qquickwidget.cpp

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// Copyright (C) 2021 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 "qquickwidget.h"
#include "qquickwidget_p.h"
#include "qaccessiblequickwidgetfactory_p.h"
#include <QtWidgets/private/qwidgetrepaintmanager_p.h>
 
#include "private/qquickwindow_p.h"
#include "private/qquickitem_p.h"
#include "private/qquickitemchangelistener_p.h"
#include "private/qquickrendercontrol_p.h"
#include "private/qsgrhisupport_p.h"
 
#include "private/qsgsoftwarerenderer_p.h"
 
#include <private/qqmldebugconnector_p.h>
#include <private/qquickprofiler_p.h>
#include <private/qqmldebugserviceinterfaces_p.h>
 
#include <QtQml/qqmlengine.h>
#include <private/qqmlengine_p.h>
#include <QtCore/qbasictimer.h>
#include <QtGui/QOffscreenSurface>
#include <QtGui/private/qguiapplication_p.h>
#include <QtGui/qpa/qplatformintegration.h>
 
#include <QtGui/QPainter>
 
#include <QtQuick/QSGRendererInterface>
 
#ifdef Q_OS_WIN
#if QT_CONFIG(messagebox)
#  include <QtWidgets/QMessageBox>
#endif
#  include <QtCore/QLibraryInfo>
#  include <QtCore/qt_windows.h>
#endif
 
#include <QtQuick/qquickgraphicsdevice.h>
#include <QtQuick/qquickrendertarget.h>
 
#include "private/qwidget_p.h"
 
#if QT_CONFIG(graphicsview)
#include <QtWidgets/qgraphicsscene.h>
#include <QtWidgets/qgraphicsview.h>
#endif
 
QT_BEGIN_NAMESPACE
 
QQuickWidgetOffscreenWindow::QQuickWidgetOffscreenWindow(QQuickWindowPrivate &dd, QQuickRenderControl *control)
:QQuickWindow(dd, control)
{
    setTitle(QString::fromLatin1("Offscreen"));
    setObjectName(QString::fromLatin1("QQuickWidgetOffscreenWindow"));
}
 
// override setVisble to prevent accidental offscreen window being created
// by base class.
class QQuickWidgetOffscreenWindowPrivate: public QQuickWindowPrivate {
public:
    void setVisible(bool visible) override {
        Q_Q(QWindow);
        // this stays always invisible
        visibility = visible ? QWindow::Windowed : QWindow::Hidden;
        q->visibilityChanged(visibility); // workaround for QTBUG-49054
    }
};
 
class QQuickWidgetRenderControlPrivate;
 
class QQuickWidgetRenderControl : public QQuickRenderControl
{
    Q_DECLARE_PRIVATE(QQuickWidgetRenderControl)
public:
    QQuickWidgetRenderControl(QQuickWidget *quickwidget);
    QWindow *renderWindow(QPoint *offset) override;
 
};
 
class QQuickWidgetRenderControlPrivate : public QQuickRenderControlPrivate
{
public:
    Q_DECLARE_PUBLIC(QQuickWidgetRenderControl)
    QQuickWidgetRenderControlPrivate(QQuickWidgetRenderControl *renderControl, QQuickWidget *qqw)
        : QQuickRenderControlPrivate(renderControl)
        , m_quickWidget(qqw)
    {
    }
 
    bool isRenderWindow(const QWindow *w) override {
#if QT_CONFIG(graphicsview)
        QWidgetPrivate *widgetd = QWidgetPrivate::get(m_quickWidget);
        auto *proxy = (widgetd && widgetd->extra) ? widgetd->extra->proxyWidget : nullptr;
        auto *scene = proxy ? proxy->scene() : nullptr;
        if (scene) {
            for (const auto &view : scene->views()) {
                if (view->window()->windowHandle() == w)
                    return true;
            }
        }
 
        return m_quickWidget->window()->windowHandle() == w;
#endif
    }
    QQuickWidget *m_quickWidget;
};
 
QQuickWidgetRenderControl::QQuickWidgetRenderControl(QQuickWidget *quickWidget)
    : QQuickRenderControl(*(new QQuickWidgetRenderControlPrivate(this, quickWidget)), nullptr)
{
}
 
QWindow *QQuickWidgetRenderControl::renderWindow(QPoint *offset)
{
    Q_D(QQuickWidgetRenderControl);
    if (offset)
        *offset = d->m_quickWidget->mapTo(d->m_quickWidget->window(), QPoint());
 
    QWindow *result = nullptr;
#if QT_CONFIG(graphicsview)
    QWidgetPrivate *widgetd = QWidgetPrivate::get(d->m_quickWidget);
    if (widgetd->extra) {
        if (auto proxy = widgetd->extra->proxyWidget) {
            auto scene = proxy->scene();
            if (scene) {
                const auto views = scene->views();
                if (!views.isEmpty()) {
                    // Get the first QGV containing the proxy. Not ideal, but the callers
                    // of this function aren't prepared to handle more than one render window.
                    auto candidateView = views.first();
                    result = candidateView->window()->windowHandle();
                }
            }
        }
    }
#endif
    if (!result)
        result = d->m_quickWidget->window()->windowHandle();
 
    return result;
}
 
void QQuickWidgetPrivate::initOffscreenWindow()
{
    Q_Q(QQuickWidget);
 
    ensureBackingScene();
    offscreenWindow->setScreen(q->screen());
    // Do not call create() on offscreenWindow.
 
    QWidget::connect(offscreenWindow, SIGNAL(sceneGraphInitialized()), q, SLOT(createFramebufferObject()));
    QWidget::connect(offscreenWindow, SIGNAL(sceneGraphInvalidated()), q, SLOT(destroyFramebufferObject()));
    QWidget::connect(offscreenWindow, &QQuickWindow::focusObjectChanged, q, &QQuickWidget::propagateFocusObjectChanged);
 
#if QT_CONFIG(accessibility)
    QAccessible::installFactory(&qAccessibleQuickWidgetFactory);
#endif
}
 
void QQuickWidgetPrivate::ensureBackingScene()
{
    // This should initialize, if not already done, the absolute minimum set of
    // mandatory backing resources, meaning the QQuickWindow and its
    // QQuickRenderControl. This function may be called very early on upon
    // construction, including before init() even.
 
    Q_Q(QQuickWidget);
    if (!renderControl)
        renderControl = new QQuickWidgetRenderControl(q);
    if (!offscreenWindow)
        offscreenWindow = new QQuickWidgetOffscreenWindow(*new QQuickWidgetOffscreenWindowPrivate(), renderControl);
 
    // Check if the Software Adaptation is being used
    auto sgRendererInterface = offscreenWindow->rendererInterface();
    if (sgRendererInterface && sgRendererInterface->graphicsApi() == QSGRendererInterface::Software)
        useSoftwareRenderer = true;
}
 
void QQuickWidgetPrivate::init(QQmlEngine* e)
{
    Q_Q(QQuickWidget);
 
    initOffscreenWindow();
 
    if (!useSoftwareRenderer) {
        if (QGuiApplicationPrivate::platformIntegration()->hasCapability(QPlatformIntegration::RhiBasedRendering))
            setRenderToTexture();
        else
            qWarning("QQuickWidget is not supported on this platform.");
    }
 
    engine = e;
 
    if (!engine.isNull() && !engine.data()->incubationController())
        engine.data()->setIncubationController(offscreenWindow->incubationController());
 
#if QT_CONFIG(quick_draganddrop)
    q->setAcceptDrops(true);
#endif
 
    QObject::connect(renderControl, SIGNAL(renderRequested()), q, SLOT(triggerUpdate()));
    QObject::connect(renderControl, SIGNAL(sceneChanged()), q, SLOT(triggerUpdate()));
}
 
void QQuickWidgetPrivate::ensureEngine() const
{
    Q_Q(const QQuickWidget);
    if (!engine.isNull())
        return;
 
    engine = new QQmlEngine(const_cast<QQuickWidget*>(q));
    engine.data()->setIncubationController(offscreenWindow->incubationController());
}
 
void QQuickWidgetPrivate::invalidateRenderControl()
{
    if (!useSoftwareRenderer && rhi) {
        // For the user's own OpenGL code connected to some QQuickWindow signals.
        rhi->makeThreadLocalNativeContextCurrent();
    }
 
    renderControl->invalidate();
}
 
void QQuickWidgetPrivate::handleWindowChange()
{
    Q_Q(QQuickWidget);
 
    if (offscreenWindow->isPersistentSceneGraph()
            && qGuiApp->testAttribute(Qt::AA_ShareOpenGLContexts)
            && rhiConfig().api() == QPlatformBackingStoreRhiConfig::OpenGL)
    {
        return;
    }
 
    // In case of !isPersistentSceneGraph or when we need a new context due to
    // the need to share resources with the new window's context, we must both
    // invalidate the scenegraph and destroy the context. QQuickRenderControl
    // must be recreated because its RHI will contain a dangling pointer to
    // the context.
 
    QScopedPointer<QQuickWindow> oldOffScreenWindow(offscreenWindow); // Do not delete before reparenting sgItem
    offscreenWindow = nullptr;
    delete renderControl;
 
    renderControl = new QQuickWidgetRenderControl(q);
    initOffscreenWindow();
 
    QObject::connect(renderControl, SIGNAL(renderRequested()), q, SLOT(triggerUpdate()));
    QObject::connect(renderControl, SIGNAL(sceneChanged()), q, SLOT(triggerUpdate()));
 
    if (!source.isEmpty())
        execute();
    else if (QQuickItem *sgItem = qobject_cast<QQuickItem *>(root))
        sgItem->setParentItem(offscreenWindow->contentItem());
}
 
QQuickWidgetPrivate::QQuickWidgetPrivate()
    : root(nullptr)
    , component(nullptr)
    , offscreenWindow(nullptr)
    , renderControl(nullptr)
    , rhi(nullptr)
    , outputTexture(nullptr)
    , depthStencil(nullptr)
    , msaaBuffer(nullptr)
    , rt(nullptr)
    , rtRp(nullptr)
    , resizeMode(QQuickWidget::SizeViewToRootObject)
    , initialSize(0,0)
    , eventPending(false)
    , updatePending(false)
    , fakeHidden(false)
    , requestedSamples(0)
    , useSoftwareRenderer(false)
    , forceFullUpdate(false)
    , deviceLost(false)
{
}
 
void QQuickWidgetPrivate::destroy()
{
    Q_Q(QQuickWidget);
    invalidateRenderControl();
    q->destroyFramebufferObject();
    delete offscreenWindow;
    delete renderControl;
    offscreenRenderer.reset();
}
 
void QQuickWidgetPrivate::execute()
{
    Q_Q(QQuickWidget);
    ensureEngine();
 
    if (root) {
        delete root;
        root = nullptr;
    }
    if (component) {
        delete component;
        component = nullptr;
    }
    if (!source.isEmpty()) {
        component = new QQmlComponent(engine.data(), source, q);
        if (!component->isLoading()) {
            q->continueExecute();
        } else {
            QObject::connect(component, SIGNAL(statusChanged(QQmlComponent::Status)),
                             q, SLOT(continueExecute()));
        }
    }
}
 
void QQuickWidgetPrivate::itemGeometryChanged(QQuickItem *resizeItem, QQuickGeometryChange change,
                                              const QRectF &oldGeometry)
{
    Q_Q(QQuickWidget);
    if (resizeItem == root && resizeMode == QQuickWidget::SizeViewToRootObject) {
        // wait for both width and height to be changed
        resizetimer.start(0,q);
    }
    QQuickItemChangeListener::itemGeometryChanged(resizeItem, change, oldGeometry);
}
 
void QQuickWidgetPrivate::render(bool needsSync)
{
    Q_Q(QQuickWidget);
    if (!useSoftwareRenderer) {
        if (deviceLost) {
            deviceLost = false;
            initializeWithRhi();
            q->createFramebufferObject();
        }
 
        if (!rhi) {
            qWarning("QQuickWidget: Attempted to render scene with no rhi");
            return;
        }
 
        // createFramebufferObject() bails out when the size is empty. In this case
        // we cannot render either.
        if (!outputTexture)
            return;
 
        renderControl->beginFrame();
        QQuickRenderControlPrivate::FrameStatus frameStatus = QQuickRenderControlPrivate::get(renderControl)->frameStatus;
        if (frameStatus == QQuickRenderControlPrivate::DeviceLostInBeginFrame) {
            // graphics resources controlled by us must be released
            invalidateRenderControl();
            // skip this round and hope that the tlw's repaint manager will manage to reinitialize
            deviceLost = true;
            return;
        }
        if (frameStatus != QQuickRenderControlPrivate::RecordingFrame) {
            qWarning("QQuickWidget: Failed to begin recording a frame");
            return;
        }
 
        if (needsSync) {
            renderControl->polishItems();
            renderControl->sync();
        }
 
        renderControl->render();
 
        renderControl->endFrame();
    } else {
        //Software Renderer
        if (needsSync) {
            renderControl->polishItems();
            renderControl->sync();
        }
        if (!offscreenWindow)
            return;
        QQuickWindowPrivate *cd = QQuickWindowPrivate::get(offscreenWindow);
        auto softwareRenderer = static_cast<QSGSoftwareRenderer*>(cd->renderer);
        if (softwareRenderer && !softwareImage.isNull()) {
            softwareRenderer->setCurrentPaintDevice(&softwareImage);
            if (forceFullUpdate) {
                softwareRenderer->markDirty();
                forceFullUpdate = false;
            }
            renderControl->render();
 
            updateRegion += softwareRenderer->flushRegion();
        }
    }
}
 
void QQuickWidgetPrivate::renderSceneGraph()
{
    Q_Q(QQuickWidget);
    updatePending = false;
 
    if (!q->isVisible() || fakeHidden)
        return;
 
    render(true);
 
#if QT_CONFIG(graphicsview)
    if (q->window()->graphicsProxyWidget())
        QWidgetPrivate::nearestGraphicsProxyWidget(q)->update();
    else
#endif
    {
        if (!useSoftwareRenderer)
            q->update(); // schedule composition
        else if (!updateRegion.isEmpty())
            q->update(updateRegion);
    }
}
 
QImage QQuickWidgetPrivate::grabFramebuffer()
{
    if (!useSoftwareRenderer && !rhi)
        return QImage();
 
    // grabWindow() does not work for the rhi case, we are in control of the
    // render target, and so it is up to us to read it back. When the software
    // renderer is in use, just call grabWindow().
 
    if (outputTexture) {
        render(true);
        QRhiCommandBuffer *cb = nullptr;
        rhi->beginOffscreenFrame(&cb);
        QRhiResourceUpdateBatch *resUpd = rhi->nextResourceUpdateBatch();
        QRhiReadbackResult readResult;
        resUpd->readBackTexture(QRhiReadbackDescription(outputTexture), &readResult);
        cb->resourceUpdate(resUpd);
        rhi->endOffscreenFrame();
        if (!readResult.data.isEmpty()) {
            QImage wrapperImage(reinterpret_cast<const uchar *>(readResult.data.constData()),
                                readResult.pixelSize.width(), readResult.pixelSize.height(),
                                QImage::Format_RGBA8888_Premultiplied);
            if (rhi->isYUpInFramebuffer())
                return wrapperImage.mirrored();
            else
                return wrapperImage.copy();
        }
        return QImage();
    }
 
    return offscreenWindow->grabWindow();
}
 
// Intentionally not overriding the QQuickWindow's focusObject.
// Key events should go to our key event handlers, and then to the
// QQuickWindow, not any in-scene item.
 
QQuickWidget::QQuickWidget(QWidget *parent)
    : QWidget(*(new QQuickWidgetPrivate), parent, {})
{
    setMouseTracking(true);
    setFocusPolicy(Qt::StrongFocus);
    setAttribute(Qt::WA_AcceptTouchEvents);
    d_func()->init();
}
 
QQuickWidget::QQuickWidget(const QUrl &source, QWidget *parent)
    : QQuickWidget(parent)
{
    setSource(source);
}
 
QQuickWidget::QQuickWidget(QQmlEngine* engine, QWidget *parent)
    : QWidget(*(new QQuickWidgetPrivate), parent, {})
{
    setMouseTracking(true);
    setFocusPolicy(Qt::StrongFocus);
    d_func()->init(engine);
}
 
QQuickWidget::~QQuickWidget()
{
    // Ensure that the component is destroyed before the engine; the engine may
    // be a child of the QQuickWidgetPrivate, and will be destroyed by its dtor
    Q_D(QQuickWidget);
    delete d->root;
    d->root = nullptr;
 
    // NB! resetting graphics resources must be done from this destructor,
    // *not* from the private class' destructor. This is due to how destruction
    // works and due to the QWidget dtor (for toplevels) destroying the repaint
    // manager and rhi before the (QObject) private gets destroyed. Hence must
    // do it here early on.
    d->destroy();
}
 
void QQuickWidget::setSource(const QUrl& url)
{
    Q_D(QQuickWidget);
    d->source = url;
    d->execute();
}
 
void QQuickWidget::setContent(const QUrl& url, QQmlComponent *component, QObject* item)
{
    Q_D(QQuickWidget);
    d->source = url;
    d->component = component;
 
    if (d->component && d->component->isError()) {
        const QList<QQmlError> errorList = d->component->errors();
        for (const QQmlError &error : errorList) {
            QMessageLogger(error.url().toString().toLatin1().constData(), error.line(), nullptr).warning()
                    << error;
        }
        emit statusChanged(status());
        return;
    }
 
    d->setRootObject(item);
    emit statusChanged(status());
}
 
QUrl QQuickWidget::source() const
{
    Q_D(const QQuickWidget);
    return d->source;
}
 
QQmlEngine* QQuickWidget::engine() const
{
    Q_D(const QQuickWidget);
    d->ensureEngine();
    return const_cast<QQmlEngine *>(d->engine.data());
}
 
QQmlContext* QQuickWidget::rootContext() const
{
    Q_D(const QQuickWidget);
    d->ensureEngine();
    return d->engine.data()->rootContext();
}
 
QQuickWidget::Status QQuickWidget::status() const
{
    Q_D(const QQuickWidget);
    if (!d->engine && !d->source.isEmpty())
        return QQuickWidget::Error;
 
    if (!d->component)
        return QQuickWidget::Null;
 
    if (d->component->status() == QQmlComponent::Ready && !d->root)
        return QQuickWidget::Error;
 
    return QQuickWidget::Status(d->component->status());
}
 
QList<QQmlError> QQuickWidget::errors() const
{
    Q_D(const QQuickWidget);
    QList<QQmlError> errs;
 
    if (d->component)
        errs = d->component->errors();
 
    if (!d->engine && !d->source.isEmpty()) {
        QQmlError error;
        error.setDescription(QLatin1String("QQuickWidget: invalid qml engine."));
        errs << error;
    }
    if (d->component && d->component->status() == QQmlComponent::Ready && !d->root) {
        QQmlError error;
        error.setDescription(QLatin1String("QQuickWidget: invalid root object."));
        errs << error;
    }
 
    return errs;
}
 
void QQuickWidget::setResizeMode(ResizeMode mode)
{
    Q_D(QQuickWidget);
    if (d->resizeMode == mode)
        return;
 
    if (d->root) {
        if (d->resizeMode == SizeViewToRootObject) {
            QQuickItemPrivate *p = QQuickItemPrivate::get(d->root);
            p->removeItemChangeListener(d, QQuickItemPrivate::Geometry);
        }
    }
 
    d->resizeMode = mode;
    if (d->root) {
        d->initResize();
    }
}
 
void QQuickWidgetPrivate::initResize()
{
    if (root) {
        if (resizeMode == QQuickWidget::SizeViewToRootObject) {
            QQuickItemPrivate *p = QQuickItemPrivate::get(root);
            p->addItemChangeListener(this, QQuickItemPrivate::Geometry);
        }
    }
    updateSize();
}
 
void QQuickWidgetPrivate::updateSize()
{
    Q_Q(QQuickWidget);
    if (!root)
        return;
 
    if (resizeMode == QQuickWidget::SizeViewToRootObject) {
        QSize newSize = QSize(root->width(), root->height());
        if (newSize.isValid()) {
            if (newSize != q->size()) {
                q->resize(newSize);
                q->updateGeometry();
            } else if (offscreenWindow->size().isEmpty()) {
                // QQuickDeliveryAgentPrivate::deliverHoverEvent() ignores events that
                // occur outside of QQuickRootItem's geometry, so we need it to match root's size.
                offscreenWindow->contentItem()->setSize(newSize);
            }
        }
    } else if (resizeMode == QQuickWidget::SizeRootObjectToView) {
        const bool needToUpdateWidth = !qFuzzyCompare(q->width(), root->width());
        const bool needToUpdateHeight = !qFuzzyCompare(q->height(), root->height());
 
        if (needToUpdateWidth && needToUpdateHeight) {
            // Make sure that we have realistic sizing behavior by following
            // what on-screen windows would do and resize everything, not just
            // the root item. We do this because other types may be relying on
            // us to behave correctly.
            const QSizeF newSize(q->width(), q->height());
            offscreenWindow->resize(newSize.toSize());
            offscreenWindow->contentItem()->setSize(newSize);
            root->setSize(newSize);
        } else if (needToUpdateWidth) {
            const int newWidth = q->width();
            offscreenWindow->setWidth(newWidth);
            offscreenWindow->contentItem()->setWidth(newWidth);
            root->setWidth(newWidth);
        } else if (needToUpdateHeight) {
            const int newHeight = q->height();
            offscreenWindow->setHeight(newHeight);
            offscreenWindow->contentItem()->setHeight(newHeight);
            root->setHeight(newHeight);
        }
    }
}
 
void QQuickWidgetPrivate::updatePosition()
{
    Q_Q(QQuickWidget);
    if (offscreenWindow == nullptr)
        return;
 
    const QPoint &pos = q->mapToGlobal(QPoint(0, 0));
    if (offscreenWindow->position() != pos)
        offscreenWindow->setPosition(pos);
}
 
QSize QQuickWidgetPrivate::rootObjectSize() const
{
    QSize rootObjectSize(0,0);
    int widthCandidate = -1;
    int heightCandidate = -1;
    if (root) {
        widthCandidate = root->width();
        heightCandidate = root->height();
    }
    if (widthCandidate > 0) {
        rootObjectSize.setWidth(widthCandidate);
    }
    if (heightCandidate > 0) {
        rootObjectSize.setHeight(heightCandidate);
    }
    return rootObjectSize;
}
 
void QQuickWidgetPrivate::handleContextCreationFailure(const QSurfaceFormat &)
{
    Q_Q(QQuickWidget);
 
    QString translatedMessage;
    QString untranslatedMessage;
    QQuickWindowPrivate::rhiCreationFailureMessage(QLatin1String("QRhi"), &translatedMessage, &untranslatedMessage);
 
    static const QMetaMethod errorSignal = QMetaMethod::fromSignal(&QQuickWidget::sceneGraphError);
    const bool signalConnected = q->isSignalConnected(errorSignal);
    if (signalConnected)
        emit q->sceneGraphError(QQuickWindow::ContextNotAvailable, translatedMessage);
 
#if defined(Q_OS_WIN) && QT_CONFIG(messagebox)
    if (!signalConnected && !QLibraryInfo::isDebugBuild() && !GetConsoleWindow())
        QMessageBox::critical(q, QCoreApplication::applicationName(), translatedMessage);
#endif // Q_OS_WIN
    if (!signalConnected)
        qFatal("%s", qPrintable(untranslatedMessage));
}
 
static inline QPlatformBackingStoreRhiConfig::Api graphicsApiToBackingStoreRhiApi(QSGRendererInterface::GraphicsApi api)
{
    switch (api) {
    case QSGRendererInterface::OpenGL:
        return QPlatformBackingStoreRhiConfig::OpenGL;
    case QSGRendererInterface::Vulkan:
        return QPlatformBackingStoreRhiConfig::Vulkan;
    case QSGRendererInterface::Direct3D11:
        return QPlatformBackingStoreRhiConfig::D3D11;
    case QSGRendererInterface::Metal:
        return QPlatformBackingStoreRhiConfig::Metal;
    default:
        return QPlatformBackingStoreRhiConfig::Null;
    }
}
 
// Never called by Software Rendering backend
void QQuickWidgetPrivate::initializeWithRhi()
{
    Q_Q(QQuickWidget);
 
    QWidgetPrivate *tlwd = QWidgetPrivate::get(q->window());
    // when reparenting, the rhi may suddenly be different
    if (rhi) {
        QRhi *tlwRhi = nullptr;
        if (QWidgetRepaintManager *repaintManager = tlwd->maybeRepaintManager())
            tlwRhi = repaintManager->rhi();
        if (tlwRhi && rhi != tlwRhi)
            rhi = nullptr;
    }
 
    // On hide-show we may invalidate() (when !isPersistentSceneGraph) but our
    // context is kept. We may need to initialize() again, though.
    const bool onlyNeedsSgInit = rhi && !offscreenWindow->isSceneGraphInitialized();
 
    if (!onlyNeedsSgInit) {
        if (rhi)
            return;
 
        if (QWidgetRepaintManager *repaintManager = tlwd->maybeRepaintManager())
            rhi = repaintManager->rhi();
 
        if (!rhi) {
            // The widget (and its parent chain, if any) may not be shown at
            // all, yet one may still want to use it for grabs. This is
            // ridiculous of course because the rendering infrastructure is
            // tied to the top-level widget that initializes upon expose, but
            // it has to be supported.
            offscreenRenderer.setConfig(rhiConfig());
            offscreenRenderer.setFormat(q->format());
            // no window passed in, so no swapchain, but we get a functional QRhi which we own
            if (offscreenRenderer.create())
                rhi = offscreenRenderer.rhi();
        }
 
        // Could be that something else already initialized the window with some
        // other graphics API for the QRhi, that's not good.
        if (rhi && rhi->backend() != QBackingStoreRhiSupport::apiToRhiBackend(graphicsApiToBackingStoreRhiApi(QQuickWindow::graphicsApi()))) {
            qWarning("The top-level window is not using the expected graphics API for composition, "
                     "'%s' is not compatible with this QQuickWidget",
                     rhi->backendName());
            rhi = nullptr;
        }
    }
 
    if (rhi) {
        if (!offscreenWindow->isSceneGraphInitialized()) {
            offscreenWindow->setGraphicsDevice(QQuickGraphicsDevice::fromRhi(rhi));
#if QT_CONFIG(vulkan)
            if (QWindow *w = q->window()->windowHandle())
                offscreenWindow->setVulkanInstance(w->vulkanInstance());
#endif
            renderControl->initialize();
        }
    } else {
        qWarning("QQuickWidget: Failed to get a QRhi from the top-level widget's window");
    }
}
 
void QQuickWidget::createFramebufferObject()
{
    Q_D(QQuickWidget);
 
    // Could come from Show -> initializeWithRhi -> sceneGraphInitialized in which case the size may
    // still be invalid on some platforms. Bail out. A resize will come later on.
    if (size().isEmpty())
        return;
 
    // Even though this is just an offscreen window we should set the position on it, as it might be
    // useful for an item to know the actual position of the scene.
    // Note: The position will be update when we get a move event (see: updatePosition()).
    const QPoint &globalPos = mapToGlobal(QPoint(0, 0));
    d->offscreenWindow->setGeometry(globalPos.x(), globalPos.y(), width(), height());
 
    if (d->useSoftwareRenderer) {
        const QSize imageSize = size() * devicePixelRatio();
        d->softwareImage = QImage(imageSize, QImage::Format_ARGB32_Premultiplied);
        d->softwareImage.setDevicePixelRatio(devicePixelRatio());
        d->forceFullUpdate = true;
        return;
    }
 
    if (!d->rhi) {
        qWarning("QQuickWidget: Attempted to create output texture with no QRhi");
        return;
    }
 
    int samples = d->requestedSamples;
    if (d->rhi->isFeatureSupported(QRhi::MultisampleRenderBuffer))
        samples = QSGRhiSupport::chooseSampleCount(samples, d->rhi);
    else
        samples = 0;
 
    const QSize fboSize = size() * devicePixelRatio();
 
    // Could be a simple hide - show, in which case the previous texture is just fine.
    if (!d->outputTexture) {
        d->outputTexture = d->rhi->newTexture(QRhiTexture::RGBA8, fboSize, 1, QRhiTexture::RenderTarget);
        if (!d->outputTexture->create()) {
            qWarning("QQuickWidget: failed to create output texture of size %dx%d",
                     fboSize.width(), fboSize.height());
        }
    }
    if (!d->depthStencil) {
        d->depthStencil = d->rhi->newRenderBuffer(QRhiRenderBuffer::DepthStencil, fboSize, samples);
        if (!d->depthStencil->create()) {
            qWarning("QQuickWidget: failed to create depth/stencil buffer of size %dx%d and sample count %d",
                     fboSize.width(), fboSize.height(), samples);
        }
    }
    if (samples > 1 && !d->msaaBuffer) {
        d->msaaBuffer = d->rhi->newRenderBuffer(QRhiRenderBuffer::Color, fboSize, samples);
        if (!d->msaaBuffer->create()) {
            qWarning("QQuickWidget: failed to create multisample renderbuffer of size %dx%d and sample count %d",
                     fboSize.width(), fboSize.height(), samples);
        }
    }
    if (!d->rt) {
        QRhiTextureRenderTargetDescription rtDesc;
        QRhiColorAttachment colorAtt;
        if (samples <= 1) {
            colorAtt.setTexture(d->outputTexture);
        } else {
            colorAtt.setRenderBuffer(d->msaaBuffer);
            colorAtt.setResolveTexture(d->outputTexture);
        }
        rtDesc.setColorAttachments({ colorAtt });
        rtDesc.setDepthStencilBuffer(d->depthStencil);
        d->rt = d->rhi->newTextureRenderTarget(rtDesc);
        d->rtRp = d->rt->newCompatibleRenderPassDescriptor();
        d->rt->setRenderPassDescriptor(d->rtRp);
        d->rt->create();
    }
    if (d->outputTexture->pixelSize() != fboSize) {
        d->outputTexture->setPixelSize(fboSize);
        if (!d->outputTexture->create()) {
            qWarning("QQuickWidget: failed to create resized output texture of size %dx%d",
                     fboSize.width(), fboSize.height());
        }
        d->depthStencil->setPixelSize(fboSize);
        if (!d->depthStencil->create()) {
            qWarning("QQuickWidget: failed to create resized depth/stencil buffer of size %dx%d",
                     fboSize.width(), fboSize.height());
        }
        if (d->msaaBuffer) {
            d->msaaBuffer->setPixelSize(fboSize);
            if (!d->msaaBuffer->create()) {
                qWarning("QQuickWidget: failed to create resized multisample renderbuffer of size %dx%d",
                         fboSize.width(), fboSize.height());
            }
        }
    }
 
    d->offscreenWindow->setRenderTarget(QQuickRenderTarget::fromRhiRenderTarget(d->rt));
 
    d->renderControl->setSamples(samples);
 
    // Sanity check: The window must not have an underlying platform window.
    // Having one would mean create() was called and platforms that only support
    // a single native window were in trouble.
    Q_ASSERT(!d->offscreenWindow->handle());
}
 
void QQuickWidget::destroyFramebufferObject()
{
    Q_D(QQuickWidget);
 
    if (d->useSoftwareRenderer) {
        d->softwareImage = QImage();
        return;
    }
 
    delete d->rt;
    d->rt = nullptr;
    delete d->rtRp;
    d->rtRp = nullptr;
    delete d->depthStencil;
    d->depthStencil = nullptr;
    delete d->msaaBuffer;
    d->msaaBuffer = nullptr;
    delete d->outputTexture;
    d->outputTexture = nullptr;
}
 
QQuickWidget::ResizeMode QQuickWidget::resizeMode() const
{
    Q_D(const QQuickWidget);
    return d->resizeMode;
}
 
void QQuickWidget::continueExecute()
{
    Q_D(QQuickWidget);
    disconnect(d->component, SIGNAL(statusChanged(QQmlComponent::Status)), this, SLOT(continueExecute()));
 
    if (d->component->isError()) {
        const QList<QQmlError> errorList = d->component->errors();
        for (const QQmlError &error : errorList) {
            QMessageLogger(error.url().toString().toLatin1().constData(), error.line(), nullptr).warning()
                    << error;
        }
        emit statusChanged(status());
        return;
    }
 
    QObject *obj = d->component->create();
 
    if (d->component->isError()) {
        const QList<QQmlError> errorList = d->component->errors();
        for (const QQmlError &error : errorList) {
            QMessageLogger(error.url().toString().toLatin1().constData(), error.line(), nullptr).warning()
                    << error;
        }
        emit statusChanged(status());
        return;
    }
 
    d->setRootObject(obj);
    emit statusChanged(status());
}
 
 
void QQuickWidgetPrivate::setRootObject(QObject *obj)
{
    Q_Q(QQuickWidget);
    if (root == obj)
        return;
    if (QQuickItem *sgItem = qobject_cast<QQuickItem *>(obj)) {
        root = sgItem;
        sgItem->setParentItem(offscreenWindow->contentItem());
    } else if (qobject_cast<QWindow *>(obj)) {
        qWarning() << "QQuickWidget does not support using windows as a root item." << Qt::endl
                   << Qt::endl
                   << "If you wish to create your root window from QML, consider using QQmlApplicationEngine instead." << Qt::endl;
    } else {
        qWarning() << "QQuickWidget only supports loading of root objects that derive from QQuickItem." << Qt::endl
                   << Qt::endl
                   << "Ensure your QML code is written for QtQuick 2, and uses a root that is or" << Qt::endl
                   << "inherits from QtQuick's Item (not a Timer, QtObject, etc)." << Qt::endl;
        delete obj;
        root = nullptr;
    }
    if (root) {
        initialSize = rootObjectSize();
        bool resized = q->testAttribute(Qt::WA_Resized);
        if ((resizeMode == QQuickWidget::SizeViewToRootObject || !resized) &&
            initialSize != q->size()) {
            q->resize(initialSize);
        }
        initResize();
    }
}
 
QPlatformBackingStoreRhiConfig QQuickWidgetPrivate::rhiConfig() const
{
    const_cast<QQuickWidgetPrivate *>(this)->ensureBackingScene();
    if (useSoftwareRenderer)
        return {};
 
    QPlatformBackingStoreRhiConfig config(graphicsApiToBackingStoreRhiApi(QQuickWindow::graphicsApi()));
 
    QQuickWindowPrivate *wd = QQuickWindowPrivate::get(offscreenWindow);
    // This is only here to support some of the env.vars. (such as
    // QSG_RHI_DEBUG_LAYER). There is currently no way to set a
    // QQuickGraphicsConfiguration for a QQuickWidget, which means things like
    // the pipeline cache are just not available. That is something to support
    // on the widget/backingstore level since that's where the QRhi is
    // controlled in this case.
    const bool debugLayerRequested = wd->graphicsConfig.isDebugLayerEnabled();
    config.setDebugLayer(debugLayerRequested);
    return config;
}
 
QWidgetPrivate::TextureData QQuickWidgetPrivate::texture() const
{
    Q_Q(const QQuickWidget);
    if (!q->isWindow() && q->internalWinId()) {
        qWarning() << "QQuickWidget cannot be used as a native child widget."
                   << "Consider setting Qt::AA_DontCreateNativeWidgetSiblings";
        return {};
    }
    return { outputTexture, nullptr };
}
 
QPlatformTextureList::Flags QQuickWidgetPrivate::textureListFlags()
{
    QPlatformTextureList::Flags flags = QWidgetPrivate::textureListFlags();
    flags |= QPlatformTextureList::NeedsPremultipliedAlphaBlending;
    return flags;
}
 
void QQuickWidget::timerEvent(QTimerEvent* e)
{
    Q_D(QQuickWidget);
    if (!e || e->timerId() == d->resizetimer.timerId()) {
        d->updateSize();
        d->resizetimer.stop();
    } else if (e->timerId() == d->updateTimer.timerId()) {
        d->eventPending = false;
        d->updateTimer.stop();
        if (d->updatePending)
            d->renderSceneGraph();
    }
}
 
QSize QQuickWidget::sizeHint() const
{
    Q_D(const QQuickWidget);
    QSize rootObjectSize = d->rootObjectSize();
    if (rootObjectSize.isEmpty()) {
        return size();
    } else {
        return rootObjectSize;
    }
}
 
QSize QQuickWidget::initialSize() const
{
    Q_D(const QQuickWidget);
    return d->initialSize;
}
 
QQuickItem *QQuickWidget::rootObject() const
{
    Q_D(const QQuickWidget);
    return d->root;
}
 
void QQuickWidget::resizeEvent(QResizeEvent *e)
{
    Q_D(QQuickWidget);
    if (d->resizeMode == SizeRootObjectToView)
        d->updateSize();
 
    if (e->size().isEmpty()) {
        //stop rendering
        d->fakeHidden = true;
        return;
    }
 
    bool needsSync = false;
    if (d->fakeHidden) {
        //restart rendering
        d->fakeHidden = false;
        needsSync = true;
    }
 
    // Software Renderer
    if (d->useSoftwareRenderer) {
        needsSync = true;
        if (d->softwareImage.size() != size() * devicePixelRatio()) {
            createFramebufferObject();
        }
    } else {
        if (d->rhi) {
            // Bail out when receiving a resize after scenegraph invalidation. This can happen
            // during hide - resize - show sequences and also during application exit.
            if (!d->outputTexture && !d->offscreenWindow->isSceneGraphInitialized())
                return;
            if (!d->outputTexture || d->outputTexture->pixelSize() != size() * devicePixelRatio()) {
                needsSync = true;
                createFramebufferObject();
            }
        } else {
            // This will result in a scenegraphInitialized() signal which
            // is connected to createFramebufferObject().
            needsSync = true;
            d->initializeWithRhi();
        }
 
        if (!d->rhi) {
            qWarning("QQuickWidget::resizeEvent() no QRhi");
            return;
        }
    }
 
    d->render(needsSync);
}
 
bool QQuickWidget::focusNextPrevChild(bool next)
{
    Q_D(QQuickWidget);
    QKeyEvent event(QEvent::KeyPress, next ? Qt::Key_Tab : Qt::Key_Backtab, Qt::NoModifier);
    Q_QUICK_INPUT_PROFILE(QQuickProfiler::Key, QQuickProfiler::InputKeyPress, event.key(),
                          Qt::NoModifier);
    QCoreApplication::sendEvent(d->offscreenWindow, &event);
 
    QKeyEvent releaseEvent(QEvent::KeyRelease, next ? Qt::Key_Tab : Qt::Key_Backtab, Qt::NoModifier);
    Q_QUICK_INPUT_PROFILE(QQuickProfiler::Key, QQuickProfiler::InputKeyRelease, releaseEvent.key(),
                          Qt::NoModifier);
    QCoreApplication::sendEvent(d->offscreenWindow, &releaseEvent);
    return event.isAccepted();
}
 
void QQuickWidget::keyPressEvent(QKeyEvent *e)
{
    Q_D(QQuickWidget);
    Q_QUICK_INPUT_PROFILE(QQuickProfiler::Key, QQuickProfiler::InputKeyPress, e->key(),
                          e->modifiers());
 
    QCoreApplication::sendEvent(d->offscreenWindow, e);
}
 
void QQuickWidget::keyReleaseEvent(QKeyEvent *e)
{
    Q_D(QQuickWidget);
    Q_QUICK_INPUT_PROFILE(QQuickProfiler::Key, QQuickProfiler::InputKeyRelease, e->key(),
                          e->modifiers());
 
    QCoreApplication::sendEvent(d->offscreenWindow, e);
}
 
void QQuickWidget::mouseMoveEvent(QMouseEvent *e)
{
    Q_D(QQuickWidget);
    Q_QUICK_INPUT_PROFILE(QQuickProfiler::Mouse, QQuickProfiler::InputMouseMove, e->position().x(),
                          e->position().y());
 
    // Put position into the event's position and scenePosition, and globalPosition into the
    // event's globalPosition. This way the scenePosition in e is ignored and is replaced by
    // position. This is necessary because QQuickWindow thinks of itself as a
    // top-level window always.
    QMouseEvent mappedEvent(e->type(), e->position(), e->position(), e->globalPosition(),
                            e->button(), e->buttons(), e->modifiers(), e->source());
    QCoreApplication::sendEvent(d->offscreenWindow, &mappedEvent);
    e->setAccepted(mappedEvent.isAccepted());
}
 
void QQuickWidget::mouseDoubleClickEvent(QMouseEvent *e)
{
    Q_D(QQuickWidget);
    Q_QUICK_INPUT_PROFILE(QQuickProfiler::Mouse, QQuickProfiler::InputMouseDoubleClick,
                          e->button(), e->buttons());
 
    // As the second mouse press is suppressed in widget windows we emulate it here for QML.
    // See QTBUG-25831
    QMouseEvent pressEvent(QEvent::MouseButtonPress, e->position(), e->position(), e->globalPosition(),
                           e->button(), e->buttons(), e->modifiers(), e->source());
    QCoreApplication::sendEvent(d->offscreenWindow, &pressEvent);
    e->setAccepted(pressEvent.isAccepted());
    QMouseEvent mappedEvent(e->type(), e->position(), e->position(), e->globalPosition(),
                            e->button(), e->buttons(), e->modifiers(), e->source());
    QCoreApplication::sendEvent(d->offscreenWindow, &mappedEvent);
}
 
void QQuickWidget::showEvent(QShowEvent *)
{
    Q_D(QQuickWidget);
    bool shouldTriggerUpdate = true;
 
    if (!d->useSoftwareRenderer) {
        d->initializeWithRhi();
 
        if (d->offscreenWindow->isSceneGraphInitialized()) {
            shouldTriggerUpdate = false;
            d->render(true);
            // render() may have led to a QQuickWindow::update() call (for
            // example, having a scene with a QQuickFramebufferObject::Renderer
            // calling update() in its render()) which in turn results in
            // renderRequested in the rendercontrol, ending up in
            // triggerUpdate. In this case just calling update() is not
            // acceptable, we need the full renderSceneGraph issued from
            // timerEvent().
            if (!d->eventPending && d->updatePending) {
                d->updatePending = false;
                update();
            }
        }
    }
 
    if (shouldTriggerUpdate)
        triggerUpdate();
 
    // note offscreenWindow  is "QQuickWidgetOffscreenWindow" instance
    d->offscreenWindow->setVisible(true);
    if (QQmlInspectorService *service = QQmlDebugConnector::service<QQmlInspectorService>())
        service->setParentWindow(d->offscreenWindow, window()->windowHandle());
}
 
void QQuickWidget::hideEvent(QHideEvent *)
{
    Q_D(QQuickWidget);
    if (!d->offscreenWindow->isPersistentSceneGraph())
        d->invalidateRenderControl();
    // note offscreenWindow  is "QQuickWidgetOffscreenWindow" instance
    d->offscreenWindow->setVisible(false);
    if (QQmlInspectorService *service = QQmlDebugConnector::service<QQmlInspectorService>())
        service->setParentWindow(d->offscreenWindow, d->offscreenWindow);
}
 
void QQuickWidget::mousePressEvent(QMouseEvent *e)
{
    Q_D(QQuickWidget);
    Q_QUICK_INPUT_PROFILE(QQuickProfiler::Mouse, QQuickProfiler::InputMousePress, e->button(),
                          e->buttons());
 
    QMouseEvent mappedEvent(e->type(), e->position(), e->position(), e->globalPosition(),
                            e->button(), e->buttons(), e->modifiers(), e->source());
    QCoreApplication::sendEvent(d->offscreenWindow, &mappedEvent);
    e->setAccepted(mappedEvent.isAccepted());
}
 
void QQuickWidget::mouseReleaseEvent(QMouseEvent *e)
{
    Q_D(QQuickWidget);
    Q_QUICK_INPUT_PROFILE(QQuickProfiler::Mouse, QQuickProfiler::InputMouseRelease, e->button(),
                          e->buttons());
 
    QMouseEvent mappedEvent(e->type(), e->position(), e->position(), e->globalPosition(),
                            e->button(), e->buttons(), e->modifiers(), e->source());
    QCoreApplication::sendEvent(d->offscreenWindow, &mappedEvent);
    e->setAccepted(mappedEvent.isAccepted());
}
 
#if QT_CONFIG(wheelevent)
void QQuickWidget::wheelEvent(QWheelEvent *e)
{
    Q_D(QQuickWidget);
    Q_QUICK_INPUT_PROFILE(QQuickProfiler::Mouse, QQuickProfiler::InputMouseWheel,
                          e->angleDelta().x(), e->angleDelta().y());
 
    // Wheel events only have local and global positions, no need to map.
    QCoreApplication::sendEvent(d->offscreenWindow, e);
}
#endif
 
void QQuickWidget::focusInEvent(QFocusEvent * event)
{
    Q_D(QQuickWidget);
    d->offscreenWindow->focusInEvent(event);
}
 
void QQuickWidget::focusOutEvent(QFocusEvent * event)
{
    Q_D(QQuickWidget);
    d->offscreenWindow->focusOutEvent(event);
}
 
static Qt::WindowState resolveWindowState(Qt::WindowStates states)
{
    // No more than one of these 3 can be set
    if (states & Qt::WindowMinimized)
        return Qt::WindowMinimized;
    if (states & Qt::WindowMaximized)
        return Qt::WindowMaximized;
    if (states & Qt::WindowFullScreen)
        return Qt::WindowFullScreen;
 
    // No state means "windowed" - we ignore Qt::WindowActive
    return Qt::WindowNoState;
}
 
static void remapInputMethodQueryEvent(QObject *object, QInputMethodQueryEvent *e)
{
    auto item = qobject_cast<QQuickItem *>(object);
    if (!item)
        return;
 
    // Remap all QRectF values.
    for (auto query : {Qt::ImCursorRectangle, Qt::ImAnchorRectangle, Qt::ImInputItemClipRectangle}) {
        if (e->queries() & query) {
            auto value = e->value(query);
            if (value.canConvert<QRectF>())
                e->setValue(query, item->mapRectToScene(value.toRectF()));
        }
    }
    // Remap all QPointF values.
    if (e->queries() & Qt::ImCursorPosition) {
        auto value = e->value(Qt::ImCursorPosition);
        if (value.canConvert<QPointF>())
            e->setValue(Qt::ImCursorPosition, item->mapToScene(value.toPointF()));
    }
}
 
bool QQuickWidget::event(QEvent *e)
{
    Q_D(QQuickWidget);
 
    switch (e->type()) {
 
    case QEvent::Leave:
    case QEvent::TouchBegin:
    case QEvent::TouchEnd:
    case QEvent::TouchUpdate:
    case QEvent::TouchCancel: {
        // Touch events only have local and global positions, no need to map.
        bool res = QCoreApplication::sendEvent(d->offscreenWindow, e);
        if (e->isAccepted() && e->type() == QEvent::TouchBegin) {
            // If the TouchBegin got accepted, then make sure all points that have
            // an exclusive grabber are also accepted so that the widget code for
            // delivering touch events make this widget an implicit grabber of those
            // points.
            QPointerEvent *pointerEvent = static_cast<QPointerEvent *>(e);
            auto deliveredPoints = pointerEvent->points();
            for (auto &point : deliveredPoints) {
                if (pointerEvent->exclusiveGrabber(point))
                    point.setAccepted(true);
            }
        }
        return res;
    }
 
    case QEvent::FocusAboutToChange:
        return QCoreApplication::sendEvent(d->offscreenWindow, e);
 
    case QEvent::InputMethod:
        return QCoreApplication::sendEvent(d->offscreenWindow->focusObject(), e);
    case QEvent::InputMethodQuery:
        {
            bool eventResult = QCoreApplication::sendEvent(d->offscreenWindow->focusObject(), e);
            // The result in focusObject are based on offscreenWindow. But
            // the inputMethodTransform won't get updated because the focus
            // is on QQuickWidget. We need to remap the value based on the
            // widget.
            remapInputMethodQueryEvent(d->offscreenWindow->focusObject(), static_cast<QInputMethodQueryEvent *>(e));
            return eventResult;
        }
 
    case QEvent::WindowAboutToChangeInternal:
        d->invalidateRenderControl();
        d->deviceLost = true;
        d->rhi = nullptr;
        break;
 
    case QEvent::WindowChangeInternal:
        d->handleWindowChange();
        break;
 
    case QEvent::ScreenChangeInternal:
    {
        QScreen *newScreen = screen();
        if (d->offscreenWindow)
            d->offscreenWindow->setScreen(newScreen);
        break;
    }
    case QEvent::DevicePixelRatioChange:
        if (d->useSoftwareRenderer || d->outputTexture) {
            // This will check the size taking the devicePixelRatio into account
            // and recreate if needed.
            createFramebufferObject();
            d->render(true);
        }
        if (d->offscreenWindow) {
            QEvent dprChangeEvent(QEvent::DevicePixelRatioChange);
            QGuiApplication::sendEvent(d->offscreenWindow, &dprChangeEvent);
        }
        break;
    case QEvent::Show:
    case QEvent::Move:
        d->updatePosition();
        break;
 
    case QEvent::WindowStateChange:
        d->offscreenWindow->setWindowState(resolveWindowState(windowState()));
        break;
 
    case QEvent::ShortcutOverride:
        return QCoreApplication::sendEvent(d->offscreenWindow, e);
 
    case QEvent::Enter: {
        QEnterEvent *enterEvent = static_cast<QEnterEvent *>(e);
        QEnterEvent mappedEvent(enterEvent->position(), enterEvent->scenePosition(),
                                enterEvent->globalPosition());
        const bool ret = QCoreApplication::sendEvent(d->offscreenWindow, &mappedEvent);
        e->setAccepted(mappedEvent.isAccepted());
        return ret;
    }
    default:
        break;
    }
 
    return QWidget::event(e);
}
 
#if QT_CONFIG(quick_draganddrop)
 
void QQuickWidget::dragEnterEvent(QDragEnterEvent *e)
{
    Q_D(QQuickWidget);
    // Don't reject drag events for the entire widget when one
    // item rejects the drag enter
    d->offscreenWindow->event(e);
    e->accept();
}
 
void QQuickWidget::dragMoveEvent(QDragMoveEvent *e)
{
    Q_D(QQuickWidget);
    // Drag/drop events only have local pos, so no need to map,
    // but QQuickWindow::event() does not return true
    d->offscreenWindow->event(e);
}
 
void QQuickWidget::dragLeaveEvent(QDragLeaveEvent *e)
{
    Q_D(QQuickWidget);
    d->offscreenWindow->event(e);
}
 
void QQuickWidget::dropEvent(QDropEvent *e)
{
    Q_D(QQuickWidget);
    d->offscreenWindow->event(e);
}
 
#endif // quick_draganddrop
 
// TODO: try to separate the two cases of
// 1. render() unconditionally without sync
// 2. sync() and then render if necessary
void QQuickWidget::triggerUpdate()
{
    Q_D(QQuickWidget);
    d->updatePending = true;
     if (!d->eventPending) {
        // There's no sense in immediately kicking a render off now, as
        // there may be a number of triggerUpdate calls to come from a multitude
        // of different sources (network, touch/mouse/keyboard, timers,
        // animations, ...), and we want to batch them all into single frames as
        // much as possible for the sake of interactivity and responsiveness.
        //
        // To achieve this, we set a timer and only perform the rendering when
        // this is complete.
        const int exhaustDelay = 5;
        d->updateTimer.start(exhaustDelay, Qt::PreciseTimer, this);
        d->eventPending = true;
    }
}
 
void QQuickWidget::setFormat(const QSurfaceFormat &format)
{
    Q_D(QQuickWidget);
    QSurfaceFormat currentFormat = d->offscreenWindow->format();
    QSurfaceFormat newFormat = format;
    newFormat.setDepthBufferSize(qMax(newFormat.depthBufferSize(), currentFormat.depthBufferSize()));
    newFormat.setStencilBufferSize(qMax(newFormat.stencilBufferSize(), currentFormat.stencilBufferSize()));
    newFormat.setAlphaBufferSize(qMax(newFormat.alphaBufferSize(), currentFormat.alphaBufferSize()));
 
    // Do not include the sample count. Requesting a multisampled context is not necessary
    // since we render into an FBO, never to an actual surface. What's more, attempting to
    // create a pbuffer with a multisampled config crashes certain implementations. Just
    // avoid the entire hassle, the result is the same.
    d->requestedSamples = newFormat.samples();
    newFormat.setSamples(0);
 
    d->offscreenWindow->setFormat(newFormat);
}
 
QSurfaceFormat QQuickWidget::format() const
{
    Q_D(const QQuickWidget);
    return d->offscreenWindow->format();
}
 
QImage QQuickWidget::grabFramebuffer() const
{
    return const_cast<QQuickWidgetPrivate *>(d_func())->grabFramebuffer();
}
 
void QQuickWidget::setClearColor(const QColor &color)
{
    Q_D(QQuickWidget);
    d->offscreenWindow->setColor(color);
}
 
QQuickWindow *QQuickWidget::quickWindow() const
{
    Q_D(const QQuickWidget);
    return d->offscreenWindow;
}
 
void QQuickWidget::paintEvent(QPaintEvent *event)
{
    Q_D(QQuickWidget);
    if (d->useSoftwareRenderer) {
        QPainter painter(this);
        d->updateRegion = d->updateRegion.united(event->region());
        if (d->updateRegion.isNull()) {
            //Paint everything
            painter.drawImage(rect(), d->softwareImage);
        } else {
            QTransform transform;
            transform.scale(devicePixelRatio(), devicePixelRatio());
            //Paint only the updated areas
            QRegion targetRegion;
            d->updateRegion.swap(targetRegion);
            for (auto targetRect : targetRegion) {
                auto sourceRect = transform.mapRect(QRectF(targetRect));
                painter.drawImage(targetRect, d->softwareImage, sourceRect);
            }
        }
    }
}
 
void QQuickWidget::propagateFocusObjectChanged(QObject *focusObject)
{
    Q_D(QQuickWidget);
    if (QApplication::focusObject() != this)
        return;
    if (QWindow *window = d->windowHandle(QWidgetPrivate::WindowHandleMode::TopLevel))
        emit window->focusObjectChanged(focusObject);
}
 
QT_END_NAMESPACE
 
#include "moc_qquickwidget_p.cpp"
 
#include "moc_qquickwidget.cpp"