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 <QString>
  17 #include <QTextDocument>
  18
  19 namespace lyx {
  20 namespace frontend {
  21
  22
  23 LaTeXHighlighter::LaTeXHighlighter(QTextDocument * parent,
  24                                    bool const at_letter)
  25         : QSyntaxHighlighter(parent), at_letter_(at_letter)
  26 {
  27         auto blend = [](QColor color1, QColor color2) {
  28                 int r = 0.5 * (color1.red() + color2.red());
  29                 int g = 0.5 * (color1.green() + color2.green());
  30                 int b = 0.5 * (color1.blue() + color2.blue());
  31                 return QColor(r, g, b);
  32         };
  33         QPalette palette = QPalette();
  34         QColor text_color = palette.color(QPalette::Active, QPalette::Text);
  35         keywordFormat.setForeground(blend(Qt::blue, text_color));
  36         keywordFormat.setFontWeight(QFont::Bold);
  37         commentFormat.setForeground(palette.color(QPalette::Disabled,
  38                                                   QPalette::Text));
  39         mathFormat.setForeground(blend(Qt::red, text_color));
  40         warningFormat.setForeground(Qt::red);
  41         warningFormat.setFontWeight(QFont::Bold);
  42 }
  43
  44
  45 void LaTeXHighlighter::highlightBlock(QString const & text)
  46 {
  47         // $ $
  48         static const QRegExp exprMath("\\$[^\\$]*\\$");
  49         int index = exprMath.indexIn(text);
  50         while (index >= 0) {
  51                 int length = exprMath.matchedLength();
  52                 setFormat(index, length, mathFormat);
  53                 index = exprMath.indexIn(text, index + length);
  54         }
  55         // [ ]
  56         static const QRegExp exprStartDispMath("(\\\\\\[|"
  57                 "\\\\begin\\{equation\\**\\}|"
  58                 "\\\\begin\\{eqnarray\\**\\}|"
  59                 "\\\\begin\\{align(ed|at)*\\**\\}|"
  60                 "\\\\begin\\{flalign\\**\\}|"
  61                 "\\\\begin\\{gather\\**\\}|"
  62                 "\\\\begin\\{multline\\**\\}|"
  63                 "\\\\begin\\{array\\**\\}|"
  64                 "\\\\begin\\{cases\\**\\}"
  65                 ")");
  66         static const QRegExp exprEndDispMath("(\\\\\\]|"
  67                 "\\\\end\\{equation\\**\\}|"
  68                 "\\\\end\\{eqnarray\\**\\}|"
  69                 "\\\\end\\{align(ed|at)*\\**\\}|"
  70                 "\\\\end\\{flalign\\**\\}|"
  71                 "\\\\end\\{gather\\**\\}|"
  72                 "\\\\end\\{multline\\**\\}|"
  73                 "\\\\end\\{array\\**\\}|"
  74                 "\\\\end\\{cases\\**\\}"
  75                 ")");
  76         int startIndex = 0;
  77         // if previous block was in 'disp math'
  78         // start search from 0 (for end disp math)
  79         // otherwise, start search from 'begin disp math'
  80         if (previousBlockState() != 1)
  81                 startIndex = exprStartDispMath.indexIn(text);
  82         while (startIndex >= 0) {
  83                 int endIndex = exprEndDispMath.indexIn(text, startIndex);
  84                 int length;
  85                 if (endIndex == -1) {
  86                         setCurrentBlockState(1);
  87                         length = text.length() - startIndex;
  88                 } else {
  89                         length = endIndex - startIndex + exprEndDispMath.matchedLength();
  90                 }
  91                 setFormat(startIndex, length, mathFormat);
  92                 startIndex = exprStartDispMath.indexIn(text, startIndex + length);
  93         }
  94         // \whatever
  95         static const QRegExp exprKeywordAtOther("\\\\[A-Za-z]+");
  96         // \wh@tever
  97         static const QRegExp exprKeywordAtLetter("\\\\[A-Za-z@]+");
  98         QRegExp const & exprKeyword = at_letter_ ? exprKeywordAtLetter
  99                                                  : exprKeywordAtOther;
 100         index = exprKeyword.indexIn(text);
 101         while (index >= 0) {
 102                 int length = exprKeyword.matchedLength();
 103                 setFormat(index, length, keywordFormat);
 104                 index = exprKeyword.indexIn(text, index + length);
 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         exprComment.indexIn(text);
 114         index = exprComment.pos(1);
 115         while (index >= 0) {
 116                 int const length = exprComment.matchedLength()
 117                                  - (index - exprComment.pos(0));
 118                 setFormat(index, length, commentFormat);
 119                 exprComment.indexIn(text, index + length);
 120                 index = exprComment.pos(1);
 121         }
 122         // <LyX Warning: ...>
 123         QString lyxwarn = qt_("LyX Warning: ");
 124         QRegExp exprWarning("<" + lyxwarn + "[^<]*>");
 125         index = exprWarning.indexIn(text);
 126         while (index >= 0) {
 127                 int length = exprWarning.matchedLength();
 128                 setFormat(index, length, warningFormat);
 129                 index = exprWarning.indexIn(text, index + length);
 130         }
 131 }
 132
 133 } // namespace frontend
 134 } // namespace lyx