qohosdisplayinfo.cpp

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// Copyright (C) 2025 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 <qohosdisplayinfo.h>
#include <QtCore/private/qnapi_p.h>
#include <qohosdeviceinfo_p.h>
 
QT_BEGIN_NAMESPACE
 
namespace
{
 
constexpr double mapPixelsToMillimeters(double pixels, double dpi)
{
    constexpr double millimetersPerInch = 25.4;
    return (pixels / dpi) * millimetersPerInch;
}
 
}
 
QOhosDisplayInfo QOhosDisplayInfo::makeFromOhosDisplayObject(QtOhos::JsState &jsState, QNapi::Object displayObject)
{
    constexpr auto forceEmptyTopLevelOffsetPixels  = true;
    constexpr auto minSupportedSdkVersionForSourceMode = 19;
 
    auto sourceMode = QOhosDeviceInfo::sdkApiVersion() >= minSupportedSdkVersionForSourceMode
        ? makeQOhosOptional(
            jsState.mapOhosEnumFromJs<DisplaySourceMode>(
                displayObject.get<QNapi::Number>("sourceMode")))
        : makeEmptyQOhosOptional();
 
    QOhosDisplayInfo result = {
        .id = JsDisplayId(displayObject.get<QNapi::Number>("id")),
        .name = QString::fromStdString(displayObject.get<QNapi::String>("name")),
        .sizePixels = QSizeF(
            displayObject.get<QNapi::Number>("width"),
            displayObject.get<QNapi::Number>("height")),
        .densityDPI = displayObject.get<QNapi::Number>("densityDPI"),
        .dpi = QDpi(
            displayObject.get<QNapi::Number>("xDPI"),
            displayObject.get<QNapi::Number>("yDPI")),
        .orientation = jsState.tryMapOhosEnumFromJs<JsDisplayOrientation>(
            displayObject.get<QNapi::Number>("orientation")),
        .sourceMode = sourceMode,
        .topLeftOffsetPixels = !forceEmptyTopLevelOffsetPixels
            ? sourceMode.andThen([&](DisplaySourceMode mode) {
                return mode == DisplaySourceMode::MAIN || mode == DisplaySourceMode::EXTEND
                    ? makeQOhosOptional(
                        QPoint(
                            displayObject.get<QNapi::Number>("x"),
                            displayObject.get<QNapi::Number>("y")))
                    : makeEmptyQOhosOptional();
            })
            : makeEmptyQOhosOptional()
    };
 
    // The value obtained via displayObject.get<QNapi::Number>("densityDPI") has only float precision.
    // However, since all high-DPI related calculations use double precision, this may introduce
    // rounding errors. Therefore, we calculate the DPI directly using the formula provided
    // in the documentation below.
    // https://developer.huawei.com/consumer/en/doc/harmonyos-references/js-apis-display#display
    result.densityPixels = result.densityScaled = result.densityDPI / 160.;
 
    return result;
}
 
QRect QOhosDisplayInfo::displayGeometryPixels() const
{
    return QRect(topLeftOffsetPixels.valueOr(QPoint()), sizePixels.toSize());
}
 
QSizeF QOhosDisplayInfo::physicalSize() const
{
    return QSizeF(
        mapPixelsToMillimeters(sizePixels.width(), dpi.first),
        mapPixelsToMillimeters(sizePixels.height(), dpi.second));
}
 
QT_END_NAMESPACE