/**************************************************************************
**
** This file is part of Qt Creator
**
** Copyright (c) 2012 Nokia Corporation and/or its subsidiary(-ies).
**
** Contact: http://www.qt-project.org/
**
**
** GNU Lesser General Public License Usage
**
** This file may be used under the terms of the GNU Lesser General Public
** License version 2.1 as published by the Free Software Foundation and
** appearing in the file LICENSE.LGPL included in the packaging of this file.
** Please review the following information to ensure the GNU Lesser General
** Public License version 2.1 requirements will be met:
** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Nokia gives you certain additional
** rights. These rights are described in the Nokia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** Other Usage
**
** Alternatively, this file may be used in accordance with the terms and
** conditions contained in a signed written agreement between you and Nokia.
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**************************************************************************/
#ifndef CPLUSPLUS_BACKWARDSSCANNER_H
#define CPLUSPLUS_BACKWARDSSCANNER_H

#include "SimpleLexer.h"

#include <QTextBlock>

QT_FORWARD_DECLARE_CLASS(QTextCursor)

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(),
                              bool skipComments = true);

    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;
};

} // namespace CPlusPlus

#endif // CPLUSPLUS_BACKWARDSSCANNER_H