qcore_wasm.cpp

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// Copyright (C) 2022 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 <QtCore/qrect.h>
 
#include <emscripten/val.h>
 
#if !defined(Q_OS_WASM)
#error This is a wasm-only file.
#endif // !defined(Q_OS_WASM)
 
QT_BEGIN_NAMESPACE
 
QRectF QRectF::fromDOMRect(emscripten::val domRect)
{
    Q_ASSERT_X(domRect["constructor"]["name"].as<std::string>() == "DOMRect", Q_FUNC_INFO,
               "Passed object is not a DOMRect");
 
    return QRectF(domRect["left"].as<qreal>(), domRect["top"].as<qreal>(),
                  domRect["width"].as<qreal>(), domRect["height"].as<qreal>());
}
 
emscripten::val QRectF::toDOMRect() const
{
    return emscripten::val::global("DOMRect").new_(left(), top(), width(), height());
}
 
QString QString::fromJsString(emscripten::val jsString)
{
    Q_ASSERT_X(jsString.isString(), Q_FUNC_INFO, "Passed object is not a string");
 
    const double length = jsString["length"].as<double>();
 
    Q_ASSERT_X((double(uint64_t(length)) != double(uint64_t(length) - 1)
                && double(uint64_t(length)) != double(uint64_t(length) + 1))
                       || !std::numeric_limits<double>::is_iec559,
               Q_FUNC_INFO, "The floating-point length cannot precisely represent an integer");
 
    constexpr int zeroTerminatorLength = 1;
    const auto lengthOfUtf16 = (length + zeroTerminatorLength) * 2;
 
    Q_ASSERT_X((double(uint64_t(lengthOfUtf16)) != double(uint64_t(lengthOfUtf16) - 1)
                && double(uint64_t(lengthOfUtf16)) != double(uint64_t(lengthOfUtf16) + 1))
                       || !std::numeric_limits<double>::is_iec559,
               Q_FUNC_INFO,
               "The floating-point lengthOfUtf16 cannot precisely represent an integer");
 
    const QString result(uint64_t(length), Qt::Uninitialized);
 
    static const emscripten::val stringToUTF16(emscripten::val::module_property("stringToUTF16"));
    stringToUTF16(jsString, emscripten::val(quintptr(result.data())),
                  emscripten::val(lengthOfUtf16));
    return result;
}
 
emscripten::val QString::toJsString() const
{
    static const emscripten::val UTF16ToString(emscripten::val::module_property("UTF16ToString"));
    return UTF16ToString(emscripten::val(quintptr(utf16())));
}
 
QT_END_NAMESPACE