Use direct access to remove backend nodes

- Stop using messages
- Remove QSceneObserverInterface
- Ensure backend node creation/destruction is done at the right time

Change-Id: I470825af344ab65bf05e93fc149b61d1b9eefc96
Reviewed-by: Paul Lemire <paul.lemire@kdab.com>

1 files changed, 22 insertions, 0 deletions

diff --git a/src/core/aspects/qaspectengine.cpp b/src/core/aspects/qaspectengine.cpp
index 41662e2a3..6d1a8ca30 100644
--- a/src/core/aspects/qaspectengine.cpp
+++ b/src/core/aspects/qaspectengine.cpp
@@ -89,6 +89,23 @@ QVector<Qt3DCore::QNode *> getNodesForCreation(Qt3DCore::QNode *root)
     return nodes;
 }
 
+QVector<Qt3DCore::QNode *> getNodesForRemoval(Qt3DCore::QNode *root)
+{
+    using namespace Qt3DCore;
+
+    QVector<QNode *> nodes;
+    QNodeVisitor visitor;
+    visitor.traverse(root, [&nodes](QNode *node) {
+        nodes.append(node);
+
+        // Mark this node as having been handled for destruction so we don't
+        // repeat it unnecessarily in an O(n^2) manner
+        QNodePrivate::get(node)->m_hasBackendNode = false;
+    });
+
+    return nodes;
+}
+
 }
 
 namespace Qt3DCore {
@@ -152,6 +169,11 @@ void QAspectEnginePrivate::addNode(QNode *node)
     m_aspectManager->addNodes(getNodesForCreation(node));
 }
 
+void QAspectEnginePrivate::removeNode(QNode *node)
+{
+    m_aspectManager->removeNodes(getNodesForRemoval(node));
+}
+
 /*!
  * \class Qt3DCore::QAspectEngine
  * \inheaderfile Qt3DCore/QAspectEngine