More fine-grained deferred property execution

This allows Qt Quick Controls 2 to defer the execution of certain
building blocks until needed. For example, a button control can
defer its background item so that the default background is not
executed at all when replaced by a custom background.

First of all, this gives a massive performance boost for customized
controls. Secondly, this avoids the most burning issue in QQC2,
problems with asynchronous incubation ("Object destroyed during
incubation").

Task-number: QTBUG-50992
Change-Id: If3616c9dac70e3a474a20070ad0452874d267164
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

1 files changed, 2 insertions, 1 deletions

diff --git a/src/qml/qml/qqmlobjectcreator_p.h b/src/qml/qml/qqmlobjectcreator_p.h
index 0c2d427c58..e2371cb4f1 100644
--- a/src/qml/qml/qqmlobjectcreator_p.h
+++ b/src/qml/qml/qqmlobjectcreator_p.h
@@ -81,7 +81,7 @@ struct QQmlObjectCreatorSharedState : public QSharedData
     QRecursionNode recursionNode;
 };
 
-class QQmlObjectCreator
+class Q_QML_PRIVATE_EXPORT QQmlObjectCreator
 {
     Q_DECLARE_TR_FUNCTIONS(QQmlObjectCreator)
 public:
@@ -90,6 +90,7 @@ public:
 
     QObject *create(int subComponentIndex = -1, QObject *parent = 0, QQmlInstantiationInterrupt *interrupt = 0);
     bool populateDeferredProperties(QObject *instance, QQmlData::DeferredData *deferredData);
+    bool populateDeferredBinding(const QQmlProperty &qmlProperty, QQmlData::DeferredData *deferredData, const QV4::CompiledData::Binding *binding);
     QQmlContextData *finalize(QQmlInstantiationInterrupt &interrupt);
     void cancel(QObject *object);
     void clear();