text: /*
   * Copyright (C) 2016 Igalia S.L. All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in the
   *    documentation and/or other materials provided with the distribution.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
   * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
   * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
   * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
   * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
   * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
   * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  
  #include "config.h"
  #include "MathMLStyle.h"
  
  #if ENABLE(MATHML)
  
  #include "MathMLElement.h"
  #include "MathMLNames.h"
  #include "RenderMathMLBlock.h"
  #include "RenderMathMLFraction.h"
  #include "RenderMathMLMath.h"
  #include "RenderMathMLRoot.h"
  #include "RenderMathMLScripts.h"
  #include "RenderMathMLToken.h"
  #include "RenderMathMLUnderOver.h"
  
  namespace WebCore {
  
  using namespace MathMLNames;
  
  Ref<MathMLStyle> MathMLStyle::create()
  {
      return adoptRef(*new MathMLStyle());
  }
  
  const MathMLStyle* MathMLStyle::getMathMLStyle(RenderObject* renderer)
  {
      // FIXME: Should we make RenderMathMLTable derive from RenderMathMLBlock in order to simplify this?
      if (is<RenderMathMLTable>(renderer))
          return &downcast<RenderMathMLTable>(*renderer).mathMLStyle();
      if (is<RenderMathMLBlock>(renderer))
          return &downcast<RenderMathMLBlock>(*renderer).mathMLStyle();
      return nullptr;
  }
  
  void MathMLStyle::resolveMathMLStyleTree(RenderObject* renderer)
  {
      for (auto* child = renderer; child; child = child->nextInPreOrder(renderer)) {
          // FIXME: Should we make RenderMathMLTable derive from RenderMathMLBlock in order to simplify this?
          if (is<RenderMathMLTable>(child))
              downcast<RenderMathMLTable>(*child).mathMLStyle().resolveMathMLStyle(child);
          else if (is<RenderMathMLBlock>(child))
              downcast<RenderMathMLBlock>(*child).mathMLStyle().resolveMathMLStyle(child);
      }
  }
  
  RenderObject* MathMLStyle::getMathMLParentNode(RenderObject* renderer)
  {
      auto* parentRenderer = renderer->parent();
  
      while (parentRenderer && !(is<RenderMathMLTable>(parentRenderer) || is<RenderMathMLBlock>(parentRenderer)))
          parentRenderer = parentRenderer->parent();
  
      return parentRenderer;
  }
  
  void MathMLStyle::updateStyleIfNeeded(RenderObject* renderer, bool oldDisplayStyle, MathMLElement::MathVariant oldMathVariant)
  {
      // RenderMathMLFencedOperator does not support mathvariant or displaystyle transforms.
      // See https://bugs.webkit.org/show_bug.cgi?id=160509#c1.
      bool isNonAnonymousTokenElement = is<RenderMathMLToken>(renderer) && !renderer->isAnonymous();
  
      if (oldDisplayStyle != m_displayStyle) {
          renderer->setNeedsLayoutAndPrefWidthsRecalc();
          if (isNonAnonymousTokenElement)
              downcast<RenderMathMLToken>(renderer)->updateTokenContent();
          else if (is<RenderMathMLFraction>(renderer))
              downcast<RenderMathMLFraction>(renderer)->updateFromElement();
      }
      if (oldMathVariant != m_mathVariant) {
          if (isNonAnonymousTokenElement)
              downcast<RenderMathMLToken>(renderer)->updateTokenContent();
      }
  }
  
  void MathMLStyle::resolveMathMLStyle(RenderObject* renderer)
  {
      ASSERT(renderer);
  
      bool oldDisplayStyle = m_displayStyle;
      MathMLElement::MathVariant oldMathVariant = m_mathVariant;
      auto* parentRenderer = getMathMLParentNode(renderer);
      const MathMLStyle* parentStyle = getMathMLStyle(parentRenderer);
  
      // By default, we just inherit the style from our parent.
      m_displayStyle = false;
      m_mathVariant = MathMLElement::MathVariant::None;
      if (parentStyle) {
          setDisplayStyle(parentStyle->displayStyle());
          setMathVariant(parentStyle->mathVariant());
      }
  
      // Early return for anonymous renderers.
      if (renderer->isAnonymous()) {
          updateStyleIfNeeded(renderer, oldDisplayStyle, oldMathVariant);
          return;
      }
  
      if (is<RenderMathMLMath>(renderer) || is<RenderMathMLTable>(renderer))
          m_displayStyle = false; // The default displaystyle of <math> and <mtable> is false.
      else if (parentRenderer) {
          if (is<RenderMathMLFraction>(parentRenderer))
              m_displayStyle = false; // <mfrac> sets displaystyle to false within its numerator and denominator.
          else if ((is<RenderMathMLRoot>(parentRenderer) && !parentRenderer->isRenderMathMLSquareRoot()) || is<RenderMathMLScripts>(parentRenderer) || is<RenderMathMLUnderOver>(parentRenderer)) {
              // <mroot>, <msub>, <msup>, <msubsup>, <mmultiscripts>, <munder>, <mover> and <munderover> elements set displaystyle to false within their scripts.
              auto* base = downcast<RenderBox>(parentRenderer)->firstChildBox();
              if (renderer != base)
                  m_displayStyle = false;
          }
      }
  
      // The displaystyle and mathvariant attributes override the default behavior.
      auto* element = downcast<RenderElement>(renderer)->element();
      if (is<MathMLElement>(element)) {
          Optional<bool> displayStyle = downcast<MathMLElement>(element)->specifiedDisplayStyle();
          if (displayStyle)
              m_displayStyle = displayStyle.value();
          Optional<MathMLElement::MathVariant> mathVariant = downcast<MathMLElement>(element)->specifiedMathVariant();
          if (mathVariant)
              m_mathVariant = mathVariant.value();
      }
      updateStyleIfNeeded(renderer, oldDisplayStyle, oldMathVariant);
  }
  
  }
  
  #endif // ENABLE(MATHML)
  