Why?

Cause - why, why, why this is needed?

• To avoid the manual handcrafting of main.cpp file because C++ is not familiar for Android developers nor UI Designers
• Change main.cpp file of each Qt Quick for Android Qt Quick QML project after exporting it from Qt Design Studio

Customer - who needs this?

• Qt Quick for Android users/customers two "groups"
  • Android Developers - so that they do not touch the main.cpp as C++ is not familiar for them
  • UI Designers - who prepare the 3D model to QMl project

Cruft - counter argument why this would not be needed?

• The handcrafted change is pretty small and only in one file

What?

Definition - what is this?

• Main.cpp changes to be done automatically by for example a Wizad. No manual modification needed from user.
• Current changes (what is need to be left there) are also described in
  • https://github.com/qt-learning/QtQuickView-Android/blob/main/Robo/App/main.cpp#L11
  • https://www.qt.io/academy#embedding-qt-quick-3d-content-in-an-android-app
• We need to
  • Remove QML Engine loading - cause when QQ4A (Qt Quick for Android) application is run the QtQuickView does the QML engine loading bit later
  • Perhaps add variable to skip ^ parts in case of Qt Quick for Android app

A typical Qt Quick application's main.cpp appears like this
   
#include <QGuiApplication>
#include <QQmlApplicationEngine>
 
int main(int argc, char *argv[])
    {
        QGuiApplication app(argc, argv);
        QQmlApplicationEngine engine;
        QObject::connect(
            &engine,
            &QQmlApplicationEngine::objectCreationFailed,
            &app,
            []() { QCoreApplication::exit(-1); },
            Qt::QueuedConnection);
        engine.loadFromModule("MyQtQuickProject", "Main");
        return app.exec();
    }
 
We don't need to create a QML Engine or load any QML handled  by the Qt Quick View APIs. All that we need is:
 
#include <QGuiApplication>
int main(int argc, char *argv[])
    {
        QGuiApplication app(argc, argv);
        return app.exec();
    }

So it could be something like Note! flag needs to be decided

int main(int argc, char *argv[])
    {
     QGuiApplication app(argc, argv);
#ifndef QT_ANDROID_QT_QUICK_FOR_ANDROID_STYLE_CPP
          QQmlApplicationEngine engine;
            __QObject::connect(
                                                _                                                &engine,_
                                                _                                                &QQmlApplicationEngine::objectCreationFailed,_
                                                _                                                &app,_
                                                _                                                []() { QCoreApplication::exit(-1); },_
                                    _            _Qt::QueuedConnection);
              _   _engine.loadFromModule("MyQtQuickProject", "Main");
#endif
      return app.exec();
          _      }_
**

Note the QT_ANDROID_NO_EXIT_CALL flag is not needed (Pixel devices do not even suffer from it) it is already set to on in QPA for QQ4A  

Demarcation - what this is not?

• This does not cover removing the main.cpp completely from Qt Quick for Android app QML project.

Dependencies - what does this needs or who needs it?

• Is needed for QTBUG-130061
  • Is needed to work with Qt 6.8 LTS to 6.11
• Needs TODO