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 namespace {
  23
  24 QColor blend(QColor color1, QColor color2) {
  25         int r = 0.5 * (color1.red() + color2.red());
  26         int g = 0.5 * (color1.green() + color2.green());
  27         int b = 0.5 * (color1.blue() + color2.blue());
  28         return QColor(r, g, b);
  29 };
  30
  31 }
  32
  33
  34 LaTeXHighlighter::LaTeXHighlighter(QTextDocument * parent)
  35         : QSyntaxHighlighter(parent)
  36 {
  37         QPalette palette = QPalette();
  38         QColor text_color = palette.color(QPalette::Active, QPalette::Text);
  39         keywordFormat.setForeground(blend(Qt::blue, text_color));
  40         keywordFormat.setFontWeight(QFont::Bold);
  41         commentFormat.setForeground(palette.color(QPalette::Disabled,
  42                                                   QPalette::Text));
  43         mathFormat.setForeground(blend(Qt::red, text_color));
  44         warningFormat.setForeground(Qt::red);
  45         warningFormat.setFontWeight(QFont::Bold);
  46 }
  47
  48
  49 void LaTeXHighlighter::highlightBlock(QString const & text)
  50 {
  51         // $ $
  52         static const QRegExp exprMath("\\$[^\\$]*\\$");
  53         int index = exprMath.indexIn(text);
  54         while (index >= 0) {
  55                 int length = exprMath.matchedLength();
  56                 setFormat(index, length, mathFormat);
  57                 index = exprMath.indexIn(text, index + length);
  58         }
  59         // [ ]
  60         static const QRegExp exprStartDispMath("(\\\\\\[|"
  61                 "\\\\begin\\{equation\\**\\}|"
  62                 "\\\\begin\\{eqnarray\\**\\}|"
  63                 "\\\\begin\\{align(ed|at)*\\**\\}|"
  64                 "\\\\begin\\{flalign\\**\\}|"
  65                 "\\\\begin\\{gather\\**\\}|"
  66                 "\\\\begin\\{multline\\**\\}|"
  67                 "\\\\begin\\{array\\**\\}|"
  68                 "\\\\begin\\{cases\\**\\}"
  69                 ")");
  70         static const QRegExp exprEndDispMath("(\\\\\\]|"
  71                 "\\\\end\\{equation\\**\\}|"
  72                 "\\\\end\\{eqnarray\\**\\}|"
  73                 "\\\\end\\{align(ed|at)*\\**\\}|"
  74                 "\\\\end\\{flalign\\**\\}|"
  75                 "\\\\end\\{gather\\**\\}|"
  76                 "\\\\end\\{multline\\**\\}|"
  77                 "\\\\end\\{array\\**\\}|"
  78                 "\\\\end\\{cases\\**\\}"
  79                 ")");
  80         int startIndex = 0;
  81         // if previous block was in 'disp math'
  82         // start search from 0 (for end disp math)
  83         // otherwise, start search from 'begin disp math'
  84         if (previousBlockState() != 1)
  85                 startIndex = exprStartDispMath.indexIn(text);
  86         while (startIndex >= 0) {
  87                 int endIndex = exprEndDispMath.indexIn(text, startIndex);
  88                 int length;
  89                 if (endIndex == -1) {
  90                         setCurrentBlockState(1);
  91                         length = text.length() - startIndex;
  92                 } else {
  93                         length = endIndex - startIndex + exprEndDispMath.matchedLength();
  94                 }
  95                 setFormat(startIndex, length, mathFormat);
  96                 startIndex = exprStartDispMath.indexIn(text, startIndex + length);
  97         }
  98         // \whatever
  99         static const QRegExp exprKeyword("\\\\[A-Za-z]+");
 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