QmlDesigner: Implement different render path for Qt 6

When building with Qt 6 or if qmlpuppet_unifiedRenderPath is set
in the environment we switch to a different render path.
In this case we use QQuickWindow::grabWindow() and render the root item.
No composition is done in the Qt Creator process anymore.
This is a similar approach we already take for the 3D view.
Performance is acceptable and we fix rendering issues related to
effects and layers.

Change-Id: Ic963eca047e0bf16ca3a099ec94658ae2af0fb63
Reviewed-by: Thomas Hartmann <thomas.hartmann@qt.io>
Reviewed-by: Miikka Heikkinen <miikka.heikkinen@qt.io>

share/qtcreator/qml/qmlpuppet/qml2puppet/instances/nodeinstanceserver.cpp

@@ -72,22 +72,23 @@
 #include <requestmodelnodepreviewimagecommand.h>
 #include <changelanguagecommand.h>
 
+#include <designersupportdelegate.h>
+#include <QAbstractAnimation>
 #include <QDebug>
-#include <QQmlEngine>
-#include <QQmlApplicationEngine>
-#include <QFileSystemWatcher>
-#include <QUrl>
-#include <QSet>
 #include <QDir>
-#include <QVariant>
+#include <QFileSystemWatcher>
 #include <QMetaType>
+#include <QMutableVectorIterator>
+#include <QQmlApplicationEngine>
 #include <QQmlComponent>
 #include <QQmlContext>
-#include <qqmllist.h>
+#include <QQmlEngine>
-#include <QAbstractAnimation>
+#include <QQuickItemGrabResult>
 #include <QQuickView>
 #include <QSet>
-#include <designersupportdelegate.h>
+#include <QUrl>
+#include <QVariant>
+#include <qqmllist.h>
 
 #include <algorithm>
 
@@ -1461,4 +1462,19 @@ void NodeInstanceServer::disableTimer()
     m_timerMode = TimerMode::DisableTimer;
 }
 
+void NodeInstanceServer::sheduleRootItemRender()
+{
+    QSharedPointer<QQuickItemGrabResult> result = m_rootNodeInstance.createGrabResult();
+    qint32 instanceId = m_rootNodeInstance.instanceId();
+
+    if (result) {
+        connect(result.data(), &QQuickItemGrabResult::ready, [this, result, instanceId] {
+            QVector<ImageContainer> imageVector;
+            ImageContainer container(instanceId, result->image(), instanceId);
+            imageVector.append(container);
+            nodeInstanceClient()->pixmapChanged(PixmapChangedCommand(imageVector));
+        });
+    }
+}
+
 } // namespace QmlDesigner

share/qtcreator/qml/qmlpuppet/qml2puppet/instances/nodeinstanceserver.h

@@ -241,6 +241,8 @@ protected:
     ComponentCompletedCommand createComponentCompletedCommand(const QList<ServerNodeInstance> &instanceList);
     ChangeSelectionCommand createChangeSelectionCommand(const QList<ServerNodeInstance> &instanceList);
 
+    void sheduleRootItemRender();
+
     void addChangedProperty(const InstancePropertyPair &property);
 
     virtual void startRenderTimer();

share/qtcreator/qml/qmlpuppet/qml2puppet/instances/objectnodeinstance.cpp

@@ -908,6 +908,11 @@ QImage ObjectNodeInstance::renderPreviewImage(const QSize & /*previewImageSize*/
     return QImage();
 }
 
+QSharedPointer<QQuickItemGrabResult> ObjectNodeInstance::createGrabResult() const
+{
+    return {};
+}
+
 QObject *ObjectNodeInstance::parent() const
 {
     if (!object())

share/qtcreator/qml/qmlpuppet/qml2puppet/instances/objectnodeinstance.h

@@ -84,6 +84,8 @@ public:
     virtual QImage renderImage() const;
     virtual QImage renderPreviewImage(const QSize &previewImageSize) const;
 
+    virtual QSharedPointer<QQuickItemGrabResult> createGrabResult() const;
+
     virtual QObject *parent() const;
 
     Pointer parentInstance() const;

share/qtcreator/qml/qmlpuppet/qml2puppet/instances/qt5nodeinstanceclientproxy.cpp

@@ -33,6 +33,7 @@
 #include "qt5previewnodeinstanceserver.h"
 #include "qt5rendernodeinstanceserver.h"
 #include "qt5testnodeinstanceserver.h"
+#include "quickitemnodeinstance.h"
 
 #include <designersupportdelegate.h>
 
@@ -56,7 +57,19 @@ Qt5NodeInstanceClientProxy::Qt5NodeInstanceClientProxy(QObject *parent) :
     NodeInstanceClientProxy(parent)
 {
     prioritizeDown();
-    DesignerSupport::activateDesignerWindowManager();
+#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
+    const bool qt6 = false;
+#else
+    const bool qt6 = true;
+#endif
+
+    const bool unifiedRenderPath = qt6 || qEnvironmentVariableIsSet("QMLPUPPET_UNIFIED_RENDER_PATH");
+
+    if (unifiedRenderPath)
+        Internal::QuickItemNodeInstance::enableUnifiedRenderPath(true);
+    else
+        DesignerSupport::activateDesignerWindowManager();
+
     if (QCoreApplication::arguments().at(1) == QLatin1String("--readcapturedstream")) {
         qputenv("DESIGNER_DONT_USE_SHARED_MEMORY", "1");
         setNodeInstanceServer(std::make_unique<Qt5TestNodeInstanceServer>(this));

share/qtcreator/qml/qmlpuppet/qml2puppet/instances/qt5nodeinstanceserver.cpp

@@ -64,6 +64,8 @@ void Qt5NodeInstanceServer::initializeView()
 
     m_quickView = new QQuickView;
 
+#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
+    /* enables grab window without show */
     QSurfaceFormat surfaceFormat = m_quickView->requestedFormat();
     surfaceFormat.setVersion(4, 1);
     surfaceFormat.setProfile(QSurfaceFormat::CoreProfile);
@@ -72,6 +74,7 @@ void Qt5NodeInstanceServer::initializeView()
     m_quickView->setFormat(surfaceFormat);
 
     DesignerSupport::createOpenGLContext(m_quickView.data());
+#endif
 
     if (qEnvironmentVariableIsSet("QML_FILE_SELECTORS")) {
         QQmlFileSelector *fileSelector = new QQmlFileSelector(engine(), engine());

share/qtcreator/qml/qmlpuppet/qml2puppet/instances/qt5rendernodeinstanceserver.cpp

@@ -87,17 +87,27 @@ void Qt5RenderNodeInstanceServer::collectItemChangesAndSendChangeCommands()
                         if (ancestorInstance.isValid())
                             m_dirtyInstanceSet.insert(ancestorInstance);
                     }
-                    DesignerSupport::updateDirtyNode(item);
+                    Internal::QuickItemNodeInstance::updateDirtyNode(item);
                 }
             }
 
             clearChangedPropertyList();
 
-            if (!m_dirtyInstanceSet.isEmpty()) {
+            if (Internal::QuickItemNodeInstance::unifiedRenderPath()) {
-                nodeInstanceClient()->pixmapChanged(createPixmapChangedCommand(QtHelpers::toList(m_dirtyInstanceSet)));
+                /* QQuickItem::grabToImage render path */
-                m_dirtyInstanceSet.clear();
+                /* TODO implement QQuickItem::grabToImage based rendering */
+                /* sheduleRootItemRender(); */
+                nodeInstanceClient()->pixmapChanged(createPixmapChangedCommand({rootNodeInstance()}));
+            } else {
+                if (!m_dirtyInstanceSet.isEmpty()) {
+                    nodeInstanceClient()->pixmapChanged(
+                        createPixmapChangedCommand(QtHelpers::toList(m_dirtyInstanceSet)));
+                    m_dirtyInstanceSet.clear();
+                }
             }
 
+            m_dirtyInstanceSet.clear();
+
             resetAllItems();
 
             slowDownRenderTimer();
@@ -137,6 +147,11 @@ void Qt5RenderNodeInstanceServer::createScene(const CreateSceneCommand &command)
     }
 
     nodeInstanceClient()->pixmapChanged(createPixmapChangedCommand(instanceList));
+
+#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
+#else
+    quickView()->show();
+#endif
 }
 
 void Qt5RenderNodeInstanceServer::clearScene(const ClearSceneCommand &command)

share/qtcreator/qml/qmlpuppet/qml2puppet/instances/quickitemnodeinstance.cpp

@@ -41,6 +41,7 @@ namespace QmlDesigner {
 namespace Internal {
 
 bool QuickItemNodeInstance::s_createEffectItem = false;
+bool QuickItemNodeInstance::s_unifiedRenderPath = false;
 
 QuickItemNodeInstance::QuickItemNodeInstance(QQuickItem *item)
    : ObjectNodeInstance(item),
@@ -58,7 +59,7 @@ QuickItemNodeInstance::QuickItemNodeInstance(QQuickItem *item)
 
 QuickItemNodeInstance::~QuickItemNodeInstance()
 {
-    if (quickItem())
+    if (quickItem() && checkIfRefFromEffect(instanceId()))
         designerSupport()->derefFromEffectItem(quickItem());
 }
 
@@ -156,6 +157,19 @@ void QuickItemNodeInstance::createEffectItem(bool createEffectItem)
     s_createEffectItem = createEffectItem;
 }
 
+void QuickItemNodeInstance::enableUnifiedRenderPath(bool unifiedRenderPath)
+{
+    s_unifiedRenderPath = unifiedRenderPath;
+}
+
+bool QuickItemNodeInstance::checkIfRefFromEffect(qint32 id)
+{
+    if (s_unifiedRenderPath)
+        return false;
+
+    return (s_createEffectItem || id == 0);
+}
+
 void QuickItemNodeInstance::initialize(const ObjectNodeInstance::Pointer &objectNodeInstance,
                                        InstanceContainer::NodeFlags flags)
 {
@@ -166,10 +180,10 @@ void QuickItemNodeInstance::initialize(const ObjectNodeInstance::Pointer &object
         quickItem()->setParentItem(qobject_cast<QQuickItem*>(nodeInstanceServer()->quickView()->rootObject()));
     }
 
-    if (quickItem()->window()) {
+    if (quickItem()->window() && checkIfRefFromEffect(instanceId())) {
-        if (s_createEffectItem || instanceId() == 0)
+        designerSupport()->refFromEffectItem(quickItem(),
-            designerSupport()->refFromEffectItem(quickItem(),
+                                             !flags.testFlag(
-                                                 !flags.testFlag(InstanceContainer::ParentTakesOverRendering));
+                                                 InstanceContainer::ParentTakesOverRendering));
     }
 
     ObjectNodeInstance::initialize(objectNodeInstance, flags);
@@ -246,6 +260,20 @@ QStringList QuickItemNodeInstance::allStates() const
     return list;
 }
 
+void QuickItemNodeInstance::updateDirtyNode(QQuickItem *item)
+{
+    if (s_unifiedRenderPath) {
+        item->update();
+        return;
+    }
+    DesignerSupport::updateDirtyNode(item);
+}
+
+bool QuickItemNodeInstance::unifiedRenderPath()
+{
+    return s_unifiedRenderPath;
+}
+
 QRectF QuickItemNodeInstance::contentItemBoundingBox() const
 {
     if (contentItem()) {
@@ -378,6 +406,9 @@ double QuickItemNodeInstance::y() const
 
 QImage QuickItemNodeInstance::renderImage() const
 {
+    if (s_unifiedRenderPath && !isRootNodeInstance())
+        return {};
+
     updateDirtyNodesRecursive(quickItem());
 
     QRectF renderBoundingRect = boundingRect();
@@ -390,7 +421,16 @@ QImage QuickItemNodeInstance::renderImage() const
     nodeInstanceServer()->quickView()->beforeSynchronizing();
     nodeInstanceServer()->quickView()->beforeRendering();
 
-    QImage renderImage = designerSupport()->renderImageForItem(quickItem(), renderBoundingRect, size);
+    QImage renderImage;
+
+#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
+    if (s_unifiedRenderPath)
+        renderImage = nodeInstanceServer()->quickView()->grabWindow();
+    else
+        renderImage = designerSupport()->renderImageForItem(quickItem(), renderBoundingRect, size);
+#else
+    renderImage = nodeInstanceServer()->quickView()->grabWindow();
+#endif
 
     nodeInstanceServer()->quickView()->afterRendering();
 
@@ -411,7 +451,20 @@ QImage QuickItemNodeInstance::renderPreviewImage(const QSize &previewImageSize)
             nodeInstanceServer()->quickView()->beforeSynchronizing();
             nodeInstanceServer()->quickView()->beforeRendering();
 
-            QImage image = designerSupport()->renderImageForItem(quickItem(), previewItemBoundingRect, size);
+            QImage image;
+#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
+            if (s_unifiedRenderPath)
+                image = nodeInstanceServer()->quickView()->grabWindow();
+            else
+                image = designerSupport()->renderImageForItem(quickItem(),
+                                                              previewItemBoundingRect,
+                                                              size);
+
+#else
+            image = nodeInstanceServer()->quickView()->grabWindow();
+#endif
+
+            image = image.scaledToWidth(size.width());
 
             nodeInstanceServer()->quickView()->afterRendering();
 
@@ -426,6 +479,11 @@ QImage QuickItemNodeInstance::renderPreviewImage(const QSize &previewImageSize)
     return QImage();
 }
 
+QSharedPointer<QQuickItemGrabResult> QuickItemNodeInstance::createGrabResult() const
+{
+    return quickItem()->grabToImage(size().toSize());
+}
+
 void QuickItemNodeInstance::updateAllDirtyNodesRecursive()
 {
     updateAllDirtyNodesRecursive(quickItem());
@@ -490,10 +548,11 @@ void QuickItemNodeInstance::updateDirtyNodesRecursive(QQuickItem *parentItem) co
 
 void QuickItemNodeInstance::updateAllDirtyNodesRecursive(QQuickItem *parentItem) const
 {
-    foreach (QQuickItem *childItem, parentItem->childItems())
+    const QList<QQuickItem *> children = parentItem->childItems();
-            updateAllDirtyNodesRecursive(childItem);
+    for (QQuickItem *childItem : children)
+        updateAllDirtyNodesRecursive(childItem);
 
-    DesignerSupport::updateDirtyNode(parentItem);
+    updateDirtyNode(parentItem);
 }
 
 static inline bool isRectangleSane(const QRectF &rect)

share/qtcreator/qml/qmlpuppet/qml2puppet/instances/quickitemnodeinstance.h

@@ -45,6 +45,7 @@ public:
 
     static Pointer create(QObject *objectToBeWrapped);
     static void createEffectItem(bool createEffectItem);
+    static void enableUnifiedRenderPath(bool createEffectItem);
 
     void initialize(const ObjectNodeInstance::Pointer &objectNodeInstance,
                     InstanceContainer::NodeFlags flags) override;
@@ -70,6 +71,8 @@ public:
     QImage renderImage() const override;
     QImage renderPreviewImage(const QSize &previewImageSize) const override;
 
+    QSharedPointer<QQuickItemGrabResult> createGrabResult() const override;
+
     void updateAllDirtyNodesRecursive() override;
 
 
@@ -98,6 +101,9 @@ public:
     QList<QQuickItem*> allItemsRecursive() const override;
     QStringList allStates() const override;
 
+    static void updateDirtyNode(QQuickItem *item);
+    static bool unifiedRenderPath();
+
 protected:
     explicit QuickItemNodeInstance(QQuickItem*);
     QQuickItem *quickItem() const;
@@ -118,6 +124,7 @@ protected:
 
     double x() const;
     double y() const;
+    bool checkIfRefFromEffect(qint32 id);
 
 private: //variables
     QPointer<QQuickItem> m_contentItem;
@@ -131,6 +138,7 @@ private: //variables
     double m_width;
     double m_height;
     static bool s_createEffectItem;
+    static bool s_unifiedRenderPath;
 };
 
 } // namespace Internal

share/qtcreator/qml/qmlpuppet/qml2puppet/instances/servernodeinstance.cpp

@@ -120,6 +120,11 @@ QImage ServerNodeInstance::renderPreviewImage(const QSize &previewImageSize) con
     return m_nodeInstance->renderPreviewImage(previewImageSize);
 }
 
+QSharedPointer<QQuickItemGrabResult> ServerNodeInstance::createGrabResult() const
+{
+    return m_nodeInstance->createGrabResult();
+}
+
 bool ServerNodeInstance::isRootNodeInstance() const
 {
     return isValid() && m_nodeInstance->isRootNodeInstance();

share/qtcreator/qml/qmlpuppet/qml2puppet/instances/servernodeinstance.h

@@ -40,6 +40,7 @@ class QGraphicsItem;
 class QGraphicsTransform;
 #if (QT_VERSION >= QT_VERSION_CHECK(5, 0, 0))
 class QQuickItem;
+class QQuickItemGrabResult;
 #endif
 QT_END_NAMESPACE
 
@@ -102,6 +103,8 @@ public:
     QImage renderImage() const;
     QImage renderPreviewImage(const QSize &previewImageSize) const;
 
+    QSharedPointer<QQuickItemGrabResult> createGrabResult() const;
+
     ServerNodeInstance parent() const;
     bool hasParent() const;