## Copyright (C) 2006, 2007 Michel D. Schmid
##
## 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/>.

## Undocumented internal function

## Author: Michel D. Schmid <michaelschmid@users.sourceforge.net>
## Adapted-by: jwe

function h = __stem__ (have_z, varargin)

  if (have_z)
    caller = "stem3";
  else
    caller = "stem";
  endif

  [ax, varargin, nargin] = __plt_get_axis_arg__ (caller, varargin{:});

  [x, y, z, dofill, llc, ls, mmc, ms, varargin] = ...
      check_stem_arg (have_z, varargin{:});

  oldax = gca ();
  unwind_protect
    axes (ax);
    hold_state = get (ax, "nextplot");
    newplot ();
    h = [];

    nx = rows (x);
    for i = 1: columns (x)
      if (have_z)
	xt = x(:)';
	xt = [xt; xt; NaN(1, nx)](:);
	yt = y(:)';
	yt = [yt; yt; NaN(1, nx)](:);
	zt = z(:)';
	zt = [zeros(1, nx); zt; NaN(1, nx)](:);
      else
	xt = x(:, i)';
	xt = [xt; xt; NaN(1, nx)](:);
	yt = y(:, i)';
	yt = [zeros(1, nx); yt; NaN(1, nx)](:);
      endif

      hg  = hggroup ();
      h = [h; hg];
      args = __add_datasource__ (caller, hg, {"x", "y", "z"}, varargin{:});
      
      if (i == 1)
	set (ax, "nextplot", "add");
      endif

      if (isempty (llc))
	lc = __next_line_color__ ();
      else
	lc = llc;
      endif

      if (isempty (mmc))
	mc = lc;
      else
	mc = mmc;
      endif

      if (dofill)
	fc = mc;
      else
	fc = "none";
      endif

      if (have_z)
	h_stems = plot3 (xt, yt, zt, "color", lc, "linestyle", ls, 
			 "parent", hg, x, y, z, "color", mc,
			 "marker",  ms, "linestyle", "none",
			 "markerfacecolor", fc, "parent", hg);

	h_baseline = [];
      else
	h_stems = plot (xt, yt, "color", lc, "linestyle", ls,
			"parent", hg, x(:,i), y(:, i), "color", mc, "marker",
			ms, "linestyle", "none", "markerfacecolor",
			fc, "parent", hg); 

	if (i == 1)
	  x_axis_range = get (ax, "xlim");
	  h_baseline = line (x_axis_range, [0, 0], "color", [0, 0, 0]);
	  set (h_baseline, "handlevisibility", "off");
	  set (h_baseline, "xliminclude", "off");
	  addlistener (ax, "xlim", @update_xlim);
	  addlistener (h_baseline, "ydata", @update_baseline);
	  addlistener (h_baseline, "visible", @update_baseline);
	endif
      endif

      ## Setup the hggroup and listeners
      addproperty ("showbaseline", hg, "radio", "{on}|off");
      addproperty ("basevalue", hg, "data", 0);
      addproperty ("baseline", hg, "data", h_baseline);

      if (!have_z)
	addlistener (hg, "showbaseline", @show_baseline);
	addlistener (hg, "basevalue", @move_baseline); 
      endif

      addproperty ("color", hg, "linecolor", lc);
      addproperty ("linewidth", hg, "linelinewidth", 0.5);
      addproperty ("linestyle", hg, "linelinestyle", ls);
      addproperty ("marker", hg, "linemarker", ms);
      addproperty ("markerfacecolor", hg, "linemarkerfacecolor", fc);
      addproperty ("markersize", hg, "linemarkersize", 6);

      addlistener (hg, "color", @update_props);
      addlistener (hg, "linewidth", @update_props); 
      addlistener (hg, "linestyle", @update_props); 
      addlistener (hg, "marker", @update_props); 
      addlistener (hg, "markerfacecolor", @update_props); 
      addlistener (hg, "markersize", @update_props);

      addproperty ("xdata", hg, "data", x(:, i));
      addproperty ("ydata", hg, "data", y(:, i));
      if (have_z)
	addproperty ("zdata", hg, "data", z(:, i));
      else
	addproperty ("zdata", hg, "data", []);
      endif

      addlistener (hg, "xdata", @update_data);
      addlistener (hg, "ydata", @update_data);
      addlistener (hg, "zdata", @update_data);

      if (! isempty (args))
	set (hg, args{:});
      endif
      if (i == 1 && !isempty(h_baseline))
	set (h_baseline, "parent", get (hg, "parent"));
      endif
    endfor

  unwind_protect_cleanup
    set (ax, "nextplot", hold_state);
    axes (oldax);
  end_unwind_protect
endfunction

function [x, y, z, dofill, lc, ls, mc, ms, newargs] = check_stem_arg (have_z, varargin)

  if (have_z)
    caller = "stem3";
  else
    caller = "stem";
  endif

  ## Remove prop/val pairs from data to consider
  i = 2;
  newargs = {};
  while (i < length (varargin))
    if (ischar (varargin{i}) && !(strcmpi ("fill", varargin{i})
				  || strcmpi ("filled", varargin{i})))
      newargs{end + 1} = varargin{i};
      newargs{end + 1} = varargin{i + 1};
      nargin = nargin - 2;
      varargin(i:i+1) = [];
    else
      i++;
    endif
  endwhile

  ## set specifiers to default values
  [lc, ls, mc, ms] = set_default_values ();
  dofill = 0;
  fill_2 = 0;
  linespec_2 = 0;
  z = [];

  ## check input arguments
  if (nargin == 2)
    if (have_z)
      z = varargin{1};
      x = 1:rows (z);
      y = 1:columns (z);
    else
      y = varargin{1};
      if (isvector (y))
	x = 1:length (y);
      elseif (ismatrix (y))
	x = 1:rows (y);
      else 
	error ("stem: Y must be a matrix");
      endif # in each case, x & y will be defined
    endif
  elseif (nargin == 3)
    ## several possibilities
    ## 1. the real y data
    ## 2. 'filled'
    ## 3. line spec
    if (ischar (varargin{2}))
      ## only 2. or 3. possible
      if (strcmpi ("fill", varargin{2}) || strcmpi ("filled", varargin{2}))
	dofill = 1;
      else
	## parse the linespec
	[lc, ls, mc, ms] = stem_line_spec (caller, varargin{2});
      endif
      if (have_z)
	z = varargin{1};
	x = 1:rows (z);
	y = 1:columns (z);
      else
	y = varargin{1};
	if (isvector (y))
	  x = 1:length (y);
	elseif (ismatrix (y))
	  x = 1:rows (y);
	else
	  error ("stem: Y must be a matrix");
	endif # in each case, x & y will be defined
      endif
    else
      if (have_z)
	error ("stem3: must define X, Y and Z");
      else
	## must be the real y data
	x = varargin{1};
	y = varargin{2};
	if (! (ismatrix (x) && ismatrix (y)))
	  error ("stem: X and Y must be matrices");
	endif
      endif
    endif
  elseif (nargin == 4)
    ## again several possibilities
    ## arg2 1. real y
    ## arg2 2. 'filled' or linespec
    ## arg3 1. real z
    ## arg3 2. 'filled' or linespec
    if (ischar (varargin{2}))
      ## only arg2 2. / arg3 1. & arg3 3. are possible
      if (strcmpi ("fill", varargin{2}) || strcmpi ("filled", varargin{2}))
	dofill = 1;
	fill_2 = 1; # be sure, no second "fill" is in the arguments
      else
	## must be a linespec
	[lc, ls, mc, ms] = stem_line_spec (caller, varargin{2});
	linespec_2 = 1;
      endif
      if (have_z)
	z = varargin{1};
	x = 1:rows (z);
	y = 1:columns (z);
      else
	y = varargin{1};
	if (isvector (y))
	  x = 1:length (y);
	elseif (ismatrix (y))
	  x = 1:rows (y);
	else
	  error ("stem: Y must be a matrix");
	endif # in each case, x & y will be defined
      endif
    else
      if (have_z)
	x = varargin{1};
	y = varargin{2};
	z = varargin{3};
	if (! (ismatrix (x) && ismatrix (y) && ismatrix (z)))
	  error ("stem3: X, Y and Z must be matrices");
	endif
      else
	## must be the real y data
	x = varargin{1};
	y = varargin{2};
	if (! (ismatrix (x) && ismatrix (y)))
	  error ("stem: X and Y must be matrices");
	endif
      endif
    endif # if ischar(varargin{2})
    if (! have_z)
      ## varargin{3} must be char
      ## check for "fill
      if ((strcmpi (varargin{3}, "fill") || strcmpi (varargin{3}, "filled"))
	  && fill_2)
	error ("stem: duplicate fill argument");
      elseif (strcmpi ("fill", varargin{3}) && linespec_2)
	## must be "fill"
	dofill = 1;
	fill_2 = 1;
      elseif ((strcmpi (varargin{3}, "fill") || strcmpi (varargin{3}, "filled"))
	  && !linespec_2)
	## must be "fill"
	dofill = 1;
	fill_2 = 1;
      elseif (! linespec_2)
	## must be linespec
	[lc, ls, mc, ms] = stem_line_spec (caller, varargin{3});
	linespec_2 = 1;
      endif
    endif
  elseif (nargin == 5)
    if (have_z)
      x = varargin{1};
      y = varargin{2};
      z = varargin{3};
      if (! (ismatrix (x) && ismatrix (y) && ismatrix (z)))
	error ("stem3: X, Y and Z must be matrices");
      endif
    else
      x = varargin{1};
      y = varargin{2};
      if (! (ismatrix (x) && ismatrix (y)))
	error ("stem: X and Y must be matrices");
      endif
    endif

    if (! have_z)
      if (strcmpi (varargin{3}, "fill") || strcmpi (varargin{3}, "filled"))
	dofill = 1;
	fill_2 = 1; # be sure, no second "fill" is in the arguments
      else
	## must be a linespec
	[lc, ls, mc, ms] = stem_line_spec (caller, varargin{3});
	linespec_2 = 1;
      endif
    endif

    ## check for "fill" ..
    if ((strcmpi (varargin{4}, "fill") || strcmpi (varargin{4}, "filled"))
	&& fill_2)
      error ("%s: duplicate fill argument", caller);
    elseif ((strcmpi (varargin{4}, "fill") || strcmpi (varargin{4}, "filled"))
	&& linespec_2)
      ## must be "fill"
      dofill = 1;
      fill_2 = 1;
    elseif (!strcmpi (varargin{4}, "fill") && !strcmpi (varargin{4}, "filled")
	&& !linespec_2)
      ## must be linespec
      [lc, ls, mc, ms] = stem_line_spec (caller, varargin{4});
      linespec_2 = 1;
    endif
  elseif (nargin == 6 && have_z)
    x = varargin{1};
    y = varargin{2};
    z = varargin{3};
    if (! (ismatrix (x) && ismatrix (y) && ismatrix (z)))
      error ("stem3: X, Y and Z must be matrices");
    endif

    if (strcmpi (varargin{4}, "fill") || strcmpi (varargin{4}, "filled"))
      dofill = 1;
      fill_2 = 1; # be sure, no second "fill" is in the arguments
    else
      ## must be a linespec
      [lc, ls, mc, ms] = stem_line_spec (caller, varargin{4});
      linespec_2 = 1;
    endif

    ## check for "fill" ..
    if ((strcmpi (varargin{5}, "fill") || strcmpi (varargin{5}, "filled"))
	&& fill_2)
      error ("stem3: duplicate fill argument");
    elseif ((strcmpi (varargin{5}, "fill") || strcmpi (varargin{5}, "filled"))
	&& linespec_2)
      ## must be "fill"
      dofill = 1;
      fill_2 = 1;
    elseif (!strcmpi (varargin{5}, "fill") && !strcmpi (varargin{5}, "filled")
	    && !linespec_2)
      ## must be linespec
      [lc, ls, mc, ms] = stem_line_spec (caller, varargin{5});
      linespec_2 = 1;
    endif
  else
    error ("%s: incorrect number of arguments", caller);
  endif

  ## Check sizes of x, y and z
  if (have_z)
    if (!size_equal (x, y, z))
      error ("stem3: inconsistent size of x, y and z");
    else
      x = x(:);
      y = y(:);
      z = z(:);
    endif
  else
    if (isvector (x))
      x = x(:);
      if (isvector (y))
	if (length (x) != length (y))
	  error ("stem: inconsistent size of x and y");
	else
	  y = y(:);
	endif
      else
	if (length (x) == rows (y))
	  x = repmat (x(:), 1, columns (y));
	else
	  error ("stem: inconsistent size of x and y");
	endif
      endif
    elseif (!size_equal (x, y ))
      error ("stem: inconsistent size of x and y");
    endif
  endif

endfunction

function [lc, ls, mc, ms] = stem_line_spec (caller, str)
  if (! ischar (str))
    error ("%s: expecting argument to be \"fill\" or a string of specifiers",
	   caller);
  endif
  [lc, ls, mc, ms] = set_default_values ();
  ## Parse the line specifier string.
  cur_props = __pltopt__ ("stem", str, false);
  for i = 1:length(cur_props)
    if (isfield (cur_props(i), "color") && ! isempty (cur_props(i).color)); # means line color
      mc = lc = cur_props(i).color;
    elseif (isfield (cur_props(i), "linestyle"))
      ls = cur_props(i).linestyle;
    elseif (isfield (cur_props(i), "marker") && ! strcmpi (cur_props(i).marker, "none"))
      ms = cur_props(i).marker;
    endif
  endfor
endfunction

function [lc, ls, mc, ms] = set_default_values ()
  ## set default values
  mc = [];
  lc = [];
  ls = "-";
  ms = "o";
endfunction

function update_xlim (h, d)
  kids = get (h, "children");
  xlim = get (h, "xlim");

  for i = 1 : length (kids)
    obj = get (kids (i));
    if (strcmp (obj.type, "hggroup") && isfield (obj, "baseline"))
      if (any (get (obj.baseline, "xdata") != xlim))
	set (obj.baseline, "xdata", xlim);
      endif
    endif
  endfor
endfunction

function update_baseline (h, d)
  visible = get (h, "visible");
  ydata = get (h, "ydata")(1);

  kids = get (get (h, "parent"), "children");
  for i = 1 : length (kids)
    obj = get (kids (i));
    if (strcmp (obj.type, "hggroup") && isfield (obj, "baseline") 
	&& obj.baseline == h)
      ## Only alter if changed to avoid recursion of the listener functions
      if (! strcmpi (get (kids(i), "showbaseline"), visible))
	set (kids (i), "showbaseline", visible);
      endif
      if (! strcmpi (get (kids(i), "basevalue"), visible))
	set (kids (i), "basevalue", ydata);
      endif
    endif
  endfor
endfunction

function show_baseline (h, d)
  set (get (h, "baseline"), "visible", get (h, "showbaseline"));
endfunction

function move_baseline (h, d)
  b0 = get (h, "basevalue");
  bl = get (h, "baseline");

  if (get (bl, "ydata") != [b0, b0])
    set (bl, "ydata", [b0, b0]);
  endif

  kids = get (h, "children");
  yt = get(h, "ydata")(:)';
  ny = length (yt);
  yt = [b0 * ones(1, ny); yt; NaN(1, ny)](:);
  set (kids(end), "ydata", yt);
endfunction

function update_props (h, d)
  kids = get (h, "children");
  set (kids(1), "color", get (h, "color"), 
       "linewidth", get (h, "linewidth"),
       "linestyle", get (h, "linestyle"));
  set (kids(2), "color", get (h, "color"), 
       "marker", get (h, "marker"),
       "markerfacecolor", get (h, "markerfacecolor"),
       "markersize", get (h, "markersize"));
endfunction

function update_data (h, d)
  x = get (h, "xdata");
  y = get (h, "ydata");
  z = get (h, "zdata");

  if (!isempty (z) && size_equal (x, y, z))
    error ("stem3: inconsistent size of x, y and z");
  elseif (numel(x) != numel (y))
    error ("stem: inconsistent size of x and y");
  else
    bl = get (h, "basevalue");
    nx = numel (x);
    x = x(:)';
    xt = [x; x; NaN(1, nx)](:);
    if (! isempty (z))
      y = y(:)';
      yt = [y; y; NaN(1, nx)](:);
      z = z(:)';
      zt = [bl * ones(1, nx); z; NaN(1, nx)](:);
    else
      y = y(:)';
      yt = [bl * ones(1, nx); y; NaN(1, nx)](:);
      zt = [];
    endif

    kids = get (h, "children");
    set (kids(1), "xdata", xt, "ydata", yt, "zdata", zt)
    set (kids(2), "xdata", x, "ydata", y, "zdata", z)
  endif
endfunction
