Custom QWindow add widgets

[Tuxedo]

I have a qt application which uses QGraphicsView and QGraphicsProxyWidget to rotate my widgets. Now I need to tell the system that my orientation has changed.
This can only be done by subclassing QWindow and do the following (view is a QWindow) [1]:

view.reportContentOrientationChange(Qt::LandscapeO rientation);
view.screen()->setOrientationUpdateMask(Qt::LandscapeOrientation );

QWindow is for me new so I was looking for an example and I found this [2].
Now I would like to know how to add widgets to this qwindow example.
I tried many things because I don't know a way to achieve this but was not successful.
Subclassing a qwindow is mostly done for gl or sdl stuff but not for widgets.

#include <QtWidgets>
class MyWindow: public QWindow
{
public:
  MyWindow():
  m_update_pending(false)
{
    m_backingStore = new QBackingStore(this);      
    setTitle("QWindow Background Image");
    resize(300,250);
}
 
bool event(QEvent *event)
{
    if (event->type() == QEvent::UpdateRequest) 
    {
        m_update_pending = false;
        renderNow();
        return true;
    }
    return QWindow::event(event);
}
 
void renderLater()
{  
    if (!m_update_pending) 
    {
        m_update_pending = true;
 
	//Post this event to event queue for later processing
        QCoreApplication::postEvent(this,
				    new QEvent(QEvent::UpdateRequest));
    }
}
 
void resizeEvent(QResizeEvent *resizeEvent)
{
    m_backingStore->resize(resizeEvent->size());
    if (isExposed())
    {
        renderNow();
    }
}
 
void exposeEvent(QExposeEvent *)
{
    if (isExposed()) 
    {
        renderNow();
    }
}
 
void renderNow()
{
    if (!isExposed())
        return;
 
    QRect rect(0, 0, width(), height());
    m_backingStore->beginPaint(rect);
 
    QPaintDevice *device = m_backingStore->paintDevice();
    QPainter painter(device);
 
    painter.drawPixmap(rect,QPixmap("background.jpg"));
    painter.drawText(QRectF(0, 0, width(), height()),
		      Qt::AlignCenter, QStringLiteral("QWindow"));
 
    m_backingStore->endPaint();
    m_backingStore->flush(rect);
}
 
private:
    QBackingStore *m_backingStore;
    bool m_update_pending;
};
 
int main(int argc, char *argv[])
{
    QApplication app(argc, argv);       
 
    MyWindow window;   
    window.show();
 
    return app.exec();
}

#include <QtWidgets>
class MyWindow: public QWindow
{
public:
  MyWindow():
  m_update_pending(false)
{
    m_backingStore = new QBackingStore(this);      
    setTitle("QWindow Background Image");
    resize(300,250);
}

bool event(QEvent *event)
{
    if (event->type() == QEvent::UpdateRequest) 
    {
        m_update_pending = false;
        renderNow();
        return true;
    }
    return QWindow::event(event);
}

void renderLater()
{  
    if (!m_update_pending) 
    {
        m_update_pending = true;
	
	//Post this event to event queue for later processing
        QCoreApplication::postEvent(this,
				    new QEvent(QEvent::UpdateRequest));
    }
}

void resizeEvent(QResizeEvent *resizeEvent)
{
    m_backingStore->resize(resizeEvent->size());
    if (isExposed())
    {
        renderNow();
    }
}

void exposeEvent(QExposeEvent *)
{
    if (isExposed()) 
    {
        renderNow();
    }
}

void renderNow()
{
    if (!isExposed())
        return;
    
    QRect rect(0, 0, width(), height());
    m_backingStore->beginPaint(rect);

    QPaintDevice *device = m_backingStore->paintDevice();
    QPainter painter(device);

    painter.drawPixmap(rect,QPixmap("background.jpg"));
    painter.drawText(QRectF(0, 0, width(), height()),
		      Qt::AlignCenter, QStringLiteral("QWindow"));

    m_backingStore->endPaint();
    m_backingStore->flush(rect);
}

private:
    QBackingStore *m_backingStore;
    bool m_update_pending;
};

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

    MyWindow window;   
    window.show();
    
    return app.exec();
}

To copy to clipboard, switch view to plain text mode 

Do I need to use a window container? What would be the best way? I have no clue, no starting point, I am lost.
I would be very happy if someone could make a small example showing a qpushbutton or some other widget on that window.
Other hints and tips are also welcome.

[1]:https://lists.sailfishos.org/piperma...ly/004833.html
[2]:http://codeprogress.com/cpp/librarie...ackgroundImage

[anda_skoa]

A top level widget (without a parent) or one of the widget window types (QMainWindow, QDialog) has an associated QWindow.

Can you explain why you need to derive a subclass from QWindow?

Cheers,
_

[Tuxedo]

A top level widget (without a parent) or one of the widget window types (QMainWindow, QDialog) has an associated QWindow.

Thank you for that explanation it is good to know.
After a hint from elros I solved my problem by doing this:

include <QtWidgets/QApplication>
include "mainwindow.h"
include <QWindow>
 
 int main(int argc, char *argv[])
 {
     QApplication a(argc, argv);
     MainWindow w;
     w.show();
     QWindow *window = w.windowHandle();
     window->reportContentOrientationChange(Qt::LandscapeOrientation);
     return a.exec();
 }

include <QtWidgets/QApplication>
include "mainwindow.h"
include <QWindow>
 
 int main(int argc, char *argv[])
 {
     QApplication a(argc, argv);
     MainWindow w;
     w.show();
     QWindow *window = w.windowHandle();
     window->reportContentOrientationChange(Qt::LandscapeOrientation);
     return a.exec();
 }

To copy to clipboard, switch view to plain text mode 

Is this the right way to access the associated QWindow from my MainWindow? However this is working.