src/frontends/qt4/LaTeXHighlighter.cpp

   1 /**
   2  * \file LaTeXHighlighter.cpp
   3  * This file is part of LyX, the document processor.
   4  * Licence details can be found in the file COPYING.
   5  *
   6  * \author Bo Peng
   7  *
   8  * Full author contact details are available in file CREDITS.
   9  */
  10
  11 #include <config.h>
  12
  13 #include "LaTeXHighlighter.h"
  14
  15 #include <QString>
  16 #include <QTextDocument>
  17
  18 namespace lyx {
  19 namespace frontend {
  20
  21 LaTeXHighlighter::LaTeXHighlighter(QTextDocument * parent)
  22         : QSyntaxHighlighter(parent)
  23 {
  24         keywordFormat.setForeground(Qt::darkBlue);
  25         keywordFormat.setFontWeight(QFont::Bold);
  26         commentFormat.setForeground(Qt::darkGray);
  27         mathFormat.setForeground(Qt::red);
  28 }
  29
  30
  31 void LaTeXHighlighter::highlightBlock(QString const & text)
  32 {
  33         // $ $
  34         static const QRegExp exprMath("\\$[^\\$]*\\$");
  35         int index = text.indexOf(exprMath);
  36         while (index >= 0) {
  37                 int length = exprMath.matchedLength();
  38                 setFormat(index, length, mathFormat);
  39                 index = text.indexOf(exprMath, index + length);
  40         }
  41         // [ ]
  42         static const QRegExp exprStartDispMath("(\\\\\\[|"
  43                 "\\\\begin\\{equation\\**\\}|"
  44                 "\\\\begin\\{eqnarray\\**\\}|"
  45                 "\\\\begin\\{align(ed|at)*\\**\\}|"
  46                 "\\\\begin\\{flalign\\**\\}|"
  47                 "\\\\begin\\{gather\\**\\}|"
  48                 "\\\\begin\\{multline\\**\\}|"
  49                 "\\\\begin\\{array\\**\\}|"
  50                 "\\\\begin\\{cases\\**\\}"
  51                 ")");
  52         static const QRegExp exprEndDispMath("(\\\\\\]|"
  53                 "\\\\end\\{equation\\**\\}|"
  54                 "\\\\end\\{eqnarray\\**\\}|"
  55                 "\\\\end\\{align(ed|at)*\\**\\}|"
  56                 "\\\\end\\{flalign\\**\\}|"
  57                 "\\\\end\\{gather\\**\\}|"
  58                 "\\\\end\\{multline\\**\\}|"
  59                 "\\\\end\\{array\\**\\}|"
  60                 "\\\\end\\{cases\\**\\}"
  61                 ")");
  62         int startIndex = 0;
  63         // if previous block was in 'disp math'
  64         // start search from 0 (for end disp math)
  65         // otherwise, start search from 'begin disp math'
  66         if (previousBlockState() != 1)
  67                 startIndex = text.indexOf(exprStartDispMath);
  68         while (startIndex >= 0) {
  69                 int endIndex = text.indexOf(exprEndDispMath, startIndex);
  70                 int length;
  71                 if (endIndex == -1) {
  72                         setCurrentBlockState(1);
  73                         length = text.length() - startIndex;
  74                 } else {
  75                         length = endIndex - startIndex + exprEndDispMath.matchedLength();
  76                 }
  77                 setFormat(startIndex, length, mathFormat);
  78                 startIndex = text.indexOf(exprStartDispMath, startIndex + length);
  79         }
  80         // \whatever
  81         static const QRegExp exprKeyword("\\\\[A-Za-z]+");
  82         index = text.indexOf(exprKeyword);
  83         while (index >= 0) {
  84                 int length = exprKeyword.matchedLength();
  85                 setFormat(index, length, keywordFormat);
  86                 index = text.indexOf(exprKeyword, index + length);
  87         }
  88         // %comment
  89         // Treat a line as a comment starting at a percent sign
  90         // * that is the first character in a line
  91         // * that is preceded by
  92         // ** an even number of backslashes
  93         // ** any character other than a backslash
  94         QRegExp exprComment("(?:^|[^\\\\])(?:\\\\\\\\)*(%).*$");
  95         text.indexOf(exprComment);
  96         index = exprComment.pos(1);
  97         while (index >= 0) {
  98                 int const length = exprComment.matchedLength()
  99                                  - (index - exprComment.pos(0));
 100                 setFormat(index, length, commentFormat);
 101                 text.indexOf(exprComment, index + length);
 102                 index = exprComment.pos(1);
 103         }
 104 }
 105
 106 } // namespace frontend
 107 } // namespace lyx