htmldocvisitor.cpp

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/******************************************************************************
 *
 * Copyright (C) 1997-2020 by Dimitri van Heesch.
 *
 * Permission to use, copy, modify, and distribute this software and its
 * documentation under the terms of the GNU General Public License is hereby
 * granted. No representations are made about the suitability of this software
 * for any purpose. It is provided "as is" without express or implied warranty.
 * See the GNU General Public License for more details.
 *
 * Documents produced by Doxygen are derivative works derived from the
 * input used in their production; they are not affected by this license.
 *
 */
 
#include "htmldocvisitor.h"
#include "docparser.h"
#include "language.h"
#include "doxygen.h"
#include "outputgen.h"
#include "outputlist.h"
#include "dot.h"
#include "message.h"
#include "config.h"
#include "htmlgen.h"
#include "parserintf.h"
#include "msc.h"
#include "dia.h"
#include "util.h"
#include "vhdldocgen.h"
#include "filedef.h"
#include "memberdef.h"
#include "htmlentity.h"
#include "emoji.h"
#include "plantuml.h"
#include "mermaid.h"
#include "formula.h"
#include "fileinfo.h"
#include "indexlist.h"
#include "portable.h"
#include "codefragment.h"
#include "cite.h"
#include "md5.h"
 
static const int NUM_HTML_LIST_TYPES = 4;
static const char g_types[][NUM_HTML_LIST_TYPES] = {"1", "a", "i", "A"};
enum class contexts_t
{
    NONE,      // 0
    STARTLI,   // 1
    STARTDD,   // 2
    ENDLI,     // 3
    ENDDD,     // 4
    STARTTD,   // 5
    ENDTD,     // 6
    INTERLI,   // 7
    INTERDD,   // 8
    INTERTD    // 9
};
 
static constexpr const char *contexts(contexts_t type)
{
  switch (type)
  {
    case contexts_t::NONE:    return nullptr;
    case contexts_t::STARTLI: return "startli";
    case contexts_t::STARTDD: return "startdd";
    case contexts_t::ENDLI:   return "endli";
    case contexts_t::ENDDD:   return "enddd";
    case contexts_t::STARTTD: return "starttd";
    case contexts_t::ENDTD:   return "endtd";
    case contexts_t::INTERLI: return "interli";
    case contexts_t::INTERDD: return "interdd";
    case contexts_t::INTERTD: return "intertd";
    default:                  return nullptr;
  }
}
static const char *hex="0123456789ABCDEF";
 
static QCString convertIndexWordToAnchor(const QCString &word)
{
  static int cnt = 0;
  QCString result="a";
  QCString cntStr;
  result += cntStr.setNum(cnt);
  result += "_";
  cnt++;
  const char *str = word.data();
  unsigned char c = 0;
  if (str)
  {
    while ((c = *str++))
    {
      if ((c >= 'a' && c <= 'z') || // ALPHA
          (c >= 'A' && c <= 'Z') || // ALPHA
          (c >= '0' && c <= '9') || // DIGIT
          c == '-' ||
          c == '.'
         )
      {
        result += c;
      }
      else
      {
        char enc[4];
        enc[0] = '_';
        enc[1] = hex[(c & 0xf0) >> 4];
        enc[2] = hex[c & 0xf];
        enc[3] = 0;
        result += enc;
      }
    }
  }
  return result;
}
 
 
 
static bool mustBeOutsideParagraph(const DocNodeVariant &n)
{
  //printf("mustBeOutsideParagraph(%s)=",docNodeName(n));
  if (holds_one_of_alternatives< /* <ul> */          DocHtmlList,   DocSimpleList, DocAutoList,
                                 /* <dl> */          DocSimpleSect, DocParamSect,  DocHtmlDescList, DocXRefItem,
                                 /* <table> */       DocHtmlTable,
                                 /* <h?> */          DocSection,    DocHtmlHeader,
                                 /* \internal */     DocInternal,
                                 /* <div> */         DocInclude,    DocSecRefList,
                                 /* <hr> */          DocHorRuler,
                                 /* <blockquote> */  DocHtmlBlockQuote,
                                 /* \parblock */     DocParBlock,
                                 /* \dotfile */      DocDotFile,
                                 /* \mscfile */      DocMscFile,
                                 /* \diafile */      DocDiaFile,
                                 /* \plantumlfile */ DocPlantUmlFile,
                                 /* \mermaidfile */  DocMermaidFile,
                                 /* <details> */     DocHtmlDetails,
                                 /* <summary> */     DocHtmlSummary,
                                                     DocIncOperator >(n))
  {
    return TRUE;
  }
  const DocVerbatim *dv = std::get_if<DocVerbatim>(&n);
  if (dv)
  {
    DocVerbatim::Type t = dv->type();
    if (t == DocVerbatim::JavaDocCode || t == DocVerbatim::JavaDocLiteral) return FALSE;
    return t!=DocVerbatim::HtmlOnly || dv->isBlock();
  }
  const DocStyleChange *sc = std::get_if<DocStyleChange>(&n);
  if (sc)
  {
    return sc->style()==DocStyleChange::Preformatted ||
           sc->style()==DocStyleChange::Div ||
           sc->style()==DocStyleChange::Center;
  }
  const DocFormula *df = std::get_if<DocFormula>(&n);
  if (df)
  {
    return !df->isInline();
  }
  const DocImage *di = std::get_if<DocImage>(&n);
  if (di)
  {
    return !di->isInlineImage();
  }
  return FALSE;
}
 
static bool isDocVerbatimVisible(const DocVerbatim &s)
{
  switch (s.type())
  {
    case DocVerbatim::ManOnly:
    case DocVerbatim::LatexOnly:
    case DocVerbatim::XmlOnly:
    case DocVerbatim::RtfOnly:
    case DocVerbatim::DocbookOnly:
      return FALSE;
    default:
      return TRUE;
  }
}
 
static bool isDocIncludeVisible(const DocInclude &s)
{
  switch (s.type())
  {
    case DocInclude::DontInclude:
    case DocInclude::LatexInclude:
    case DocInclude::RtfInclude:
    case DocInclude::ManInclude:
    case DocInclude::XmlInclude:
    case DocInclude::DocbookInclude:
      return FALSE;
    default:
      return TRUE;
  }
}
 
static bool isDocIncOperatorVisible(const DocIncOperator &s)
{
  switch (s.type())
  {
    case DocIncOperator::Skip:
      return FALSE;
    default:
      return TRUE;
  }
}
 
static bool isInvisibleNode(const DocNodeVariant &node)
{
  //printf("isInvisibleNode(%s)\n",docNodeName(node));
  // skip over white space
  const DocWhiteSpace *ws = std::get_if<DocWhiteSpace>(&node);
  if (ws) return true;
  // skip over image nodes that are not for HTML output
  const DocImage *di = std::get_if<DocImage>(&node);
  if (di) return di->type()!=DocImage::Html;
  // skip over verbatim nodes that are not visible in the HTML output
  const DocVerbatim *dv = std::get_if<DocVerbatim>(&node);
  if (dv) return !isDocVerbatimVisible(*dv);
  // skip over include nodes that are not visible in the HTML output
  const DocInclude *dinc = std::get_if<DocInclude>(&node);
  if (dinc) return !isDocIncludeVisible(*dinc);
  const DocIncOperator *dio = std::get_if<DocIncOperator>(&node);
  // skip over include operator nodes that are not visible in the HTML output
  if (dio) return !isDocIncOperatorVisible(*dio);
  return false;
}
 
//-------------------------------------------------------------------------
 
HtmlDocVisitor::HtmlDocVisitor(TextStream &t,OutputCodeList &ci,
                               const Definition *ctx,const QCString &fn)
  : m_t(t), m_ci(ci), m_ctx(ctx), m_fileName(fn)
{
  if (ctx) m_langExt=ctx->getDefFileExtension();
}
 
template<class T>
void HtmlDocVisitor::visitCaption(TextStream &t,const T &n)
{
  if (n.hasCaption())
  {
    t << "<div class=\"caption\">\n";
    for (const auto &child : n.children())
    {
      std::visit(*this, child);
    }
    t << "</div>\n";
  }
}
 
  //--------------------------------------
  // visitor functions for leaf nodes
  //--------------------------------------
 
void HtmlDocVisitor::operator()(const DocWord &w)
{
  if (m_hide) return;
  filter(w.word());
}
 
void HtmlDocVisitor::operator()(const DocLinkedWord &w)
{
  if (m_hide) return;
  //printf("linked word: %s\n",qPrint(w.word()));
  startLink(w.ref(),w.file(),w.relPath(),w.anchor(),w.tooltip());
  filter(w.word());
  endLink();
}
 
void HtmlDocVisitor::operator()(const DocWhiteSpace &w)
{
  if (m_hide) return;
  if (m_insidePre)
  {
    m_t << w.chars();
  }
  else
  {
    m_t << " ";
  }
}
 
void HtmlDocVisitor::operator()(const DocSymbol &s)
{
  if (m_hide) return;
  if (m_insideTitle &&
      (s.symbol()==HtmlEntityMapper::Sym_Quot || s.symbol()==HtmlEntityMapper::Sym_quot)) // escape "'s inside title="..."
  {
    m_t << "&quot;";
  }
  else
  {
    const char *res = HtmlEntityMapper::instance().html(s.symbol());
    if (res)
    {
      m_t << res;
    }
    else
    {
      err("HTML: non supported HTML-entity found: {}\n",
          HtmlEntityMapper::instance().html(s.symbol(),TRUE));
    }
  }
}
 
void HtmlDocVisitor::operator()(const DocEmoji &s)
{
  if (m_hide) return;
  const char *res = EmojiEntityMapper::instance().unicode(s.index());
  if (res)
  {
    m_t << "<span class=\"emoji\">" << res << "</span>";
  }
  else
  {
    m_t << s.name();
  }
}
 
void HtmlDocVisitor::writeObfuscatedMailAddress(const QCString &url)
{
  if (!Config_getBool(OBFUSCATE_EMAILS))
  {
    m_t << "<a href=\"mailto:" << url << "\">";
  }
  else
  {
    m_t << "<a href=\"#\" onclick=\"location.href='mai'+'lto:'";
    if (!url.isEmpty())
    {
      const char *p = url.data();
      uint32_t size=3;
      while (*p)
      {
        m_t << "+'";
        for (uint32_t j=0;j<size && *p;j++)
        {
          p = writeUTF8Char(m_t,p);
        }
        m_t << "'";
        if (size==3) size=2; else size=3;
      }
    }
    m_t << "; return false;\">";
  }
}
 
void HtmlDocVisitor::operator()(const DocURL &u)
{
  if (m_hide) return;
  if (u.isEmail()) // mail address
  {
    QCString url = u.url();
    // obfuscate the mail address link
    writeObfuscatedMailAddress(url);
    if (!Config_getBool(OBFUSCATE_EMAILS))
    {
      m_t << url;
    }
    else
    {
      const char *p = url.data();
      // also obfuscate the address as shown on the web page
      uint32_t size=5;
      while (*p)
      {
        for (uint32_t j=0;j<size && *p;j++)
        {
          p = writeUTF8Char(m_t,p);
        }
        if (*p) m_t << "<span class=\"obfuscator\">.nosp@m.</span>";
        if (size==5) size=4; else size=5;
      }
    }
    m_t << "</a>";
  }
  else // web address
  {
    m_t << "<a href=\"";
    filter(u.url());
    m_t << "\">";
    filter(u.url());
    m_t << "</a>";
  }
}
 
void HtmlDocVisitor::operator()(const DocLineBreak &br)
{
  if (m_hide) return;
  m_t << "<br "<< br.attribs().toString() << " />\n";
}
 
void HtmlDocVisitor::operator()(const DocHorRuler &hr)
{
  if (m_hide) return;
  forceEndParagraph(hr);
  m_t << "<hr "<< hr.attribs().toString() << " />\n";
  forceStartParagraph(hr);
}
 
void HtmlDocVisitor::operator()(const DocStyleChange &s)
{
  if (m_hide) return;
  switch (s.style())
  {
    case DocStyleChange::Bold:
      if (s.enable()) m_t << "<b" << s.attribs().toString() << ">";      else m_t << "</b>";
      break;
    case DocStyleChange::S:
      if (s.enable()) m_t << "<s" << s.attribs().toString() << ">";      else m_t << "</s>";
      break;
    case DocStyleChange::Strike:
      if (s.enable()) m_t << "<strike" << s.attribs().toString() << ">"; else m_t << "</strike>";
      break;
    case DocStyleChange::Del:
      if (s.enable()) m_t << "<del" << s.attribs().toString() << ">";    else m_t << "</del>";
      break;
    case DocStyleChange::Underline:
      if (s.enable()) m_t << "<u" << s.attribs().toString() << ">";      else m_t << "</u>";
      break;
    case DocStyleChange::Ins:
      if (s.enable()) m_t << "<ins" << s.attribs().toString() << ">";    else m_t << "</ins>";
      break;
    case DocStyleChange::Italic:
      if (s.enable())
      {
        auto attribs = s.attribs();
        if (s.tagName()=="a")
        {
          attribs.mergeAttribute("class","arg");
        }
        m_t << "<em" << attribs.toString() << ">";
      }
      else
      {
        m_t << "</em>";
      }
      break;
    case DocStyleChange::Kbd:
      if (s.enable()) m_t << "<kbd" << s.attribs().toString() << ">";    else m_t << "</kbd>";
      break;
    case DocStyleChange::Typewriter:
      if (s.enable())
      {
        m_t << "<span class=\"tt\"" << s.attribs().toString() << ">";
        m_insidePre=true;
      }
      else
      {
        m_t << "</span>";
        m_insidePre=false;
      }
      break;
    case DocStyleChange::Code:
      if (s.enable())
      {
        auto attribs = s.attribs();
        if (s.tagName()=="p")
        {
          attribs.mergeAttribute("class","param");
        }
        m_t << "<code" << attribs.toString() << ">";
        m_insidePre=true;
      }
      else
      {
        m_insidePre=false;
        m_t << "</code>";
      }
      break;
    case DocStyleChange::Subscript:
      if (s.enable()) m_t << "<sub" << s.attribs().toString() << ">"; else m_t << "</sub>";
      break;
    case DocStyleChange::Superscript:
      if (s.enable()) m_t << "<sup" << s.attribs().toString() << ">"; else m_t << "</sup>";
      break;
    case DocStyleChange::Center:
      if (s.enable())
      {
        forceEndParagraph(s);
        m_t << "<center" << s.attribs().toString() << ">";
      }
      else
      {
        m_t << "</center>";
        forceStartParagraph(s);
      }
      break;
    case DocStyleChange::Small:
      if (s.enable()) m_t << "<small" << s.attribs().toString() << ">";  else m_t << "</small>";
      break;
    case DocStyleChange::Cite:
      if (s.enable()) m_t << "<cite" << s.attribs().toString() << ">";  else m_t << "</cite>";
      break;
    case DocStyleChange::Preformatted:
      if (s.enable())
      {
        forceEndParagraph(s);
        m_t << "<pre" << s.attribs().toString() << ">";
        m_insidePre=TRUE;
      }
      else
      {
        m_insidePre=FALSE;
        m_t << "</pre>";
        forceStartParagraph(s);
      }
      break;
    case DocStyleChange::Div:
      if (s.enable())
      {
        forceEndParagraph(s);
        m_t << "<div" << s.attribs().toString() << ">";
      }
      else
      {
        m_t << "</div>";
        forceStartParagraph(s);
      }
      break;
    case DocStyleChange::Span:
      if (s.enable()) m_t << "<span" << s.attribs().toString() << ">";  else m_t << "</span>";
      break;
  }
}
 
///--------------------------------------------------------------------------------------
 
void HtmlDocVisitor::operator()(const DocVerbatim &s)
{
  if (m_hide) return;
  QCString lang = m_langExt;
  if (!s.language().isEmpty()) // explicit language setting
  {
    lang = s.language();
  }
  SrcLangExt langExt = getLanguageFromCodeLang(lang);
  switch(s.type())
  {
    case DocVerbatim::Code:
      forceEndParagraph(s);
      m_ci.startCodeFragment("DoxyCode");
      getCodeParser(lang).parseCode(m_ci,
                                        s.context(),
                                        s.text(),
                                        langExt,
                                        Config_getBool(STRIP_CODE_COMMENTS),
                                        CodeParserOptions()
                                        .setExample(s.isExample(), s.exampleFile())
                                        .setInlineFragment(true)
                                        .setSearchCtx(m_ctx)
                                       );
      m_ci.endCodeFragment("DoxyCode");
      forceStartParagraph(s);
      break;
    case DocVerbatim::Verbatim:
      forceEndParagraph(s);
      m_t << "<pre class=\"fragment\">";
      filter(s.text());
      m_t << "</pre>";
      forceStartParagraph(s);
      break;
    case DocVerbatim::JavaDocLiteral:
      filter(s.text(), true);
      break;
    case DocVerbatim::JavaDocCode:
      m_t << "<code class=\"JavaDocCode\">";
      filter(s.text(), true);
      m_t << "</code>";
      break;
    case DocVerbatim::HtmlOnly:
      {
        if (s.isBlock()) forceEndParagraph(s);
        m_t << s.text();
        if (s.isBlock()) forceStartParagraph(s);
      }
      break;
    case DocVerbatim::ManOnly:
    case DocVerbatim::LatexOnly:
    case DocVerbatim::XmlOnly:
    case DocVerbatim::RtfOnly:
    case DocVerbatim::DocbookOnly:
      /* nothing */
      break;
 
    case DocVerbatim::Dot:
      {
        forceEndParagraph(s);
 
        bool exists = false;
        auto fileName = writeFileContents(Config_getString(HTML_OUTPUT)+"/inline_dotgraph_", // baseName
                                          ".dot",                                            // extension
                                          s.text(),                                          // contents
                                          exists);
        if (!fileName.isEmpty())
        {
          m_t << "<div class=\"dotgraph\">\n";
          writeDotFile(fileName,s.relPath(),s.context(),s.srcFile(),s.srcLine(),!exists);
          visitCaption(m_t, s);
          m_t << "</div>\n";
        }
 
        forceStartParagraph(s);
      }
      break;
    case DocVerbatim::Msc:
      {
        forceEndParagraph(s);
 
        bool exists = false;
        auto fileName = writeFileContents(Config_getString(HTML_OUTPUT)+"/inline_mscgraph_", // baseName
                                          ".msc",                                            // extension
                                          "msc {"+s.text()+"}",                              // contents
                                          exists);
        if (!fileName.isEmpty())
        {
          m_t << "<div class=\"mscgraph\">\n";
          writeMscFile(fileName,s.relPath(),s.context(),s.srcFile(),s.srcLine(),!exists);
          visitCaption(m_t, s);
          m_t << "</div>\n";
        }
 
        forceStartParagraph(s);
      }
      break;
    case DocVerbatim::PlantUML:
      {
        forceEndParagraph(s);
        QCString htmlOutput = Config_getString(HTML_OUTPUT);
        QCString imgExt = getDotImageExtension();
        PlantumlManager::OutputFormat format = PlantumlManager::PUML_BITMAP;    // default : PUML_BITMAP
        if (imgExt=="svg")
        {
          format = PlantumlManager::PUML_SVG;
        }
        auto baseNameVector = PlantumlManager::instance().writePlantUMLSource(
                                    htmlOutput,s.exampleFile(),
                                    s.text(),format,s.engine(),s.srcFile(),s.srcLine(),true);
        for (const auto &baseName: baseNameVector)
        {
          m_t << "<div class=\"plantumlgraph\">\n";
          writePlantUMLFile(baseName,s.relPath(),s.context(),s.srcFile(),s.srcLine());
          visitCaption(m_t, s);
          m_t << "</div>\n";
        }
        forceStartParagraph(s);
      }
      break;
    case DocVerbatim::Mermaid:
      {
        forceEndParagraph(s);
        if (Config_getEnum(MERMAID_RENDER_MODE)==MERMAID_RENDER_MODE_t::CLI) // CLI mode: pre-generate image via mmdc
        {
          auto htmlOutput = Config_getString(HTML_OUTPUT);
          auto outputFormat = MermaidManager::OutputFormat::HTML;
          auto imageFormat  = MermaidManager::convertToImageFormat(outputFormat);
          QCString baseName = MermaidManager::instance().writeMermaidSource(
                                      htmlOutput,s.exampleFile(),
                                      s.text(),imageFormat,s.srcFile(),s.srcLine());
          m_t << "<div class=\"mermaidgraph\">\n";
          writeMermaidFile(baseName,s.relPath(),s.context(),s.srcFile(),s.srcLine());
          visitCaption(m_t, s);
          m_t << "</div>\n";
        }
        else // CLIENT_SIDE or AUTO mode: embed for client-side rendering
        {
          m_t << "<div class=\"mermaidgraph\">\n";
          m_t << "<pre class=\"mermaid\">\n";
          m_t << convertToHtml(s.text());
          m_t << "</pre>\n";
          visitCaption(m_t, s);
          m_t << "</div>\n";
        }
        forceStartParagraph(s);
      }
      break;
  }
}
 
void HtmlDocVisitor::operator()(const DocAnchor &anc)
{
  if (m_hide) return;
  m_t << "<a class=\"anchor\" id=\"" << anc.anchor() << "\"" << anc.attribs().toString() << "></a>";
}
 
void HtmlDocVisitor::operator()(const DocInclude &inc)
{
  if (m_hide) return;
  SrcLangExt langExt = getLanguageFromFileName(inc.extension());
  switch(inc.type())
  {
    case DocInclude::Include:
      forceEndParagraph(inc);
      m_ci.startCodeFragment("DoxyCode");
      getCodeParser(inc.extension()).parseCode(m_ci,
                                        inc.context(),
                                        inc.text(),
                                        langExt,
                                        inc.stripCodeComments(),
                                        CodeParserOptions()
                                        .setExample(inc.isExample(), inc.exampleFile())
                                        .setInlineFragment(true)
                                        .setShowLineNumbers(false)
                                        .setSearchCtx(m_ctx)
                                       );
      m_ci.endCodeFragment("DoxyCode");
      forceStartParagraph(inc);
      break;
    case DocInclude::IncWithLines:
      {
         forceEndParagraph(inc);
         m_ci.startCodeFragment("DoxyCode");
         FileInfo cfi( inc.file().str() );
         auto fd = createFileDef( cfi.dirPath(), cfi.fileName() );
         getCodeParser(inc.extension()).parseCode(m_ci,
                                           inc.context(),
                                           inc.text(),
                                           langExt,
                                           inc.stripCodeComments(),
                                           CodeParserOptions()
                                           .setExample(inc.isExample(), inc.exampleFile())
                                           .setFileDef(fd.get())
                                           .setInlineFragment(true)
                                           .setSearchCtx(m_ctx)
                                           );
         m_ci.endCodeFragment("DoxyCode");
         forceStartParagraph(inc);
      }
      break;
    case DocInclude::DontInclude:
    case DocInclude::LatexInclude:
    case DocInclude::RtfInclude:
    case DocInclude::ManInclude:
    case DocInclude::XmlInclude:
    case DocInclude::DocbookInclude:
    case DocInclude::DontIncWithLines:
      break;
    case DocInclude::HtmlInclude:
      {
        if (inc.isBlock()) forceEndParagraph(inc);
        m_t << inc.text();
        if (inc.isBlock()) forceStartParagraph(inc);
      }
      break;
    case DocInclude::VerbInclude:
      forceEndParagraph(inc);
      m_t << "<pre class=\"fragment\">";
      filter(inc.text());
      m_t << "</pre>";
      forceStartParagraph(inc);
      break;
    case DocInclude::Snippet:
    case DocInclude::SnippetWithLines:
      forceEndParagraph(inc);
      m_ci.startCodeFragment("DoxyCode");
      CodeFragmentManager::instance().parseCodeFragment(m_ci,
                                       inc.file(),
                                       inc.blockId(),
                                       inc.context(),
                                       inc.type()==DocInclude::SnippetWithLines,
                                       inc.trimLeft(),
                                       inc.stripCodeComments()
                                      );
      m_ci.endCodeFragment("DoxyCode");
      forceStartParagraph(inc);
      break;
  }
}
 
void HtmlDocVisitor::operator()(const DocIncOperator &op)
{
  //printf("DocIncOperator: type=%d first=%d, last=%d text='%s'\n",
  //    op.type(),op.isFirst(),op.isLast(),qPrint(op.text()));
  if (op.isFirst())
  {
    forceEndParagraph(op);
    if (!m_hide) m_ci.startCodeFragment("DoxyCode");
    pushHidden(m_hide);
    m_hide=TRUE;
  }
  QCString locLangExt = getFileNameExtension(op.includeFileName());
  if (locLangExt.isEmpty()) locLangExt = m_langExt;
  SrcLangExt langExt = getLanguageFromFileName(locLangExt);
  if (op.type()!=DocIncOperator::Skip)
  {
    m_hide = popHidden();
    if (!m_hide)
    {
      std::unique_ptr<FileDef> fd;
      if (!op.includeFileName().isEmpty())
      {
        FileInfo cfi( op.includeFileName().str() );
        fd = createFileDef( cfi.dirPath(), cfi.fileName() );
      }
      getCodeParser(locLangExt).parseCode(
                                m_ci,
                                op.context(),
                                op.text(),
                                langExt,
                                op.stripCodeComments(),
                                CodeParserOptions()
                                .setExample(op.isExample(), op.exampleFile())
                                .setFileDef(fd.get())
                                .setStartLine(op.line())
                                .setShowLineNumbers(op.showLineNo())
                                .setSearchCtx(m_ctx)
                               );
    }
    pushHidden(m_hide);
    m_hide=TRUE;
  }
  if (op.isLast())
  {
    m_hide = popHidden();
    if (!m_hide) m_ci.endCodeFragment("DoxyCode");
    forceStartParagraph(op);
  }
  else
  {
    if (!m_hide) m_t << "\n";
  }
}
 
void HtmlDocVisitor::operator()(const DocFormula &f)
{
  if (m_hide) return;
  bool bDisplay = !f.isInline();
  if (bDisplay)
  {
    forceEndParagraph(f);
    m_t << "<p class=\"formulaDsp\">\n";
  }
 
  if (Config_getBool(USE_MATHJAX))
  {
    QCString text = f.text();
    bool closeInline = FALSE;
    if (!bDisplay && !text.isEmpty() && text.at(0)=='$' &&
                      text.at(text.length()-1)=='$')
    {
      closeInline=TRUE;
      text = text.mid(1,text.length()-2);
      m_t << "\\(";
    }
    else if (!bDisplay && !text.isEmpty())
    {
      closeInline=TRUE;
      m_t << "\\(";
    }
    m_t << convertToHtml(text);
    if (closeInline)
    {
      m_t << "\\)";
    }
  }
  else
  {
    const Formula *formula = FormulaManager::instance().findFormula(f.id());
 
    enum class ImageType { Light, Dark };
    enum class Visibility { Always, Dark, Light, AutoDark, AutoLight };
    auto writeFormula = [&](ImageType imgType,Visibility visibility) -> QCString {
      // see https://chipcullen.com/how-to-have-dark-mode-image-that-works-with-user-choice for the design idea
      TextStream t;
      QCString extension = Config_getEnum(HTML_FORMULA_FORMAT)==HTML_FORMULA_FORMAT_t::svg ? ".svg":".png" ;
      if (visibility==Visibility::AutoDark || visibility==Visibility::AutoLight)
      {
        t << "<picture>";
        t << "<source srcset=\"" << f.relPath() << f.name();
        if (visibility==Visibility::AutoDark)
        {
          t << extension;
          t << "\" media=\"(prefers-color-scheme: light)\"";
        }
        else // AutoLight
        {
          t << "_dark";
          t << extension;
          t << "\" media=\"(prefers-color-scheme: dark)\"";
        }
        t << "/>";
      }
      t << "<img class=\"formula";
      t << (bDisplay ? "Dsp" : "Inl");
      if (visibility==Visibility::Light)     t << " light-mode-visible";
      else if (visibility==Visibility::Dark) t << " dark-mode-visible";
      t << "\" alt=\"" << filterQuotedCdataAttr(f.text()) << "\"" << " src=\"" << f.relPath() << f.name();
      if (imgType==ImageType::Dark) t << "_dark";
      t << extension;
      if (formula && formula->width()!=-1)
      {
        t << "\" width=\"";
        t << formula->width();
      }
      if (formula && formula->height()!=-1)
      {
        t << "\" height=\"";
        t << formula->height();
      }
      t << "\"/>";
      if (visibility==Visibility::AutoDark || visibility==Visibility::AutoLight)
      {
        t << "</picture>";
      }
      return t.str();
    };
 
    auto colorStyle = Config_getEnum(HTML_COLORSTYLE);
    switch(colorStyle)
    {
      case HTML_COLORSTYLE_t::LIGHT:
        m_t << writeFormula(ImageType::Light,Visibility::Always);
        break;
      case HTML_COLORSTYLE_t::DARK:
        m_t << writeFormula(ImageType::Dark, Visibility::Always);
        break;
      case HTML_COLORSTYLE_t::AUTO_LIGHT:
        m_t << writeFormula(ImageType::Light, Visibility::AutoLight);
        break;
      case HTML_COLORSTYLE_t::AUTO_DARK:
        m_t << writeFormula(ImageType::Dark, Visibility::AutoDark);
        break;
      case HTML_COLORSTYLE_t::TOGGLE:
        // write the image twice and use javascript (darkmode_toggle.js) to show only one of them
        m_t << writeFormula(ImageType::Light,Visibility::Light);
        m_t << writeFormula(ImageType::Dark, Visibility::Dark);
        break;
    }
  }
  if (bDisplay)
  {
    m_t << "\n</p>\n";
    forceStartParagraph(f);
  }
}
 
void HtmlDocVisitor::operator()(const DocIndexEntry &e)
{
  QCString anchor = convertIndexWordToAnchor(e.entry());
  if (e.member())
  {
    anchor.prepend(e.member()->anchor()+"_");
  }
  m_t << "<a id=\"" << anchor << "\" name=\"" << anchor << "\"></a>";
  //printf("*** DocIndexEntry: word='%s' scope='%s' member='%s'\n",
  //       qPrint(e.entry()),
  //       e.scope()  ? qPrint(e.scope()->name())  : "<null>",
  //       e.member() ? qPrint(e.member()->name()) : "<null>"
  //      );
  Doxygen::indexList->addIndexItem(e.scope(),e.member(),anchor,e.entry());
}
 
void HtmlDocVisitor::operator()(const DocSimpleSectSep &)
{
  m_t << "</dd>\n";
  m_t << "<dd>\n";
}
 
void HtmlDocVisitor::operator()(const DocCite &cite)
{
  if (m_hide) return;
  auto opt = cite.option();
  if (!cite.file().isEmpty())
  {
    if (!opt.noCite()) startLink(cite.ref(),cite.file(),cite.relPath(),cite.anchor());
    filter(cite.getText());
    if (!opt.noCite()) endLink();
  }
  else
  {
    m_t << "<b>";
    if (!opt.noPar()) filter("[");
    filter(cite.target());
    if (!opt.noPar()) filter("]");
    m_t << "</b>";
  }
}
 
 
//--------------------------------------
// visitor functions for compound nodes
//--------------------------------------
 
 
void HtmlDocVisitor::operator()(const DocAutoList &l)
{
  //printf("DocAutoList::visitPre\n");
  if (m_hide) return;
  forceEndParagraph(l);
  if (l.isEnumList())
  {
    //
    // Do list type based on depth:
    // 1.
    //   a.
    //     i.
    //       A.
    //         1. (repeat)...
    //
    m_t << "<ol type=\"" << g_types[l.depth() % NUM_HTML_LIST_TYPES] << "\">";
  }
  else
  {
    if (l.isCheckedList())
    {
      m_t << "<ul class=\"check\">";
    }
    else
    {
      m_t << "<ul>";
    }
  }
  if (!l.isPreformatted()) m_t << "\n";
  visitChildren(l);
  if (l.isEnumList())
  {
    m_t << "</ol>";
  }
  else
  {
    m_t << "</ul>";
  }
  if (!l.isPreformatted()) m_t << "\n";
  forceStartParagraph(l);
}
 
void HtmlDocVisitor::operator()(const DocAutoListItem &li)
{
  if (m_hide) return;
  switch (li.itemNumber())
  {
    case DocAutoList::Unchecked: // unchecked
      m_t << "<li class=\"unchecked\">";
      break;
    case DocAutoList::Checked_x: // checked with x
    case DocAutoList::Checked_X: // checked with X
      m_t << "<li class=\"checked\">";
      break;
    default:
      m_t << "<li>";
      break;
  }
  visitChildren(li);
  m_t << "</li>";
  if (!li.isPreformatted()) m_t << "\n";
}
 
template<class Node>
static bool holds_value(const Node *val,const DocNodeVariant &v)
{
  bool b = std::visit([&](auto &&x) {
      //printf("holds_value val=%s (%p) v=%s (%p)\n",
      //        docNodeName(*val),(void*)val,docNodeName(v),(void *)&x);
      return val==static_cast<const DocNode*>(&x);
  }, v);
  return b;
}
 
template<class T>
bool isFirstChildNode(const T *parent, const DocPara &node)
{
   return !parent->children().empty() && holds_value(&node,parent->children().front());
}
 
template<class T>
bool isLastChildNode(const T *parent, const DocPara &node)
{
   return !parent->children().empty() && holds_value(&node,parent->children().back());
}
 
bool isSeparatedParagraph(const DocSimpleSect &parent,const DocPara &par)
{
  const DocNodeList &nodes = parent.children();
  auto it = std::find_if(std::begin(nodes),std::end(nodes),[&par](const auto &n) { return holds_value(&par,n); });
  if (it==std::end(nodes)) return FALSE;
  size_t count = parent.children().size();
  auto isSeparator = [](auto &&it_) { return std::get_if<DocSimpleSectSep>(&(*it_))!=nullptr; };
  if (count>1 && it==std::begin(nodes)) // it points to first node
  {
    return isSeparator(std::next(it));
  }
  else if (count>1 && it==std::prev(std::end(nodes))) // it points to last node
  {
    return isSeparator(std::prev(it));
  }
  else if (count>2 && it!=std::begin(nodes) && it!=std::prev(std::end(nodes))) // it points to intermediate node
  {
    return isSeparator(std::prev(it)) && isSeparator(std::next(it));
  }
  return false;
}
 
static contexts_t getParagraphContext(const DocPara &p,bool &isFirst,bool &isLast)
{
  contexts_t t=contexts_t::NONE;
  isFirst=FALSE;
  isLast=FALSE;
  if (p.parent())
  {
    const auto parBlock = std::get_if<DocParBlock>(p.parent());
    if (parBlock)
    {
      // hierarchy: node N -> para -> parblock -> para
      // adapt return value to kind of N
      const DocNodeVariant *p3 = nullptr;
      if (::parent(p.parent()) && ::parent(::parent(p.parent())) )
      {
        p3 = ::parent(::parent(p.parent()));
      }
      isFirst=isFirstChildNode(parBlock,p);
      isLast =isLastChildNode (parBlock,p);
      bool isLI = p3!=nullptr && holds_one_of_alternatives<DocHtmlListItem,DocSecRefItem>(*p3);
      bool isDD = p3!=nullptr && holds_one_of_alternatives<DocHtmlDescData,DocXRefItem,DocSimpleSect>(*p3);
      bool isTD = p3!=nullptr && holds_one_of_alternatives<DocHtmlCell,DocParamList>(*p3);
      t=contexts_t::NONE;
      if (isFirst)
      {
        if (isLI) t=contexts_t::STARTLI; else if (isDD) t=contexts_t::STARTDD; else if (isTD) t=contexts_t::STARTTD;
      }
      if (isLast)
      {
        if (isLI) t=contexts_t::ENDLI;   else if (isDD) t=contexts_t::ENDDD;   else if (isTD) t=contexts_t::ENDTD;
      }
      if (!isFirst && !isLast)
      {
        if (isLI) t=contexts_t::INTERLI; else if (isDD) t=contexts_t::INTERDD; else if (isTD) t=contexts_t::INTERTD;
      }
      return t;
    }
    const auto docAutoListItem = std::get_if<DocAutoListItem>(p.parent());
    if (docAutoListItem)
    {
      isFirst=isFirstChildNode(docAutoListItem,p);
      isLast =isLastChildNode (docAutoListItem,p);
      t=contexts_t::STARTLI; // not used
      return t;
    }
    const auto docSimpleListItem = std::get_if<DocSimpleListItem>(p.parent());
    if (docSimpleListItem)
    {
      isFirst=TRUE;
      isLast =TRUE;
      t=contexts_t::STARTLI; // not used
      return t;
    }
    const auto docParamList = std::get_if<DocParamList>(p.parent());
    if (docParamList)
    {
      isFirst=TRUE;
      isLast =TRUE;
      t=contexts_t::STARTLI; // not used
      return t;
    }
    const auto docHtmlListItem = std::get_if<DocHtmlListItem>(p.parent());
    if (docHtmlListItem)
    {
      isFirst=isFirstChildNode(docHtmlListItem,p);
      isLast =isLastChildNode (docHtmlListItem,p);
      if (isFirst) t=contexts_t::STARTLI;
      if (isLast)  t=contexts_t::ENDLI;
      if (!isFirst && !isLast) t = contexts_t::INTERLI;
      return t;
    }
    const auto docSecRefItem = std::get_if<DocSecRefItem>(p.parent());
    if (docSecRefItem)
    {
      isFirst=isFirstChildNode(docSecRefItem,p);
      isLast =isLastChildNode (docSecRefItem,p);
      if (isFirst) t=contexts_t::STARTLI;
      if (isLast)  t=contexts_t::ENDLI;
      if (!isFirst && !isLast) t = contexts_t::INTERLI;
      return t;
    }
    const auto docHtmlDescData = std::get_if<DocHtmlDescData>(p.parent());
    if (docHtmlDescData)
    {
      isFirst=isFirstChildNode(docHtmlDescData,p);
      isLast =isLastChildNode (docHtmlDescData,p);
      if (isFirst) t=contexts_t::STARTDD;
      if (isLast)  t=contexts_t::ENDDD;
      if (!isFirst && !isLast) t = contexts_t::INTERDD;
      return t;
    }
    const auto docXRefItem = std::get_if<DocXRefItem>(p.parent());
    if (docXRefItem)
    {
      isFirst=isFirstChildNode(docXRefItem,p);
      isLast =isLastChildNode (docXRefItem,p);
      if (isFirst) t=contexts_t::STARTDD;
      if (isLast)  t=contexts_t::ENDDD;
      if (!isFirst && !isLast) t = contexts_t::INTERDD;
      return t;
    }
    const auto docSimpleSect = std::get_if<DocSimpleSect>(p.parent());
    if (docSimpleSect)
    {
      isFirst=isFirstChildNode(docSimpleSect,p);
      isLast =isLastChildNode (docSimpleSect,p);
      if (isFirst) t=contexts_t::STARTDD;
      if (isLast)  t=contexts_t::ENDDD;
      if (isSeparatedParagraph(*docSimpleSect,p))
        // if the paragraph is enclosed with separators it will
        // be included in <dd>..</dd> so avoid addition paragraph
        // markers
      {
        isFirst=isLast=TRUE;
      }
      if (!isFirst && !isLast) t = contexts_t::INTERDD;
      return t;
    }
    const auto docHtmlCell = std::get_if<DocHtmlCell>(p.parent());
    if (docHtmlCell)
    {
      isFirst=isFirstChildNode(docHtmlCell,p);
      isLast =isLastChildNode (docHtmlCell,p);
      if (isFirst) t=contexts_t::STARTTD;
      if (isLast)  t=contexts_t::ENDTD;
      if (!isFirst && !isLast) t = contexts_t::INTERTD;
      return t;
    }
  }
  return t;
}
 
static bool determineIfNeedsTag(const DocPara &p)
{
  bool needsTag = FALSE;
  if (p.parent())
  {
    if (holds_one_of_alternatives<DocSection,
                         DocInternal,
                         DocHtmlListItem,
                         DocHtmlDescData,
                         DocHtmlCell,
                         DocSimpleListItem,
                         DocAutoListItem,
                         DocSimpleSect,
                         DocXRefItem,
                         DocHtmlBlockQuote,
                         DocParBlock,
                         DocHtmlDetails,
                         DocHtmlSummary
                         >(*p.parent()))
    {
      needsTag = TRUE;
    }
    else if (std::get_if<DocRoot>(p.parent()))
    {
      needsTag = !std::get<DocRoot>(*p.parent()).singleLine();
    }
  }
  return needsTag;
}
 
void HtmlDocVisitor::operator()(const DocPara &p)
{
  if (m_hide) return;
 
  //printf("> DocPara\n");
  //dumpDocNodeList(p.children());
 
  bool needsTag = determineIfNeedsTag(p);
  //printf("  needsTag=%d\n",needsTag);
  bool needsTagBefore = needsTag;
  bool needsTagAfter  = needsTag;
 
  // if the first element of a paragraph is something that should be outside of
  // the paragraph (<ul>,<dl>,<table>,..) then that will already started the
  // paragraph and we don't need to do it here
  if (!p.children().empty())
  {
    auto it = std::find_if(std::begin(p.children()),std::end(p.children()),
                           [](const auto &node) { return !isInvisibleNode(node); });
    if (it!=std::end(p.children()))
    {
      const DocNodeVariant &n = *it;
      if (mustBeOutsideParagraph(n))
      {
        needsTagBefore = FALSE;
      }
    }
  }
 
  // check if this paragraph is the first or last or intermediate child of a <li> or <dd>.
  // this allows us to mark the tag with a special class so we can
  // fix the otherwise ugly spacing.
  bool isFirst = false;
  bool isLast  = false;
  contexts_t t = getParagraphContext(p,isFirst,isLast);
  //printf("startPara first=%d last=%d\n",isFirst,isLast);
  if (isFirst && isLast) needsTagBefore=FALSE;
 
  //printf("  needsTagBefore=%d\n",needsTagBefore);
  // write the paragraph tag (if needed)
  if (needsTagBefore)
  {
    if (contexts(t))
      m_t << "<p class=\"" << contexts(t) << "\"" << p.attribs().toString() << ">";
    else
      m_t << "<p" << p.attribs().toString() << ">";
  }
 
  visitChildren(p);
 
  // if the last element of a paragraph is something that should be outside of
  // the paragraph (<ul>,<dl>,<table>) then that will already have ended the
  // paragraph and we don't need to do it here
  if (!p.children().empty())
  {
    auto it = std::prev(std::end(p.children()));
    for (;;)
    {
      const DocNodeVariant &n = *it;
      if (!isInvisibleNode(n))
      {
        if (mustBeOutsideParagraph(n))
        {
          needsTagAfter = FALSE;
        }
        // stop searching if we found a node that is visible
        break;
      }
      if (it==std::begin(p.children()))
      {
        // stop searching if we are at the beginning of the list
        break;
      }
      else
      {
        --it;
      }
    }
  }
 
  //printf("endPara first=%d last=%d\n",isFirst,isLast);
  if (isFirst && isLast) needsTagAfter=FALSE;
 
  //printf("  needsTagAfter=%d\n",needsTagAfter);
  if (needsTagAfter) m_t << "</p>\n";
  //printf("< DocPara\n");
}
 
void HtmlDocVisitor::operator()(const DocRoot &r)
{
  //printf("> DocRoot\n");
  //dumpDocNodeList(r.children());
  visitChildren(r);
  //printf("< DocRoot\n");
}
 
void HtmlDocVisitor::operator()(const DocSimpleSect &s)
{
  if (m_hide) return;
  forceEndParagraph(s);
  m_t << "<dl class=\"section " << s.typeString() << "\"><dt>";
  switch(s.type())
  {
    case DocSimpleSect::See:
      m_t << theTranslator->trSeeAlso(); break;
    case DocSimpleSect::Return:
      m_t << theTranslator->trReturns(); break;
    case DocSimpleSect::Author:
      m_t << theTranslator->trAuthor(TRUE,TRUE); break;
    case DocSimpleSect::Authors:
      m_t << theTranslator->trAuthor(TRUE,FALSE); break;
    case DocSimpleSect::Version:
      m_t << theTranslator->trVersion(); break;
    case DocSimpleSect::Since:
      m_t << theTranslator->trSince(); break;
    case DocSimpleSect::Date:
      m_t << theTranslator->trDate(); break;
    case DocSimpleSect::Note:
      m_t << theTranslator->trNote(); break;
    case DocSimpleSect::Warning:
      m_t << theTranslator->trWarning(); break;
    case DocSimpleSect::Pre:
      m_t << theTranslator->trPrecondition(); break;
    case DocSimpleSect::Post:
      m_t << theTranslator->trPostcondition(); break;
    case DocSimpleSect::Copyright:
      m_t << theTranslator->trCopyright(); break;
    case DocSimpleSect::Invar:
      m_t << theTranslator->trInvariant(); break;
    case DocSimpleSect::Remark:
      m_t << theTranslator->trRemarks(); break;
    case DocSimpleSect::Attention:
      m_t << theTranslator->trAttention(); break;
    case DocSimpleSect::Important:
      m_t << theTranslator->trImportant(); break;
    case DocSimpleSect::User: break;
    case DocSimpleSect::Rcs: break;
    case DocSimpleSect::Unknown:  break;
  }
 
  if (s.title())
  {
    std::visit(*this,*s.title());
  }
  m_t << "</dt><dd>";
  visitChildren(s);
  m_t << "</dd></dl>\n";
  forceStartParagraph(s);
}
 
void HtmlDocVisitor::operator()(const DocTitle &t)
{
  if (m_hide) return;
  visitChildren(t);
}
 
void HtmlDocVisitor::operator()(const DocSimpleList &sl)
{
  if (m_hide) return;
  forceEndParagraph(sl);
  m_t << "<ul>";
  if (!sl.isPreformatted()) m_t << "\n";
  visitChildren(sl);
  m_t << "</ul>";
  if (!sl.isPreformatted()) m_t << "\n";
  forceStartParagraph(sl);
}
 
void HtmlDocVisitor::operator()(const DocSimpleListItem &li)
{
  if (m_hide) return;
  m_t << "<li>";
  if (li.paragraph())
  {
    visit(*this,*li.paragraph());
  }
  m_t << "</li>";
  if (!li.isPreformatted()) m_t << "\n";
}
 
void HtmlDocVisitor::operator()(const DocSection &s)
{
  if (m_hide) return;
  forceEndParagraph(s);
  m_t << "<h" << s.level() << " class=\"doxsection\">";
  m_t << "<a class=\"anchor\" id=\"" << s.anchor();
  m_t << "\"></a>\n";
  if (s.title())
  {
    std::visit(*this,*s.title());
  }
  m_t << "</h" << s.level() << ">\n";
  visitChildren(s);
  forceStartParagraph(s);
}
 
void HtmlDocVisitor::operator()(const DocHtmlList &s)
{
  if (m_hide) return;
  forceEndParagraph(s);
  if (s.type()==DocHtmlList::Ordered)
  {
    m_t << "<ol" << s.attribs().toString();
  }
  else
  {
    m_t << "<ul" << s.attribs().toString();
  }
  m_t << ">\n";
  visitChildren(s);
  if (s.type()==DocHtmlList::Ordered)
  {
    m_t << "</ol>";
  }
  else
  {
    m_t << "</ul>";
  }
  if (!s.isPreformatted()) m_t << "\n";
  forceStartParagraph(s);
}
 
void HtmlDocVisitor::operator()(const DocHtmlListItem &i)
{
  if (m_hide) return;
  m_t << "<li" << i.attribs().toString() << ">";
  if (!i.isPreformatted()) m_t << "\n";
  visitChildren(i);
  m_t << "</li>\n";
}
 
void HtmlDocVisitor::operator()(const DocHtmlDescList &dl)
{
  if (m_hide) return;
  forceEndParagraph(dl);
  m_t << "<dl" << dl.attribs().toString() << ">\n";
  visitChildren(dl);
  m_t << "</dl>\n";
  forceStartParagraph(dl);
}
 
void HtmlDocVisitor::operator()(const DocHtmlDescTitle &dt)
{
  if (m_hide) return;
  m_t << "<dt" << dt.attribs().toString() << ">";
  visitChildren(dt);
  m_t << "</dt>\n";
}
 
void HtmlDocVisitor::operator()(const DocHtmlDescData &dd)
{
  if (m_hide) return;
  m_t << "<dd" << dd.attribs().toString() << ">";
  visitChildren(dd);
  m_t << "</dd>\n";
}
 
void HtmlDocVisitor::operator()(const DocHtmlTable &t)
{
  if (m_hide) return;
 
  forceEndParagraph(t);
 
  if (t.caption())
  {
    QCString anc = std::get<DocHtmlCaption>(*t.caption()).anchor();
    if (!anc.isEmpty())
    {
      m_t << "<a class=\"anchor\" id=\"" << anc << "\"></a>\n";
    }
  }
 
  QCString attrs = t.attribs().toString();
  if (attrs.isEmpty())
  {
    m_t << "<table class=\"doxtable\">\n";
  }
  else
  {
    m_t << "<table" << t.attribs().toString() << ">\n";
  }
  if (t.caption())
  {
    std::visit(*this,*t.caption());
  }
  visitChildren(t);
  m_t << "</table>\n";
  forceStartParagraph(t);
}
 
void HtmlDocVisitor::operator()(const DocHtmlRow &tr)
{
  if (m_hide) return;
  m_t << "<tr" << tr.attribs().toString() << ">\n";
  visitChildren(tr);
  m_t << "</tr>\n";
}
 
void HtmlDocVisitor::operator()(const DocHtmlCell &c)
{
  if (m_hide) return;
  if (c.isHeading())
  {
    m_t << "<th" << c.attribs().toString() << ">";
  }
  else
  {
    m_t << "<td" << c.attribs().toString() << ">";
  }
  visitChildren(c);
  if (c.isHeading()) m_t << "</th>"; else m_t << "</td>";
}
 
void HtmlDocVisitor::operator()(const DocHtmlCaption &c)
{
  if (m_hide) return;
  m_t << "<caption" << c.attribs().toString() << ">";
  visitChildren(c);
  m_t << "</caption>\n";
}
 
void HtmlDocVisitor::operator()(const DocInternal &i)
{
  if (m_hide) return;
  visitChildren(i);
}
 
void HtmlDocVisitor::operator()(const DocHRef &href)
{
  if (m_hide) return;
  if (href.url().startsWith("mailto:"))
  {
    writeObfuscatedMailAddress(href.url().mid(7));
  }
  else
  {
    QCString url = correctURL(href.url(),href.relPath());
    m_t << "<a href=\"" << convertToHtml(url)  << "\""
        << href.attribs().toString() << ">";
  }
  visitChildren(href);
  m_t << "</a>";
}
 
void HtmlDocVisitor::operator()(const DocHtmlSummary &s)
{
  if (m_hide) return;
  m_t << "<summary " << s.attribs().toString() << ">\n";
  visitChildren(s);
  m_t << "</summary>\n";
}
 
void HtmlDocVisitor::operator()(const DocHtmlDetails &d)
{
  if (m_hide) return;
  forceEndParagraph(d);
  m_t << "<details " << d.attribs().toString() << ">\n";
  auto summary = d.summary();
  if (summary)
  {
    std::visit(*this,*summary);
  }
  visitChildren(d);
  m_t << "</details>\n";
  forceStartParagraph(d);
}
 
void HtmlDocVisitor::operator()(const DocHtmlHeader &header)
{
  if (m_hide) return;
  forceEndParagraph(header);
  m_t << "<h" << header.level() << header.attribs().toString() << ">";
  visitChildren(header);
  m_t << "</h" << header.level() << ">\n";
  forceStartParagraph(header);
}
 
void HtmlDocVisitor::operator()(const DocImage &img)
{
  if (img.type()==DocImage::Html)
  {
    bool inlineImage = img.isInlineImage();
    bool typeSVG = img.isSVG();
    QCString url = img.url();
 
    if (!inlineImage)
    {
      forceEndParagraph(img);
    }
    if (m_hide) return;
    QCString baseName=stripPath(img.name());
    if (!inlineImage) m_t << "<div class=\"image\">\n";
    QCString sizeAttribs;
    if (!img.width().isEmpty())
    {
      sizeAttribs+=" width=\""+img.width()+"\"";
    }
    if (!img.height().isEmpty()) // link to local file
    {
      sizeAttribs+=" height=\""+img.height()+"\"";
    }
    // 16 cases: url.isEmpty() | typeSVG | inlineImage | img.hasCaption()
 
    HtmlAttribList attribs = img.attribs();
    if (typeSVG)
    {
      attribs.mergeAttribute("style","pointer-events: none;");
    }
    QCString alt;
    QCString attrs = attribs.toString(&alt);
    QCString src;
    if (url.isEmpty())
    {
      src = img.relPath()+img.name();
    }
    else
    {
      src = correctURL(url,img.relPath());
    }
    if (typeSVG && !inlineImage && !src.startsWith("http://") && !src.startsWith("https://"))
    {
      m_t << "<object type=\"image/svg+xml\" data=\"" << convertToHtml(src)
        << "\"" << sizeAttribs << attrs;
      if (inlineImage)
      {
        // skip closing tag
      }
      else
      {
        m_t << ">" << alt << "</object>\n";
      }
    }
    else
    {
      m_t << "<img src=\"" << convertToHtml(src) << "\" alt=\"" << alt << "\"" << sizeAttribs << attrs;
      if (inlineImage)
      {
        m_t << " class=\"inline\"";
      }
      else
      {
        m_t << "/>\n";
      }
    }
    if (img.hasCaption())
    {
      if (inlineImage)
      {
        m_t << " title=\"";
        m_insideTitle=true;
      }
      else
      {
        m_t << "<div class=\"caption\">\n";
      }
    }
    else if (inlineImage)
    {
      m_t << "/>";
    }
 
    visitChildren(img);
 
    if (img.hasCaption())
    {
      if (inlineImage)
      {
        m_t << "\"/>";
        m_insideTitle=false;
      }
      else // end <div class="caption">
      {
        m_t << "</div>";
      }
    }
    if (!inlineImage) // end <div class="image">
    {
      m_t << "</div>\n";
      forceStartParagraph(img);
    }
  }
  else // other format -> skip
  {
  }
}
 
void HtmlDocVisitor::operator()(const DocDotFile &df)
{
  if (m_hide) return;
  forceEndParagraph(df);
  bool exists = false;
  std::string inBuf;
  if (readInputFile(df.file(),inBuf))
  {
    auto fileName = writeFileContents(Config_getString(HTML_OUTPUT)+"/"+stripPath(df.file())+"_", // baseName
                                      ".dot",                                                     // extension
                                      inBuf,                                                      // contents
                                      exists);
    if (!fileName.isEmpty())
    {
      m_t << "<div class=\"dotgraph\">\n";
      writeDotFile(fileName,df.relPath(),df.context(),df.srcFile(),df.srcLine(),!exists);
      if (df.hasCaption())
      {
        m_t << "<div class=\"caption\">\n";
      }
      visitChildren(df);
      if (df.hasCaption())
      {
        m_t << "</div>\n";
      }
      m_t << "</div>\n";
  }
  }
  forceStartParagraph(df);
}
 
void HtmlDocVisitor::operator()(const DocMscFile &df)
{
  if (m_hide) return;
  forceEndParagraph(df);
  bool exists = false;
  std::string inBuf;
  if (readInputFile(df.file(),inBuf))
  {
    auto fileName = writeFileContents(Config_getString(HTML_OUTPUT)+"/"+stripPath(df.file())+"_", // baseName
                                      ".msc",                                                     // extension
                                      inBuf,                                                      // contents
                                      exists);
    if (!fileName.isEmpty())
    {
      m_t << "<div class=\"mscgraph\">\n";
      writeMscFile(fileName,df.relPath(),df.context(),df.srcFile(),df.srcLine(),!exists);
      if (df.hasCaption())
      {
        m_t << "<div class=\"caption\">\n";
      }
      visitChildren(df);
      if (df.hasCaption())
      {
        m_t << "</div>\n";
      }
      m_t << "</div>\n";
    }
  }
  forceStartParagraph(df);
}
 
void HtmlDocVisitor::operator()(const DocDiaFile &df)
{
  if (m_hide) return;
  forceEndParagraph(df);
  bool exists = false;
  std::string inBuf;
  if (readInputFile(df.file(),inBuf))
  {
    auto fileName = writeFileContents(Config_getString(HTML_OUTPUT)+"/"+stripPath(df.file())+"_", // baseName
                                      ".dia",                                                     // extension
                                      inBuf,                                                      // contents
                                      exists);
    if (!fileName.isEmpty())
    {
      m_t << "<div class=\"diagraph\">\n";
      writeDiaFile(fileName,df.relPath(),df.context(),df.srcFile(),df.srcLine(),!exists);
      if (df.hasCaption())
      {
        m_t << "<div class=\"caption\">\n";
      }
      visitChildren(df);
      if (df.hasCaption())
      {
        m_t << "</div>\n";
      }
      m_t << "</div>\n";
    }
  }
  forceStartParagraph(df);
}
 
void HtmlDocVisitor::operator()(const DocPlantUmlFile &df)
{
  if (m_hide) return;
  if (!Config_getBool(DOT_CLEANUP)) copyFile(df.file(),Config_getString(HTML_OUTPUT)+"/"+stripPath(df.file()));
  forceEndParagraph(df);
  QCString htmlOutput = Config_getString(HTML_OUTPUT);
  QCString imgExt = getDotImageExtension();
  PlantumlManager::OutputFormat format = PlantumlManager::PUML_BITMAP;  // default : PUML_BITMAP
  if (imgExt=="svg")
  {
    format = PlantumlManager::PUML_SVG;
  }
  std::string inBuf;
  readInputFile(df.file(),inBuf);
  auto baseNameVector = PlantumlManager::instance().writePlantUMLSource(htmlOutput,QCString(),
                                    inBuf,format,QCString(),df.srcFile(),df.srcLine(),false);
  for (const auto &bName: baseNameVector)
  {
    QCString baseName=makeBaseName(bName,".pu");
    m_t << "<div class=\"plantumlgraph\">\n";
    writePlantUMLFile(baseName,df.relPath(),QCString(),df.srcFile(),df.srcLine());
    if (df.hasCaption())
    {
      m_t << "<div class=\"caption\">\n";
    }
    visitChildren(df);
    if (df.hasCaption())
    {
      m_t << "</div>\n";
    }
    m_t << "</div>\n";
  }
  forceStartParagraph(df);
}
 
void HtmlDocVisitor::operator()(const DocMermaidFile &df)
{
  if (m_hide) return;
  if (!Config_getBool(DOT_CLEANUP)) copyFile(df.file(),Config_getString(HTML_OUTPUT)+"/"+stripPath(df.file()));
  forceEndParagraph(df);
  if (Config_getEnum(MERMAID_RENDER_MODE)==MERMAID_RENDER_MODE_t::CLI)
  {
    std::string inBuf;
    readInputFile(df.file(),inBuf);
    auto htmlOutput   = Config_getString(HTML_OUTPUT);
    auto outputFormat = MermaidManager::OutputFormat::HTML;
    auto imageFormat  = MermaidManager::convertToImageFormat(outputFormat);
    QCString baseName = MermaidManager::instance().writeMermaidSource(htmlOutput,QCString(),
                                      inBuf,imageFormat,df.srcFile(),df.srcLine());
    m_t << "<div class=\"mermaidgraph\">\n";
    writeMermaidFile(baseName,df.relPath(),QCString(),df.srcFile(),df.srcLine());
    if (df.hasCaption())
    {
      m_t << "<div class=\"caption\">\n";
    }
    visitChildren(df);
    if (df.hasCaption())
    {
      m_t << "</div>\n";
    }
    m_t << "</div>\n";
  }
  else // AUTO or CLIENT_SIDE
  {
    // CLIENT_SIDE or AUTO: embed mermaid source for client-side rendering
    std::string inBuf;
    readInputFile(df.file(),inBuf);
    m_t << "<div class=\"mermaidgraph\">\n";
    m_t << "<pre class=\"mermaid\">\n";
    m_t << convertToHtml(inBuf);
    m_t << "</pre>\n";
    if (df.hasCaption())
    {
      m_t << "<div class=\"caption\">\n";
    }
    visitChildren(df);
    if (df.hasCaption())
    {
      m_t << "</div>\n";
    }
    m_t << "</div>\n";
  }
  forceStartParagraph(df);
}
 
void HtmlDocVisitor::operator()(const DocLink &lnk)
{
  if (m_hide) return;
  startLink(lnk.ref(),lnk.file(),lnk.relPath(),lnk.anchor());
  visitChildren(lnk);
  endLink();
}
 
void HtmlDocVisitor::operator()(const DocRef &ref)
{
  if (m_hide) return;
  if (!ref.file().isEmpty())
  {
    // when ref.isSubPage()==TRUE we use ref.file() for HTML and
    // ref.anchor() for LaTeX/RTF
    startLink(ref.ref(),ref.file(),ref.relPath(),ref.isSubPage() ? QCString() : ref.anchor(), ref.targetTitle());
  }
  if (!ref.hasLinkText()) filter(ref.targetTitle());
  visitChildren(ref);
  if (!ref.file().isEmpty()) endLink();
  //m_t << " ";
}
 
void HtmlDocVisitor::operator()(const DocSecRefItem &ref)
{
  if (m_hide) return;
  if (!ref.file().isEmpty())
  {
    m_t << "<li>";
    startLink(ref.ref(),ref.file(),ref.relPath(),ref.isSubPage() ? QCString() : ref.anchor());
  }
  visitChildren(ref);
  if (!ref.file().isEmpty())
  {
    endLink();
    m_t << "</li>\n";
  }
}
 
void HtmlDocVisitor::operator()(const DocSecRefList &s)
{
  if (m_hide) return;
  forceEndParagraph(s);
  m_t << "<div>\n";
  m_t << "<ul class=\"multicol\">\n";
  visitChildren(s);
  m_t << "</ul>\n";
  m_t << "</div>\n";
  forceStartParagraph(s);
}
 
void HtmlDocVisitor::operator()(const DocParamSect &s)
{
  if (m_hide) return;
  forceEndParagraph(s);
  QCString className;
  QCString heading;
  switch(s.type())
  {
    case DocParamSect::Param:
      heading=theTranslator->trParameters();
      className="params";
      break;
    case DocParamSect::RetVal:
      heading=theTranslator->trReturnValues();
      className="retval";
      break;
    case DocParamSect::Exception:
      heading=theTranslator->trExceptions();
      className="exception";
      break;
    case DocParamSect::TemplateParam:
      heading=theTranslator->trTemplateParameters();
      className="tparams";
      break;
    default:
      ASSERT(0);
  }
  m_t << "<dl class=\"" << className << "\"><dt>";
  m_t << heading;
  m_t << "</dt><dd>\n";
  m_t << "  <table class=\"" << className << "\">\n";
  visitChildren(s);
  m_t << "  </table>\n";
  m_t << "  </dd>\n";
  m_t << "</dl>\n";
  forceStartParagraph(s);
}
 
void HtmlDocVisitor::operator()(const DocSeparator &s)
{
  if (m_hide) return;
  m_t << "&#160;" << s.chars() << "&#160;";
}
 
void HtmlDocVisitor::operator()(const DocParamList &pl)
{
  //printf("DocParamList::visitPre\n");
  if (m_hide) return;
  m_t << "    <tr>";
  const DocParamSect *sect = std::get_if<DocParamSect>(pl.parent());
  if (sect && sect->hasInOutSpecifier())
  {
    m_t << "<td class=\"paramdir\">";
    if (pl.direction()!=DocParamSect::Unspecified)
    {
      m_t << "[";
      if (pl.direction()==DocParamSect::In)
      {
        m_t << "in";
      }
      else if (pl.direction()==DocParamSect::Out)
      {
        m_t << "out";
      }
      else if (pl.direction()==DocParamSect::InOut)
      {
        m_t << "in,out";
      }
      m_t << "]";
    }
    m_t << "</td>";
  }
  if (sect && sect->hasTypeSpecifier())
  {
    m_t << "<td class=\"paramtype\">";
    for (const auto &type : pl.paramTypes())
    {
      std::visit(*this,type);
    }
    m_t << "</td>";
  }
  m_t << "<td class=\"paramname\">";
  bool first=TRUE;
  for (const auto &param : pl.parameters())
  {
    if (!first) m_t << ","; else first=FALSE;
    std::visit(*this,param);
  }
  m_t << "</td><td>";
  for (const auto &par : pl.paragraphs())
  {
    std::visit(*this,par);
  }
  m_t << "</td></tr>\n";
}
 
void HtmlDocVisitor::operator()(const DocXRefItem &x)
{
  if (m_hide) return;
  if (x.title().isEmpty()) return;
 
  forceEndParagraph(x);
  bool anonymousEnum = x.file()=="@";
  if (!anonymousEnum)
  {
    QCString fn = x.file();
    addHtmlExtensionIfMissing(fn);
    m_t << "<dl class=\"" << x.key() << "\"><dt><b><a class=\"el\" href=\""
        << x.relPath() << fn
        << "#" << x.anchor() << "\">";
  }
  else
  {
    m_t << "<dl class=\"" << x.key() << "\"><dt><b>";
  }
  filter(x.title());
  if (!anonymousEnum) m_t << "</a>";
  m_t << "</b></dt><dd>";
  visitChildren(x);
  if (x.title().isEmpty()) return;
  m_t << "</dd></dl>\n";
  forceStartParagraph(x);
}
 
void HtmlDocVisitor::operator()(const DocInternalRef &ref)
{
  if (m_hide) return;
  startLink(QCString(),ref.file(),ref.relPath(),ref.anchor());
  visitChildren(ref);
  endLink();
  m_t << " ";
}
 
void HtmlDocVisitor::operator()(const DocText &t)
{
  visitChildren(t);
}
 
void HtmlDocVisitor::operator()(const DocHtmlBlockQuote &b)
{
  if (m_hide) return;
  forceEndParagraph(b);
  m_t << "<blockquote class=\"doxtable\"" << b.attribs().toString() << ">\n";
  visitChildren(b);
  m_t << "</blockquote>\n";
  forceStartParagraph(b);
}
 
void HtmlDocVisitor::operator()(const DocVhdlFlow &vf)
{
  if (m_hide) return;
  if (VhdlDocGen::getFlowMember()) // use VHDL flow chart creator
  {
    forceEndParagraph(vf);
    QCString fname=FlowChart::convertNameToFileName();
    m_t << "<p>";
    m_t << theTranslator->trFlowchart();
    m_t << " ";
    m_t << "<a href=\"";
    m_t << fname;
    m_t << ".svg\">";
    m_t << VhdlDocGen::getFlowMember()->name();
    m_t << "</a>";
    if (vf.hasCaption())
    {
      m_t << "<br />";
    }
  }
  visitChildren(vf);
  if (VhdlDocGen::getFlowMember()) // use VHDL flow chart creator
  {
    m_t << "</p>";
    forceStartParagraph(vf);
  }
}
 
void HtmlDocVisitor::operator()(const DocParBlock &pb)
{
  if (m_hide) return;
  visitChildren(pb);
}
 
void HtmlDocVisitor::filter(const QCString &str, const bool retainNewline)
{
  if (str.isEmpty()) return;
  const char *p=str.data();
  while (*p)
  {
    char c=*p++;
    switch(c)
    {
      case '\n': if(retainNewline) m_t << "<br/>"; m_t << c; break;
      case '<':  m_t << "&lt;"; break;
      case '>':  m_t << "&gt;"; break;
      case '&':  m_t << "&amp;"; break;
      case '\\':
        if ((*p == '(') || (*p == ')') || (*p == '[') || (*p == ']'))
          m_t << "\\&zwj;" << *p++;
        else
          m_t << c;
        break;
      default:
        {
          uint8_t uc = static_cast<uint8_t>(c);
          if (uc<32 && !isspace(c)) // non-printable control characters
          {
            m_t << "&#x24" << hex[uc>>4] << hex[uc&0xF] << ";";
          }
          else
          {
            m_t << c;
          }
        }
        break;
    }
  }
}
 
/// Escape basic entities to produce a valid CDATA attribute value,
/// assume that the outer quoting will be using the double quote &quot;
QCString HtmlDocVisitor::filterQuotedCdataAttr(const QCString &str)
{
  if (str.isEmpty()) return str;
  QCString result;
  result.reserve(str.length()+8);
  const char *p=str.data();
  while (*p)
  {
    char c=*p++;
    switch(c)
    {
      case '&':  result+="&amp;"; break;
      case '"':  result+="&quot;"; break;
      case '<':  result+="&lt;"; break;
      case '>':  result+="&gt;"; break;
      case '\\':
        if ((*p == '(') || (*p == ')') || (*p == '[') || (*p == ']'))
        {
          result+="\\&zwj;";
          result+=*p++;
        }
        else
        {
          result+=c;
        }
        break;
      default:
        {
          uint8_t uc = static_cast<uint8_t>(c);
          if (uc<32 && !isspace(c)) // non-printable control characters
          {
            result+="&#x24";
            result+=hex[uc>>4];
            result+=hex[uc&0xF];
            result+=";";
          }
          else
          {
            result+=c;
          }
        }
        break;
    }
  }
  return result;
}
 
void HtmlDocVisitor::startLink(const QCString &ref,const QCString &file,
                               const QCString &relPath,const QCString &anchor,
                               const QCString &tooltip)
{
  //printf("HtmlDocVisitor: file=%s anchor=%s\n",qPrint(file),qPrint(anchor));
  if (!ref.isEmpty()) // link to entity imported via tag file
  {
    m_t << "<a class=\"elRef\" ";
    m_t << externalLinkTarget();
  }
  else // local link
  {
    m_t << "<a class=\"el\" ";
  }
  m_t << "href=\"";
  QCString fn = file;
  addHtmlExtensionIfMissing(fn);
  m_t << createHtmlUrl(relPath,ref,true,
                       m_fileName == Config_getString(HTML_OUTPUT)+"/"+fn,
                       fn,
                       anchor);
  m_t << "\"";
  if (!tooltip.isEmpty()) m_t << " title=\"" << convertToHtml(tooltip) << "\"";
  m_t << ">";
}
 
void HtmlDocVisitor::endLink()
{
  m_t << "</a>";
}
 
void HtmlDocVisitor::writeDotFile(const QCString &fileName,const QCString &relPath,
                                  const QCString &context,const QCString &srcFile,int srcLine,bool newFile)
{
  QCString baseName=makeBaseName(fileName,".dot");
  baseName.prepend("dot_");
  QCString outDir = Config_getString(HTML_OUTPUT);
  if (newFile) writeDotGraphFromFile(fileName,outDir,baseName,GraphOutputFormat::BITMAP,srcFile,srcLine,true);
  writeDotImageMapFromFile(m_t,fileName,outDir,relPath,baseName,context,-1,srcFile,srcLine,newFile);
}
 
void HtmlDocVisitor::writeMscFile(const QCString &fileName,const QCString &relPath,
                                  const QCString &context,const QCString &srcFile,int srcLine, bool newFile)
{
  QCString baseName=makeBaseName(fileName,".msc");
  baseName.prepend("msc_");
  QCString outDir = Config_getString(HTML_OUTPUT);
  QCString imgExt = getDotImageExtension();
  MscOutputFormat mscFormat = imgExt=="svg" ? MscOutputFormat::SVG : MscOutputFormat::BITMAP;
  if (newFile) writeMscGraphFromFile(fileName,outDir,baseName,mscFormat,srcFile,srcLine,true);
  writeMscImageMapFromFile(m_t,fileName,outDir,relPath,baseName,context,mscFormat,srcFile,srcLine);
}
 
void HtmlDocVisitor::writeDiaFile(const QCString &fileName, const QCString &relPath,
                                  const QCString &,const QCString &srcFile,int srcLine, bool newFile)
{
  QCString baseName=makeBaseName(fileName,".dia");
  baseName.prepend("dia_");
  QCString outDir = Config_getString(HTML_OUTPUT);
  if (newFile) writeDiaGraphFromFile(fileName,outDir,baseName,DiaOutputFormat::BITMAP,srcFile,srcLine,true);
 
  m_t << "<img src=\"" << relPath << baseName << ".png" << "\" />\n";
}
 
void HtmlDocVisitor::writePlantUMLFile(const QCString &fileName, const QCString &relPath,
                                       const QCString &,const QCString &/* srcFile */,int /* srcLine */)
{
  QCString baseName=makeBaseName(fileName,".pu");
  QCString outDir = Config_getString(HTML_OUTPUT);
  QCString imgExt = getDotImageExtension();
  if (imgExt=="svg")
  {
    PlantumlManager::instance().generatePlantUMLOutput(fileName,outDir,PlantumlManager::PUML_SVG,true);
    //m_t << "<iframe scrolling=\"no\" frameborder=\"0\" src=\"" << relPath << baseName << ".svg" << "\" />\n";
    //m_t << "<p><b>This browser is not able to show SVG: try Firefox, Chrome, Safari, or Opera instead.</b></p>";
    //m_t << "</iframe>\n";
    m_t << "<object type=\"image/svg+xml\" data=\"" << relPath << baseName << ".svg\"></object>\n";
  }
  else
  {
    PlantumlManager::instance().generatePlantUMLOutput(fileName,outDir,PlantumlManager::PUML_BITMAP,true);
    m_t << "<img src=\"" << relPath << baseName << ".png" << "\" />\n";
  }
}
 
void HtmlDocVisitor::writeMermaidFile(const QCString &fileName, const QCString &relPath,
                                      const QCString &,const QCString &/* srcFile */,int /* srcLine */)
{
  auto baseName     = makeBaseName(fileName,".mmd");
  auto outDir       = Config_getString(HTML_OUTPUT);
  auto outputFormat = MermaidManager::OutputFormat::HTML;
  auto imageFormat  = MermaidManager::convertToImageFormat(outputFormat);
  auto imgExt       = MermaidManager::imageExtension(imageFormat);
  MermaidManager::instance().generateMermaidOutput(fileName,outDir,imageFormat,true);
  if (imageFormat == MermaidManager::ImageFormat::SVG)
  {
    m_t << "<object type=\"image/svg+xml\" data=\"" << relPath << baseName << "." << imgExt << "\"></object>\n";
  }
  else
  {
    m_t << "<img src=\"" << relPath << baseName << "." << imgExt << "\" />\n";
  }
}
 
/** Returns TRUE if the child nodes in paragraph \a para until \a nodeIndex
    contain a style change node that is still active and that style change is one that
    must be located outside of a paragraph, i.e. it is a center, div, or pre tag.
    See also bug746162.
 */
static bool insideStyleChangeThatIsOutsideParagraph(const DocPara *para,
                                                    DocNodeList::const_iterator it)
{
  //printf("insideStyleChangeThatIsOutputParagraph(index=%d)\n",nodeIndex);
  int styleMask=0;
  bool styleOutsideParagraph=FALSE;
  while (!styleOutsideParagraph)
  {
    const DocNodeVariant *n = &(*it);
    const DocStyleChange *sc = std::get_if<DocStyleChange>(n);
    if (sc)
    {
      if (!sc->enable()) // remember styles that has been closed already
      {
        styleMask|=static_cast<int>(sc->style());
      }
      bool paraStyle = sc->style()==DocStyleChange::Center ||
                       sc->style()==DocStyleChange::Div    ||
                       sc->style()==DocStyleChange::Preformatted;
      //printf("Found style change %s enabled=%d\n",sc->styleString(),sc->enable());
      if (sc->enable() && (styleMask&static_cast<int>(sc->style()))==0 && // style change that is still active
          paraStyle
         )
      {
        styleOutsideParagraph=TRUE;
      }
    }
    if (it!=std::begin(para->children()))
    {
      --it;
    }
    else
    {
      break;
    }
  }
  return styleOutsideParagraph;
}
 
/** Used for items found inside a paragraph, which due to XHTML restrictions
 *  have to be outside of the paragraph. This method will forcefully end
 *  the current paragraph and forceStartParagraph() will restart it.
 */
template<class Node>
void HtmlDocVisitor::forceEndParagraph(const Node &n)
{
  const DocPara *para=std::get_if<DocPara>(n.parent());
  if (para)
  {
    const DocNodeList &children = para->children();
 
    //printf("forceEndParagraph\n");
    //dumpDocNodeList(children);
 
    auto it = std::find_if(std::begin(children),std::end(children),
        [&n](const auto &np) { return holds_value(&n,np); });
    if (it==std::end(children))   return;
    if (it==std::begin(children)) return; // first node in paragraph
    it = std::prev(it);
    bool found=false;
    while (!found)
    {
      found = !isInvisibleNode(*it);
      if (found) break;
      if (it!=std::begin(children))
      {
        --it;
      }
      else
      {
        break;
      }
    }
    if (!found) return; // first visible node in paragraph
    const DocNodeVariant &v = *it;
    if (mustBeOutsideParagraph(v)) return; // previous node already outside paragraph context
    bool styleOutsideParagraph=false;
    if (it!=std::begin(children))
    {
      it = std::prev(it);
      styleOutsideParagraph=insideStyleChangeThatIsOutsideParagraph(para,it);
    }
    bool isFirst = false;
    bool isLast = false;
    getParagraphContext(*para,isFirst,isLast);
    //printf("forceEnd first=%d last=%d styleOutsideParagraph=%d\n",isFirst,isLast,styleOutsideParagraph);
    if (isFirst && isLast) return;
    if (styleOutsideParagraph) return;
 
    //printf("adding </p>\n");
    m_t << "</p>";
  }
}
 
/** Used for items found inside a paragraph, which due to XHTML restrictions
 *  have to be outside of the paragraph. This method will forcefully start
 *  the paragraph, that was previously ended by forceEndParagraph().
 */
template<class Node>
void HtmlDocVisitor::forceStartParagraph(const Node &n)
{
  //printf("> forceStartParagraph(%s)\n",docNodeName(n));
  const DocPara *para=nullptr;
  if (n.parent() && (para = std::get_if<DocPara>(n.parent()))) // if we are inside a paragraph
  {
    const DocNodeList &children = para->children();
 
    auto it = std::find_if(std::begin(children),
                           std::end(children),
                           [&n](const auto &np)
                           { return holds_value(&n,np); });
    if (it==std::end(children)) return;
    bool styleOutsideParagraph=insideStyleChangeThatIsOutsideParagraph(para,it);
    //printf("it=%s (%p) styleOutsideParagraph=%d\n",
    //    docNodeName(*it), (void *)&*it, styleOutsideParagraph);
    if (styleOutsideParagraph) return;
    it = std::next(it);
    while (it!=std::end(children) && isInvisibleNode(*it))
    {
      ++it;
    }
    if (it!=std::end(children))
    {
      const DocNodeVariant &v = *it;
      if (mustBeOutsideParagraph(v)) return; // next element also outside paragraph
    }
    else
    {
      return; // only whitespace at the end!
    }
 
    bool needsTag = true;
    bool isFirst = false;
    bool isLast = false;
    getParagraphContext(*para,isFirst,isLast);
    if (isFirst && isLast)  needsTag = false;
    //printf("forceStart first=%d last=%d needsTag=%d\n",isFirst,isLast,needsTag);
 
    if (needsTag) m_t << "<p>";
  }
}