## Copyright (C) 2005 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 2, 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, write to the Free
## Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
## 02110-1301, USA.

## -*- texinfo -*-
## @deftypefn {Function File} {} ishandle (@var{h})
## Return 1 if @var{h} is a graphics handle and 0 otherwise.
## @end deftypefn

## Author: jwe

function retval = ishandle (h)

  if (nargin == 1)
    ## Ensure that we have a root figure object.
    __uiobject_init_root_figure__ ();
    retval = (isnumeric (h) && isscalar (h) && round (h) == h
	      && ! isempty (__uiobject_handle2idx__ (h)));
  else
    print_usage ();
  endif

endfunction