qt-creator/src/libs/cplusplus/BackwardsScanner.h

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#ifndef CPLUSPLUS_BACKWARDSSCANNER_H
#define CPLUSPLUS_BACKWARDSSCANNER_H

#include "SimpleLexer.h"

#include <QtGui/QTextCursor>
#include <QtGui/QTextBlock>

namespace CPlusPlus {

class CPLUSPLUS_EXPORT BackwardsScanner
{
    enum { MAX_BLOCK_COUNT = 10 };

public:
    explicit BackwardsScanner(const QTextCursor &cursor,
                              int maxBlockCount = MAX_BLOCK_COUNT,
                              const QString &suffix = QString());

    int startToken() const;

    int startPosition() const;

    QString text() const;
    QString mid(int index) const;

    QString text(int index) const;
    QStringRef textRef(int index) const;
    // 1-based
    Token LA(int index) const;

    // n-la token is [startToken - n]
    Token operator[](int index) const; // ### deprecate

    QString indentationString(int index) const;

    int startOfLine(int index) const;
    int startOfMatchingBrace(int index) const;
    int startOfBlock(int index) const;

    int size() const;

    static int previousBlockState(const QTextBlock &block);

private:
    const Token &fetchToken(int tokenIndex);

private:
    QList<Token> _tokens;
    int _offset;
    int _blocksTokenized;
    QTextBlock _block;
    SimpleLexer _tokenize;
    QString _text;
    int _maxBlockCount;
    int _startToken;
};

} // end of namespace CPlusPlus

#endif // CPLUSPLUS_BACKWARDSSCANNER_H