Recently, the Linux Mint Blog published Monthly News – April 2024, which goes into detail about wanting to fork and maintain older GNOME apps in collaboration with other GTK-based desktop environments. Despite the good intentions of the author, Clem, many readers interpreted this as an attack against GNOME. Specifically: GTK, libadwaita, the relationship between them, and their relevance to any desktop environment or desktop operating system. Unfortunately, many of these readers seem to have a lot of difficulty understanding what GTK is trying to be, and how libadwaita helps. In this article, we’ll look at the history of why and how libadwaita was born, the differences between GTK 4 and libadwaita in terms of scope of support, their relevance to each desktop environment and desktop operating system, and the state of GTK 4 today.
When an app targets a platform-specific library like Adwaita it explicitly forgoes supporting generic, cross-platform GTK.
Depends what you mean by “usable”.
Will it run, yes, most likely. But the UI will be full of Gnome-y things that make little sense on other DE’s, among which the theme is just one. Could be other stuff, like accessibility, features etc.
As long as none of the shortcomings are deal-breakers for you I guess you can call it “usable”.
At the end of the day there’s always going to be DE’s that expand their UI features, and apps that take advantage of those. Cosmic, Plasma, Granite etc. are all examples of such platform-specific UI libs. Even in a cross-platform library like GTK or Qt there’s no guarantee that they’re compatible with each other. Bottom line is, when you mix and match apps made for different toolkits there’s always going to be variations.
It was nice for a while having common themes that could target both GTK and Qt and having unified-looking desktops. I guess that era is over. Back to each app having its own incompatible theming and the only common point being that they’re all “light-ish” or “dark-ish”.