When window goes fullscreen, show something different

[l1psync]

@pl45m4 Even though the QMainWindow is going to fullscreen, its ok for me for first (probably later try minimizing the app). But this strange behavior that some random black fullscreen view opens up is confusing me...

[Pl45m4]

@l1psync

Do you see the window title of that black window? Or anything which identifies the black window, so you can see where it actually comes from?

[l1psync]

@pl45m4
No I cannot see the title bar nor the menu bar.

There can be a lot of fullscreen windows because each window then is getting its „own desktop“.

My thoughts were that the black view and the QMainWindow are in real one piece and result in a fullscreen QMainWindow. I tried repaint on it but this does not work.

[Pl45m4]

@l1psync

Ok, the "own-desktop"-thing is Mac related (I'm not a mac-expert)

What happens if you set only the MainWindow to fullscreen without the new widget? Do you get a black screen on one virtual desktop too?

[l1psync]

@pl45m4
I just get my Mainwindow in fullscreen. No black view.

[l1psync]

I am now 100% sure the black view has something to do with my application. When I move into the "desktop overview" I can see that the black view has the name of my application. So its probably that the QMainWindow does not gets painted.

I think I know what the problem is and that is on the side of macOS. When I call just showmy new QWidget is just showing up without any mistakes (but not in fullscreen). The problem here is probably that I try to launch another window in fullscreen while I am in fullscreen. So the solution to that would be catching up before we go fullscreen. But as I think there's no Qt solution to that, or am I wrong?

[l1psync]

BOOM, I got this!

void MainWindow::changeEvent(QEvent *event) {
	if (event->type() == QEvent::WindowStateChange) {
		Qt::WindowStates state = this->windowState(); // debug reasons
		if (this->windowState() == Qt::WindowFullScreen) {
			appIsFs = true;
			showEditViewFs();
		}
	}
}

void MainWindow::showEditViewFs() {
	if (appIsFs == true) {
        fsWindow->show();
        fsWindow->setWindowState(windowState() & Qt::WindowFullScreen);
        this->setWindowState(windowState() & ~(Qt::WindowFullScreen));
	}
}

@Pl45m4 Now I am hanging here at the point that it just ignores the this->setWindowState(windowState() & ~(Qt::WindowFullScreen));.

[J.Hilk]

@l1psync
question, why do you make your 2nd Window as Independent window?

Let the QMainWindow go fullscreen, detect that, and simply exchange the content of or QMainWindow.

You can do that for example via setContentWidget, make sure to keep a valid pointer of your original contentWidget to realign it, once the fullscreen exits

[l1psync]

@j-hilk Good point, you mean setCentralWidget(). I'll try it out...

[J.Hilk]

@l1psync said in When window goes fullscreen, show something different:

@j-hilk Good point, you mean setCentralWidget()

Yes, of course. Too much QML lately ;)
https://doc.qt.io/qt-5/qmainwindow.html#setCentralWidget

[SGaist]

Hi,

QStackedWidget comes to mind for that.

[l1psync]

Just like @SGaist with QStackedWidget this works perfectly. Thanks to everyone!