Fix performance of ListModel::get()

When called, the function would return a full-fledged QObject that maps the
list element addressed. It would contain a _copy_ of all values in the list
item and it would create a new meta-object for each list element.

This function exists for the JavaScript API, and therefore we now return a much
more lightweight object. For compatbility reasons it still has to be a QObject,
but the meta-object of it is created on-demand, i.e. only when accessing
properties from the C++ side or when connecting to the changed signal of a
property. Otherwise the JavaScript wrapper will return the live values from the
model without copying them.

Change-Id: Iabf3ca22192d2aee06ae9d4b4cfb2fcde2a021b1
Reviewed-by: Lars Knoll <lars.knoll@theqtcompany.com>
Reviewed-by: Michael Brasser <michael.brasser@live.com>
Reviewed-by: Spencer Schumann <spencer.schumann@echostar.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/src/qml/qml/qqmlopenmetaobject_p.h b/src/qml/qml/qqmlopenmetaobject_p.h
index 6a29d08d4e..75ce9addd6 100644
--- a/src/qml/qml/qqmlopenmetaobject_p.h
+++ b/src/qml/qml/qqmlopenmetaobject_p.h
@@ -54,6 +54,7 @@ public:
     QQmlOpenMetaObjectType(const QMetaObject *base, QQmlEngine *engine);
     ~QQmlOpenMetaObjectType();
 
+    void createProperties(const QVector<QByteArray> &names);
     int createProperty(const QByteArray &name);
 
     int propertyOffset() const;
@@ -101,6 +102,8 @@ public:
 
     QQmlOpenMetaObjectType *type() const;
 
+    void emitPropertyNotification(const QByteArray &propertyName);
+
 protected:
     virtual int metaCall(QMetaObject::Call _c, int _id, void **_a);
     virtual int createProperty(const char *, const char *);