Method doSearch

src/TeXDocumentWindow.cpp:2602–2664

}

QTextCursor TeXDocumentWindow::doSearch(const QString& searchText, const QRegularExpression * regex, QTextDocument::FindFlags flags, int s, int e)
{
	QTextCursor curs;
	using pos_type = decltype(curs.position());
	QTextDocument * theDoc = textEdit->document();
	const QString& docText = textEdit->text();

	if ((flags & QTextDocument::FindBackward) != 0) {
		if (regex) {
			// this doesn't seem to match \n or even \x2029 for newline
			// curs = theDoc->find(*regex, e, flags);
			QRegularExpressionMatch m;
#if QT_VERSION >= 0x050500
			QString::size_type offset = docText.lastIndexOf(*regex, e, &m);
#else
			int offset = docText.lastIndexOf(*regex, e);
			if (offset >= 0)
				m = regex->match(docText, offset);
#endif
			while (offset >= s && m.capturedEnd() > e) {
#if QT_VERSION >= 0x050500
				offset = docText.lastIndexOf(*regex, offset - 1, &m);
#else
				offset = docText.lastIndexOf(*regex, offset - 1);
				if (offset >= 0)
					m = regex->match(docText, offset);
#endif
			}
			if (offset >= s) {
				curs = QTextCursor(textEdit->document());
				curs.setPosition(static_cast<pos_type>(m.capturedStart()));
				curs.setPosition(static_cast<pos_type>(m.capturedEnd()), QTextCursor::KeepAnchor);
			}
		}
		else {
			curs = theDoc->find(searchText, e, flags);
			if (!curs.isNull()) {
				if (curs.selectionEnd() > e)
					curs = theDoc->find(searchText, curs, flags);
				if (curs.selectionStart() < s)
					curs = QTextCursor();
			}
		}
	}
	else {
		if (regex) {
			// this doesn't seem to match \n or even \x2029 for newline
			// curs = theDoc->find(*regex, s, flags);
			QRegularExpressionMatch m = regex->match(docText, s);
			if (m.hasMatch()) {
				curs = QTextCursor(theDoc);
				curs.setPosition(static_cast<pos_type>(m.capturedStart()));
				curs.setPosition(static_cast<pos_type>(m.capturedEnd()), QTextCursor::KeepAnchor);
			}
		}
		else {
			curs = theDoc->find(searchText, s, flags);
		}