QML: Allow namespaces as extensions to types

This way we can access the enums of namespaces as properties of the
primary type. This is achieved by:

1. Making enums of extended types available in the base type
2. Allowing the extension to be specified as plain metaObject rather
   than as type name.
3. Refraining from creating the extension if the create function does
   not exist.

The goal of this is to declare the Qt namespace in a civilized way, but
will also help with cleaning up the QtQuick value types and their enums.

Change-Id: I13399741d30ce38d1bff753cfa1b11e72ccfbf6a
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>

2 files changed, 50 insertions, 0 deletions

diff --git a/tests/auto/qml/qqmllanguage/testtypes.h b/tests/auto/qml/qqmllanguage/testtypes.h
index 1156d265ed..518f52f4e7 100644
--- a/tests/auto/qml/qqmllanguage/testtypes.h
+++ b/tests/auto/qml/qqmllanguage/testtypes.h
@@ -1534,6 +1534,35 @@ class UncreatableElementNoReason : public QObject
     QML_UNCREATABLE("")
 };
 
+namespace ExtensionNamespace {
+Q_NAMESPACE
+
+enum Foo {
+    Bar = 9,
+    Baz = 12
+};
+Q_ENUM_NS(Foo)
+}
+
+class ExtendedByNamespace : public QObject
+{
+    Q_OBJECT
+    QML_ELEMENT
+    QML_EXTENDED_NAMESPACE(ExtensionNamespace)
+
+    Q_PROPERTY(int own READ own CONSTANT)
+public:
+
+    enum OwnEnum {
+        Moo = 16,
+        Maeh = 17
+    };
+    Q_ENUM(OwnEnum)
+
+    ExtendedByNamespace(QObject *parent = nullptr) : QObject(parent) {}
+    int own() const { return 93; }
+};
+
 void registerTypes();
 
 #endif // TESTTYPES_H
diff --git a/tests/auto/qml/qqmllanguage/tst_qqmllanguage.cpp b/tests/auto/qml/qqmllanguage/tst_qqmllanguage.cpp
index 4e8e668c18..74b7c0e64e 100644
--- a/tests/auto/qml/qqmllanguage/tst_qqmllanguage.cpp
+++ b/tests/auto/qml/qqmllanguage/tst_qqmllanguage.cpp
@@ -340,6 +340,7 @@ private slots:
 
     void checkURLtoURLObject();
     void registerValueTypes();
+    void extendedNamespace();
 
 private:
     QQmlEngine engine;
@@ -6027,6 +6028,26 @@ void tst_qqmllanguage::accessNullPointerPropertyCache()
     QVERIFY(!obj.isNull());
 }
 
+void tst_qqmllanguage::extendedNamespace()
+{
+    QQmlEngine engine;
+    QQmlComponent c(&engine);
+    c.setData("import StaticTest\n"
+              "import QtQml\n"
+              "ExtendedByNamespace {\n"
+              "    property int mine: own\n"
+              "    property int myEnum: ExtendedByNamespace.Moo\n"
+              "    property int fromExtension: ExtendedByNamespace.Bar\n"
+              "}", QUrl());
+    QVERIFY2(c.isReady(), qPrintable(c.errorString()));
+    QScopedPointer<QObject> obj(c.create());
+    QVERIFY(!obj.isNull());
+
+    QCOMPARE(obj->property("mine").toInt(), 93);
+    QCOMPARE(obj->property("myEnum").toInt(), 16);
+    QCOMPARE(obj->property("fromExtension").toInt(), 9);
+}
+
 QTEST_MAIN(tst_qqmllanguage)
 
 #include "tst_qqmllanguage.moc"