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 #include "qt_helpers.h"
  15
  16 #include "support/lassert.h"
  17
  18 #include <QString>
  19 #include <QTextDocument>
  20
  21
  22 using namespace lyx::support;
  23
  24 namespace lyx {
  25 namespace frontend {
  26
  27 LaTeXHighlighter::LaTeXHighlighter(QTextDocument * parent)
  28         : QSyntaxHighlighter(parent)
  29 {
  30         keywordFormat.setForeground(Qt::darkBlue);
  31         keywordFormat.setFontWeight(QFont::Bold);
  32         commentFormat.setForeground(Qt::darkGray);
  33         mathFormat.setForeground(Qt::red);
  34         warningFormat.setForeground(Qt::red);
  35         warningFormat.setFontWeight(QFont::Bold);
  36 }
  37
  38
  39 void LaTeXHighlighter::highlightBlock(QString const & text)
  40 {
  41         // $ $
  42         static const QRegExp exprMath("\\$[^\\$]*\\$");
  43         int index = text.indexOf(exprMath);
  44         while (index >= 0) {
  45                 int length = exprMath.matchedLength();
  46                 setFormat(index, length, mathFormat);
  47                 index = text.indexOf(exprMath, index + length);
  48         }
  49         // [ ]
  50         static const QRegExp exprStartDispMath("(\\\\\\[|"
  51                 "\\\\begin\\{equation\\**\\}|"
  52                 "\\\\begin\\{eqnarray\\**\\}|"
  53                 "\\\\begin\\{align(ed|at)*\\**\\}|"
  54                 "\\\\begin\\{flalign\\**\\}|"
  55                 "\\\\begin\\{gather\\**\\}|"
  56                 "\\\\begin\\{multline\\**\\}|"
  57                 "\\\\begin\\{array\\**\\}|"
  58                 "\\\\begin\\{cases\\**\\}"
  59                 ")");
  60         static const QRegExp exprEndDispMath("(\\\\\\]|"
  61                 "\\\\end\\{equation\\**\\}|"
  62                 "\\\\end\\{eqnarray\\**\\}|"
  63                 "\\\\end\\{align(ed|at)*\\**\\}|"
  64                 "\\\\end\\{flalign\\**\\}|"
  65                 "\\\\end\\{gather\\**\\}|"
  66                 "\\\\end\\{multline\\**\\}|"
  67                 "\\\\end\\{array\\**\\}|"
  68                 "\\\\end\\{cases\\**\\}"
  69                 ")");
  70         int startIndex = 0;
  71         // if previous block was in 'disp math'
  72         // start search from 0 (for end disp math)
  73         // otherwise, start search from 'begin disp math'
  74         if (previousBlockState() != 1)
  75                 startIndex = text.indexOf(exprStartDispMath);
  76         // We try to avoid infinite loops...
  77         static size_t max_loop = 1000;
  78         for (size_t i = 0; i != max_loop; ++i) {
  79                 int endIndex = text.indexOf(exprEndDispMath, startIndex);
  80                 int length;
  81                 if (endIndex == -1) {
  82                         setCurrentBlockState(1);
  83                         length = text.length() - startIndex;
  84                 } else {
  85                         length = endIndex - startIndex + exprEndDispMath.matchedLength();
  86                 }
  87                 setFormat(startIndex, length, mathFormat);
  88                 startIndex = text.indexOf(exprStartDispMath, startIndex + length);
  89                 if (startIndex == -1)
  90                         break;
  91         }
  92         LASSERT(startIndex >= 0, return);
  93
  94         // \whatever
  95         static const QRegExp exprKeyword("\\\\[A-Za-z]+");
  96         index = text.indexOf(exprKeyword);
  97         for (size_t i = 0; i != max_loop; ++i) {
  98                 int length = exprKeyword.matchedLength();
  99                 setFormat(index, length, keywordFormat);
 100                 index = text.indexOf(exprKeyword, index + length);
 101                 if (index == -1)
 102                         break;
 103         }
 104         LASSERT(index >= 0, return);
 105
 106         // %comment
 107         // Treat a line as a comment starting at a percent sign
 108         // * that is the first character in a line
 109         // * that is preceded by
 110         // ** an even number of backslashes
 111         // ** any character other than a backslash
 112         QRegExp exprComment("(?:^|[^\\\\])(?:\\\\\\\\)*(%).*$");
 113         text.indexOf(exprComment);
 114         index = exprComment.pos(1);
 115         for (size_t i = 0; i != max_loop; ++i) {
 116                 int const length = exprComment.matchedLength()
 117                                  - (index - exprComment.pos(0));
 118                 setFormat(index, length, commentFormat);
 119                 text.indexOf(exprComment, index + length);
 120                 index = exprComment.pos(1);
 121                 if (index == -1)
 122                         break;
 123         }
 124         LASSERT(index >= 0, return);
 125
 126         // <LyX Warning: ...>
 127         QString lyxwarn = qt_("LyX Warning: ");
 128         QRegExp exprWarning("<" + lyxwarn + "[^<]*>");
 129         index = text.indexOf(exprWarning);
 130         for (size_t i = 0; i != max_loop; ++i) {
 131                 int length = exprWarning.matchedLength();
 132                 setFormat(index, length, warningFormat);
 133                 index = text.indexOf(exprWarning, index + length);
 134                 if (index == -1)
 135                         break;
 136         }
 137         LASSERT(index >= 0, return);
 138 }
 139
 140 } // namespace frontend
 141 } // namespace lyx