// Copyright (C) 2000-2007, Luca Padovani <padovani@sti.uniurb.it>.
// 
// This file is part of GtkMathView, a flexible, high-quality rendering
// engine for MathML documents.
// 
// GtkMathView is free software; you can redistribute it and/or modify it
// under the terms of the GNU Lesser General Public License as published
// by the Free Software Foundation; either version 3 of the License, or
// (at your option) any later version.
// 
// GtkMathView 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
// Lesser General Public License for more details.
// 
// You should have received a copy of the GNU Lesser General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

#include <config.h>

#include <cassert>

#include "MathMLElement.hh"
#include "AreaFactory.hh"
#include "ShapingContext.hh"
#include "MathGraphicDevice.hh"
#include "ShaperManager.hh"
#include "SpaceShaper.hh"

struct FixedSpaceData
{
  Char16 ch;
  int space;
} fixedSpaceMap[] = {
  { 0x0009, 9 * 8 }, // Tab
  { 0x0020,  9 }, // Space
  { 0x00a0,  9 }, // NonBreakingSpace
  { 0x2000,  9 }, // EN QUAD
  { 0x2001, 18 }, // EM QUAD
  { 0x2002,  9 }, // EN SPACE (HALF AN EM)
  { 0x2003, 18 }, // EM SPACE 
  { 0x2004,  6 }, // THREE-PER-EM SPACE (THICK SPACE)
  { 0x2005,  4 }, // FOUR-PER-EM SPACE (MID SPACE)
  { 0x2006,  3 }, // SIX-PER-EM SPACE (THIN SPACE)
  { 0x2009,  3 }, // THIN SPACE
  { 0x200a,  1 }, // HAIR SPACE (VERY THIN SPACE)
  { 0x200b,  0 }, // ZERO-WIDTH SPACE
  { 0x205f,  4 }, // MEDIUM MATH SPACE

  { 0x0000,  0 }
};

void
SpaceShaper::registerShaper(const SmartPtr<ShaperManager>& sm, unsigned shaperId)
{
  assert(sm);

  for (unsigned i = 0; fixedSpaceMap[i].ch; i++)
    sm->registerChar(fixedSpaceMap[i].ch, GlyphSpec(shaperId, 0, i));
}

void
SpaceShaper::unregisterShaper(const SmartPtr<ShaperManager>&, unsigned)
{
  // nothing to do???
}

void
SpaceShaper::shape(ShapingContext& context) const
{
  assert(!context.done());
  shapeFixedSpace(context, context.getSpec());
}

void
SpaceShaper::pushSpace(ShapingContext& context, int space, unsigned n)
{
  assert(n > 0);
  const SmartPtr<AreaFactory> factory = context.getFactory();
  std::vector<AreaRef> content;
  content.reserve(2);
  content.push_back(factory->verticalSpace(scaled::zero(), scaled::zero()));
  content.push_back(factory->horizontalSpace(context.getSize() * space / 18));  
  context.pushArea(n, factory->glyphWrapper(factory->horizontalArray(content), n));
}

void
SpaceShaper::shapeFixedSpace(ShapingContext& context, const GlyphSpec& spec)
{
  unsigned n = 1;
  assert(spec.getGlyphId() < sizeof(fixedSpaceMap) / sizeof(FixedSpaceData));
  assert(context.thisChar() == fixedSpaceMap[spec.getGlyphId()].ch);
  int space = fixedSpaceMap[spec.getGlyphId()].space;
  if (context.nextChar() == 0xfe00)
    {
      space = -space;
      n++;
    }
  pushSpace(context, space, n);
}