Allow non-nodes outside Layer

...both in .uip and when added dynmically.

This makes it possible to construct scenes like the following:

Scene
  - DefaultMaterial
  -- DefaultMaterial
  -- DefaultMaterial
  ...
  - Layer
  -- Camera
  -- Light
  -- Model
  -- ReferencedMaterial

because referencing a material via ReferencedMaterial will work as
expected regardless of where the target object lives in the tree.

Change-Id: I3cae99403b35f62f5819a96d29c72a87b87470d6
Reviewed-by: Jere Tuliniemi <jere.tuliniemi@qt.io>
Reviewed-by: Christian Stromme <christian.stromme@qt.io>

3 files changed, 18 insertions, 9 deletions

diff --git a/src/runtime/q3dsscenemanager.cpp b/src/runtime/q3dsscenemanager.cpp
index c350f61..2c8155c 100644
--- a/src/runtime/q3dsscenemanager.cpp
+++ b/src/runtime/q3dsscenemanager.cpp
@@ -8358,10 +8358,13 @@ void Q3DSSceneManager::handleSceneChange(Q3DSScene *, Q3DSGraphObject::DirtyFlag
         // of buildLayer().
 
         if (obj->type() != Q3DSGraphObject::Layer) {
-            Q_ASSERT(obj->parent() && obj->parent()->attached());
-            Q3DSLayerNode *layer3DS = findLayerForObjectInScene(obj);
+            Q3DSLayerNode *layer3DS = nullptr;
+            if (obj->parent() && obj->parent()->attached())
+                layer3DS = findLayerForObjectInScene(obj);
             if (layer3DS)
                 addLayerContent(obj, obj->parent(), layer3DS);
+            else
+                addNonLayerContent(obj);
         } else {
             addLayer(static_cast<Q3DSLayerNode *>(obj));
         }
@@ -8451,6 +8454,15 @@ void Q3DSSceneManager::handleSceneChange(Q3DSScene *, Q3DSGraphObject::DirtyFlag
     }
 }
 
+void Q3DSSceneManager::addNonLayerContent(Q3DSGraphObject *obj)
+{
+    initSubTree(obj);
+
+    // and that's it. This is not suitable for nodes as they won't be
+    // functional, but Image, DefaultMaterial, CustomMaterial can live outside
+    // a Layer just fine.
+}
+
 void Q3DSSceneManager::addLayerContent(Q3DSGraphObject *obj, Q3DSGraphObject *parent, Q3DSLayerNode *layer3DS)
 {
     // obj can have children, process the entire subtree recursively
diff --git a/src/runtime/q3dsscenemanager_p.h b/src/runtime/q3dsscenemanager_p.h
index c57e20d..35c1afa 100644
--- a/src/runtime/q3dsscenemanager_p.h
+++ b/src/runtime/q3dsscenemanager_p.h
@@ -890,6 +890,7 @@ private:
 
     void handleNodeGlobalChange(Q3DSNode *node);
     void handleSceneChange(Q3DSScene *scene, Q3DSGraphObject::DirtyFlag change, Q3DSGraphObject *obj);
+    void addNonLayerContent(Q3DSGraphObject *obj);
     void addLayerContent(Q3DSGraphObject *obj, Q3DSGraphObject *parent, Q3DSLayerNode *layer3DS);
     void addLayer(Q3DSLayerNode *layer3DS);
     void handleSlideGraphChange(Q3DSSlide *master, Q3DSGraphObject::DirtyFlag change, Q3DSSlide *slide);
diff --git a/src/runtime/q3dsuipparser.cpp b/src/runtime/q3dsuipparser.cpp
index 0aa3607..0528ef8 100644
--- a/src/runtime/q3dsuipparser.cpp
+++ b/src/runtime/q3dsuipparser.cpp
@@ -54,7 +54,7 @@ QT_BEGIN_NAMESPACE
         </BufferData>
         <Graph>
             <Scene id="Scene">
-                <Layer id="layer"> scene can only have layer children
+                <Layer id="layer">
                     <Camera id="Camera" />
                     <Light id="Light" />
                     ...
@@ -307,12 +307,8 @@ void Q3DSUipParser::parseScene()
     m_presentation->registerObject(id, scene);
     m_presentation->setScene(scene);
 
-    while (r->readNextStartElement()) {
-        if (r->name() == QStringLiteral("Layer") || r->name() == QStringLiteral("Behavior"))
-            parseObjects(scene);
-        else
-            r->raiseError(QObject::tr("Scene can only have Layer or Behavior children."));
-    }
+    while (r->readNextStartElement())
+        parseObjects(scene);
 }
 
 void Q3DSUipParser::parseObjects(Q3DSGraphObject *parent)