Allow custom named value types in QML

You can now add your own, lower-case named, value types to your own
module, and use them in QML. Previously the names had been ignored, but
now you can actually declare properties using the value types.

The QtQuick value types are now handled exactly this way, and their
special casing at compile time is removed.

[ChangeLog][QML][Important Behavior Changes] You can now add your own
value types to QML modules. This works exactly like the registration of
object types, just with Q_GADGET instead of QObject/Q_OBJECT. In turn,
the QtQuick value types are only available from QtQuick now. Previously
you could declare unusable properties of QtQuick value types when only
importing QtQml. This is not possible anymore.

Task-number: QTBUG-82443
Change-Id: I5b2e867141244531cb13d789678fb7e06a6e41e7
Reviewed-by: Andrei Golubev <andrei.golubev@qt.io>
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
Reviewed-by: Konstantin Shegunov <kshegunov@gmail.com>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>

1 files changed, 76 insertions, 42 deletions

diff --git a/src/qml/qml/qqmlvmemetaobject.cpp b/src/qml/qml/qqmlvmemetaobject.cpp
index 8c61e03595..70c6b2e45e 100644
--- a/src/qml/qml/qqmlvmemetaobject.cpp
+++ b/src/qml/qml/qqmlvmemetaobject.cpp
@@ -582,7 +582,21 @@ QDate QQmlVMEMetaObject::readPropertyAsDate(int id) const
     return v->d()->data().value<QDate>();
 }
 
-QDateTime QQmlVMEMetaObject::readPropertyAsDateTime(int id)
+QTime QQmlVMEMetaObject::readPropertyAsTime(int id) const
+{
+    QV4::MemberData *md = propertyAndMethodStorageAsMemberData();
+    if (!md)
+        return QTime();
+
+    QV4::Scope scope(engine);
+    QV4::ScopedValue sv(scope, *(md->data() + id));
+    const QV4::VariantObject *v = sv->as<QV4::VariantObject>();
+    if (!v || v->d()->data().userType() != QMetaType::QTime)
+        return QTime();
+    return v->d()->data().value<QTime>();
+}
+
+QDateTime QQmlVMEMetaObject::readPropertyAsDateTime(int id) const
 {
     QV4::MemberData *md = propertyAndMethodStorageAsMemberData();
     if (!md)
@@ -698,9 +712,6 @@ int QQmlVMEMetaObject::metaCall(QObject *o, QMetaObject::Call c, int _id, void *
                         ? nullptr
                         : QQmlEnginePrivate::get(ctxt->engine());
 
-                const QMetaType fallbackMetaType
-                        = QQmlPropertyCacheCreatorBase::metaTypeForPropertyType(t);
-
                 if (c == QMetaObject::ReadProperty) {
                     switch (t) {
                     case QV4::CompiledData::BuiltinType::Int:
@@ -733,22 +744,8 @@ int QQmlVMEMetaObject::metaCall(QObject *o, QMetaObject::Call c, int _id, void *
                     case QV4::CompiledData::BuiltinType::Point:
                         *reinterpret_cast<QPointF *>(a[0]) = readPropertyAsPointF(id);
                         break;
-                    case QV4::CompiledData::BuiltinType::Font:
                     case QV4::CompiledData::BuiltinType::Time:
-                    case QV4::CompiledData::BuiltinType::Color:
-                    case QV4::CompiledData::BuiltinType::Vector2D:
-                    case QV4::CompiledData::BuiltinType::Vector3D:
-                    case QV4::CompiledData::BuiltinType::Vector4D:
-                    case QV4::CompiledData::BuiltinType::Matrix4x4:
-                    case QV4::CompiledData::BuiltinType::Quaternion:
-                        Q_ASSERT(fallbackMetaType.isValid());
-                        if (QV4::MemberData *md = propertyAndMethodStorageAsMemberData()) {
-                            QVariant propertyAsVariant;
-                            if (const QV4::VariantObject *v = (md->data() + id)->as<QV4::VariantObject>())
-                                propertyAsVariant = v->d()->data();
-                            QQml_valueTypeProvider()->readValueType(
-                                        fallbackMetaType, propertyAsVariant, a[0]);
-                        }
+                        *reinterpret_cast<QTime *>(a[0]) = readPropertyAsTime(id);
                         break;
                     case QV4::CompiledData::BuiltinType::Var:
                         if (ep) {
@@ -785,15 +782,37 @@ int QQmlVMEMetaObject::metaCall(QObject *o, QMetaObject::Call c, int _id, void *
                             }
                             quintptr encodedIndex = (inheritanceDepth << (usableBits/2)) + id;
 
-
                             readPropertyAsList(id); // Initializes if necessary
                             *static_cast<QQmlListProperty<QObject> *>(a[0])
                                     = QQmlListProperty<QObject>(
                                         object, reinterpret_cast<void *>(quintptr(encodedIndex)),
                                         list_append, list_count, list_at,
                                         list_clear, list_replace, list_removeLast);
+                        } else if (QV4::MemberData *md = propertyAndMethodStorageAsMemberData()) {
+                            QV4::Scope scope(engine);
+                            QV4::ScopedValue sv(scope, *(md->data() + id));
+
+                            // _id because this is an absolute property ID.
+                            const QQmlPropertyData *propertyData = cache->property(_id);
+
+                            if (propertyData->isQObject()) {
+                                if (const auto *wrap = sv->as<QV4::QObjectWrapper>())
+                                    *reinterpret_cast<QObject **>(a[0]) = wrap->object();
+                                else
+                                    *reinterpret_cast<QObject **>(a[0]) = nullptr;
+                            } else {
+                                const QMetaType propType = propertyData->propType();
+                                const void *data = nullptr;
+                                if (const QV4::VariantObject *v = sv->as<QV4::VariantObject>()) {
+                                    const QVariant &variant = v->d()->data();
+                                    if (variant.metaType() == propType)
+                                        data = variant.constData();
+                                }
+                                propType.destruct(a[0]);
+                                propType.construct(a[0], data);
+                            }
                         } else {
-                            *reinterpret_cast<QObject **>(a[0]) = readPropertyAsQObject(id);
+                            qmlWarning(object) << "Cannot find member data";
                         }
                     }
 
@@ -840,25 +859,9 @@ int QQmlVMEMetaObject::metaCall(QObject *o, QMetaObject::Call c, int _id, void *
                         needActivate = *reinterpret_cast<QPointF *>(a[0]) != readPropertyAsPointF(id);
                         writeProperty(id, *reinterpret_cast<QPointF *>(a[0]));
                         break;
-                    case QV4::CompiledData::BuiltinType::Font:
                     case QV4::CompiledData::BuiltinType::Time:
-                    case QV4::CompiledData::BuiltinType::Color:
-                    case QV4::CompiledData::BuiltinType::Vector2D:
-                    case QV4::CompiledData::BuiltinType::Vector3D:
-                    case QV4::CompiledData::BuiltinType::Vector4D:
-                    case QV4::CompiledData::BuiltinType::Matrix4x4:
-                    case QV4::CompiledData::BuiltinType::Quaternion:
-                        Q_ASSERT(fallbackMetaType.isValid());
-                        if (QV4::MemberData *md = propertyAndMethodStorageAsMemberData()) {
-                            const QV4::VariantObject *v = (md->data() + id)->as<QV4::VariantObject>();
-                            if (!v) {
-                                md->set(engine, id, engine->newVariantObject(QVariant()));
-                                v = (md->data() + id)->as<QV4::VariantObject>();
-                                QQml_valueTypeProvider()->initValueType(fallbackMetaType, v->d()->data());
-                            }
-                            needActivate = !QQml_valueTypeProvider()->equalValueType(fallbackMetaType, a[0], v->d()->data());
-                            QQml_valueTypeProvider()->writeValueType(fallbackMetaType, a[0], v->d()->data());
-                        }
+                        needActivate = *reinterpret_cast<QTime *>(a[0]) != readPropertyAsTime(id);
+                        writeProperty(id, *reinterpret_cast<QTime *>(a[0]));
                         break;
                     case QV4::CompiledData::BuiltinType::Var:
                         if (ep)
@@ -868,11 +871,42 @@ int QQmlVMEMetaObject::metaCall(QObject *o, QMetaObject::Call c, int _id, void *
                         if (property.isList) {
                             // Writing such a property is not supported. Content is added through the list property
                             // methods.
+                        } else if (QV4::MemberData *md = propertyAndMethodStorageAsMemberData()) {
+                            QV4::Scope scope(engine);
+                            QV4::ScopedValue sv(scope, *(md->data() + id));
+
+                            // _id because this is an absolute property ID.
+                            const QQmlPropertyData *propertyData = cache->property(_id);
+
+                            if (propertyData->isQObject()) {
+                                QObject *arg = *reinterpret_cast<QObject **>(a[0]);
+                                if (const QV4::QObjectWrapper *wrap = sv->as<QV4::QObjectWrapper>())
+                                    needActivate = wrap->object() != arg;
+                                else
+                                    needActivate = true;
+                                if (needActivate)
+                                    writeProperty(id, arg);
+                            } else {
+                                const QMetaType propType = propertyData->propType();
+                                if (const QV4::VariantObject *v = sv->as<QV4::VariantObject>()) {
+                                    QVariant &variant = v->d()->data();
+                                    if (variant.metaType() != propType) {
+                                        needActivate = true;
+                                        variant = QVariant(propType, a[0]);
+                                    } else if (!propType.equals(variant.constData(), a[0])) {
+                                        needActivate = true;
+                                        propType.destruct(variant.data());
+                                        propType.construct(variant.data(), a[0]);
+                                    }
+                                } else {
+                                    needActivate = true;
+                                    md->set(engine, id, engine->newVariantObject(
+                                                QVariant(propType, a[0])));
+                                }
+                            }
                         } else {
-                            needActivate = *reinterpret_cast<QObject **>(a[0]) != readPropertyAsQObject(id);
-                            writeProperty(id, *reinterpret_cast<QObject **>(a[0]));
+                            qmlWarning(object) << "Cannot find member data";
                         }
-
                     }
 
                     if (needActivate)