## Copyright (C) 2011 Konstantinos Poulios
##
## 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} __sync_subplots__ (@address@hidden)
## Undocumented internal function.
## @end deftypefn

## Author: Konstantinos Poulios <address@hidden>
## Created: 2011-03-03

function __sync_subplots__ (h, d, fig)

  ref_axes = h;

  ref_outbox = get (ref_axes, "outerposition");
  ref_outbox(3) = ref_outbox(1) + ref_outbox(3);
  ref_outbox(4) = ref_outbox(2) + ref_outbox(4);
  ref_box = [0 0 1 1];

  l_align = [ref_axes];
  r_align = [ref_axes];
  b_align = [ref_axes];
  t_align = [ref_axes];
  involved = [ref_axes];

  figureunits = get (fig, "units");
  unwind_protect
    set (fig, "units", "pixels");

    kids = get (fig, "children");
    for child = reshape (kids, 1, numel (kids))
      if (child == ref_axes)
        continue;
      endif
      if (strcmp (get (child, "type"), "axes"))
        ## Skip legend and colorbar objects.
        if (strcmp (get (child, "tag"), "legend")
            || strcmp (get (child, "tag"), "colorbar"))
          continue;
        endif
        outpos = get (child, "outerposition");
        l_involved = false;
        b_involved = false;
        r_involved = false;
        t_involved = false;
        if (abs(outpos(1)-ref_outbox(1)) < 1e-5)
          l_align(end+1) = child;
          l_involved = true;
        endif
        if (abs(outpos(2)-ref_outbox(2)) < 1e-5)
          b_align(end+1) = child;
          b_involved = true;
        endif
        if (abs(outpos(1)+outpos(3)-ref_outbox(3)) < 1e-5)
          r_align(end+1) = child;
          r_involved = true;
        endif
        if (abs(outpos(2)+outpos(4)-ref_outbox(4)) < 1e-5)
          t_align(end+1) = child;
          t_involved = true;
        endif
        if (l_involved || b_involved || r_involved || t_involved)
          involved(end+1) = child;
          dellistener (child, "tightinset", "persistent")
          ref_box = subplot_box (child, ref_box, l_involved, ...
                                 b_involved, r_involved, t_involved);
        endif
      endif
    endfor

    l_involved = (length(l_align) > 1);
    b_involved = (length(b_align) > 1);
    r_involved = (length(r_align) > 1);
    t_involved = (length(t_align) > 1);
    if length(involved) > 1
      dellistener (ref_axes, "tightinset", "persistent")
      ref_box = subplot_box (ref_axes, ref_box, l_involved, ...
                             b_involved, r_involved, t_involved);
    endif

    if (l_involved)
      for ax = l_align
        outpos = get (ax, "outerposition");
        lins = get (ax, "looseinset");
        lins(1) = (ref_box(1)-outpos(1))/outpos(3);
        set (ax, "looseinset", lins)
      endfor
    endif
    if (b_involved)
      for ax = b_align
        outpos = get (ax, "outerposition");
        lins = get (ax, "looseinset");
        lins(2) = (ref_box(2)-outpos(2))/outpos(4);
        set (ax, "looseinset", lins)
      endfor
    endif
    if (r_involved)
      for ax = r_align
        outpos = get (ax, "outerposition");
        lins = get (ax, "looseinset");
        lins(3) = (outpos(1)+outpos(3)-ref_box(3))/outpos(3);
        set (ax, "looseinset", lins)
      endfor
    endif
    if (t_involved)
      for ax = t_align
        outpos = get (ax, "outerposition");
        lins = get (ax, "looseinset");
        lins(4) = (outpos(2)+outpos(4)-ref_box(4))/outpos(4);
        set (ax, "looseinset", lins)
      endfor
    endif

    if length(involved) > 1
      addlistener (ref_axes, "tightinset", address@hidden, fig},
                   "persistent")
      for ax = involved
        addlistener (ax, "tightinset", address@hidden, fig},
                     "persistent")
      endfor
    endif

  unwind_protect_cleanup
    set (fig, "units", figureunits);
  end_unwind_protect

endfunction

function box = subplot_box (ax, box0, left, bottom, right, top)

  lins = get (ax, "looseinset");
  if (left)
    lins(1) = 0.;
  endif
  if (bottom)
    lins(2) = 0.;
  endif
  if (right)
    lins(3) = 0.;
  endif
  if (top)
    lins(4) = 0.;
  endif
  set (ax, "looseinset", lins);
  pos = get (ax, "position");

  if (left)
    box0(1) = max(box0(1), pos(1));
  endif
  if (bottom)
    box0(2) = max(box0(2), pos(2));
  endif
  if (right)
    box0(3) = min(box0(3), pos(1)+pos(3));
  endif
  if (top)
    box0(4) = min(box0(4), pos(2)+pos(4));
  endif

  box = box0;

endfunction