Generate a vector of QNodeCreatedChanges at startup

First step towards using these at application startup.

Task-number: QTBUG-51835
Change-Id: If0ee58c8ba859d00ace17bd95972bee285d3e1d0
Reviewed-by: Giuseppe D'Angelo <giuseppe.dangelo@kdab.com>

2 files changed, 21 insertions, 0 deletions

diff --git a/src/core/aspects/qaspectengine.cpp b/src/core/aspects/qaspectengine.cpp
index 8b7c4a667..af6798407 100644
--- a/src/core/aspects/qaspectengine.cpp
+++ b/src/core/aspects/qaspectengine.cpp
@@ -98,6 +98,19 @@ void QAspectEnginePrivate::initEntity(QEntity *entity)
     }
 }
 
+void QAspectEnginePrivate::generateCreationChanges(QNode *root)
+{
+    m_creationChanges.clear();
+    QNodeVisitor creationVisitor;
+    creationVisitor.traverse(root, this, &QAspectEnginePrivate::createCreationChange);
+}
+
+void QAspectEnginePrivate::createCreationChange(QNode *node)
+{
+    const auto creationChange = node->createNodeCreationChange();
+    m_creationChanges.push_back(creationChange);
+}
+
 QAspectEngine::QAspectEngine(QObject *parent)
     : QObject(*new QAspectEnginePrivate, parent)
 {
@@ -312,6 +325,9 @@ void QAspectEngine::setRootEntity(QEntityPtr root)
     // deregister the nodes from the scene
     d->initNodeTree(root.data());
 
+    // Traverse tree to generate a vector of creation changes
+    d->generateCreationChanges(root.data());
+
     // Finally, tell the aspects about the new scene object tree. This is done
     // in a blocking manner to allow the aspects to get synchronized before the
     // main thread starts triggering potentially more notifications
diff --git a/src/core/aspects/qaspectengine_p.h b/src/core/aspects/qaspectengine_p.h
index 334df28b2..7a46d5cc2 100644
--- a/src/core/aspects/qaspectengine_p.h
+++ b/src/core/aspects/qaspectengine_p.h
@@ -52,6 +52,7 @@
 //
 
 #include <private/qobject_p.h>
+#include <Qt3DCore/qnodecreatedchange.h>
 #include <Qt3DCore/private/qaspectfactory_p.h>
 #include <QtCore/qsharedpointer.h>
 
@@ -87,6 +88,10 @@ public:
     void initNodeTree(QNode *node);
     void initNode(QNode *node);
     void initEntity(QEntity *entity);
+
+    void generateCreationChanges(QNode *rootNode);
+    void createCreationChange(QNode *node); // visitor function
+    QVector<QNodeCreatedChangeBasePtr> m_creationChanges;
 };
 
 } // Qt3D