## set (h2, "linestyle", "--");
+## @end group
+## @end example
+##
+## @end deftypefn
+
+function hlink = linkprop (h, prop)
+  if (ischar (prop))
+    prop = {prop};
+  elseif (!iscellstr (prop))
+    error ("linkprop: properties must be a string or cell string array");
+  endif
+
+  for i = 1 : numel (h)
+    for j = 1 : numel (prop)
+      addlistener (h(i), prop{j}, {@update_prop, h, prop{j}});
+    endfor
+  endfor
+
+  ## This should be an object that when destroyed removes the links
+  ## The below is not quite right. As when you call "clear hlink" the
+  ## hggroup continues to exist.
+  hlink = hggroup ();
+  set (hlink, "deletefcn", {@delete_prop, h, prop});
+endfunction
+
+function update_prop (h, d, hlist, prop)
+  persistent recursion = false;
+
+  ## Don't allow recursion
+  if (! recursion)
+    unwind_protect
+      recursion = true;
+      val = get (h, prop);
+      for hh = hlist(:)'
+        if (hh != h)
+          oldval = get (hh, prop);
+          if (! isequal (val, oldval))
+            set (hh, prop, val);
+          endif
+        endif
+      endfor
+    unwind_protect_cleanup
+      recursion = false;
+    end_unwind_protect
+  endif
+endfunction
+
+function delete_prop (h, d, hlist, prop)
+  ## FIXME. Actually need to delete the linked properties.
+  ## However, only warn if the graphics objects aren't being deleted.
+  warn = false;
+  for h = hlist(:)'
+    if (ishandle (h) && !strcmpi (get (h, "beingdeleted"), "on"))
+      warn = true;
+      break;
+    endif
+  endfor
+  if (warn)
+    warning ("linkprop: can not remove linked properties");
+  endif
+endfunction