Allow for when a Scene3D item switches screens

When a Scene3D item switches screens then it will need to be
reinitalized so that the supporting contexts, offscreen surfaces are
set to use the same screen and not the original one. This ensures that
the item is still rendered correctly on the new screen.

This includes a manual test using QQuickWidget in separate windows that
enables it going from one screen to the other.

This is a fresh version after the previous version was found to have a
bug shown in the scene3d-loader test which has now been resolved.

Change-Id: I3c711e894018db52ec00a8a5d2e0fb0128743ab1
Done-with: Antti Kokko <antti.kokko@qt.io>
Fixes: QTBUG-79192
Reviewed-by: Paul Lemire <paul.lemire@kdab.com>
Reviewed-by: Mike Krus <mike.krus@kdab.com>

16 files changed, 694 insertions, 217 deletions

diff --git a/src/quick3d/imports/scene3d/importsscene3d.pro b/src/quick3d/imports/scene3d/importsscene3d.pro
index e29f7b831..c4c1b7cc8 100644
--- a/src/quick3d/imports/scene3d/importsscene3d.pro
+++ b/src/quick3d/imports/scene3d/importsscene3d.pro
@@ -13,7 +13,6 @@ HEADERS += \
     qtquickscene3dplugin.h \
     scene3dlogging_p.h \
     scene3ditem_p.h \
-    scene3dcleaner_p.h \
     scene3drenderer_p.h \
     scene3dsgnode_p.h \
     scene3dsgmaterialshader_p.h \
@@ -24,7 +23,6 @@ SOURCES += \
     qtquickscene3dplugin.cpp \
     scene3ditem.cpp \
     scene3dlogging.cpp \
-    scene3dcleaner.cpp \
     scene3drenderer.cpp \
     scene3dsgnode.cpp \
     scene3dsgmaterialshader.cpp \
diff --git a/src/quick3d/imports/scene3d/scene3dcleaner.cpp b/src/quick3d/imports/scene3d/scene3dcleaner.cpp
deleted file mode 100644
index ec371410d..000000000
--- a/src/quick3d/imports/scene3d/scene3dcleaner.cpp
+++ /dev/null
@@ -1,75 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2016 Klaralvdalens Datakonsult AB (KDAB).
-** Contact: https://www.qt.io/licensing/
-**
-** This file is part of the Qt3D module of the Qt Toolkit.
-**
-** $QT_BEGIN_LICENSE:LGPL$
-** Commercial License Usage
-** Licensees holding valid commercial Qt licenses may use this file in
-** accordance with the commercial license agreement provided with the
-** Software or, alternatively, in accordance with the terms contained in
-** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see https://www.qt.io/terms-conditions. For further
-** information use the contact form at https://www.qt.io/contact-us.
-**
-** GNU Lesser General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU Lesser
-** General Public License version 3 as published by the Free Software
-** Foundation and appearing in the file LICENSE.LGPL3 included in the
-** packaging of this file. Please review the following information to
-** ensure the GNU Lesser General Public License version 3 requirements
-** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
-**
-** GNU General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU
-** General Public License version 2.0 or (at your option) the GNU General
-** Public license version 3 or any later version approved by the KDE Free
-** Qt Foundation. The licenses are as published by the Free Software
-** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
-** included in the packaging of this file. Please review the following
-** information to ensure the GNU General Public License requirements will
-** be met: https://www.gnu.org/licenses/gpl-2.0.html and
-** https://www.gnu.org/licenses/gpl-3.0.html.
-**
-** $QT_END_LICENSE$
-**
-****************************************************************************/
-
-#include "scene3dcleaner_p.h"
-
-#include <Qt3DCore/qaspectengine.h>
-#include <QtCore/qthread.h>
-
-#include <scene3dlogging_p.h>
-#include <scene3drenderer_p.h>
-
-QT_BEGIN_NAMESPACE
-
-namespace Qt3DRender {
-
-Scene3DCleaner::Scene3DCleaner(QObject *parent)
-    : QObject(parent)
-    , m_renderer(nullptr)
-{
-}
-
-Scene3DCleaner::~Scene3DCleaner()
-{
-    qCDebug(Scene3D) << Q_FUNC_INFO << QThread::currentThread();
-}
-
-void Scene3DCleaner::cleanup()
-{
-    Q_ASSERT(m_renderer);
-    delete m_renderer->m_aspectEngine; // also deletes m_renderer->m_renderAspect
-    m_renderer->m_aspectEngine = nullptr;
-    m_renderer->m_renderAspect = nullptr;
-    m_renderer->deleteLater();
-    deleteLater();
-}
-
-} // namespace Qt3DRender
-
-QT_END_NAMESPACE
diff --git a/src/quick3d/imports/scene3d/scene3dcleaner_p.h b/src/quick3d/imports/scene3d/scene3dcleaner_p.h
deleted file mode 100644
index a246cbde7..000000000
--- a/src/quick3d/imports/scene3d/scene3dcleaner_p.h
+++ /dev/null
@@ -1,82 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2016 Klaralvdalens Datakonsult AB (KDAB).
-** Contact: https://www.qt.io/licensing/
-**
-** This file is part of the Qt3D module of the Qt Toolkit.
-**
-** $QT_BEGIN_LICENSE:LGPL$
-** Commercial License Usage
-** Licensees holding valid commercial Qt licenses may use this file in
-** accordance with the commercial license agreement provided with the
-** Software or, alternatively, in accordance with the terms contained in
-** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see https://www.qt.io/terms-conditions. For further
-** information use the contact form at https://www.qt.io/contact-us.
-**
-** GNU Lesser General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU Lesser
-** General Public License version 3 as published by the Free Software
-** Foundation and appearing in the file LICENSE.LGPL3 included in the
-** packaging of this file. Please review the following information to
-** ensure the GNU Lesser General Public License version 3 requirements
-** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
-**
-** GNU General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU
-** General Public License version 2.0 or (at your option) the GNU General
-** Public license version 3 or any later version approved by the KDE Free
-** Qt Foundation. The licenses are as published by the Free Software
-** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
-** included in the packaging of this file. Please review the following
-** information to ensure the GNU General Public License requirements will
-** be met: https://www.gnu.org/licenses/gpl-2.0.html and
-** https://www.gnu.org/licenses/gpl-3.0.html.
-**
-** $QT_END_LICENSE$
-**
-****************************************************************************/
-
-#ifndef QT3DRENDER_SCENE3DCLEANER_P_H
-#define QT3DRENDER_SCENE3DCLEANER_P_H
-
-//
-//  W A R N I N G
-//  -------------
-//
-// This file is not part of the Qt API.  It exists purely as an
-// implementation detail.  This header file may change from version to
-// version without notice, or even be removed.
-//
-// We mean it.
-//
-
-#include <QtCore/QObject>
-
-QT_BEGIN_NAMESPACE
-
-namespace Qt3DRender {
-
-class Scene3DRenderer;
-
-class Scene3DCleaner : public QObject
-{
-    Q_OBJECT
-public:
-    explicit Scene3DCleaner(QObject *parent = 0);
-    ~Scene3DCleaner();
-
-    void setRenderer(Scene3DRenderer *renderer) { m_renderer = renderer; }
-
-public Q_SLOTS:
-    void cleanup();
-
-private:
-    Scene3DRenderer *m_renderer;
-};
-
-} // namespace Qt3DRender
-
-QT_END_NAMESPACE
-
-#endif // QT3DRENDER_SCENE3DCLEANER_H
diff --git a/src/quick3d/imports/scene3d/scene3ditem.cpp b/src/quick3d/imports/scene3d/scene3ditem.cpp
index f824d2c4e..6a1085a85 100644
--- a/src/quick3d/imports/scene3d/scene3ditem.cpp
+++ b/src/quick3d/imports/scene3d/scene3ditem.cpp
@@ -68,7 +68,6 @@
 #include <Qt3DRender/private/qrendersurfaceselector_p.h>
 #include <Qt3DRender/private/qrenderaspect_p.h>
 #include <Qt3DRender/private/rendersettings_p.h>
-#include <scene3dcleaner_p.h>
 #include <scene3dlogging_p.h>
 #include <scene3drenderer_p.h>
 #include <scene3dsgnode_p.h>
@@ -150,8 +149,8 @@ Scene3DItem::Scene3DItem(QQuickItem *parent)
     , m_viewHolderFG(nullptr)
     , m_aspectEngine(new Qt3DCore::QAspectEngine())
     , m_renderAspect(nullptr)
+    , m_aspectToDelete(nullptr)
     , m_renderer(nullptr)
-    , m_rendererCleaner(new Scene3DCleaner())
     , m_multisample(true)
     , m_dirty(true)
     , m_dirtyViews(false)
@@ -179,6 +178,8 @@ Scene3DItem::~Scene3DItem()
     // When the window is closed, it first destroys all of its children. At
     // this point, Scene3DItem is destroyed but the Renderer, AspectEngine and
     // Scene3DSGNode still exist and will perform their cleanup on their own.
+    m_aspectEngine->deleteLater();
+    m_renderer->deleteLater();
 }
 
 /*!
@@ -204,18 +205,11 @@ QStringList Scene3DItem::aspects() const
  */
 Qt3DCore::QEntity *Scene3DItem::entity() const
 {
-    return m_entity;
+    return m_entity.data();
 }
 
-void Scene3DItem::setAspects(const QStringList &aspects)
+void Scene3DItem::applyAspects()
 {
-    if (!m_aspects.isEmpty()) {
-        qCWarning(Scene3D) << "Aspects already set on the Scene3D, ignoring";
-        return;
-    }
-
-    m_aspects = aspects;
-
     // Aspects are owned by the aspect engine
     for (const QString &aspect : qAsConst(m_aspects)) {
         if (aspect == QLatin1String("render")) // This one is hardwired anyway
@@ -246,16 +240,27 @@ void Scene3DItem::setAspects(const QStringList &aspects)
         }
         m_aspectEngine->registerAspect(aspect);
     }
+}
+
+void Scene3DItem::setAspects(const QStringList &aspects)
+{
+    if (!m_aspects.isEmpty()) {
+        qWarning() << "Aspects already set on the Scene3D, ignoring";
+        return;
+    }
+
+    m_aspects = aspects;
+    applyAspects();
 
     emit aspectsChanged();
 }
 
 void Scene3DItem::setEntity(Qt3DCore::QEntity *entity)
 {
-    if (entity == m_entity)
+    if (entity == m_entity.data())
         return;
 
-    m_entity = entity;
+    m_entity.reset(entity);
     emit entityChanged();
 }
 
@@ -398,14 +403,21 @@ void Scene3DItem::removeView(Scene3DView *view)
 
 void Scene3DItem::applyRootEntityChange()
 {
-    if (m_aspectEngine->rootEntity() != m_entity) {
-        m_aspectEngine->setRootEntity(Qt3DCore::QEntityPtr(m_entity));
+    if (m_aspectEngine->rootEntity() != m_entity.data()) {
+        m_aspectEngine->setRootEntity(m_entity);
+
+        /* If we changed window, the old aspect engine must be deleted only after we have set
+           the root entity for the new one so that it doesn't delete the root node. */
+        if (m_aspectToDelete) {
+            delete m_aspectToDelete;
+            m_aspectToDelete = nullptr;
+        }
 
         // Set the render surface
         if (!m_entity)
             return;
 
-        setWindowSurface(m_entity);
+        setWindowSurface(entity());
 
         if (m_cameraAspectRatioMode == AutomaticAspectRatio) {
             // Set aspect ratio of first camera to match the window
@@ -481,6 +493,8 @@ void Scene3DItem::onBeforeSync()
     // if the Scene3D item is not visible
     if (!isVisible() && dontRenderWhenHidden)
         return;
+    if (m_renderer->m_resetRequested)
+        return;
 
     Q_ASSERT(QThread::currentThread() == thread());
 
@@ -496,7 +510,7 @@ void Scene3DItem::onBeforeSync()
     // Make renderer aware of any Scene3DView we are dealing with
     if (m_dirtyViews) {
         // Scene3DViews checks
-        if (m_entity != m_viewHolderEntity) {
+        if (entity() != m_viewHolderEntity) {
             qCWarning(Scene3D) << "Scene3DView is not supported if the Scene3D entity property has been set";
         }
         if (!usesFBO) {
@@ -544,6 +558,20 @@ void Scene3DItem::requestUpdate()
     }
 }
 
+void Scene3DItem::updateWindowSurface()
+{
+    if (!m_entity || !m_dummySurface)
+        return;
+    Qt3DRender::QRenderSurfaceSelector *surfaceSelector =
+        Qt3DRender::QRenderSurfaceSelectorPrivate::find(entity());
+    if (surfaceSelector) {
+        if (QWindow *rw = QQuickRenderControl::renderWindowFor(this->window())) {
+            m_dummySurface->deleteLater();
+            createDummySurface(rw, surfaceSelector);
+        }
+    }
+}
+
 void Scene3DItem::setWindowSurface(QObject *rootObject)
 {
     Qt3DRender::QRenderSurfaceSelector *surfaceSelector = Qt3DRender::QRenderSurfaceSelectorPrivate::find(rootObject);
@@ -554,20 +582,25 @@ void Scene3DItem::setWindowSurface(QObject *rootObject)
         // We may not have a real, exposed QQuickWindow when the Quick rendering
         // is redirected via QQuickRenderControl (f.ex. QQuickWidget).
         if (QWindow *rw = QQuickRenderControl::renderWindowFor(this->window())) {
-            // rw is the top-level window that is backed by a native window. Do
-            // not use that though since we must not clash with e.g. the widget
-            // backingstore compositor in the gui thread.
-            m_dummySurface = new QOffscreenSurface;
-            m_dummySurface->setParent(qGuiApp); // parent to something suitably long-living
-            m_dummySurface->setFormat(rw->format());
-            m_dummySurface->setScreen(rw->screen());
-            m_dummySurface->create();
-            surfaceSelector->setSurface(m_dummySurface);
+            createDummySurface(rw, surfaceSelector);
         } else {
             surfaceSelector->setSurface(this->window());
         }
     }
 }
+
+void Scene3DItem::createDummySurface(QWindow *rw, Qt3DRender::QRenderSurfaceSelector *surfaceSelector)
+{
+    // rw is the top-level window that is backed by a native window. Do
+    // not use that though since we must not clash with e.g. the widget
+    // backingstore compositor in the gui thread.
+    m_dummySurface = new QOffscreenSurface;
+    m_dummySurface->setParent(qGuiApp); // parent to something suitably long-living
+    m_dummySurface->setFormat(rw->format());
+    m_dummySurface->setScreen(rw->screen());
+    m_dummySurface->create();
+    surfaceSelector->setSurface(m_dummySurface);
+}
 /*!
     \qmlmethod void Scene3D::setItemAreaAndDevicePixelRatio(size area, real devicePixelRatio)
 
@@ -575,7 +608,8 @@ void Scene3DItem::setWindowSurface(QObject *rootObject)
  */
 void Scene3DItem::setItemAreaAndDevicePixelRatio(QSize area, qreal devicePixelRatio)
 {
-    Qt3DRender::QRenderSurfaceSelector *surfaceSelector = Qt3DRender::QRenderSurfaceSelectorPrivate::find(m_entity);
+    Qt3DRender::QRenderSurfaceSelector *surfaceSelector
+            = Qt3DRender::QRenderSurfaceSelectorPrivate::find(entity());
     if (surfaceSelector) {
         surfaceSelector->setExternalRenderTargetSize(area);
         surfaceSelector->setSurfacePixelRatio(devicePixelRatio);
@@ -665,6 +699,22 @@ void Scene3DItem::setMultisample(bool enable)
 
 QSGNode *Scene3DItem::updatePaintNode(QSGNode *node, QQuickItem::UpdatePaintNodeData *)
 {
+    // m_resetRequested is set to true by Scene3DRenderer::shutdown()
+    if (m_renderer && m_renderer->m_resetRequested) {
+        qCWarning(Scene3D) << "Renderer for Scene3DItem has requested a reset due to the item "
+                              "moving to another window";
+        QObject::disconnect(m_windowConnection);
+        m_aspectEngine->unregisterAspect(m_renderAspect); // Deletes the renderAspect
+        m_renderAspect = nullptr;
+        m_aspectToDelete = m_aspectEngine;
+        m_aspectEngine = new Qt3DCore::QAspectEngine();
+        m_aspectEngine->setRunMode(Qt3DCore::QAspectEngine::Manual);
+        applyAspects();
+        // Needs to belong in the same thread as the item which is the same as the original
+        // QAspectEngine
+        m_aspectEngine->moveToThread(thread());
+        m_renderer->m_resetRequested = false;
+    }
     // If the render aspect wasn't created yet, do so now
     if (m_renderAspect == nullptr) {
         m_renderAspect = new QRenderAspect(QRenderAspect::Synchronous);
@@ -675,16 +725,24 @@ QSGNode *Scene3DItem::updatePaintNode(QSGNode *node, QQuickItem::UpdatePaintNode
 
         // Before Synchronizing is in the SG Thread, we want beforeSync to be triggered
         // in the context of the main thread
-        QObject::connect(window(), &QQuickWindow::afterAnimating,
-                         this, &Scene3DItem::onBeforeSync, Qt::DirectConnection);
+        m_windowConnection = QObject::connect(window(), &QQuickWindow::afterAnimating,
+                                    this, &Scene3DItem::onBeforeSync, Qt::DirectConnection);
         auto renderAspectPriv = static_cast<QRenderAspectPrivate*>(QRenderAspectPrivate::get(m_renderAspect));
         QObject::connect(renderAspectPriv->m_aspectManager->changeArbiter(), &Qt3DCore::QChangeArbiter::receivedChange,
                          this, [this] { m_dirty = true; }, Qt::DirectConnection);
     }
 
     if (m_renderer == nullptr) {
-        m_renderer = new Scene3DRenderer(this, m_aspectEngine, m_renderAspect);
-        m_renderer->setCleanerHelper(m_rendererCleaner);
+        m_renderer = new Scene3DRenderer();
+        m_renderer->init(this, m_aspectEngine, m_renderAspect);
+    } else if (m_renderer->renderAspect() != m_renderAspect) {
+        // If the renderer's renderAspect is not equal to the aspect used
+        // by the item, then it means that we have created a new one due to
+        // the fact that shutdown() was called on the renderer previously.
+        // This is a typical situation when the window the item is in has
+        // moved from one screen to another.
+        updateWindowSurface();
+        m_renderer->init(this, m_aspectEngine, m_renderAspect);
     }
     const bool usesFBO = m_compositingMode == FBO;
     const bool hasScene3DViews = !m_views.empty();
diff --git a/src/quick3d/imports/scene3d/scene3ditem_p.h b/src/quick3d/imports/scene3d/scene3ditem_p.h
index e46bb20af..0beaf94c0 100644
--- a/src/quick3d/imports/scene3d/scene3ditem_p.h
+++ b/src/quick3d/imports/scene3d/scene3ditem_p.h
@@ -71,6 +71,7 @@ class Scene3DRenderer;
 class Scene3DCleaner;
 class Scene3DView;
 class QFrameGraphNode;
+class QRenderSurfaceSelector;
 
 class Scene3DItem : public QQuickItem
 {
@@ -138,16 +139,20 @@ private:
     void updateCameraAspectRatio();
     void mousePressEvent(QMouseEvent *event) override;
     bool needsRender();
+    void updateWindowSurface();
+    void createDummySurface(QWindow *window, QRenderSurfaceSelector *surfaceSelector);
+    void applyAspects();
 
     QStringList m_aspects;
-    Qt3DCore::QEntity *m_entity;
+    // Store as shared pointer so that aspect engine doesn't delete it.
+    QSharedPointer<Qt3DCore::QEntity> m_entity;
     Qt3DCore::QEntity *m_viewHolderEntity;
     Qt3DRender::QFrameGraphNode *m_viewHolderFG;
 
     Qt3DCore::QAspectEngine *m_aspectEngine;
+    Qt3DCore::QAspectEngine *m_aspectToDelete;
     QRenderAspect *m_renderAspect;
     Scene3DRenderer *m_renderer;
-    Scene3DCleaner *m_rendererCleaner;
 
     bool m_multisample;
     bool m_dirty;
@@ -160,6 +165,7 @@ private:
     CompositingMode m_compositingMode;
     QOffscreenSurface *m_dummySurface;
     QVector<Scene3DView *> m_views;
+    QMetaObject::Connection m_windowConnection;
 };
 
 } // Qt3DRender
diff --git a/src/quick3d/imports/scene3d/scene3drenderer.cpp b/src/quick3d/imports/scene3d/scene3drenderer.cpp
index 312dc41cb..f28633c88 100644
--- a/src/quick3d/imports/scene3d/scene3drenderer.cpp
+++ b/src/quick3d/imports/scene3d/scene3drenderer.cpp
@@ -53,7 +53,6 @@
 #include <Qt3DCore/private/qchangearbiter_p.h>
 #include <Qt3DCore/private/qservicelocator_p.h>
 
-#include <scene3dcleaner_p.h>
 #include <scene3ditem_p.h>
 #include <scene3dlogging_p.h>
 #include <scene3dsgnode_p.h>
@@ -144,16 +143,15 @@ private:
     signal of the window is not called. Therefore the cleanup method is invoked
     to properly destroy the aspect engine.
  */
-Scene3DRenderer::Scene3DRenderer(Scene3DItem *item, Qt3DCore::QAspectEngine *aspectEngine, QRenderAspect *renderAspect)
+Scene3DRenderer::Scene3DRenderer()
     : QObject()
-    , m_item(item)
-    , m_aspectEngine(aspectEngine)
-    , m_renderAspect(renderAspect)
+    , m_item(nullptr)
+    , m_aspectEngine(nullptr)
+    , m_renderAspect(nullptr)
     , m_multisampledFBO(nullptr)
     , m_finalFBO(nullptr)
     , m_texture(nullptr)
     , m_node(nullptr)
-    , m_cleaner(nullptr)
     , m_window(nullptr)
     , m_multisample(false) // this value is not used, will be synced from the Scene3DItem instead
     , m_lastMultisample(false)
@@ -165,6 +163,17 @@ Scene3DRenderer::Scene3DRenderer(Scene3DItem *item, Qt3DCore::QAspectEngine *asp
     , m_allowRendering(0)
     , m_compositingMode(Scene3DItem::FBO)
 {
+}
+
+void Scene3DRenderer::init(Scene3DItem *item, Qt3DCore::QAspectEngine *aspectEngine,
+                           QRenderAspect *renderAspect)
+{
+    m_item = item;
+    m_window = m_item->window();
+    m_aspectEngine = aspectEngine;
+    m_renderAspect = renderAspect;
+    m_needsShutdown = true;
+
     Q_CHECK_PTR(m_item);
     Q_CHECK_PTR(m_item->window());
 
@@ -215,21 +224,14 @@ void Scene3DRenderer::scheduleRootEntityChange()
     QMetaObject::invokeMethod(m_item, "applyRootEntityChange", Qt::QueuedConnection);
 }
 
-void Scene3DRenderer::setCleanerHelper(Scene3DCleaner *cleaner)
-{
-    m_cleaner = cleaner;
-    if (m_cleaner) {
-        // Window closed case
-        QObject::connect(m_item->window(), &QQuickWindow::destroyed, m_cleaner, &Scene3DCleaner::cleanup);
-        m_cleaner->setRenderer(this);
-    }
-}
-
 // Executed in the QtQuick render thread (which may even be the gui/main with QQuickWidget / RenderControl).
 void Scene3DRenderer::shutdown()
 {
     qCDebug(Scene3D) << Q_FUNC_INFO << QThread::currentThread();
 
+    // In case the same item is rendered on another window reset it
+    m_resetRequested = true;
+
     // Set to null so that subsequent calls to render
     // would return early
     m_item = nullptr;
@@ -243,8 +245,13 @@ void Scene3DRenderer::shutdown()
 
     // Shutdown the Renderer Aspect while the OpenGL context
     // is still valid
-    if (m_renderAspect)
+    if (m_renderAspect) {
         static_cast<QRenderAspectPrivate*>(QRenderAspectPrivate::get(m_renderAspect))->renderShutdown();
+        m_renderAspect = nullptr;
+    }
+    m_aspectEngine = nullptr;
+    m_finalFBO.reset();
+    m_multisampledFBO.reset();
 }
 
 // QtQuick render thread (which may also be the gui/main thread with QQuickWidget / RenderControl)
@@ -254,7 +261,6 @@ void Scene3DRenderer::onSceneGraphInvalidated()
     if (m_needsShutdown) {
         m_needsShutdown = false;
         shutdown();
-        QMetaObject::invokeMethod(m_cleaner, "cleanup");
     }
 }
 
@@ -265,7 +271,6 @@ void Scene3DRenderer::onWindowChanged(QQuickWindow *w)
         if (m_needsShutdown) {
             m_needsShutdown = false;
             shutdown();
-            QMetaObject::invokeMethod(m_cleaner, "cleanup");
         }
     }
 }
diff --git a/src/quick3d/imports/scene3d/scene3drenderer_p.h b/src/quick3d/imports/scene3d/scene3drenderer_p.h
index 08a2c60a3..5674f21c2 100644
--- a/src/quick3d/imports/scene3d/scene3drenderer_p.h
+++ b/src/quick3d/imports/scene3d/scene3drenderer_p.h
@@ -78,9 +78,7 @@ class Scene3DRenderer : public QObject
 {
     Q_OBJECT
 public:
-    Scene3DRenderer(Scene3DItem *item,
-                    Qt3DCore::QAspectEngine *aspectEngine,
-                    QRenderAspect *renderAspect);
+    Scene3DRenderer();
     ~Scene3DRenderer();
 
     void setSGNode(Scene3DSGNode *node);
@@ -89,7 +87,12 @@ public:
     void setCompositingMode(Scene3DItem::CompositingMode mode);
     void setSkipFrame(bool skip);
     void setScene3DViews(const QVector<Scene3DView *> views);
+    void init(Scene3DItem *item, Qt3DCore::QAspectEngine *aspectEngine, QRenderAspect *renderAspect);
 
+    QRenderAspect *renderAspect() const
+    {
+        return m_renderAspect;
+    }
 public Q_SLOTS:
     void render();
     void shutdown();
@@ -103,13 +106,12 @@ private:
     void scheduleRootEntityChange();
 
     Scene3DItem *m_item; // Will be released by the QQuickWindow/QML Engine
-    Qt3DCore::QAspectEngine *m_aspectEngine; // Will be released by the Scene3DRendererCleaner
+    Qt3DCore::QAspectEngine *m_aspectEngine; // Will be released by the Scene3DItem
     QRenderAspect *m_renderAspect; // Will be released by the aspectEngine
     QScopedPointer<QOpenGLFramebufferObject> m_multisampledFBO;
     QScopedPointer<QOpenGLFramebufferObject> m_finalFBO;
     QScopedPointer<QSGTexture> m_texture;
     Scene3DSGNode *m_node; // Will be released by the QtQuick SceneGraph
-    Scene3DCleaner *m_cleaner;
     QQuickWindow *m_window;
     QMutex m_windowMutex;
     QSize m_lastSize;
@@ -123,8 +125,9 @@ private:
     QSemaphore m_allowRendering;
     Scene3DItem::CompositingMode m_compositingMode;
     QVector<Scene3DView *> m_views;
+    bool m_resetRequested = false;
 
-    friend class Scene3DCleaner;
+    friend class Scene3DItem;
 };
 
 } // namespace Qt3DRender
diff --git a/tests/manual/manual.pro b/tests/manual/manual.pro
index 2f630e0d9..de9dd861b 100644
--- a/tests/manual/manual.pro
+++ b/tests/manual/manual.pro
@@ -88,3 +88,5 @@ qtHaveModule(widgets): {
         rendercapture-cpp \
         texture-updates-cpp
 }
+
+qtHaveModule(quickwidgets): SUBDIRS += quickwidget-switch
diff --git a/tests/manual/quickwidget-switch/main.cpp b/tests/manual/quickwidget-switch/main.cpp
new file mode 100644
index 000000000..ebadc458d
--- /dev/null
+++ b/tests/manual/quickwidget-switch/main.cpp
@@ -0,0 +1,125 @@
+/****************************************************************************
+**
+** Copyright (C) 2020 The Qt Company.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the Qt3D module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
+**
+** "Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above copyright
+**     notice, this list of conditions and the following disclaimer in
+**     the documentation and/or other materials provided with the
+**     distribution.
+**   * Neither the name of The Qt Company Ltd nor the names of its
+**     contributors may be used to endorse or promote products derived
+**     from this software without specific prior written permission.
+**
+**
+** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <QDesktopWidget>
+#include <QScreen>
+#include <QApplication>
+#include <QMainWindow>
+#include <QMdiArea>
+#include <QMdiSubWindow>
+#include <QQuickWidget>
+#include <QVBoxLayout>
+#include <QPushButton>
+
+void configureMainWindow(QMainWindow *w, QMdiArea *mdiArea, QPushButton *button)
+{
+    auto widget = new QWidget;
+    auto layout = new QVBoxLayout;
+    layout->addWidget(mdiArea);
+    layout->addWidget(button);
+    widget->setLayout(layout);
+    w->setCentralWidget(widget);
+}
+
+int main(int argc, char* argv[])
+{
+    QApplication app(argc, argv);
+
+    QMainWindow w1;
+    w1.winId();
+    w1.windowHandle()->setScreen(QGuiApplication::screens().at(0));
+    auto mdiArea1 = new QMdiArea;
+    auto button1 = new QPushButton("Switch to this window");
+    configureMainWindow(&w1, mdiArea1, button1);
+    w1.setGeometry(0, 0, 800, 800);
+    w1.show();
+
+    QMainWindow w2;
+    w2.winId();
+    w2.windowHandle()->setScreen(QGuiApplication::screens().at(1));
+    auto mdiArea2 = new QMdiArea;
+    auto button2 = new QPushButton("Switch to this window");
+    configureMainWindow(&w2, mdiArea2, button2);
+    w2.setGeometry(0, 0, 800, 800);
+    w2.show();
+
+    QMdiSubWindow* subWindow = new QMdiSubWindow();
+
+    QQuickWidget *quickWidget = new QQuickWidget();
+    quickWidget->resize(QSize(400, 400));
+    quickWidget->setResizeMode(QQuickWidget::SizeRootObjectToView);
+    quickWidget->setSource(QUrl("qrc:/main.qml"));
+
+    subWindow->setWidget(quickWidget);
+
+    QObject::connect(button1, &QPushButton::clicked,
+                     [mdiArea1, mdiArea2, subWindow, button1, button2]() {
+        mdiArea2->removeSubWindow(subWindow);
+        mdiArea1->addSubWindow(subWindow);
+        subWindow->show();
+        button1->setEnabled(false);
+        button2->setEnabled(true);
+    });
+
+    QObject::connect(button2, &QPushButton::clicked,
+                     [mdiArea1, mdiArea2, subWindow, button1, button2]() {
+        mdiArea1->removeSubWindow(subWindow);
+        mdiArea2->addSubWindow(subWindow);
+        subWindow->show();
+        button1->setEnabled(true);
+        button2->setEnabled(false);
+    });
+
+    mdiArea2->addSubWindow(subWindow);
+    button2->setEnabled(false);
+    subWindow->show();
+
+    return app.exec();
+}
diff --git a/tests/manual/quickwidget-switch/main.qml b/tests/manual/quickwidget-switch/main.qml
new file mode 100644
index 000000000..d4bce020c
--- /dev/null
+++ b/tests/manual/quickwidget-switch/main.qml
@@ -0,0 +1,152 @@
+/****************************************************************************
+**
+** Copyright (C) 2020 The Qt Company.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the Qt3D module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
+**
+** "Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above copyright
+**     notice, this list of conditions and the following disclaimer in
+**     the documentation and/or other materials provided with the
+**     distribution.
+**   * Neither the name of The Qt Company Ltd nor the names of its
+**     contributors may be used to endorse or promote products derived
+**     from this software without specific prior written permission.
+**
+**
+** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+import QtQuick 2.2 as QQ2
+import Qt3D.Core 2.0
+import Qt3D.Render 2.0
+import Qt3D.Input 2.0
+import Qt3D.Extras 2.0
+
+import QtQuick.Scene3D 2.0
+
+QQ2.Item {
+    id: mioitem
+    width: 300
+    height: 300
+    Scene3D {
+        id: scene3d
+        anchors.fill: parent
+        Entity {
+            id: sceneRoot
+
+            Camera {
+                id: camera
+                projectionType: CameraLens.PerspectiveProjection
+                fieldOfView: 45
+                aspectRatio: 16/9
+                nearPlane : 0.1
+                farPlane : 1000.0
+                position: Qt.vector3d( 0.0, 0.0, -40.0 )
+                upVector: Qt.vector3d( 0.0, 1.0, 0.0 )
+                viewCenter: Qt.vector3d( 0.0, 0.0, 0.0 )
+            }
+
+            OrbitCameraController {
+                camera: camera
+            }
+
+            components: [
+                RenderSettings {
+                    activeFrameGraph: ForwardRenderer {
+                        clearColor: Qt.rgba(0, 0.5, 1, 1)
+                        camera: camera
+                    }
+                },
+                // Event Source will be set by the Qt3DQuickWindow
+                InputSettings { }
+            ]
+
+            PhongMaterial {
+                id: material
+            }
+
+            TorusMesh {
+                id: torusMesh
+                radius: 5
+                minorRadius: 1
+                rings: 100
+                slices: 20
+            }
+
+            Transform {
+                id: torusTransform
+                scale3D: Qt.vector3d(1.5, 1, 0.5)
+                rotation: fromAxisAndAngle(Qt.vector3d(1, 0, 0), 45)
+            }
+
+            Entity {
+                id: torusEntity
+                components: [ torusMesh, material, torusTransform ]
+            }
+
+            SphereMesh {
+                id: sphereMesh
+                radius: 3
+            }
+
+            Transform {
+                id: sphereTransform
+                property real userAngle: 0.0
+                matrix: {
+                    var m = Qt.matrix4x4();
+                    m.rotate(userAngle, Qt.vector3d(0, 1, 0));
+                    m.translate(Qt.vector3d(20, 0, 0));
+                    return m;
+                }
+            }
+
+            QQ2.NumberAnimation {
+                target: sphereTransform
+                property: "userAngle"
+                duration: 10000
+                from: 0
+                to: 360
+
+                loops: QQ2.Animation.Infinite
+                running: true
+            }
+
+            Entity {
+                id: sphereEntity
+                components: [ sphereMesh, material, sphereTransform ]
+            }
+        }
+    }
+}
diff --git a/tests/manual/quickwidget-switch/quickwidget-switch.pro b/tests/manual/quickwidget-switch/quickwidget-switch.pro
new file mode 100644
index 000000000..2f1cb98f5
--- /dev/null
+++ b/tests/manual/quickwidget-switch/quickwidget-switch.pro
@@ -0,0 +1,13 @@
+TEMPLATE = app
+
+QT += 3dextras
+CONFIG += resources_big
+
+QT += 3dcore 3drender 3dinput 3dquick 3dlogic qml quick 3dquickextras widgets quickwidgets
+
+SOURCES += \
+    main.cpp
+
+RESOURCES += \
+    quickwidget-switch.qrc
+
diff --git a/tests/manual/quickwidget-switch/quickwidget-switch.qrc b/tests/manual/quickwidget-switch/quickwidget-switch.qrc
new file mode 100644
index 000000000..5f6483ac3
--- /dev/null
+++ b/tests/manual/quickwidget-switch/quickwidget-switch.qrc
@@ -0,0 +1,5 @@
+<RCC>
+    <qresource prefix="/">
+        <file>main.qml</file>
+    </qresource>
+</RCC>
diff --git a/tests/manual/quickwindow-switch/main.cpp b/tests/manual/quickwindow-switch/main.cpp
new file mode 100644
index 000000000..7bebe0c75
--- /dev/null
+++ b/tests/manual/quickwindow-switch/main.cpp
@@ -0,0 +1,68 @@
+/****************************************************************************
+**
+** Copyright (C) 2020 The Qt Company.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the Qt3D module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
+**
+** "Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above copyright
+**     notice, this list of conditions and the following disclaimer in
+**     the documentation and/or other materials provided with the
+**     distribution.
+**   * Neither the name of The Qt Company Ltd nor the names of its
+**     contributors may be used to endorse or promote products derived
+**     from this software without specific prior written permission.
+**
+**
+** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <QGuiApplication>
+#include <QQmlApplicationEngine>
+
+int main(int argc, char* argv[])
+{
+    QGuiApplication app(argc, argv);
+
+    QQmlApplicationEngine engine;
+    const QUrl url(QStringLiteral("qrc:/main.qml"));
+    QObject::connect(&engine, &QQmlApplicationEngine::objectCreated,
+        &app, [url](QObject *obj, const QUrl &objUrl) {
+        if (!obj && url == objUrl)
+            QCoreApplication::exit(-1);
+    }, Qt::QueuedConnection);
+    engine.load(url);
+
+    return app.exec();
+}
diff --git a/tests/manual/quickwindow-switch/main.qml b/tests/manual/quickwindow-switch/main.qml
new file mode 100644
index 000000000..4b474bd11
--- /dev/null
+++ b/tests/manual/quickwindow-switch/main.qml
@@ -0,0 +1,181 @@
+/****************************************************************************
+**
+** Copyright (C) 2020 The Qt Company.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the Qt3D module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
+**
+** "Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above copyright
+**     notice, this list of conditions and the following disclaimer in
+**     the documentation and/or other materials provided with the
+**     distribution.
+**   * Neither the name of The Qt Company Ltd nor the names of its
+**     contributors may be used to endorse or promote products derived
+**     from this software without specific prior written permission.
+**
+**
+** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+import QtQuick 2.2
+import QtQuick.Window 2.12 as Win
+import Qt3D.Core 2.0
+import Qt3D.Render 2.0
+import Qt3D.Input 2.0
+import Qt3D.Extras 2.0
+
+import QtQuick.Scene3D 2.0
+
+Win.Window {
+    id: win
+    width: 300
+    height: 350
+    visible: true
+    x: Win.Screen.width / 2 - width / 2
+    y: Win.Screen.height / 2 - height / 2
+    Item {
+        id: mioitem
+        width: 300
+        height: 300
+        Scene3D {
+            id: scene3d
+            anchors.fill: parent
+            Entity {
+                id: sceneRoot
+
+                Camera {
+                    id: camera
+                    projectionType: CameraLens.PerspectiveProjection
+                    fieldOfView: 45
+                    aspectRatio: 16/9
+                    nearPlane : 0.1
+                    farPlane : 1000.0
+                    position: Qt.vector3d( 0.0, 0.0, -40.0 )
+                    upVector: Qt.vector3d( 0.0, 1.0, 0.0 )
+                    viewCenter: Qt.vector3d( 0.0, 0.0, 0.0 )
+                }
+
+                OrbitCameraController {
+                    camera: camera
+                }
+
+                components: [
+                    RenderSettings {
+                        activeFrameGraph: ForwardRenderer {
+                            clearColor: Qt.rgba(0, 0.5, 1, 1)
+                            camera: camera
+                        }
+                    },
+                    // Event Source will be set by the Qt3DQuickWindow
+                    InputSettings { }
+                ]
+
+                PhongMaterial {
+                    id: material
+                }
+
+                TorusMesh {
+                    id: torusMesh
+                    radius: 5
+                    minorRadius: 1
+                    rings: 100
+                    slices: 20
+                }
+
+                Transform {
+                    id: torusTransform
+                    scale3D: Qt.vector3d(1.5, 1, 0.5)
+                    rotation: fromAxisAndAngle(Qt.vector3d(1, 0, 0), 45)
+                }
+
+                Entity {
+                    id: torusEntity
+                    components: [ torusMesh, material, torusTransform ]
+                }
+
+                SphereMesh {
+                    id: sphereMesh
+                    radius: 3
+                }
+
+                Transform {
+                    id: sphereTransform
+                    property real userAngle: 0.0
+                    matrix: {
+                        var m = Qt.matrix4x4();
+                        m.rotate(userAngle, Qt.vector3d(0, 1, 0));
+                        m.translate(Qt.vector3d(20, 0, 0));
+                        return m;
+                    }
+                }
+
+                NumberAnimation {
+                    target: sphereTransform
+                    property: "userAngle"
+                    duration: 10000
+                    from: 0
+                    to: 360
+
+                    loops: Animation.Infinite
+                    running: true
+                }
+
+                Entity {
+                    id: sphereEntity
+                    components: [ sphereMesh, material, sphereTransform ]
+                }
+            }
+        }
+    }
+    Rectangle {
+        height: 50
+        anchors.left: parent.left
+        anchors.right: parent.right
+        anchors.bottom: parent.bottom
+        color: "yellow"
+        MouseArea {
+            anchors.fill: parent
+            z: 5
+            onClicked: {
+                win.screen = (win.screen === Qt.application.screens[0] ? Qt.application.screens[1] : Qt.application.screens[0])
+            }
+        }
+        Text {
+            anchors.centerIn: parent
+            minimumPointSize: 12
+            fontSizeMode: Text.Fit
+            text: "Move to the other screen"
+        }
+    }
+}
diff --git a/tests/manual/quickwindow-switch/quickwindow-switch.pro b/tests/manual/quickwindow-switch/quickwindow-switch.pro
new file mode 100644
index 000000000..2f338d36d
--- /dev/null
+++ b/tests/manual/quickwindow-switch/quickwindow-switch.pro
@@ -0,0 +1,13 @@
+TEMPLATE = app
+
+QT += 3dextras
+CONFIG += resources_big
+
+QT += 3dcore 3drender 3dinput 3dquick 3dlogic qml quick 3dquickextras
+
+SOURCES += \
+    main.cpp
+
+RESOURCES += \
+    quickwindow-switch.qrc
+
diff --git a/tests/manual/quickwindow-switch/quickwindow-switch.qrc b/tests/manual/quickwindow-switch/quickwindow-switch.qrc
new file mode 100644
index 000000000..5f6483ac3
--- /dev/null
+++ b/tests/manual/quickwindow-switch/quickwindow-switch.qrc
@@ -0,0 +1,5 @@
+<RCC>
+    <qresource prefix="/">
+        <file>main.qml</file>
+    </qresource>
+</RCC>