diff options
| -rw-r--r-- | src/qml/qml/qqmlglobal.cpp | 45 | ||||
| -rw-r--r-- | src/qml/qml/qqmlglobal_p.h | 2 |
2 files changed, 40 insertions, 7 deletions
diff --git a/src/qml/qml/qqmlglobal.cpp b/src/qml/qml/qqmlglobal.cpp index 730687fc2f..045b6fc948 100644 --- a/src/qml/qml/qqmlglobal.cpp +++ b/src/qml/qml/qqmlglobal.cpp @@ -924,12 +924,45 @@ bool qmlobject_can_cpp_cast(QObject *object, const QMetaObject *mo) return object->metaObject()->inherits(mo); } -bool qmlobject_can_qml_cast(QObject *object, const QMetaObject *mo) -{ - Q_ASSERT(mo); - if (const QQmlData *ddata = ddata_for_cast(object)) - return ddata->propertyCache->metaObject()->inherits(mo); - return object->metaObject()->inherits(mo); +bool qmlobject_can_qml_cast(QObject *object, const QQmlType &type) +{ + Q_ASSERT(type.isValid()); + + // A non-composite type will always have a metaobject. + const QMetaObject *typeMetaObject = type.metaObject(); + const QQmlPropertyCache::ConstPtr typePropertyCache = typeMetaObject + ? QQmlPropertyCache::ConstPtr() + : QQmlMetaType::findPropertyCacheInCompositeTypes(type.typeId()); + + if (const QQmlData *ddata = ddata_for_cast(object)) { + for (const QQmlPropertyCache *propertyCache = ddata->propertyCache.data(); propertyCache; + propertyCache = propertyCache->parent().data()) { + + if (typeMetaObject) { + // Prefer the metaobject inheritance mechanism, since it is more accurate. + // + // Assume the object can be casted to the type. Then, if we have a type metaobject, + // the object's property cache inheritance has to contain it. Otherwise we would + // end up with diverging metaobject hierarchies if we created the object's + // metaobject. This would be a disaster. + if (const QMetaObject *objectMetaObject = propertyCache->metaObject()) + return objectMetaObject->inherits(typeMetaObject); + } else { + // This is a best effort attempt. There are a number of ways for the + // property caches to be unrelated but the types still convertible. + // Multiple property caches can hold the same metaobject, for example for + // versions of non-composite types. + if (propertyCache == typePropertyCache.data()) + return true; + } + } + } + + // If nothing else works, we have to create the metaobjects. + + return object->metaObject()->inherits(typeMetaObject + ? typeMetaObject + : (typePropertyCache ? typePropertyCache->createMetaObject() : nullptr)); } QT_END_NAMESPACE diff --git a/src/qml/qml/qqmlglobal_p.h b/src/qml/qml/qqmlglobal_p.h index bed5bd10b1..db0365f49c 100644 --- a/src/qml/qml/qqmlglobal_p.h +++ b/src/qml/qml/qqmlglobal_p.h @@ -124,7 +124,7 @@ do { \ } while (0) Q_QML_PRIVATE_EXPORT bool qmlobject_can_cpp_cast(QObject *object, const QMetaObject *mo); -Q_QML_PRIVATE_EXPORT bool qmlobject_can_qml_cast(QObject *object, const QMetaObject *mo); +Q_QML_PRIVATE_EXPORT bool qmlobject_can_qml_cast(QObject *object, const QQmlType &type); /*! This method is identical to qobject_cast<T>() except that it does not require lazy |