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## -*- texinfo -*-
## @deftypefn  {} {} setappdata (@var{h}, @var{name}, @var{value})
## @deftypefnx {} {} setappdata (@var{h}, @var{name1}, @var{value1}, @var{name2}, @var{value3}, @dots{})
## @deftypefnx {} {} setappdata (@var{h}, @{@var{name1}, @var{name2}, @dots{}@}, @{@var{value1}, @var{value2}, @dots{}@})
## Set the application data @var{name} to @var{value} for the graphics object
## with handle @var{h}.
##
## @var{h} may also be a vector of graphics handles.  If the application data
## with the specified @var{name} does not exist, it is created.
##
## Multiple @var{name}/@var{value} pairs can be specified.  Alternatively, a
## cell array of @var{names} and a corresponding cell array of @var{values} can
## be specified.  Details on obtaining a list of valid application data
## properties can be found in @ref{XREFgetappdata, ,getappdata}.
##
## @seealso{getappdata, isappdata, rmappdata, guidata, get, set, getpref, setpref}
## @end deftypefn

function setappdata (h, varargin)

  if (nargin < 3)
    print_usage ();
  endif

  h = h(:).';
  if (! all (ishghandle (h)))
    error ("setappdata: H must be a scalar or vector of graphic handles");
  elseif (mod (numel (varargin), 2) != 0)
    error ("setappdata: NAME/VALUE arguments must occur in pairs");
  endif

  if (iscellstr (varargin{1}))
    if (nargin != 3)
      error ("setappdata: only 3 arguments possible when NAME is a cellstr");
    elseif (! iscell (varargin{2}))
      varargin{2} = varargin(2);  # convert to cell
    endif
    names = varargin{1};
    values = varargin{2};
    n_names = numel (names);
    n_value = numel (values);
    if (n_value == 1 && n_names > 1)
      values = repmat (values, [1, n_names]);
    elseif (n_names != n_value)
      error ("setappdata: number of NAME and VALUE arguments must match");
    endif
    varargin = cell (1, 2*numel (names));
    varargin(1:2:end) = names;
    varargin(2:2:end) = values;

  elseif (! all (cellfun ("isclass", varargin(1:2:end), "char")))
    error ("setappdata: NAME must be a string or cellstr");
  endif

  for hg = h
    appdata = get (hg, "__appdata__");

    ## Slow, but not likely to be that many elements in loop
    for narg = 1:2:numel (varargin)
      appdata.(varargin{narg}) = varargin{narg+1};
    endfor

    set (hg, "__appdata__", appdata);
  endfor

endfunction


%!test
%! unwind_protect
%!   setappdata (0, "%hello%", "world");
%!   assert (isappdata (0, "%hello%"), true);
%!   assert (getappdata (0, "%hello%"), "world");
%! unwind_protect_cleanup
%!   rmappdata (0, "%hello%");
%! end_unwind_protect

%!test
%! unwind_protect
%!   setappdata (0, "%data1%", ones (3), "%data2%", "hello world");
%!   assert (getappdata (0, "%data1%"), ones (3));
%!   assert (getappdata (0, "%data2%"), "hello world");
%!   setappdata (0, "%data1%", zeros (3));
%!   assert (getappdata (0, "%data1%"), zeros (3));
%! unwind_protect_cleanup
%!   rmappdata (0, "%data1%", "%data2%");
%! end_unwind_protect

%!test
%! unwind_protect
%!   setappdata (0, {"%data1%", "%data2%"}, {ones(3), "hello world"});
%!   assert (getappdata (0, "%data1%"), ones (3));
%!   assert (getappdata (0, "%data2%"), "hello world");
%!   setappdata (0, "%data1%", zeros (3));
%!   assert (getappdata (0, "%data1%"), zeros (3));
%!   rmappdata (0, "%data1%", "%data2%");
%!   setappdata (0, {"%data1%", "%data2%"}, pi);
%!   assert (getappdata (0, "%data1%"), pi);
%!   assert (getappdata (0, "%data2%"), pi);
%! unwind_protect_cleanup
%!   rmappdata (0, "%data1%", "%data2%");
%! end_unwind_protect

## Test input validation
%!error setappdata ()
%!error setappdata (0)
%!error setappdata (0, "name")
%!error <H must be a scalar .* graphic handle> setappdata (-1, "foo", "bar")
%!error <NAME/VALUE arguments must occur in pairs> setappdata (0, "1", 2, "3")
%!error <only 3 arguments possible> setappdata (0, {"1"}, 2, "3", 4)
%!error <number of NAME and VALUE arguments must match>
%! setappdata (0, {"1", "2"}, {2, 3, 4})
%!error <NAME must be a string> setappdata (0, 1, 2)
