qtextlist.cpp

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// Copyright (C) 2016 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
 
 
#include "qtextlist.h"
#include "qtextobject_p.h"
#include "qtextcursor.h"
#include "qtextdocument_p.h"
#include <qdebug.h>
 
QT_BEGIN_NAMESPACE
 
using namespace Qt::StringLiterals;
 
class QTextListPrivate : public QTextBlockGroupPrivate
{
public:
    QTextListPrivate(QTextDocument *doc)
        : QTextBlockGroupPrivate(doc)
    {
    }
};
 
QTextList::QTextList(QTextDocument *doc)
    : QTextBlockGroup(*new QTextListPrivate(doc), doc)
{
}
 
QTextList::~QTextList()
{
}
 
int QTextList::count() const
{
    Q_D(const QTextList);
    return d->blocks.size();
}
 
QTextBlock QTextList::item(int i) const
{
    Q_D(const QTextList);
    if (i < 0 || i >= d->blocks.size())
        return QTextBlock();
    return d->blocks.at(i);
}
 
int QTextList::itemNumber(const QTextBlock &blockIt) const
{
    Q_D(const QTextList);
    return d->blocks.indexOf(blockIt);
}
 
QString QTextList::itemText(const QTextBlock &blockIt) const
{
    Q_D(const QTextList);
    int item = d->blocks.indexOf(blockIt) + 1;
    if (item <= 0)
        return QString();
 
    QTextBlock block = d->blocks.at(item-1);
    QTextBlockFormat blockFormat = block.blockFormat();
 
    QString result;
 
    const int style = format().style();
    QString numberPrefix;
    QString numberSuffix = u"."_s;
 
    // the number of the item might be offset by start, which defaults to 1
    const int itemNumber = item + format().start() - 1;
 
    if (format().hasProperty(QTextFormat::ListNumberPrefix))
        numberPrefix = format().numberPrefix();
    if (format().hasProperty(QTextFormat::ListNumberSuffix))
        numberSuffix = format().numberSuffix();
 
    switch (style) {
        case QTextListFormat::ListDecimal:
            result = QString::number(itemNumber);
            break;
            // from the old richtext
        case QTextListFormat::ListLowerAlpha:
        case QTextListFormat::ListUpperAlpha:
            {
                // match the html default behavior of falling back to decimal numbers
                if (itemNumber < 1) {
                    result = QString::number(itemNumber);
                    break;
                }
 
                const char baseChar = style == QTextListFormat::ListUpperAlpha ? 'A' : 'a';
 
                int c = itemNumber;
                while (c > 0) {
                    c--;
                    result.prepend(QChar::fromUcs2(baseChar + (c % 26)));
                    c /= 26;
                }
            }
            break;
        case QTextListFormat::ListLowerRoman:
        case QTextListFormat::ListUpperRoman:
            {
                // match the html default behavior of falling back to decimal numbers
                if (itemNumber < 1) {
                    result = QString::number(itemNumber);
                } else if (itemNumber < 5000) {
                    QString romanNumeral;
 
                    // works for up to 4999 items
                    QLatin1StringView romanSymbols;
                    if (style == QTextListFormat::ListLowerRoman)
                        romanSymbols = "iiivixxxlxcccdcmmmm"_L1;
                    else
                        romanSymbols = "IIIVIXXXLXCCCDCMMMM"_L1;
 
                    int c[] = { 1, 4, 5, 9, 10, 40, 50, 90, 100, 400, 500, 900, 1000 };
                    int n = itemNumber;
                    for (int i = 12; i >= 0; n %= c[i], i--) {
                        int q = n / c[i];
                        if (q > 0) {
                            int startDigit = i + (i+3)/4;
                            int numDigits;
                            if (i % 4) {
                                // c[i] == 4|5|9|40|50|90|400|500|900
                                if ((i-2) % 4) {
                                    // c[i] == 4|9|40|90|400|900 => with subtraction (IV, IX, XL, XC, ...)
                                    numDigits = 2;
                                }
                                else {
                                    // c[i] == 5|50|500 (V, L, D)
                                    numDigits = 1;
                                }
                            }
                            else {
                                // c[i] == 1|10|100|1000 (I, II, III, X, XX, ...)
                                numDigits = q;
                            }
 
                            romanNumeral.append(romanSymbols.sliced(startDigit, numDigits));
                        }
                    }
                    result = std::move(romanNumeral);
                } else {
                    result = u"?"_s;
                }
 
            }
            break;
        default:
            Q_ASSERT(false);
    }
    if (blockIt.textDirection() == Qt::RightToLeft)
        return numberSuffix + result + numberPrefix;
    else
        return numberPrefix + result + numberSuffix;
}
 
void QTextList::removeItem(int i)
{
    Q_D(QTextList);
    if (i < 0 || i >= d->blocks.size())
        return;
 
    QTextBlock block = d->blocks.at(i);
    remove(block);
}
 
 
void QTextList::remove(const QTextBlock &block)
{
    QTextBlockFormat fmt = block.blockFormat();
    fmt.setIndent(fmt.indent() + format().indent());
    fmt.setObjectIndex(-1);
    const_cast<QTextDocumentPrivate *>(QTextDocumentPrivate::get(block))->setBlockFormat(block, block, fmt, QTextDocumentPrivate::SetFormat);
}
 
void QTextList::add(const QTextBlock &block)
{
    QTextBlockFormat fmt = block.blockFormat();
    fmt.setObjectIndex(objectIndex());
    const_cast<QTextDocumentPrivate *>(QTextDocumentPrivate::get(block))->setBlockFormat(block, block, fmt, QTextDocumentPrivate::SetFormat);
}
 
QT_END_NAMESPACE
 
#include "moc_qtextlist.cpp"