Fullscreen and transparent window on MacOS

[gladamyran]

Hello community!

The problem I am trying to solve is to make a sort of screen recorder / screencast program. For that I am creating a window to select a rectangular area which should be recorded. I wanted to solve it solved like this: I create a fully transparent fullscreen window in order to paint on the whole screen (for the rectangle that I drag with the mouse) and receive mouse signals. Unfortunately when I make a window and initialize it like this

setWindowState(windowState() | Qt::WindowFullScreen);
setWindowOpacity(0);

the background is lost, it just gets black. I've tried to change all sorts of flags, but nothing solved the problem. It works if I exchange it to

    setWindowState(windowState() | Qt::WindowMaximized);
    setWindowOpacity(0);

but it's a bad solution, because I cannot record the menu bar in MacOS, which I need to do.

So my question: Is there any way to

• Grab all mouse events on the screen
• with simultaneously being able to paint on the whole screen?

[mpergand]

@gladamyran said in Fullscreen and transparent window on MacOS:

Try to call showFullScreen() instead of of setting Qt::WindowFullScreen attribute.

[gladamyran]

I tried that, it is the same result.

[mpergand]

All right, I understand what you mean by black background :)
Unfortunatly, it's the default background.

One possible workaround could be to take a snapshoot of the all desktop screen and draw this image as the background of the full screen window.

btw, I don't know of multiplaform way to do this snapshoot ...
I don't think Qt can do that.

[gladamyran]

I am actually not concerned with a cross platform solution, although it would be nice.
It is a good idea taking a screenshot. It is a dirty solution, however, because of the flickering when I change to the window and the animation when I close the window.

I guess for better results I would have to dig deeper into how to build GUI on MacOS in general.

Thanks, anyway!