Custom titlebar on Linux with Desktop Integration

[Dan D]

I want to create a transparent title bar, which is a part of application body as there is a gradient that should be visible through the title bar (re: transparent).

I have implemented a title bar using Qt::FramelessWindowHint integrated close/maximize/minimize and move/resize using QWindow APIs.

I want to integrate the normal window interactions as well at least for popular DEs like Gnome.

The screenshot shows the file manager on Ubuntu 24.04 has heavily customized title bar and window interactions as well. I've verified this on Firefox, and Ubunut's terminal as well.

How can I achieve the same? What are the limitations and drawbacks? Is it encouraged / discouraged to do such things?

Are there existing libs?

Thanks! Looking forward for your suggestions.