Highlighting multiline text in quotes

MyNick 0

Code:

quotationFormat.setForeground(Qt::darkGreen);
rule.pattern = QRegularExpression(QStringLiteral("\".*\""));
rule.format = quotationFormat;
highlightingRules.append(rule);

highlights text only to the end of the line.
How to make any number of lines highlighted?

JonB

@MyNick-0
Difficult to know when the types of quotationFormat and highlightingRules are not mentioned....

In the absence of that, regular expression for that is usually

QStringLiteral("\"(.|\\n)*\"")

Or you can use the QRegularExpression::DotMatchesEverythingOption option from https://doc.qt.io/qt-5/qregularexpression.html#PatternOption-enum as an argument to QRegularExpression() and stick with your original pattern.

MyNick 0

this expression doesn't work for me.

You need to highlight several lines of subrad, for example:
"str 1
str 2
str 3"

JonB

@MyNick-0 said in Highlighting multiline text in quotes:

this expression doesn't work for me.

Who knows, since you still don't give any context....

Try matching the regular expression I gave you against a C string like "Hello\\nGoodbye\\nForever".

MyNick 0

i have code from documentation:

#include "highlighter.h"

Highlighter::Highlighter(QTextDocument *parent)
    : QSyntaxHighlighter(parent)
{
    HighlightingRule rule;

    //functionFormat.setFontItalic(true);
    //functionFormat.setFontWeight(QFont::Bold);
    functionFormat.setForeground(QColor(00, 00, 00));
    rule.pattern = QRegularExpression(QStringLiteral("\\b[A-Za-z0-9_]+(?=\\()"));
    rule.format = functionFormat;
    highlightingRules.append(rule);

    keywordFormat.setForeground(QColor(00, 80, 80));
    keywordFormat.setFontWeight(QFont::Bold);
    const QString keywordPatternsC[] = {
        QStringLiteral("\\becho\\b"), QStringLiteral("\\bclass\\b"), QStringLiteral("\\bconst\\b"),
        QStringLiteral("\\bdouble\\b"), QStringLiteral("\\benum\\b"), QStringLiteral("\\bexplicit\\b"),
        QStringLiteral("\\bfriend\\b"), QStringLiteral("\\binline\\b"), QStringLiteral("\\bint\\b"),
        QStringLiteral("\\blong\\b"), QStringLiteral("\\bnamespace\\b"), QStringLiteral("\\boperator\\b"),
        QStringLiteral("\\bprivate\\b"), QStringLiteral("\\bprotected\\b"), QStringLiteral("\\bpublic\\b"),
        QStringLiteral("\\bshort\\b"), QStringLiteral("\\bsignals\\b"), QStringLiteral("\\bsigned\\b"),
        QStringLiteral("\\bslots\\b"), QStringLiteral("\\bstatic\\b"), QStringLiteral("\\bstruct\\b"),
        QStringLiteral("\\btemplate\\b"), QStringLiteral("\\btypedef\\b"), QStringLiteral("\\btypename\\b"),
        QStringLiteral("\\bunion\\b"), QStringLiteral("\\bunsigned\\b"), QStringLiteral("\\bvirtual\\b"),
        QStringLiteral("\\bvoid\\b"), QStringLiteral("\\bvolatile\\b"), QStringLiteral("\\bbool\\b")
    };
    for (const QString &pattern : keywordPatterns) {
        rule.pattern = QRegularExpression(pattern);
        rule.format = keywordFormat;
        highlightingRules.append(rule);
    }

    classFormat.setFontWeight(QFont::Bold);
    classFormat.setForeground(Qt::darkMagenta);
    rule.pattern = QRegularExpression(QStringLiteral("\\bQ[A-Za-z]+\\b"));
    rule.format = classFormat;
    highlightingRules.append(rule);

    quotationFormat.setForeground(QColor(80, 00, 00));//Qt::darkGreen
    rule.pattern = QRegularExpression(QStringLiteral("\"(.|\\n)*\""));
    rule.format = quotationFormat;
    highlightingRules.append(rule);

    singleLineCommentFormat.setForeground(Qt::gray);
    rule.pattern = QRegularExpression(QStringLiteral("#[^\n]*|//[^\n]*"));//"//[^\n]*"
    rule.format = singleLineCommentFormat;
    highlightingRules.append(rule);

    multiLineCommentFormat.setForeground(Qt::gray);

    commentStartExpression = QRegularExpression(QStringLiteral("/\\*"));
    commentEndExpression = QRegularExpression(QStringLiteral("\\*/"));
}

void Highlighter::highlightBlock(const QString &text)
{
    for (const HighlightingRule &rule : qAsConst(highlightingRules)) {
        QRegularExpressionMatchIterator matchIterator = rule.pattern.globalMatch(text);
        while (matchIterator.hasNext()) {
            QRegularExpressionMatch match = matchIterator.next();
            setFormat(match.capturedStart(), match.capturedLength(), rule.format);
        }
    }
    setCurrentBlockState(0);

    int startIndex = 0;
    if (previousBlockState() != 1)
        startIndex = text.indexOf(commentStartExpression);

    while (startIndex >= 0) {
        QRegularExpressionMatch match = commentEndExpression.match(text, startIndex);
        int endIndex = match.capturedStart();
        int commentLength = 0;
        if (endIndex == -1) {
            setCurrentBlockState(1);
            commentLength = text.length() - startIndex;
        } else {
            commentLength = endIndex - startIndex
                            + match.capturedLength();
        }
        setFormat(startIndex, commentLength, multiLineCommentFormat);
        startIndex = text.indexOf(commentStartExpression, startIndex + commentLength);
    }
}

And I use it like this:

highlighter = new Highlighter(textEdit->document());

MyNick 0

My operating system, Windows 7 x64

JonB

@MyNick-0
This is a lot of code. I don't know why/whether the multiline does not work for you. I gave you the correct regular expression for you to test out. It's your job to reduce the code to minimal if you are having a problem.

Meanwhile, your "#[^\n]*|//[^\n]*" at least is wrong, I don't know whether that has any effect.

MyNick 0

i am using regex you gave me here:

quotationFormat.setForeground(QColor(80, 00, 00));
rule.pattern = QRegularExpression(QStringLiteral("\"(.|\\n)*\""));
rule.format = quotationFormat;
highlightingRules.append(rule);

JonB

@MyNick-0
I don't know about the behaviour of QSyntaxHighlighter which you have now started mentioning, not mentioned in your topic title or original question. The regular expression I gave should be right as a regular expression.

However, in your case of wanting leading & trailing " characters, and * being greedy, you would probably want something more like (even if it works)

"\"([^\"]|\\n)*\""

Even then it won't work right if your C literal string contain any embedded \" sequences....

Start by removing all your code except for this one and only one rule, while you see its behaviour/debug. Test that the reg ex I have given you does work against a multiline string, independent of anything to do with QSyntaxHighlighter.

Then, I think but don't know, read carefully what https://doc.qt.io/qt-5/qsyntaxhighlighter.html#details says:

Some syntaxes can have constructs that span several text blocks. For example, a C++ syntax highlighter should be able to cope with /*...*/ multiline comments. To deal with these cases it is necessary to know the end state of the previous text block (e.g. "in comment").

Since the quoted-string-multiline-format is similar to the C-comment-multiline-format, and the same code you are copying from has special code for that which does not use newline-in-regular-experssion, I'm guessing you need to implement multiline string in an analogous way to how that implements the code for its multiLineCommentFormat? It says:

But the multiline comment needs special care due to the design of the QSyntaxHighlighter class.