7 files changed, 276 insertions, 2 deletions
diff --git a/sources/pyside6/libpysideqml/CMakeLists.txt b/sources/pyside6/libpysideqml/CMakeLists.txt
index aa07a5077..28ec31721 100644
--- a/sources/pyside6/libpysideqml/CMakeLists.txt
+++ b/sources/pyside6/libpysideqml/CMakeLists.txt
@@ -3,6 +3,7 @@ set(libpysideqml_libraries Qt::Core Qt::CorePrivate Qt::Qml Qt::QmlPrivate)
 set(libpysideqml_SRC
     pysideqml.cpp
     pysideqmlforeign.cpp
+    pysideqmlextended.cpp
     pysideqmlregistertype.cpp
     pysideqmlmetacallerror.cpp
     pysideqmllistproperty.cpp
diff --git a/sources/pyside6/libpysideqml/pysideqml.cpp b/sources/pyside6/libpysideqml/pysideqml.cpp
index 06646a6e8..5babc7eee 100644
--- a/sources/pyside6/libpysideqml/pysideqml.cpp
+++ b/sources/pyside6/libpysideqml/pysideqml.cpp
@@ -39,6 +39,7 @@
 
 #include "pysideqml.h"
 #include "pysideqmllistproperty_p.h"
+#include "pysideqmlextended_p.h"
 #include "pysideqmlforeign_p.h"
 #include "pysideqmlnamedelement_p.h"
 #include "pysideqmluncreatable.h"
@@ -53,6 +54,7 @@ void init(PyObject *module)
 {
     initQtQmlListProperty(module);
     initQmlForeign(module);
+    initQmlExtended(module);
     initQmlNamedElement(module);
     initQmlUncreatable(module);
     PySide::SignalManager::setQmlMetaCallErrorHandler(PySide::Qml::qmlMetaCallErrorHandler);
diff --git a/sources/pyside6/libpysideqml/pysideqmlextended.cpp b/sources/pyside6/libpysideqml/pysideqmlextended.cpp
new file mode 100644
index 000000000..2ae4afd83
--- /dev/null
+++ b/sources/pyside6/libpysideqml/pysideqmlextended.cpp
@@ -0,0 +1,182 @@
+/****************************************************************************
+**
+** Copyright (C) 2022 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of Qt for Python.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "pysideqmlextended_p.h"
+#include "pysideqmltypeinfo_p.h"
+#include "pysideqmlregistertype_p.h"
+
+#include <pyside_p.h>
+#include <pysideclassdecorator_p.h>
+
+#include <shiboken.h>
+#include <signature.h>
+#include <sbkstring.h>
+
+#include <QtCore/QtGlobal>
+#include <QtQml/qqml.h>
+
+// The QmlExtended decorator modifies QmlElement to register an extension.
+// Due to the (reverse) execution order of decorators, it needs to follow
+// QmlElement.
+class PySideQmlExtendedPrivate : public PySide::ClassDecorator::TypeDecoratorPrivate
+{
+public:
+    PyObject *tp_call(PyObject *self, PyObject *args, PyObject * /* kw */) override;
+    const char *name() const override;
+};
+
+// The call operator is passed the class type and registers the type
+// in QmlTypeInfo.
+PyObject *PySideQmlExtendedPrivate::tp_call(PyObject *self, PyObject *args, PyObject * /* kw */)
+{
+    PyObject *klass = tp_call_check(args, CheckMode::WrappedType);
+    if (klass == nullptr)
+        return nullptr;
+
+    auto *data = DecoratorPrivate::get<PySideQmlExtendedPrivate>(self);
+    PySide::Qml::ensureQmlTypeInfo(klass)->extensionType = data->type();
+
+    Py_INCREF(klass);
+    return klass;
+}
+
+const char *PySideQmlExtendedPrivate::name() const
+{
+    return "QmlExtended";
+}
+
+extern "C" {
+
+static PyTypeObject *createPySideQmlExtendedType(void)
+{
+    auto typeSlots =
+        PySide::ClassDecorator::Methods<PySideQmlExtendedPrivate>::typeSlots();
+
+    PyType_Spec PySideQmlExtendedType_spec = {
+        "2:PySide6.QtCore.qmlExtended",
+        sizeof(PySideClassDecorator),
+        0,
+        Py_TPFLAGS_DEFAULT,
+        typeSlots.data()
+    };
+    return SbkType_FromSpec(&PySideQmlExtendedType_spec);
+}
+
+PyTypeObject *PySideQmlExtended_TypeF(void)
+{
+    static auto *type = createPySideQmlExtendedType();
+    return type;
+}
+
+} // extern "C"
+
+static const char *qmlExtended_SignatureStrings[] = {
+    "PySide6.QtQml.QmlExtended(self,type:type)",
+    nullptr // Sentinel
+};
+
+namespace PySide::Qml {
+
+static QObject *extensionFactory(QObject *o)
+{
+    Shiboken::GilState gilState;
+    Shiboken::Conversions::SpecificConverter converter("QObject");
+    Q_ASSERT(converter);
+    PyObject *pyObj = converter.toPython(&o);
+    Q_ASSERT(pyObj);
+
+    // Search for the extension type and create an instance by invoking
+    // the call operator on type with the parent parameter.
+    // If there is an error and nullptr is returned, a crash occurs,
+    // so, errors should at least be printed.
+
+    auto *pyObjType = Py_TYPE(pyObj);
+    const auto info = qmlTypeInfo(reinterpret_cast<PyObject *>(pyObjType));
+    if (info.isNull() || info->extensionType == nullptr) {
+        qWarning("QmlExtended: Cannot find extension of %s.", pyObjType->tp_name);
+        return nullptr;
+    }
+
+    Shiboken::AutoDecRef args(PyTuple_New(1));
+    PyTuple_SET_ITEM(args.object(), 0, pyObj);
+    auto *extensionTypeObj = reinterpret_cast<PyObject *>(info->extensionType);
+    Shiboken::AutoDecRef pyResult(PyObject_Call(extensionTypeObj, args, nullptr));
+    if (pyResult.isNull() || PyErr_Occurred()) {
+        PyErr_Print();
+        return nullptr;
+    }
+
+    if (PyType_IsSubtype(pyResult->ob_type, qObjectType()) == 0) {
+        qWarning("QmlExtended: Extension objects must inherit QObject, got %s.",
+                 pyResult->ob_type->tp_name);
+        return nullptr;
+    }
+
+    QObject *result = nullptr;
+    converter.toCpp(pyResult.object(), &result);
+    return result;
+}
+
+void initQmlExtended(PyObject *module)
+{
+    if (InitSignatureStrings(PySideQmlExtended_TypeF(), qmlExtended_SignatureStrings) < 0)
+        return;
+
+    Py_INCREF(PySideQmlExtended_TypeF());
+    PyModule_AddObject(module, "QmlExtended",
+                       reinterpret_cast<PyObject *>(PySideQmlExtended_TypeF()));
+}
+
+PySide::Qml::QmlExtensionInfo qmlExtendedInfo(PyObject *t,
+                                              const QSharedPointer<QmlTypeInfo> &info)
+{
+    PySide::Qml::QmlExtensionInfo result{nullptr, nullptr};
+    if (!info.isNull() && info->extensionType) {
+        result.metaObject = PySide::retrieveMetaObject(info->extensionType);
+        if (result.metaObject) {
+            result.factory = extensionFactory;
+        } else {
+            qWarning("Unable to retrieve meta object for %s",
+                     reinterpret_cast<PyTypeObject *>(t)->tp_name);
+        }
+    }
+    return result;
+}
+
+} // namespace PySide::Qml
diff --git a/sources/pyside6/libpysideqml/pysideqmlextended_p.h b/sources/pyside6/libpysideqml/pysideqmlextended_p.h
new file mode 100644
index 000000000..03551d1f4
--- /dev/null
+++ b/sources/pyside6/libpysideqml/pysideqmlextended_p.h
@@ -0,0 +1,57 @@
+/****************************************************************************
+**
+** Copyright (C) 2022 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of Qt for Python.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef PYSIDEQMLEXTENDED_P_H
+#define PYSIDEQMLEXTENDED_P_H
+
+#include <sbkpython.h>
+
+#include <QtCore/QSharedPointer>
+
+namespace PySide::Qml {
+struct QmlExtensionInfo;
+struct QmlTypeInfo;
+
+void initQmlExtended(PyObject *module);
+
+PySide::Qml::QmlExtensionInfo qmlExtendedInfo(PyObject *t,
+                                              const QSharedPointer<QmlTypeInfo> &info);
+} // namespace PySide::Qml
+
+#endif // PYSIDEQMLEXTENDED_P_H
diff --git a/sources/pyside6/libpysideqml/pysideqmlregistertype.cpp b/sources/pyside6/libpysideqml/pysideqmlregistertype.cpp
index 30f8f2bfb..aee013627 100644
--- a/sources/pyside6/libpysideqml/pysideqmlregistertype.cpp
+++ b/sources/pyside6/libpysideqml/pysideqmlregistertype.cpp
@@ -40,6 +40,7 @@
 #include "pysideqmlregistertype.h"
 #include "pysideqmlregistertype_p.h"
 #include "pysideqmltypeinfo_p.h"
+#include "pysideqmlextended_p.h"
 
 #include <limits>
 
@@ -137,6 +138,7 @@ int qmlRegisterType(PyObject *pyObj, const char *uri, int versionMajor,
         // FIXME: Fix this to assign new type ids each time.
         type.typeId = QMetaType(QMetaType::QObjectStar);
         type.listId = QMetaType::fromType<QQmlListProperty<QObject> >();
+        const auto typeInfo = qmlTypeInfo(pyObj);
         type.attachedPropertiesFunction = QQmlPrivate::attachedPropertiesFunc<QObject>();
         type.attachedPropertiesMetaObject = QQmlPrivate::attachedPropertiesMetaObject<QObject>();
 
@@ -157,8 +159,9 @@ int qmlRegisterType(PyObject *pyObj, const char *uri, int versionMajor,
         type.version = QTypeRevision::fromVersion(versionMajor, versionMinor);
         type.elementName = qmlName;
 
-        type.extensionObjectCreate = 0;
-        type.extensionMetaObject = 0;
+        auto info = qmlExtendedInfo(pyObj, typeInfo);
+        type.extensionObjectCreate = info.factory;
+        type.extensionMetaObject = info.metaObject;
         type.customParser = 0;
     }
     type.metaObject = metaObject; // Snapshot may have changed.
diff --git a/sources/pyside6/libpysideqml/pysideqmltypeinfo.cpp b/sources/pyside6/libpysideqml/pysideqmltypeinfo.cpp
index 2d5b48c98..f8256524f 100644
--- a/sources/pyside6/libpysideqml/pysideqmltypeinfo.cpp
+++ b/sources/pyside6/libpysideqml/pysideqmltypeinfo.cpp
@@ -82,9 +82,25 @@ QDebug operator<<(QDebug d, const QmlTypeInfo &i)
         d << ", noCreationReason=\"" << i.noCreationReason.c_str() << '"';
     if (i.foreignType)
         d << ", foreignType=" << i.foreignType->tp_name;
+    if (i.extensionType)
+        d << ", extensionType=" << i.extensionType->tp_name;
     d << ')';
     return d;
 }
+
+QDebug operator<<(QDebug d, const QmlExtensionInfo &e)
+{
+    QDebugStateSaver saver(d);
+    d.noquote();
+    d.nospace();
+    d << "QmlExtensionInfo(";
+    if (e.factory  != nullptr && e.metaObject != nullptr)
+        d << '"' << e.metaObject->className() << "\", factory="
+          << reinterpret_cast<const void *>(e.factory);
+    d << ')';
+    return d;
+}
+
 #endif // QT_NO_DEBUG_STREAM
 
 } // namespace PySide::Qml
diff --git a/sources/pyside6/libpysideqml/pysideqmltypeinfo_p.h b/sources/pyside6/libpysideqml/pysideqmltypeinfo_p.h
index 26ea782d3..17ca967c6 100644
--- a/sources/pyside6/libpysideqml/pysideqmltypeinfo_p.h
+++ b/sources/pyside6/libpysideqml/pysideqmltypeinfo_p.h
@@ -48,6 +48,8 @@
 #include <string>
 
 QT_FORWARD_DECLARE_CLASS(QDebug)
+QT_FORWARD_DECLARE_CLASS(QObject)
+QT_FORWARD_DECLARE_STRUCT(QMetaObject)
 
 namespace PySide::Qml {
 
@@ -66,6 +68,7 @@ struct QmlTypeInfo
     QmlTypeFlags flags;
     std::string noCreationReason;
     PyTypeObject *foreignType = nullptr;
+    PyTypeObject *extensionType = nullptr;
 };
 
 using QmlTypeInfoPtr = QSharedPointer<QmlTypeInfo>;
@@ -74,8 +77,18 @@ QmlTypeInfoPtr ensureQmlTypeInfo(const PyObject *o);
 void insertQmlTypeInfoAlias(const PyObject *o, const QmlTypeInfoPtr &value);
 QmlTypeInfoPtr qmlTypeInfo(const PyObject *o);
 
+// Meta Object and factory function for QmlExtended/QmlAttached
+struct QmlExtensionInfo
+{
+    using Factory = QObject *(*)(QObject *);
+
+    Factory factory;
+    const QMetaObject *metaObject;
+};
+
 #ifndef QT_NO_DEBUG_STREAM
 QDebug operator<<(QDebug d, const QmlTypeInfo &);
+QDebug operator<<(QDebug d, const QmlExtensionInfo &);
 #endif
 
 } // namespace PySide::Qml