qt-creator/src/libs/utils/textutils.h

/****************************************************************************
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** Copyright (C) 2016 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
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** This file is part of Qt Creator.
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#pragma once

#include "linecolumn.h"
#include "utils_global.h"

#include <QString>
#include <QTextCursor>

QT_FORWARD_DECLARE_CLASS(QTextDocument)
QT_FORWARD_DECLARE_CLASS(QTextCursor)

namespace Utils {
namespace Text {

// line is 1-based, column is 0-based
QTCREATOR_UTILS_EXPORT bool convertPosition(const QTextDocument *document,
                                            int pos,
                                            int *line, int *column);
QTCREATOR_UTILS_EXPORT
OptionalLineColumn convertPosition(const QTextDocument *document, int pos);

// line and column are 1-based
QTCREATOR_UTILS_EXPORT int positionInText(QTextDocument *textDocument, int line, int column);

QTCREATOR_UTILS_EXPORT QString textAt(QTextCursor tc, int pos, int length);

QTCREATOR_UTILS_EXPORT QTextCursor selectAt(QTextCursor textCursor, uint line, uint column, uint length);

QTCREATOR_UTILS_EXPORT QTextCursor flippedCursor(const QTextCursor &cursor);

QTCREATOR_UTILS_EXPORT QTextCursor wordStartCursor(const QTextCursor &cursor);

template <class CharacterProvider>
void moveToPrevChar(CharacterProvider &provider, QTextCursor &cursor)
{
    cursor.movePosition(QTextCursor::PreviousCharacter);
    while (provider.characterAt(cursor.position()).isSpace())
        cursor.movePosition(QTextCursor::PreviousCharacter);
}

template <class CharacterProvider>
bool matchPreviousWord(CharacterProvider &provider, QTextCursor cursor, QString pattern)
{
    cursor.movePosition(QTextCursor::PreviousWord);
    while (provider.characterAt(cursor.position()) == ':')
        cursor.movePosition(QTextCursor::PreviousWord, QTextCursor::MoveAnchor, 2);

    int previousWordStart = cursor.position();
    cursor.movePosition(QTextCursor::NextWord);
    moveToPrevChar(provider, cursor);
    QString toMatch = provider.textAt(previousWordStart, cursor.position() - previousWordStart + 1);

    pattern = pattern.simplified();
    while (!pattern.isEmpty() && pattern.endsWith(toMatch)) {
        pattern.chop(toMatch.length());
        if (pattern.endsWith(' '))
            pattern.chop(1);
        if (!pattern.isEmpty()) {
            cursor.movePosition(QTextCursor::StartOfWord);
            cursor.movePosition(QTextCursor::PreviousWord);
            previousWordStart = cursor.position();
            cursor.movePosition(QTextCursor::NextWord);
            moveToPrevChar(provider, cursor);
            toMatch = provider.textAt(previousWordStart, cursor.position() - previousWordStart + 1);
        }
    }
    return pattern.isEmpty();
}

} // Text
} // Utils