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>

1 files changed, 14 insertions, 1 deletions

diff --git a/share/qtcreator/qml/qmlpuppet/qml2puppet/instances/qt5nodeinstanceclientproxy.cpp b/share/qtcreator/qml/qmlpuppet/qml2puppet/instances/qt5nodeinstanceclientproxy.cpp
index defbf5614a..64b6eb409c 100644
--- a/share/qtcreator/qml/qmlpuppet/qml2puppet/instances/qt5nodeinstanceclientproxy.cpp
+++ b/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));