src/frontends/qt/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, bool at_letter)
  24         : QSyntaxHighlighter(parent), at_letter_(at_letter)
  25 {
  26         auto blend = [](QColor color1, QColor color2) {
  27                 int r = 0.5 * (color1.red() + color2.red());
  28                 int g = 0.5 * (color1.green() + color2.green());
  29                 int b = 0.5 * (color1.blue() + color2.blue());
  30                 return QColor(r, g, b);
  31         };
  32         QPalette palette = QPalette();
  33         QColor text_color = palette.color(QPalette::Active, QPalette::Text);
  34         keywordFormat.setForeground(blend(Qt::blue, text_color));
  35         keywordFormat.setFontWeight(QFont::Bold);
  36         commentFormat.setForeground(palette.color(QPalette::Disabled,
  37                                                   QPalette::Text));
  38         mathFormat.setForeground(blend(Qt::red, text_color));
  39         warningFormat.setForeground(Qt::red);
  40         warningFormat.setFontWeight(QFont::Bold);
  41 }
  42
  43
  44 void LaTeXHighlighter::highlightBlock(QString const & text)
  45 {
  46 #if QT_VERSION < 0x060000
  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 #else
 132         // $ $
 133         static const QRegularExpression exprMath("\\$[^\\$]*\\$");
 134         QRegularExpressionMatch match = exprMath.match(text);
 135         int index = match.capturedStart(1);
 136         while (index >= 0) {
 137                 int length = match.capturedEnd(1) - index;
 138                 setFormat(index, length, mathFormat);
 139                 match = exprMath.match(text, index + length);
 140                 index = match.capturedStart(1);
 141         }
 142         // [ ]
 143         static const QRegularExpression exprStartDispMath("(\\\\\\[|"
 144                 "\\\\begin\\{equation\\**\\}|"
 145                 "\\\\begin\\{eqnarray\\**\\}|"
 146                 "\\\\begin\\{align(ed|at)*\\**\\}|"
 147                 "\\\\begin\\{flalign\\**\\}|"
 148                 "\\\\begin\\{gather\\**\\}|"
 149                 "\\\\begin\\{multline\\**\\}|"
 150                 "\\\\begin\\{array\\**\\}|"
 151                 "\\\\begin\\{cases\\**\\}"
 152                 ")");
 153         static const QRegularExpression exprEndDispMath("(\\\\\\]|"
 154                 "\\\\end\\{equation\\**\\}|"
 155                 "\\\\end\\{eqnarray\\**\\}|"
 156                 "\\\\end\\{align(ed|at)*\\**\\}|"
 157                 "\\\\end\\{flalign\\**\\}|"
 158                 "\\\\end\\{gather\\**\\}|"
 159                 "\\\\end\\{multline\\**\\}|"
 160                 "\\\\end\\{array\\**\\}|"
 161                 "\\\\end\\{cases\\**\\}"
 162                 ")");
 163         int startIndex = 0;
 164         // if previous block was in 'disp math'
 165         // start search from 0 (for end disp math)
 166         // otherwise, start search from 'begin disp math'
 167         if (previousBlockState() != 1) {
 168                 match = exprStartDispMath.match(text);
 169                 startIndex = match.capturedStart(1);
 170         }
 171         while (startIndex >= 0) {
 172                 match = exprEndDispMath.match(text, startIndex);
 173                 int endIndex = match.capturedStart(1);
 174                 int length;
 175                 if (endIndex == -1) {
 176                         setCurrentBlockState(1);
 177                         length = text.length() - startIndex;
 178                 } else {
 179                         length = match.capturedEnd(1) - startIndex;
 180                 }
 181                 setFormat(startIndex, length, mathFormat);
 182                 match = exprStartDispMath.match(text, startIndex + length);
 183                 startIndex = match.capturedStart(1);
 184         }
 185         // \whatever
 186         static const QRegularExpression exprKeywordAtOther("\\\\[A-Za-z]+");
 187         // \wh@tever
 188         static const QRegularExpression exprKeywordAtLetter("\\\\[A-Za-z@]+");
 189         QRegularExpression const & exprKeyword = at_letter_
 190                         ? exprKeywordAtLetter : exprKeywordAtOther;
 191         match = exprKeyword.match(text);
 192         index = match.capturedStart(1);
 193         while (index >= 0) {
 194                 int length = match.capturedEnd(1) - index;
 195                 setFormat(index, length, keywordFormat);
 196                 match = exprKeyword.match(text, index + length);
 197                 index = match.capturedStart(1);
 198         }
 199         // %comment
 200         // Treat a line as a comment starting at a percent sign
 201         // * that is the first character in a line
 202         // * that is preceded by
 203         // ** an even number of backslashes
 204         // ** any character other than a backslash
 205         QRegularExpression exprComment("(?:^|[^\\\\])(?:\\\\\\\\)*(%).*$");
 206         match = exprComment.match(text);
 207         index = match.capturedStart(1);
 208         while (index >= 0) {
 209                 int const length = match.capturedEnd(1) - index
 210                                  - (index - match.capturedStart(0));
 211                 setFormat(index, length, commentFormat);
 212                 match = exprComment.match(text, index + length);
 213                 index = match.capturedStart(1);
 214         }
 215         // <LyX Warning: ...>
 216         QString lyxwarn = qt_("LyX Warning: ");
 217         QRegularExpression exprWarning("<" + lyxwarn + "[^<]*>");
 218         match = exprWarning.match(text);
 219         index = match.capturedStart(1);
 220         while (index >= 0) {
 221                 int length = match.capturedEnd(1) - index;
 222                 setFormat(index, length, warningFormat);
 223                 match = exprWarning.match(text, index + length);
 224                 index = match.capturedStart(1);
 225         }
 226 #endif
 227 }
 228
 229 } // namespace frontend
 230 } // namespace lyx