dquickimageprovider.cpp

// SPDX-FileCopyrightText: 2020 - 2022 UnionTech Software Technology Co., Ltd.
//
// SPDX-License-Identifier: LGPL-3.0-or-later

#include "dqmlglobalobject_p.h"
#include "dquickimageprovider_p.h"

#include <DIconTheme>
#include <DDciIcon>
#include <DGuiApplicationHelper>
#include <DPlatformTheme>
#include <DSGApplication>

#include <QIcon>
#include <QUrlQuery>
#include <QPainter>
#include <QPainterPath>
#include <QtMath>
#include <QFile>

#include <private/dquickdciiconimage_p.h>

#include <cmath>

DQUICK_BEGIN_NAMESPACE
DGUI_USE_NAMESPACE
DCORE_USE_NAMESPACE

static inline QImage invalidIcon(QSize *size, const QSize &requestedSize) {
    QIcon icon = DIconTheme::findQIcon("application-x-desktop");
    const QImage img = icon.pixmap(requestedSize).toImage();
    *size = img.size();
    return img;
}

static QImage requestImageFromQIcon(const QString &id, QSize *size, const QSize &requestedSize) {
    QUrlQuery urlQuery(id);
    QString name = urlQuery.queryItemValue("name");

    if (name.isEmpty())
        return QImage();

    QIcon icon;
    if (auto cached = DIconTheme::cached()) {
        icon = cached->findQIcon(name);
    } else {
        icon = DIconTheme::findQIcon(name);
    }

    QIcon::Mode qMode = QIcon::Normal;
    QIcon::State qState = QIcon::Off;

    if (urlQuery.hasQueryItem("mode"))
        qMode = static_cast<QIcon::Mode>(urlQuery.queryItemValue("mode").toInt());

    if (urlQuery.hasQueryItem("state"))
        qState = static_cast<QIcon::State>(urlQuery.queryItemValue("state").toInt());

    // 获取图标的缩放比例
    qreal devicePixelRatio = 1.0;
    if (urlQuery.hasQueryItem("devicePixelRatio")) {
        devicePixelRatio = urlQuery.queryItemValue("devicePixelRatio").toDouble();
        if (qIsNull(devicePixelRatio))
            devicePixelRatio = 1.0;
    }

    if (icon.isNull()) {
        QSize icon_size = requestedSize;
        return invalidIcon(size, icon_size /= devicePixelRatio);
    }

    QSize icon_size = requestedSize;
    // 初始时可能没有为图标设置期望的大小
    if (icon_size.isEmpty()) {
        const auto &sizes = icon.availableSizes(qMode, qState);
        if (!sizes.isEmpty())
            icon_size = sizes.first();
    } else {
        // 因为传入的requestedSize是已经乘过缩放的, 因此此处要除以缩放比例获取真实的图标大小
        icon_size /= devicePixelRatio;
    }

    QImage image(icon_size * devicePixelRatio, QImage::Format_ARGB32);
    image.setDevicePixelRatio(devicePixelRatio);
    image.fill(Qt::transparent);
    QPainter painter(&image);

    QColor color(urlQuery.queryItemValue("color"));
    // Fixed filling icon when color is transparent.
    if (color.isValid() && color.alpha() > 0)
        painter.setPen(color);

    // 务必要使用paint的方式获取图片, 有部分可变色的图标类型, 在图标引擎中会使用QPainter::pen的颜色
    // 作为图标的填充颜色
    icon.paint(&painter, QRect(QPoint(0, 0), icon_size), Qt::AlignCenter, qMode, qState);

    if (size)
        *size = icon_size;

    return image;
}

static QImage generateDciIconImage(const QImage &src, DDciIcon::Theme theme, DDciIcon::Mode mode) {
    Q_UNUSED(theme)
    qint8 hue = 0, saturation = 0, lightness = 0,
          red = 0, green = 0, blue = 0, alpha = 0;
    switch (mode) {
    case DDciIcon::Hover:
        lightness += 10;
        break;
    case DDciIcon::Pressed:
        lightness -= 10;
        break;
    default:
        return src;
    }

    return DGuiApplicationHelper::adjustColor(src, hue, saturation, lightness, red, green, blue, alpha);

}

DQuickIconProvider::DQuickIconProvider()
    : QQuickImageProvider(QQuickImageProvider::Image)
{

}

QImage DQuickIconProvider::requestImage(const QString &id, QSize *size, const QSize &requestedSize)
{
    return requestImageFromQIcon(id, size, requestedSize);
}

DQuickDciIconProvider::DQuickDciIconProvider()
    : QQuickImageProvider(QQuickImageProvider::Image)
{
}

static inline DDciIcon::Theme toDciTheme(DGuiApplicationHelper::ColorType type) {
    return type == DGuiApplicationHelper::DarkType ? DDciIcon::Dark : DDciIcon::Light;
}
/*!
    \internal
    \brief A function that handles DCI icon for use in QML.

    This provider is added when the dtk qml plugin construction
    and use to generate the icon resource data needed in the \a id.
    This function adds icon of specified size for the different states,
    topics, types, and other attributes needed in the id.

    \note You should not add a wrong DCI icon here.
 */
QImage DQuickDciIconProvider::requestImage(const QString &id, QSize *size, const QSize &requestedSize)
{
    QUrlQuery urlQuery(id);
    QString name = urlQuery.queryItemValue("name");
    if (name.isEmpty())
        return QImage();

    if (!DSGApplication::id().isEmpty()) {
        // allow the icon theme to override the icon for a given application
        name.prepend(DSGApplication::id() + "/");
    }

    const QString themeName = urlQuery.queryItemValue("themeName");
    QString iconPath;
    if (auto cached = DIconTheme::cached()) {
        iconPath = cached->findDciIconFile(name, themeName);
    } else {
        iconPath = DIconTheme::findDciIconFile(name, themeName);
    }

    const bool fallbackToQIcon = urlQuery.queryItemValue("fallbackToQIcon").toInt();

    if (Q_UNLIKELY(iconPath.isEmpty())) {
        if (!fallbackToQIcon)
            return invalidIcon(size, requestedSize);
        // Fallback to normal qicon.
       return requestImageFromQIcon(id, size, requestedSize);
    }
    DDciIcon dciIcon(iconPath);
    if (dciIcon.isNull()) {
        if (!fallbackToQIcon)
            return invalidIcon(size, requestedSize);
        return requestImageFromQIcon(id, size, requestedSize);
    }

    DDciIcon::Mode mode = DDciIcon::Normal;
    if (urlQuery.hasQueryItem("mode")) {
        int modeValue = urlQuery.queryItemValue("mode").toInt();
        switch (modeValue) {
        case DQMLGlobalObject::NormalState:
            mode = DDciIcon::Normal;
            break;
        case DQMLGlobalObject::DisabledState:
            mode = DDciIcon::Disabled;
            break;
        case DQMLGlobalObject::HoveredState:
            mode = DDciIcon::Hover;
            break;
        case DQMLGlobalObject::PressedState:
            mode = DDciIcon::Pressed;
            break;
        default:
            break;
        }
    }

    auto theme = DGuiApplicationHelper::ColorType::UnknownType;
    if (urlQuery.hasQueryItem("theme"))
        theme = static_cast<DGuiApplicationHelper::ColorType>(urlQuery.queryItemValue("theme").toInt());

    if (theme == DGuiApplicationHelper::ColorType::UnknownType) {
        QColor window = DGuiApplicationHelper::instance()->applicationPalette().window().color();
        theme = DGuiApplicationHelper::toColorType(window);
    }

    // Get the icon pixel ratio
    qreal devicePixelRatio = 1.0;
    if (urlQuery.hasQueryItem("devicePixelRatio")) {
        devicePixelRatio = urlQuery.queryItemValue("devicePixelRatio").toDouble();
        if (qIsNull(devicePixelRatio))
            devicePixelRatio = 1.0;
    }

    DDciIconPalette palette;
    if (urlQuery.hasQueryItem("palette")) {
        palette = DDciIconPalette::convertFromString(urlQuery.queryItemValue("palette"));
    }

    // If the target mode icon didn't found, we should find the normal mode icon
    // and decorate to the target mode.

    // When the application uses the AA_UseHighDpiPixmaps attribute,
    // the boundingSize should typically divide by devicePixelRatio,
    // see Qt::AA_UseHighDpiPixmaps.
    int boundingSize = qMax(requestedSize.width(), requestedSize.height());
#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
    if (qApp->testAttribute(Qt::AA_UseHighDpiPixmaps)) {
        boundingSize = qRound(boundingSize / devicePixelRatio);
    }
#else
    boundingSize = qRound(boundingSize / devicePixelRatio);
#endif

    const auto currentTheme = toDciTheme(theme);
    auto currentMode = mode;
    DDciIconMatchResult result = dciIcon.matchIcon(boundingSize, currentTheme, currentMode, DDciIcon::DontFallbackMode);
    if (!result) {
        currentMode = DDciIcon::Normal;
        result = dciIcon.matchIcon(boundingSize, currentTheme, currentMode);
    }

    if (!result)
        return invalidIcon(size, requestedSize);

    const QPixmap &pixmap = dciIcon.pixmap(devicePixelRatio, boundingSize, result, palette);
    if (pixmap.isNull())
        return invalidIcon(size, requestedSize);

    QImage image = pixmap.toImage();
    if (currentMode != mode && currentMode == DDciIcon::Normal
            && !dciIcon.isSupportedAttribute(result, DDciIcon::HasPalette))
        image = generateDciIconImage(image, currentTheme, mode);

    if (size)
        *size = image.size();
    return image;
}

class ShadowImage : public QSharedData {
public:
    ShadowImage(DQuickShadowProvider *sp, const DQuickShadowProvider::ShadowConfig &c, const QImage &data)
        : sp(sp)
        , config(c)
        , image(data)
    {
        sp->cache.insert(config, this);
    }

    ~ShadowImage() {
        sp->cache.remove(config);
    }

    DQuickShadowProvider *sp;
    DQuickShadowProvider::ShadowConfig config;
    QImage image;
};

DQuickShadowProvider::DQuickShadowProvider()
    : QQuickImageProvider(QQuickImageProvider::Image,
                          QQuickImageProvider::ForceAsynchronousImageLoading)
{

}

DQuickShadowProvider::~DQuickShadowProvider()
{
    qDeleteAll(cache.values());
}

QUrl DQuickShadowProvider::toUrl(qreal boxSize, qreal topLeftRadius, qreal topRightRadius, qreal bottomLeftRadius, qreal bottomRightRadius, qreal shadowBlur, QColor color,
                                 qreal xOffset, qreal yOffset, qreal spread, bool hollow, bool inner)
{
    QUrl url;
    url.setScheme("image");
    url.setHost("dtk.shadow");
    QUrlQuery args;
    args.setQueryItems({
                           {"boxSize", QString::number(boxSize)},
                           {"topLeftRadius", QString::number(topLeftRadius)},
                           {"topRightRadius", QString::number(topRightRadius)},
                           {"bottomLeftRadius", QString::number(bottomLeftRadius)},
                           {"bottomRightRadius", QString::number(bottomRightRadius)},
                           {"shadowBlur", QString::number(shadowBlur)},
                           {"color", color.name(QColor::HexArgb)},
                           {"xOffset", QString::number(xOffset)},
                           {"yOffset", QString::number(yOffset)},
                           {"spread", QString::number(spread)},
                           {"hollow", QString::number(static_cast<uint>(hollow))},
                           {"inner", QString::number(static_cast<uint>(inner))}
                       });
    url.setQuery(args);
    return url;
}

inline static bool getNumberFromString(const QString &string, qreal *number) {
    bool ok = false;
    *number = string.toDouble(&ok);
    return ok;
}

inline static bool getNumberFromString(const QString &string, bool *number) {
    bool ok = false;
    *number = string.toUInt(&ok);
    return ok;
}

static bool fromString(const QString &string, DQuickShadowProvider::ShadowConfig &config,
                       QColor *color, qreal *xOffset, qreal *yOffset, bool *hollow, bool *inner)
{
    QUrlQuery args(string);

    if (!getNumberFromString(args.queryItemValue("boxSize"), &config.boxSize))
        return false;
    if (!getNumberFromString(args.queryItemValue("topLeftRadius"), &config.topLeftRadius))
        return false;
    if (!getNumberFromString(args.queryItemValue("topRightRadius"), &config.topRightRadius))
        return false;
    if (!getNumberFromString(args.queryItemValue("bottomLeftRadius"), &config.bottomLeftRadius))
        return false;
    if (!getNumberFromString(args.queryItemValue("bottomRightRadius"), &config.bottomRightRadius))
        return false;
    if (!getNumberFromString(args.queryItemValue("shadowBlur"), &config.blurRadius))
        return false;
    if (!getNumberFromString(args.queryItemValue("xOffset"), xOffset))
        return false;
    if (!getNumberFromString(args.queryItemValue("yOffset"), yOffset))
        return false;
    if (!getNumberFromString(args.queryItemValue("spread"), &config.spread))
        return false;
    if (!getNumberFromString(args.queryItemValue("hollow"), hollow))
        return false;
    if (!getNumberFromString(args.queryItemValue("inner"), inner))
        return false;

    const QString colorName = args.queryItemValue("color");
    if (colorName.isEmpty())
        return false;

    *color = QColor(colorName);
    if (!color->isValid())
        return false;

    return true;
}

static QPainterPath roundedRectPath(const QRectF &rect,
                                    qreal topLeftRadius,
                                    qreal topRightRadius,
                                    qreal bottomLeftRadius,
                                    qreal bottomRightRadius)
{
    QPainterPath roundedPath;
    roundedPath.addRect(rect);

    const auto width = rect.width();
    const auto height = rect.height();

    QPainterPath path;
    if (topLeftRadius > 0.0) {
        int radius = topLeftRadius;
        path.moveTo(0, 0);
        path.arcTo(0, 0,  radius * 2,  radius * 2, 90, 90);
        path.lineTo(0, 0);
    }

    if (topRightRadius > 0.0) {
        int radius = topRightRadius;
        path.moveTo(width, 0);
        QRectF rect1(width -  radius * 2, 0, radius * 2,  radius * 2);
        path.arcTo(rect1, 0, 90);
        path.lineTo(width, 0);
    }

    if (bottomLeftRadius > 0.0) {
        int radius = bottomLeftRadius;
        path.moveTo(0, height);
        QRectF rect2(0, height -  radius * 2, radius * 2, radius * 2);
        path.arcTo(rect2, 180, 90);
        path.lineTo(0, height);
    }

    if (bottomRightRadius > 0.0) {
        int radius = bottomRightRadius;
        path.moveTo(width, height);
        QRectF f2(width -  radius * 2, height - radius * 2, radius * 2,  radius * 2);
        path.arcTo(f2, 270, 90);
        path.lineTo(width,  height);
    }

    if (!path.isEmpty()) {
        path.translate(rect.x(), rect.y());
        roundedPath = roundedPath - path;
    }
    return roundedPath;
}

static QPainterPath roundedRectPath(const QRectF &rect, const DQuickShadowProvider::ShadowConfig &config)
{
    return roundedRectPath(rect, config.topLeftRadius, config.topRightRadius, config.bottomLeftRadius, config.bottomRightRadius);
}

QImage DQuickShadowProvider::requestImage(const QString &id, QSize *size, const QSize &requestedSize)
{
    Q_UNUSED(requestedSize)
    ShadowConfig config;
    QColor color;
    qreal xOffset;
    qreal yOffset;
    bool hollow;
    bool isInner;

    QImage image;

    do {
        if (!fromString(id, config, &color, &xOffset, &yOffset, &hollow, &isInner)) {
            break;
        }

        if (isInner)
            config.type |= Inner;

        auto shadow = getRawShadow(config);
        if (!shadow)
            break;

        const qreal shadowSize = config.boxSize + config.blurRadius * (config.isInner() ? 2 : 4)
                + (config.isInner() ? 0 : 2 * config.spread);
        image = QImage(qRound(shadowSize), qRound(shadowSize), QImage::Format_ARGB32_Premultiplied);
        image.fill(Qt::transparent);
        QRectF shadowRect(image.rect());
        shadowRect.moveCenter(QRectF(shadow->image.rect()).center());

        QPainter painter(&image);
        painter.setRenderHint(QPainter::Antialiasing, true);
        painter.setPen(Qt::NoPen);

        QPainterPath clipPath = roundedRectPath(image.rect(), config);
        painter.setClipPath(clipPath);

        QPointF offset(xOffset, yOffset);
        if (config.isInner()) {
            shadowRect.translate(-offset);
        }

        painter.setCompositionMode(QPainter::CompositionMode_Source);
        painter.drawImage(QPointF(0, 0), shadow->image, shadowRect);
        painter.end();

        // draw color
        painter.begin(&image);
        painter.setCompositionMode(QPainter::CompositionMode_SourceIn);
        painter.fillRect(image.rect(), color);
        painter.end();

        if (hollow && !config.isInner()) {
            painter.begin(&image);
            painter.setRenderHint(QPainter::Antialiasing, true);
            painter.setCompositionMode(QPainter::CompositionMode_Clear);
            painter.setPen(Qt::NoPen);
            painter.setBrush(color);
            QRectF boxRect(0, 0, image.width() - 2 * (config.blurRadius + config.spread),
                           image.height() - 2 * (config.blurRadius + config.spread));
            boxRect.moveCenter(QRectF(image.rect()).center() - offset);

            painter.drawPath(roundedRectPath(boxRect, config));

            painter.end();
        }
    } while (false);

    if (size)
        *size = image.size();

    return image;
}

/**
 * @brief calculateEffectiveBlurRadius get blur Factor
 * Refer to KDE breeze project and Firefox
 * @param radius shaodw blur Radius
 * @return
 */
static inline int calculateEffectiveBlurRadius(qreal radius)
{
    // https://www.w3.org/TR/css-backgrounds-3/#shadow-blur
    const qreal stdDeviation = radius * 0.5;
    // https://www.w3.org/TR/SVG11/filters.html#feGaussianBlurElement
    const qreal gaussianScaleFactor = (3.0 * M_SQRT2 * qSqrt(M_PI) / 4.0) * 1.5;
    return qMax(2, qFloor(stdDeviation * gaussianScaleFactor + 0.5));
}

typedef QPair<int, int> BoxFilters;

static QVector<BoxFilters> computeBoxFilter(int radius)
{
    int major;
    int minor;
    int final;

    const int averageFactor = 3;
    const int blurRadius = calculateEffectiveBlurRadius(radius);
    const int radiusFactor = blurRadius / averageFactor;

    if (blurRadius % averageFactor < averageFactor) {
        major = radiusFactor + (blurRadius % averageFactor == 0 ? 0 : 1);
        minor = radiusFactor;
        final = radiusFactor + (blurRadius % averageFactor == 2 ? 1 : 0);
    } else {
        Q_UNREACHABLE();
    }

    Q_ASSERT(major + minor + final == blurRadius);

    return {
        {major, minor},
        {minor, major},
        {final, final}
    };
}

static inline void imageConvoluteFilter(const uint8_t *startRow, uint8_t *destination, int rowWidth, int horizontalStride,
                                   int verticalStride, const BoxFilters &boxFilter, bool transposeInput, bool transposeOutput)
{
    const int inputStep = transposeInput ? verticalStride : horizontalStride;
    const int outputStep = transposeOutput ? verticalStride : horizontalStride;
    const int boxSize = boxFilter.first + 1 + boxFilter.second;
    const int reciprocal = (1 << 24) / boxSize;

    uint32_t alphaSum = uint32_t((boxSize + 1) / 2);

    const uint8_t *leftRow = startRow;
    const uint8_t *rightRow = startRow;
    uint8_t *outDestination = destination;

    const uint8_t firstValue = startRow[0];
    const uint8_t lastValue = startRow[(rowWidth - 1) * inputStep];

    alphaSum += uint32_t(firstValue * boxFilter.first);

    const uint8_t *initEnd = startRow + (boxSize - boxFilter.first) * inputStep;
    while (rightRow < initEnd) {
        alphaSum += *rightRow;
        rightRow += inputStep;
    }

    const uint8_t *leftEnd = startRow + boxSize * inputStep;
    while (rightRow < leftEnd) {
        *outDestination = (alphaSum * uint32_t(reciprocal)) >> 24;
        alphaSum += *rightRow - firstValue;
        rightRow += inputStep;
        outDestination += outputStep;
    }

    const uint8_t *centerEnd = startRow + rowWidth * inputStep;
    while (rightRow < centerEnd) {
        *outDestination = (alphaSum * uint32_t(reciprocal)) >> 24;
        alphaSum += *rightRow - *leftRow;
        leftRow += inputStep;
        rightRow += inputStep;
        outDestination += outputStep;
    }

    const uint8_t *rightEnd = destination + rowWidth * outputStep;
    while (outDestination < rightEnd) {
        *outDestination = (alphaSum * uint32_t(reciprocal)) >> 24;
        alphaSum += lastValue - *leftRow;
        leftRow += inputStep;
        outDestination += outputStep;
    }
}

static inline void doBoxShdowBlur(QImage &image, int radius, const QRect &rect = QRect())
{
    if (radius < 2) {
        return;
    }

    const QVector<BoxFilters> filters = computeBoxFilter(radius);
    const QRect blurRect = rect.isNull() ? image.rect() : rect;
    const int alphaOffset = (image.depth() == 8 || QSysInfo::ByteOrder == QSysInfo::BigEndian) ? 0 : 3;
    const int blurWidth = blurRect.width();
    const int blurHeight = blurRect.height();
    const int widthStride = image.bytesPerLine();
    const int pixelBPP = image.depth() >> 3;

    // the amount of memory space occupied by row pixels or column pixels
    const int maxStride = qMax(blurWidth, blurHeight) * pixelBPP;
    QScopedPointer<uint8_t, QScopedPointerArrayDeleter<uint8_t> > twoStride(new uint8_t[2 * maxStride]);
    uint8_t *nextStride = twoStride.data() + maxStride;

    for (int i = 0; i < blurHeight; ++i) {
        uint8_t *row = image.scanLine(blurRect.y() + i) + blurRect.x() * pixelBPP + alphaOffset;
        imageConvoluteFilter(row, twoStride.data(), blurWidth, pixelBPP, widthStride, filters[0], false, false);
        imageConvoluteFilter(twoStride.data(), nextStride, blurWidth, pixelBPP, widthStride, filters[1], false, false);
        imageConvoluteFilter(nextStride, row, blurWidth, pixelBPP, widthStride, filters[2], false, false);
    }

    for (int i = 0; i < blurWidth; ++i) {
        uint8_t *column = image.scanLine(blurRect.y()) + (blurRect.x() + i) * pixelBPP + alphaOffset;
        imageConvoluteFilter(column, twoStride.data(), blurHeight, pixelBPP, widthStride, filters[0], true, false);
        imageConvoluteFilter(twoStride.data(), nextStride, blurHeight, pixelBPP, widthStride, filters[1], false, false);
        imageConvoluteFilter(nextStride, column, blurHeight, pixelBPP, widthStride, filters[2], false, true);
    }
}

static inline void mirrorTopLeftQuadrant(QImage &image, bool horizontal = true, bool vertical = true)
{
    const int width = image.width();
    const int height = image.height();
    const int centerX = qCeil(width * 0.5);
    const int centerY = qCeil(height * 0.5);
    const int alphaOffset = (image.depth() == 8 || QSysInfo::ByteOrder == QSysInfo::BigEndian) ? 0 : 3;
    const int pixelBPP = image.depth() >> 3;

    if (horizontal) {
        for (int y = 0; y < centerY; ++y) {
            uint8_t *sourceAlphaStride = image.scanLine(y) + alphaOffset;
            uint8_t *mirroredPixelPointer = sourceAlphaStride + (width - 1) * pixelBPP;

            for (int x = 0; x < centerX; ++x, sourceAlphaStride += pixelBPP, mirroredPixelPointer -= pixelBPP) {
                *mirroredPixelPointer = *sourceAlphaStride;
            }
        }
    }

    if (!vertical)
        return;

    for (int y = 0; y < centerY; ++y) {
        const uint8_t *sourceAlphaStride = image.scanLine(y) + alphaOffset;
        uint8_t *mirroredPixelPointer = image.scanLine(width - y - 1) + alphaOffset;

        for (int x = 0; x < width; ++x, sourceAlphaStride += pixelBPP, mirroredPixelPointer += pixelBPP) {
            *mirroredPixelPointer = *sourceAlphaStride;
        }
    }
}

static void cleanFunction(void *image) { delete static_cast<QImage*>(image); }

ShadowImage *DQuickShadowProvider::getRawShadow(const ShadowConfig &config)
{
    if (Q_UNLIKELY(qIsNull(config.blurRadius))) {
        return nullptr;
    }

    ShadowImage *image = this->cache.value(config);
    if (Q_LIKELY(image))
        return image;

    const QString path = getShadowFilePath(config);
    if (QFile::exists(path)) {
        QImage *tmp = new QImage(path);
        QImage target(tmp->bits(), tmp->width(), tmp->height(), tmp->bytesPerLine(), QImage::Format_Alpha8, cleanFunction, tmp);
        image = new ShadowImage(this, config, target);
    }

    if (!image) {
        const int effectiveBlurRadius = calculateEffectiveBlurRadius(config.blurRadius);
        const qreal imageSize = (effectiveBlurRadius + config.blurRadius) * 2 + config.boxSize;
        QImage source(qRound(imageSize), qRound(imageSize), QImage::Format_Alpha8);
        source.fill(config.isInner() ? Qt::black : Qt::transparent);

        QRectF boxRect(effectiveBlurRadius, effectiveBlurRadius,
                       imageSize - 2 * effectiveBlurRadius, imageSize - 2 * effectiveBlurRadius);
        QPainter sourcePainter(&source);
        sourcePainter.setRenderHint(QPainter::Antialiasing, true);
        sourcePainter.setPen(Qt::NoPen);
        sourcePainter.setBrush(Qt::black);

        if (config.isInner()) {
            sourcePainter.setCompositionMode(QPainter::CompositionMode_Clear);
            boxRect -= QMarginsF(config.spread, config.spread, config.spread, config.spread);
        } else {
            boxRect += QMarginsF(config.spread, config.spread, config.spread, config.spread);
        }

        sourcePainter.drawPath(roundedRectPath(boxRect, config));

        sourcePainter.end();
        const QRect blurRect(0, 0, qCeil(imageSize * 0.5), qCeil(imageSize * 0.5));
        doBoxShdowBlur(source, static_cast<int>(config.blurRadius), blurRect);
        mirrorTopLeftQuadrant(source);

        // you can save the source to the local directory here and add it to the qrc,
        // prevent repeated drawing of shadow pictures.
        // auto alpha = QImage(source.bits(), source.width(), source.height(), source.bytesPerLine(), QImage::Format_Grayscale8);
        // alpha.save("...." + config.toString() + ".png", "PNG");

        image = new ShadowImage(this, config, source);
    }

    return image;
}

DQUICK_END_NAMESPACE