File indexing completed on 2024-05-26 04:57:58

 /**
  * \file formatreplacer.cpp
  * Replaces format codes in a string.
  *
  * \b Project: Kid3
  * \author Urs Fleisch
  * \date 06 Jul 2008
  *
  * Copyright (C) 2008-2024  Urs Fleisch
  *
  * This file is part of Kid3.
  *
  * Kid3 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 2 of the License, or
  * (at your option) any later version.
  *
  * Kid3 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 this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
 #include "formatreplacer.h"
 #include <QUrl>
 #include "saferename.h"
 
 /**
  * Constructor.
  *
  * @param str string with format codes
  */
 FormatReplacer::FormatReplacer(const QString& str) : m_str(str) {}
 
 /**
  * Destructor.
  */
 FormatReplacer::~FormatReplacer()
 {
 }
 
 /**
  * Replace escaped characters.
  * Replaces the escaped characters ("\n", "\t", "\r", "\\", "\a", "\b",
  * "\f", "\v") with the corresponding characters.
  */
 void FormatReplacer::replaceEscapedChars()
 {
   if (!m_str.isEmpty()) {
     constexpr int numEscCodes = 8;
     constexpr QChar escCode[numEscCodes] = {
       QLatin1Char('n'), QLatin1Char('t'), QLatin1Char('r'), QLatin1Char('\\'),
       QLatin1Char('a'), QLatin1Char('b'), QLatin1Char('f'), QLatin1Char('v')};
     constexpr char escChar[numEscCodes] = {
       '\n', '\t', '\r', '\\', '\a', '\b', '\f', '\v'};
 
     for (int pos = 0; pos < m_str.length();) {
       pos = m_str.indexOf(QLatin1Char('\\'), pos);
       if (pos == -1) break;
       ++pos;
       for (int k = 0;; ++k) {
         if (k >= numEscCodes) {
           // invalid code at pos
           ++pos;
           break;
         }
         if (m_str[pos] == escCode[k]) {
           // code found, replace it
           m_str.replace(pos - 1, 2, QLatin1Char(escChar[k]));
           break;
         }
       }
     }
   }
 }
 
 /**
  * Replace percent codes.
  *
  * @param flags flags: FSF_SupportUrlEncode to support modifier u
  *              (with code c "%uc") to URL encode,
  *              FSF_ReplaceSeparators to replace directory separators
  *              ('/', '\\', ':') in tags,
  *              FSF_SupportHtmlEscape to support modifier h
  *              (with code c "%hc") to replace HTML metacharacters
  *              ('<', '>', '&', '"', ''', non-ascii) in tags.
  */
 void FormatReplacer::replacePercentCodes(unsigned flags)
 {
   if (!m_str.isEmpty()) {
     for (int pos = 0; pos < m_str.length();) {
       pos = m_str.indexOf(QLatin1Char('%'), pos);
       if (pos == -1) break;
 
       int codePos = pos + 1;
       int codeLen = 0;
       QString prefix, postfix;
       bool urlEncode = false;
       bool htmlEscape = false;
       QString repl;
       if ((flags & FSF_SupportUrlEncode) && m_str[codePos] == QLatin1Char('u')) {
         ++codePos;
         urlEncode = true;
       }
       if ((flags & FSF_SupportHtmlEscape) && m_str[codePos] == QLatin1Char('h')) {
         ++codePos;
         htmlEscape = true;
       }
       if (m_str[codePos] == QLatin1Char('{')) {
         if (int closingBracePos = m_str.indexOf(QLatin1Char('}'), codePos + 1);
             closingBracePos > codePos + 1) {
           QString longCode =
             m_str.mid(codePos + 1, closingBracePos - codePos - 1).toLower();
           if (longCode.startsWith(QLatin1Char('"'))) {
             if (int prefixEnd = longCode.indexOf(QLatin1Char('"'), 1);
                 prefixEnd != -1 && prefixEnd < longCode.length() - 2) {
               prefix = longCode.mid(1, prefixEnd - 1);
               longCode.remove(0, prefixEnd + 1);
             }
           }
           if (longCode.endsWith(QLatin1Char('"'))) {
             if (int postfixStart = longCode.lastIndexOf(QLatin1Char('"'), -2);
                 postfixStart > 1) {
               postfix = longCode.mid(postfixStart + 1,
                                      longCode.length() - postfixStart - 2);
               longCode.truncate(postfixStart);
             }
           }
           repl = getReplacement(longCode);
           codeLen = closingBracePos - pos + 1;
         }
       } else {
         repl = getReplacement(QString(m_str[codePos]));
         codeLen = codePos - pos + 1;
       }
 
       if (codeLen > 0) {
         if (flags & FSF_ReplaceSeparators) {
 #ifdef Q_OS_WIN32
           static constexpr char illegalChars[] = "<>:\"|?*\\/";
 #else
           // ':' and '\' are included in the set of illegal characters to
           // keep the old behavior when no string replacement is enabled.
           static constexpr char illegalChars[] = ":\\/";
 #endif
           Utils::replaceIllegalFileNameCharacters(repl, QLatin1String("-"),
                                                   illegalChars);
         }
         if (urlEncode) {
           repl = QString::fromLatin1(QUrl::toPercentEncoding(repl));
         }
         if (htmlEscape) {
           repl = escapeHtml(repl);
         }
         if (!repl.isEmpty()) {
           if (!prefix.isEmpty()) {
             repl = prefix + repl;
           }
           if (!postfix.isEmpty()) {
             repl += postfix;
           }
         }
         if (!repl.isNull() || codeLen > 2) {
           m_str.replace(pos, codeLen, repl);
           pos += repl.length();
         } else {
           ++pos;
         }
       } else {
         ++pos;
       }
     }
   }
 }
 
 /**
  * Converts the plain text string @a plain to a HTML string with
  * HTML metacharacters replaced by HTML entities.
  * @param plain plain text
  * @return html text with HTML entities.
  */
 QString FormatReplacer::escapeHtml(const QString& plain)
 {
   QString rich;
   rich.reserve(static_cast<int>(plain.length() * 1.1));
   for (int i = 0; i < plain.length(); ++i) {
     if (ushort ch = plain.at(i).unicode(); ch == '<')
       rich += QLatin1String("&lt;");
     else if (ch == '>')
       rich += QLatin1String("&gt;");
     else if (ch == '&')
       rich += QLatin1String("&amp;");
     else if (ch == '"')
       rich += QLatin1String("&quot;");
     else if (ch == '\'')
       rich += QLatin1String("&apos;");
     else if (ch >= 128)
       rich += QString(QLatin1String("&#%1;")).arg(ch);
     else
       rich += plain.at(i);
   }
   return rich;
 }