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#include "highlighter.h"

//! [0]
Highlighter::Highlighter(QTextDocument *parent)
    : QSyntaxHighlighter(parent)
{
    HighlightingRule rule;

    keywordFormat.setForeground(Qt::darkBlue);
    keywordFormat.setFontWeight(QFont::Bold);
    const QString keywordPatterns[] = {

        //import
        QStringLiteral("\\bimport\\b"),
        //1 QStringLiteral("\\bof\\b"),
        //1 QStringLiteral("\\bexport\\b"),
        //1 QStringLiteral("\\bstatic\\b"),
        QStringLiteral("\\bnum\\b"),
        QStringLiteral("\\bstring\\b"),
        QStringLiteral("\\bfunc\\b"),
        QStringLiteral("\\bbool\\b"),
        QStringLiteral("\\btrue\\b"),
        QStringLiteral("\\bfalse\\b"),
        QStringLiteral("\\bnull\\b"),
        QStringLiteral("\\bif\\b"),
        QStringLiteral("\\belif\\b"),
        QStringLiteral("\\belse\\b"),
        QStringLiteral("\\bfor\\b"),
        QStringLiteral("\\bwhile\\b"),
        QStringLiteral("\\bbreak\\b"),
        QStringLiteral("\\breturn\\b")

    };
    for (const QString &pattern : keywordPatterns) {
        rule.pattern = QRegularExpression(pattern);
        rule.format = keywordFormat;
        highlightingRules.append(rule);
//! [0] //! [1]
    }
//! [1]

//! [2]
    classFormat.setFontWeight(QFont::Bold);
    classFormat.setForeground(Qt::darkMagenta);
    rule.pattern = QRegularExpression(QStringLiteral("\\bQ[A-Za-z]+\\b"));
    rule.format = classFormat;
    highlightingRules.append(rule);
//! [2]

//! [3]
    singleLineCommentFormat.setForeground(QColor(255 , 0, 255));
    rule.pattern = QRegularExpression(QStringLiteral("//[^\n]*"));
    rule.format = singleLineCommentFormat;
    highlightingRules.append(rule);



    // red  red
    multiLineCommentFormat.setForeground(QColor(255 , 0, 255));
//! [3]

//! [4]
    quotationFormat.setForeground(Qt::darkGreen);
    rule.pattern = QRegularExpression(QStringLiteral("\".*\""));
    rule.format = quotationFormat;
    highlightingRules.append(rule);
//! [4]

//! [5]
    functionFormat.setFontItalic(true);
    functionFormat.setForeground(Qt::blue);
    rule.pattern = QRegularExpression(QStringLiteral("\\b[A-Za-z0-9_]+(?=\\()"));
    rule.format = functionFormat;
    highlightingRules.append(rule);
//! [5]

//! [6]
    commentStartExpression = QRegularExpression(QStringLiteral("/\\*"));
    commentEndExpression = QRegularExpression(QStringLiteral("\\*/"));
}
//! [6]

//! [7]
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);
        }
    }
//! [7] //! [8]
    setCurrentBlockState(0);
//! [8]

//! [9]
    int startIndex = 0;
    if (previousBlockState() != 1)
        startIndex = text.indexOf(commentStartExpression);

//! [9] //! [10]
    while (startIndex >= 0) {
//! [10] //! [11]
        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);
    }
}
//! [11]
