Introduce a new mechanism to iterate over object properties

The old advanceIterator schema was extremely ugly and in addition
not flexible enough to support the requirements for Proxy.ownKeys
and some of the methods in Object

Implemented a new scheme through a OwnPropertyKeys method in the
Object VTable that creates and returns an iterator object. Ported
QJSValueIterator and for-in to use the new mechanism.

There's still many places where we use the old ObjectIterator (that
relies on advanceIterator). Those will be ported in subsequent
commits.

Change-Id: I091a9bea9ff6b2b63630cc336814700757a718be
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

1 files changed, 40 insertions, 0 deletions

diff --git a/src/qml/qml/qqmlvaluetypewrapper.cpp b/src/qml/qml/qqmlvaluetypewrapper.cpp
index 1fde5945ba..29f37fc217 100644
--- a/src/qml/qml/qqmlvaluetypewrapper.cpp
+++ b/src/qml/qml/qqmlvaluetypewrapper.cpp
@@ -282,6 +282,46 @@ void QQmlValueTypeWrapper::virtualAdvanceIterator(Managed *m, ObjectIterator *it
     QV4::Object::virtualAdvanceIterator(m, it, name, index, p, attributes);
 }
 
+struct QQmlValueTypeWrapperOwnPropertyKeyIterator : ObjectOwnPropertyKeyIterator
+{
+    int propertyIndex = 0;
+    ~QQmlValueTypeWrapperOwnPropertyKeyIterator() override = default;
+    PropertyKey next(const Object *o, Property *pd = nullptr, PropertyAttributes *attrs = nullptr) override;
+
+};
+
+PropertyKey QQmlValueTypeWrapperOwnPropertyKeyIterator::next(const Object *o, Property *pd, PropertyAttributes *attrs) {
+    const QQmlValueTypeWrapper *that = static_cast<const QQmlValueTypeWrapper *>(o);
+
+    if (const QQmlValueTypeReference *ref = that->as<QQmlValueTypeReference>()) {
+        if (!ref->readReferenceValue())
+            return PropertyKey::invalid();
+    }
+
+    if (that->d()->propertyCache()) {
+        const QMetaObject *mo = that->d()->propertyCache()->createMetaObject();
+        const int propertyCount = mo->propertyCount();
+        if (propertyIndex < propertyCount) {
+            Scope scope(that->engine());
+            ScopedString propName(scope, that->engine()->newString(QString::fromUtf8(mo->property(propertyIndex).name())));
+            ++propertyIndex;
+            if (attrs)
+                *attrs = QV4::Attr_Data;
+            if (pd)
+                pd->value = that->QV4::Object::get(propName);
+            return propName->toPropertyKey();
+        }
+    }
+
+    return ObjectOwnPropertyKeyIterator::next(o, pd, attrs);
+}
+
+
+OwnPropertyKeyIterator *QQmlValueTypeWrapper::virtualOwnPropertyKeys(const Object *)
+{
+    return new QQmlValueTypeWrapperOwnPropertyKeyIterator;
+}
+
 bool QQmlValueTypeWrapper::isEqual(const QVariant& value) const
 {
     if (const QQmlValueTypeReference *ref = as<const QQmlValueTypeReference>())