I'm using the qml qtvirtual keyboard: <https://github.com/qt/qtvirtualkeyboard>

I'm trying to "connect" it with the rest of my Qt app which is based on widgets. For example, when I click on a QLineEdit, I want the keyboard to show up and to act like a physical one in the app context.

To do so, I installed what's in qtvirtualkeyboard/src (qmake && make && make install) and here is my main.cpp : 

```
#include <QQuickView>
#include <QApplication>
#include <QQmlEngine>
#include <QQmlContext>

int main(int argc, char *argv[]){

    qputenv("QT_IM_MODULE", QByteArray("qtvirtualkeyboard"));

    QApplication app(argc, argv);
    MainWindow w();  // This is a QWidget / QMainWindow
    w.setFixedSize(800, 480);
    w.show();

    return app.exec();
}

```

When I execute this on my desktop, the Keyboard takes half of my screen despite that my app is 800x480.

And when I execute it on my Raspberry Pi with its 7" touchscreen, the keyboard takes half of the page and a black border appears on the top.

I want to fix the keyboard size myself. When I create a QML file with an Item and so on, the keyboard doesn't show up anymore.