lyx_mirror/src/frontends/qt4/LaTeXHighlighter.cpp
Vincent van Ravesteijn 8768fa7251 Proper fix to avoid an infinite loop with Qt4.5.
see: 
http://www.qtsoftware.com/developer/faqs/why-does-qstring-indexof-qregexp-cause-a-crash-or-hang-in-qt-4.5

git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/trunk@28746 a592a061-630c-0410-9148-cb99ea01b6c8
2009-03-09 19:54:47 +00:00

120 lines
3.4 KiB
C++

/**
* \file LaTeXHighlighter.cpp
* This file is part of LyX, the document processor.
* Licence details can be found in the file COPYING.
*
* \author Bo Peng
*
* Full author contact details are available in file CREDITS.
*/
#include <config.h>
#include "LaTeXHighlighter.h"
#include "qt_helpers.h"
#include <QString>
#include <QTextDocument>
namespace lyx {
namespace frontend {
LaTeXHighlighter::LaTeXHighlighter(QTextDocument * parent)
: QSyntaxHighlighter(parent)
{
keywordFormat.setForeground(Qt::darkBlue);
keywordFormat.setFontWeight(QFont::Bold);
commentFormat.setForeground(Qt::darkGray);
mathFormat.setForeground(Qt::red);
warningFormat.setForeground(Qt::red);
warningFormat.setFontWeight(QFont::Bold);
}
void LaTeXHighlighter::highlightBlock(QString const & text)
{
// $ $
static const QRegExp exprMath("\\$[^\\$]*\\$");
int index = exprMath.indexIn(text);
while (index >= 0) {
int length = exprMath.matchedLength();
setFormat(index, length, mathFormat);
index = exprMath.indexIn(text, index + length);
}
// [ ]
static const QRegExp exprStartDispMath("(\\\\\\[|"
"\\\\begin\\{equation\\**\\}|"
"\\\\begin\\{eqnarray\\**\\}|"
"\\\\begin\\{align(ed|at)*\\**\\}|"
"\\\\begin\\{flalign\\**\\}|"
"\\\\begin\\{gather\\**\\}|"
"\\\\begin\\{multline\\**\\}|"
"\\\\begin\\{array\\**\\}|"
"\\\\begin\\{cases\\**\\}"
")");
static const QRegExp exprEndDispMath("(\\\\\\]|"
"\\\\end\\{equation\\**\\}|"
"\\\\end\\{eqnarray\\**\\}|"
"\\\\end\\{align(ed|at)*\\**\\}|"
"\\\\end\\{flalign\\**\\}|"
"\\\\end\\{gather\\**\\}|"
"\\\\end\\{multline\\**\\}|"
"\\\\end\\{array\\**\\}|"
"\\\\end\\{cases\\**\\}"
")");
int startIndex = 0;
// if previous block was in 'disp math'
// start search from 0 (for end disp math)
// otherwise, start search from 'begin disp math'
if (previousBlockState() != 1)
startIndex = exprStartDispMath.indexIn(text);
while (startIndex >= 0) {
int endIndex = exprEndDispMath.indexIn(text, startIndex);
int length;
if (endIndex == -1) {
setCurrentBlockState(1);
length = text.length() - startIndex;
} else {
length = endIndex - startIndex + exprEndDispMath.matchedLength();
}
setFormat(startIndex, length, mathFormat);
startIndex = exprStartDispMath.indexIn(text, startIndex + length);
}
// \whatever
static const QRegExp exprKeyword("\\\\[A-Za-z]+");
index = exprKeyword.indexIn(text);
while (index >= 0) {
int length = exprKeyword.matchedLength();
setFormat(index, length, keywordFormat);
index = exprKeyword.indexIn(text, index + length);
}
// %comment
// Treat a line as a comment starting at a percent sign
// * that is the first character in a line
// * that is preceded by
// ** an even number of backslashes
// ** any character other than a backslash
QRegExp exprComment("(?:^|[^\\\\])(?:\\\\\\\\)*(%).*$");
exprComment.indexIn(text);
index = exprComment.pos(1);
while (index >= 0) {
int const length = exprComment.matchedLength()
- (index - exprComment.pos(0));
setFormat(index, length, commentFormat);
exprComment.indexIn(text, index + length);
index = exprComment.pos(1);
}
// <LyX Warning: ...>
QString lyxwarn = qt_("LyX Warning: ");
QRegExp exprWarning("<" + lyxwarn + "[^<]*>");
index = exprWarning.indexIn(text);
while (index >= 0) {
int length = exprWarning.matchedLength();
setFormat(index, length, warningFormat);
index = exprWarning.indexIn(text, index + length);
}
}
} // namespace frontend
} // namespace lyx