Update NodeInstantiator's children on parent update

Currently the parent for elements created by NodeInstantiator are set to
the instantiator's parent. This doesn't work for nested instantiators,
since at the time the inner instantiator's children are being created
the instantiator itself doesn't yet have a parent node yet.

Update the parent of elements created by the instantiator when the
instantiator's parent changes.

Change-Id: I6f260ad2a8a81af5551799e6c643d8849f46e342
Reviewed-by: Sean Harmer <sean.harmer@kdab.com>
Reviewed-by: Kevin Ottens <kevin.ottens@kdab.com>

5 files changed, 60 insertions, 0 deletions

diff --git a/src/quick3d/quick3d/items/quick3dnodeinstantiator.cpp b/src/quick3d/quick3d/items/quick3dnodeinstantiator.cpp
index c6e8aa7c1..b99f6ae75 100644
--- a/src/quick3d/quick3d/items/quick3dnodeinstantiator.cpp
+++ b/src/quick3d/quick3d/items/quick3dnodeinstantiator.cpp
@@ -245,6 +245,7 @@ void Quick3DNodeInstantiatorPrivate::makeModel()
 Quick3DNodeInstantiator::Quick3DNodeInstantiator(QNode *parent)
     : QNode(*new Quick3DNodeInstantiatorPrivate, parent)
 {
+    connect(this, &QNode::parentChanged, this, &Quick3DNodeInstantiator::onParentChanged);
 }
 
 /*!
@@ -501,6 +502,17 @@ void Quick3DNodeInstantiator::componentComplete()
     }
 }
 
+/*!
+ \internal
+*/
+void Quick3DNodeInstantiator::onParentChanged(QObject *parent)
+{
+    Q_D(const Quick3DNodeInstantiator);
+    auto parentNode = static_cast<QNode *>(parent);
+    for (auto obj : d->m_objects)
+        static_cast<QNode *>(obj.data())->setParent(parentNode);
+}
+
 // TODO: Avoid cloning here
 //void Quick3DNodeInstantiator::copy(const QNode *ref)
 //{
diff --git a/src/quick3d/quick3d/items/quick3dnodeinstantiator_p.h b/src/quick3d/quick3d/items/quick3dnodeinstantiator_p.h
index fd7a1d83d..a79cb4f90 100644
--- a/src/quick3d/quick3d/items/quick3dnodeinstantiator_p.h
+++ b/src/quick3d/quick3d/items/quick3dnodeinstantiator_p.h
@@ -113,6 +113,9 @@ Q_SIGNALS:
     void objectAdded(int index, QObject *object);
     void objectRemoved(int index, QObject *object);
 
+private slots:
+    void onParentChanged(QObject *parent);
+
 private:
     Q_DISABLE_COPY(Quick3DNodeInstantiator)
     Q_DECLARE_PRIVATE(Quick3DNodeInstantiator)
diff --git a/tests/auto/quick3d/quick3dnodeinstantiator/data/createNested.qml b/tests/auto/quick3d/quick3dnodeinstantiator/data/createNested.qml
new file mode 100644
index 000000000..55be54297
--- /dev/null
+++ b/tests/auto/quick3d/quick3dnodeinstantiator/data/createNested.qml
@@ -0,0 +1,15 @@
+import QtQml 2.1
+import Qt3D.Core 2.0
+
+Entity {
+    NodeInstantiator {
+        model: 3
+        delegate: NodeInstantiator {
+            model: 4
+            delegate: Entity {
+                property bool success: true
+                property int idx: index
+            }
+        }
+    }
+}
diff --git a/tests/auto/quick3d/quick3dnodeinstantiator/quick3dnodeinstantiator.pro b/tests/auto/quick3d/quick3dnodeinstantiator/quick3dnodeinstantiator.pro
index 15435d13e..9026f91ff 100644
--- a/tests/auto/quick3d/quick3dnodeinstantiator/quick3dnodeinstantiator.pro
+++ b/tests/auto/quick3d/quick3dnodeinstantiator/quick3dnodeinstantiator.pro
@@ -12,6 +12,7 @@ OTHER_FILES = \
     data/createMultiple.qml \
     data/createNone.qml \
     data/createSingle.qml \
+    data/createNested.qml \
     data/inactive.qml \
     data/stringModel.qml
 
diff --git a/tests/auto/quick3d/quick3dnodeinstantiator/tst_quick3dnodeinstantiator.cpp b/tests/auto/quick3d/quick3dnodeinstantiator/tst_quick3dnodeinstantiator.cpp
index acaba6690..d4d0d56e2 100644
--- a/tests/auto/quick3d/quick3dnodeinstantiator/tst_quick3dnodeinstantiator.cpp
+++ b/tests/auto/quick3d/quick3dnodeinstantiator/tst_quick3dnodeinstantiator.cpp
@@ -50,6 +50,7 @@ private slots:
     void createNone();
     void createSingle();
     void createMultiple();
+    void createNested();
     void stringModel();
     void activeProperty();
     void intModelChange();
@@ -109,6 +110,34 @@ void tst_quick3dnodeinstantiator::createMultiple()
     }
 }
 
+void tst_quick3dnodeinstantiator::createNested()
+{
+    QQmlEngine engine;
+    QQmlComponent component(&engine, testFileUrl("createNested.qml"));
+    const auto root = qobject_cast<Qt3DCore::QNode*>(component.create());
+    QVERIFY(root != 0);
+
+    auto instantiators = root->findChildren<Quick3DNodeInstantiator*>();
+    QCOMPARE(instantiators.count(), 4);
+
+    const auto outerInstantiator = instantiators.takeFirst();
+    QCOMPARE(outerInstantiator->isActive(), true);
+    QCOMPARE(outerInstantiator->count(), 3);
+
+    for (const auto instantiator : instantiators) {
+        QCOMPARE(instantiator->isActive(), true);
+        QCOMPARE(instantiator->count(), 4);
+
+        for (int i = 0; i < 4; i++) {
+            auto object = instantiator->objectAt(i);
+            QVERIFY(object);
+            QCOMPARE(object->parent(), root);
+            QCOMPARE(object->property("success").toBool(), true);
+            QCOMPARE(object->property("idx").toInt(), i);
+        }
+    }
+}
+
 void tst_quick3dnodeinstantiator::stringModel()
 {
     QQmlEngine engine;