Add option to use native window decoration on linux.

[Tahosol]

Before submitting an issue, please check the following

• I have searched for similar issues (both open and closed) and cannot find a duplicate
• I agree to follow the Code of Conduct

Motivation

On some linux setup, the client side decoration look out of place like in my case. The default GTK lib Adwaita window decoration will look out of place for most linux OS except Gnome.

Solution

I think the best solution would be have an option to use native window decoration on linux, or just enable it as the default behavior.

Alternatives

If it is too much to implement a native option, maybe saber can have an option to disable the client side window decoration.

Saber version

0.26.10(Linux flatpak)

Device

• Device: Deskctop
• OS: Linux(kernel 6.17.4-arch2-1)

Anything else?

No response

[adil192]

I'm not well-versed in Linux window decorations, but as far as I'm aware, it is using the native title bar. You can see in my "before" screenshot, it's using the COSMIC DE titlebar.
To fix the ugliness, I've added a setting (default: turned on) to use a themed (Yaru) titlebar:

Before	After

[Tahosol]

Hi @adil192, indeed the decoration right now is Linux‑native, but it is a client‑side decoration, not server‑side. In many desktop environments on Linux, this makes it look out of place, not just ugly. This issue is related to the fact that Flutter uses the GTK 3 header bar, which is technically Linux‑native but not native to desktop environments. On Cosmic, it looks fine because its UI design is highly influenced by GTK; on KDE, it looks somewhat broken. flutter/#94381 has an issue on it.

It seems like this isn’t a fix that upstream will address anytime soon. Another Flutter app, LocalSend, was able to do it via this pull request #2360, but I imagine it would be too much work. I hope I know enough about Flutter to fix the issue myself and submit a patch, but I am not sadly.

My suggestion for an alternative is simply to provide an option to turn off the CSD(client side decoration) for people who want it (e.g., me), but I do understand it is a niche feature. Sorry for all the complaints.