qndefnfctextrecord.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 <qndefnfctextrecord.h>
 
#include <QtCore/QStringConverter>
#include <QtCore/QLocale>
 
QT_BEGIN_NAMESPACE
 
/*!
    \class QNdefNfcTextRecord
    \brief The QNdefNfcTextRecord class provides an NFC RTD-Text.
 
    \ingroup connectivity-nfc
    \inmodule QtNfc
    \since 5.2
 
    RTD-Text encapsulates a user displayable text record.
*/
 
/*!
    \enum QNdefNfcTextRecord::Encoding
 
    This enum describes the text encoding standard used.
 
    \value Utf8     The text is encoded with UTF-8.
    \value Utf16    The text is encoding with UTF-16.
*/
 
/*!
    \fn QNdefNfcTextRecord::QNdefNfcTextRecord()
 
    Constructs an empty NFC text record of type \l QNdefRecord::NfcRtd.
*/
 
/*!
    \fn QNdefNfcTextRecord::QNdefNfcTextRecord(const QNdefRecord& other)
 
    Constructs a new NFC text record that is a copy of \a other.
*/
 
/*!
    Returns the locale of the text record.
*/
QString QNdefNfcTextRecord::locale() const
{
    const QByteArray p = payload();
 
    if (p.isEmpty())
        return QString();
 
    const quint8 status = p.at(0);
 
    const quint8 codeLength = status & 0x3f;
 
    if (p.size() < 1 + codeLength)
        return QString();
 
    return QString::fromLatin1(p.constData() + 1, codeLength);
}
 
/*!
    Sets the locale of the text record to \a locale. Locales longer
    than 63 bytes will be truncated.
*/
void QNdefNfcTextRecord::setLocale(const QString &locale)
{
    QByteArray p = payload();
 
    const quint8 status = p.isEmpty() ? 0 : p.at(0);
 
    const quint8 codeLength = status & 0x3f;
 
    // Preserve encoding and RFU bits only (bits 7 and 6)
    const quint8 statusWithoutLanguageCodeLength = status & 0xc0;
 
    QByteArray localeData = locale.toLatin1();
    if (localeData.size() > 0x3f) {
        qWarning("QNdefNfcTextRecord::setLocale(): locale is %" PRIdQSIZETYPE " bytes long but max "
                 "is 63. Truncating it.", localeData.size());
        localeData.truncate(0x3f);
    }
 
    const quint8 newStatus = statusWithoutLanguageCodeLength | localeData.size();
 
    p[0] = newStatus;
    p.replace(1, codeLength, localeData);
 
    setPayload(p);
}
 
/*!
    Returns the contents of the text record as a string.
*/
QString QNdefNfcTextRecord::text() const
{
    const QByteArray p = payload();
 
    if (p.isEmpty())
        return QString();
 
    const quint8 status = p.at(0);
    const bool utf16 = status & 0x80;
    const quint8 codeLength = status & 0x3f;
 
    if (p.size() < 1 + codeLength)
        return QString();
 
    auto toUnicode = QStringDecoder(
        utf16 ? QStringDecoder::Encoding::Utf16BE : QStringDecoder::Encoding::Utf8,
        QStringDecoder::Flag::Stateless);
 
    return toUnicode(QByteArrayView(p.constData() + 1 + codeLength, p.size() - 1 - codeLength));
}
 
/*!
    Sets the contents of the text record to \a text.
*/
void QNdefNfcTextRecord::setText(const QString text)
{
    if (payload().isEmpty())
        setLocale(QLocale().name());
 
    QByteArray p = payload();
 
    const quint8 status = p.at(0);
 
    const bool utf16 = status & 0x80;
    const quint8 codeLength = status & 0x3f;
 
    p.truncate(1 + codeLength);
 
    auto fromUnicode = QStringEncoder(
        utf16? QStringEncoder::Encoding::Utf16BE : QStringEncoder::Encoding::Utf8,
        QStringEncoder::Flag::Stateless|QStringEncoder::Flag::WriteBom);
 
    p += fromUnicode(text);
 
    setPayload(p);
}
 
/*!
    Returns the encoding of the contents.
*/
QNdefNfcTextRecord::Encoding QNdefNfcTextRecord::encoding() const
{
    if (payload().isEmpty())
        return Utf8;
 
    QByteArray p = payload();
 
    const quint8 status = p.at(0);
 
    const bool utf16 = status & 0x80;
 
    if (utf16)
        return Utf16;
    else
        return Utf8;
}
 
/*!
    Sets the enconding of the contents to \a encoding.
*/
void QNdefNfcTextRecord::setEncoding(Encoding encoding)
{
    QByteArray p = payload();
 
    quint8 status = p.isEmpty() ? 0 : p.at(0);
 
    const QString string = text();
 
    if (encoding == Utf8)
        status &= ~0x80;
    else
        status |= 0x80;
 
    p[0] = status;
 
    setPayload(p);
 
    setText(string);
}
 
QT_END_NAMESPACE