qmltc: generate code into namespaces

Generate code into namespaces to avoid clashes between qmltc-generated
and user code. Code generated by qmltc will by default be put in the
URI_OF_MODULE namespace, and will generate subnamespaces
to follow the module hierarchy if URI_OF_MODULE contains dots('.').

Also fix the test to use the new namespaces.

[ChangeLog][Qml][qmltc] The type compiler will generate C++-code into
a namespace by default. The  new default namespace is inferred from
the module's URI, where dots are interpreted as separating subnamespaces
from each other,
e.g., a type in module MyCompany.MyModule.Sub will be generated in the namespace
MyCompany::MyModule::Sub.

Fixes: QTBUG-109274
Change-Id: I3bfe2697b81e90bb63a079dc44c2810fc9925f97
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>

2 files changed, 12 insertions, 1 deletions

diff --git a/src/qml/doc/snippets/qmltc/tst_qmltc_examples.cpp b/src/qml/doc/snippets/qmltc/tst_qmltc_examples.cpp
index a78da416e2..7bda70f985 100644
--- a/src/qml/doc/snippets/qmltc/tst_qmltc_examples.cpp
+++ b/src/qml/doc/snippets/qmltc/tst_qmltc_examples.cpp
@@ -53,7 +53,7 @@ void tst_qmltc_examples::app()
     QQmlEngine e;
     QQuickWindow window;
 
-    QScopedPointer<myApp> documentRoot(new myApp(&e));
+    QScopedPointer<QmltcExample::myApp> documentRoot(new QmltcExample::myApp(&e));
 
     documentRoot->setParentItem(window.contentItem());
     window.setHeight(documentRoot->height());
diff --git a/src/qml/doc/src/cmake/qt_add_qml_module.qdoc b/src/qml/doc/src/cmake/qt_add_qml_module.qdoc
index 9bef299970..7617d19033 100644
--- a/src/qml/doc/src/cmake/qt_add_qml_module.qdoc
+++ b/src/qml/doc/src/cmake/qt_add_qml_module.qdoc
@@ -655,4 +655,15 @@ with \l{QML Type Compiler}{qmltc}. Files with the source property
 C++ code resides. By default, no namespace is specified for user projects. The
 code generated from Qt's own sources is put under a QT_NAMESPACE namespace.
 
+\c TYPE_COMPILER_NAMESPACE argument allows to override the namespace in which
+\l{QML Type Compiler}{qmltc} generates code.
+By default, the namespace of the generated code follows the module
+hierarchy as depicted in the URI,
+e.g., \c MyModule for a module with URI \c MyModule or
+\c com::example::Module for URI \c com.example.MyModule.
+By specifying the \c TYPE_COMPILER_NAMESPACE option, the generated code
+can be put instead in a custom namespace, where different subnamespaces are to
+be separated by a "::", e.g. "MyNamespace::MySubnamespace" for the namespace MySubnamespace that
+is inside the MyNamespace. Apart from the "::", C++ namespace naming rules
+apply.
 */