Compatibility with Gnome Shell themes needs to be improved

[clefebvre]

In the overview you can now see all installed themes and select the one you want. Cinnamon detects both Gnome Shell and Cinnamon themes. Under the theme name you can see the theme type (whether it's a Gnome Shell Theme or a Cinnamon Theme).

Gnome Shell themes miss important info and as a result they're not fully compatible with Cinnamon. Well, they are, but then selected, some parts of Cinnamon aren't properly themed or even don't work as expected.

So when that's the case and Cinnamon loads a Gnome Shell, it doesn't find things like overview.png in it for instance. We should go through the code and make sure any resource loaded from the selected theme is surrounded by a try/catch or a Gio file_exists test, so that if the resource isn't there, we load the one from the default Cinnamon theme instead.

That way, we gain full compatibility with Gnome Shell themes, and whatever they don't define (Cinnamon specifics), we load from the Cinnamon default theme.

[AlbertJP]

Good idea. Providing partial compatibility is better than just saying that it's not possible and this way we're also encouraging people to fix those issues and turn the theme into a Cinnamon one. Or perhaps a theme which is compatible with both Gnome 3 and Cinnamon? Would be great if that were possible.

[clefebvre]

Yes, that is possible. You can define Cinnamon styles within the gnome-shell part of the theme and this will result in a theme which will be detected as being a "Gnome Shell" theme, but which will be 100% functional in both Gnome Shell and Cinnamon.

[clefebvre]

We're changing quite a lot of things and introducing new widgets and styles with every new features so it's a little bit early for people to work on themes for Cinnamon, but eventually we'll work on making this as easy as possible.