Fix visual parent ownership with scenes that create windows

Commit 39540124dd0900e0c99dcda8c0ebdf4f3cea8d5e introduced the concept that
a visual parent marks its children, by recursively marking the children of
the root item in a QQuickView. This allowed for the removal of an ugly hack
in QtQuick Controls.

Unfortunately that fix is incomplete in the sense that it makes the incorrect
assumption that a QQuickView is always used. The use-case in the bug report is
to have child items inside a QtQuick.Window (a regular ApplicationWindow in
fact). That window - implemented by QQuickWindowQmlImpl - also needs to mark
its children, so this patch introduces the use of the same GC marking helper
class (which now operates on a QQuickWindow instead of a QQuickViewPrivate).

Task-number: QTBUG-37711
Change-Id: Id788e84dbb041ac8ba6ff23dc4ef56f6fe9e465a
Reviewed-by: Lars Knoll <lars.knoll@digia.com>

1 files changed, 5 insertions, 5 deletions

diff --git a/src/quick/items/qquickview.cpp b/src/quick/items/qquickview.cpp
index 82c1b3a6ae..72c66448b4 100644
--- a/src/quick/items/qquickview.cpp
+++ b/src/quick/items/qquickview.cpp
@@ -58,16 +58,16 @@ QT_BEGIN_NAMESPACE
 
 DEFINE_OBJECT_VTABLE(QQuickRootItemMarker);
 
-QQuickRootItemMarker::QQuickRootItemMarker(QQuickViewPrivate *view)
-    : QV4::Object(QQmlEnginePrivate::getV4Engine(view->engine.data()))
-    , view(view)
+QQuickRootItemMarker::QQuickRootItemMarker(QQmlEngine *engine, QQuickWindow *window)
+    : QV4::Object(QQmlEnginePrivate::getV4Engine(engine))
+    , window(window)
 {
     setVTable(staticVTable());
 }
 
 void QQuickRootItemMarker::markObjects(QV4::Managed *that, QV4::ExecutionEngine *e)
 {
-    QQuickItem *root = static_cast<QQuickRootItemMarker*>(that)->view->root;
+    QQuickItem *root = static_cast<QQuickRootItemMarker*>(that)->window->contentItem();
     if (root) {
         QQuickItemPrivate *rootPrivate = QQuickItemPrivate::get(root);
         rootPrivate->markObjects(e);
@@ -91,7 +91,7 @@ void QQuickViewPrivate::init(QQmlEngine* e)
     {
         QV4::ExecutionEngine *v4 = QQmlEnginePrivate::getV4Engine(engine.data());
         QV4::Scope scope(v4);
-        QV4::Scoped<QQuickRootItemMarker> v(scope, new (v4->memoryManager) QQuickRootItemMarker(this));
+        QV4::Scoped<QQuickRootItemMarker> v(scope, new (v4->memoryManager) QQuickRootItemMarker(engine.data(), q));
         rootItemMarker = v;
     }