QSyntaxHighlighter多行注释在文档中显示不正确。

Question

参考QT官网提供的语法高亮示例，我尝试在我的应用程序中实现（可以称之为复制粘贴）多行注释相同的逻辑。下面是多行注释高亮的代码：

在构造函数内：

quotationFormat.setForeground(QColor(164, 14, 14));
rule.pattern = QRegExp("\".*\"");
rule.format = quotationFormat;
highlightingRules.append(rule);

charFormat.setForeground(QColor(164, 14, 14));
rule.pattern = QRegExp("\'.*\'");
rule.format = charFormat;
highlightingRules.append(rule);

singleLineCommentFormat.setForeground(Qt::darkGreen);
rule.pattern = QRegExp("//[^\n]*");
rule.format = singleLineCommentFormat;
highlightingRules.append(rule);
multiLineCommentFormat.setForeground(Qt::darkGreen);

commentStartExpression = QRegExp("/\\*");
commentEndExpression = QRegExp("\\*/");

在highlightBlock()函数内部：

foreach (const HighlightingRule &rule, highlightingRules) {
    QRegExp expression(rule.pattern);
    int index = expression.indexIn(text);
    while (index >= 0) {
        int length = expression.matchedLength();
        setFormat(index, length, rule.format);
        index = expression.indexIn(text, index + length);
    }
}
setCurrentBlockState(0);

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

while (startIndex >= 0) {
    int endIndex = commentEndExpression.indexIn(text, startIndex);
    int commentLength;
    if (endIndex == -1) {
        setCurrentBlockState(1);
        commentLength = text.length() - startIndex;
    } else {
        commentLength = endIndex - startIndex
                        + commentEndExpression.matchedLength();
    }
    setFormat(startIndex, commentLength, multiLineCommentFormat);
    startIndex = commentStartExpression.indexIn(text, startIndex + commentLength);
}

但是我仍然遇到了一个问题，当/*出现在引号内时。它会以多行注释的颜色（绿色）一直持续到最后（/*.png" ] }）请参考以下示例文档内容：

{
    "code": [
        "./Code/Main.js"
    ],

    "textures": [
        "./Content/*.png"
    ]
}

我不是正则表达式的专家，但我猜测这个正则表达式有问题。

- gmuhammad

---

我是不是在这个宇宙中唯一面临这个问题的人？:( - gmuhammad

Answer 1

我经过一些运气和努力找到了一个解决方法（但仍然不能涵盖所有情况）

    int MySyntaxHighlighter::getCommentStartIndex(const QString &text, const int offset)
    {
        int startIndex = -1;

        qDebug() << "offset: " << offset;

        if(text.length() > 1 && offset < (text.length() - 1)) {

            int commentStartIndex = commentStartExpression.indexIn(text, offset);
            qDebug() << "commentStartIndex: " << commentStartIndex;

            QRegExp quotationExpression(quotationRule.pattern);

            int quotationStartIndex = quotationExpression.indexIn(text, offset);
            qDebug() << "quotationStartIndex: " << quotationStartIndex;

            if (quotationStartIndex >= 0) {

                int quotationLength = quotationExpression.matchedLength();
                qDebug() << "quotationLength: " << quotationLength;

                if(commentStartIndex > quotationStartIndex &&
                        commentStartIndex < (quotationStartIndex + quotationLength)) {

                    startIndex = getCommentStartIndex(text, (commentStartIndex + 2));
                } else {
                    startIndex = commentStartIndex;
                }
            } else if(commentStartIndex >= 0) {
                startIndex = commentStartIndex;
            } else {
                startIndex = -1;
            }
        }

        qDebug() << "startIndex: " << startIndex;

        return startIndex;
    }

    void MySyntaxHighlighter::highlightBlock(const QString &text)
    {
        setCurrentBlockState(0);

        qDebug() << "text: " << text;
        qDebug() << "previousBlockState(): " << previousBlockState();

        int startIndex = 0;
        if (previousBlockState() != 1) {
//        startIndex = commentEndExpression.indexIn(text);
            startIndex = getCommentStartIndex(text, 0);
        }

        while (startIndex >= 0) {
            int endIndex = commentEndExpression.indexIn(text, startIndex);
            int commentLength;
            if (endIndex == -1) {
                setCurrentBlockState(1);
                commentLength = text.length() - startIndex;
            } else {
                commentLength = endIndex - startIndex
                                + commentEndExpression.matchedLength();
            }
            setFormat(startIndex, commentLength, multiLineCommentFormat);

    //        startIndex = commentStartExpression.indexIn(text, startIndex + commentLength);
            startIndex = getCommentStartIndex(text, startIndex + commentLength);
        }    
    }

如果有人找到更好的解决方案，请与我分享。

- gmuhammad