## Copyright (C) 1996, 1997, 2007, 2008, 2009 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 {Function File} {} __bars__ (@var{ax}, @var{vertical}, @var{x}, @var{y}, @var{xb}, @var{yb}, @var{width}, @var{group}, @var{have_color_spec}, @var{base_value}, @dots{})
## Undocumented internal function.
## @end deftypefn

## Author: jwe

function tmp = __bars__ (ax, vertical, x, y, xb, yb, width, group, have_color_spec, base_value, varargin)

  ycols = columns (y);
  clim = get (ax, "clim");
  tmp = [];

  for i = 1:ycols
    hg = hggroup ();
    tmp = [tmp; hg];
    args = __add_datasource__ ("bar", hg, {"x", "y"}, varargin{:});
    
    if (vertical)
      if (! have_color_spec)
	if (ycols == 1)
	  lev = clim(1);
	else
	  lev = (i - 1) * (clim(2) - clim(1)) / (ycols - 1) - clim(1);
	endif
	h = patch(xb(:,:,i), yb(:,:,i), "FaceColor", "flat", 
		  "cdata", lev, "parent", hg);
      else
	h = patch(xb(:,:,i), yb(:,:,i), "parent", hg);
      endif
    else
      if (! have_color_spec)
	if (ycols == 1)
	  lev = clim(1)
	else
	  lev = (i - 1) * (clim(2) - clim(1)) / (ycols - 1) - clim(1);
	endif
	h = patch(yb(:,:,i), xb(:,:,i), "FaceColor", "flat", 
		  "cdata", lev, "parent", hg);
      else
	h = patch(yb(:,:,i), xb(:,:,i), "parent", hg);
      endif
    endif

    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

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

    addlistener (hg, "showbaseline", @show_baseline);
    addlistener (hg, "basevalue", @move_baseline); 

    addproperty ("barwidth", hg, "data", width);
    if (group)
      addproperty ("barlayout", hg, "radio", "stacked|{grouped}", "grouped");
    else
      addproperty ("barlayout", hg, "radio", "{stacked}|grouped", "stacked");
    endif
    if (vertical)
      addproperty ("horizontal", hg, "radio", "on|{off}", "off")
    else
      addproperty ("horizontal", hg, "radio", "{on}|off", "on")
    endif

    addlistener (hg, "barwidth", @update_group);
    addlistener (hg, "barlayout", @update_group);
    addlistener (hg, "horizontal", @update_group);

    addproperty ("edgecolor", hg, "patchedgecolor", get (h, "edgecolor"));
    addproperty ("linewidth", hg, "patchlinewidth", get (h, "linewidth"));
    addproperty ("linestyle", hg, "patchlinestyle", get (h, "linestyle"));
    addproperty ("facecolor", hg, "patchfacecolor", get (h, "facecolor"));

    addlistener (hg, "edgecolor", @update_props);
    addlistener (hg, "linewidth", @update_props); 
    addlistener (hg, "linestyle", @update_props); 
    addlistener (hg, "facecolor", @update_props); 

    if (isvector (x))
      addproperty ("xdata", hg, "data", x);
    else
      addproperty ("xdata", hg, "data", x(:, i));
    endif
    addproperty ("ydata", hg, "data", y(:, i));
 
    addlistener (hg, "xdata", @update_data);
    addlistener (hg, "ydata", @update_data);

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

  update_xlim (ax, []);
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)
  persistent recursion = false;

  ## Don't allow recursion
  if (! recursion)
    unwind_protect
      recursion = true;
      hlist = get (h, "bargroup");
      showbaseline = get (h, "showbaseline");
      for hh = hlist(:)'
	if (hh != h)
	  set (hh, "showbaseline", showbaseline);
	endif
      endfor
      set (get (h, "baseline"), "visible", showbaseline);
    unwind_protect_cleanup
      recursion = false;
    end_unwind_protect
  endif
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

  if (strcmpi (get (h, "barlayout"), "grouped"))
    update_data (h, d);
  endif
endfunction

function update_props (h, d)
  kids = get (h, "children");
  set (kids, "edgecolor", get (h, "edgecolor"), 
       "linewidth", get (h, "linewidth"),
       "linestyle", get (h, "linestyle"),
       "facecolor", get (h, "facecolor"));
endfunction

function update_data (h, d)
  persistent recursion = false;

  ## Don't allow recursion
  if (! recursion)
    unwind_protect
      recursion = true;
      hlist = get (h, "bargroup");
      x = get (h, "xdata");
      if (!isvector (x))
	x = x(:);
      endif
      y = [];
      for hh = hlist(:)'
	ytmp = get (hh, "ydata");
	y = [y ytmp(:)];
      endfor

      [xb, yb] = bar (x, y, get (h, "barwidth"), get (h, "barlayout"),
		      "basevalue", get (h, "basevalue"));
      ny = columns (y);
      vert = strcmpi (get (h, "horizontal"), "off");

      for i = 1:ny
	hp = get (hlist(i), "children");
	if (vert)
	  set (hp, "xdata", xb(:,:,i), "ydata", yb(:,:,i));
	else
	  set (hp, "xdata", yb(:,:,i), "ydata", xb(:,:,i));
	endif
      endfor
    unwind_protect_cleanup
      recursion = false;
    end_unwind_protect
  endif
endfunction

function update_group (h, d)
  persistent recursion = false;

  ## Don't allow recursion
  if (! recursion)
    unwind_protect
      recursion = true;
      hlist = get (h, "bargroup");
      barwidth = get(h, "barwidth");
      barlayout = get (h, "barlayout");
      horizontal = get (h, "horizontal");

      ## To prevent recursion, only change if modified
      for hh = hlist(:)'
	if (hh != h)
	  if (get (hh, "barwidth") != barwidth)
	    set (hh, "barwidth", barwidth);
	  endif
	  if (! strcmpi (get (hh, "barlayout"), barlayout))
	    set (hh, "barlayout", barlayout);
	  endif
	  if (! strcmpi (get (hh, "horizontal"), horizontal))
	    set (hh, "horizontal", horizontal);
	  endif
	endif
      endfor
      update_data (h, d);
    unwind_protect_cleanup
      recursion = false;
    end_unwind_protect
  endif
endfunction