Describe how to add a stylesheet

[mijorus]

Hi,

I think a paragraph about how to add a CSS file (even just mentioning fact that you can do it) might be useful. Let me know what you think and if you have suggestions on this first draft.

[Taiko2k]

Certainly it would be good to have a topic on this.

But I wonder, is applying individual CSS classes to individual widgets the correct approach? I assumed it would be more standard to add a CSS file to the whole window all at once?

[mijorus]

Right, the code I proposed is not actually what I do when I create an app. Usually, I hook into the do_activate event and register a CSS file there (usually just one, using gresource).

However, some topics need to be introduced in order to talk about this approach, like startup hooks and gresources.

[mijorus]

Btw it's funny because I was attempting to create something similar, but have had no time since

[Taiko2k]

Applying to single widgets is useful, but I think readers will still be left wondering how apply it to the whole window. So I think you should add how to do that.

And this whole tutorial pretty much takes place in the on_activate method anyway right?

Here's essentially what I did in one of my apps:

style_context = self.get_style_context()
style_context.add_provider_for_display(self.get_display(), css_provider, Gtk.STYLE_PROVIDER_PRIORITY_USER)

Another issue, for me I have to give a gio.file object and cant use a basic string as an argument to load_from_file like your your example. Are you using an older version?

[mijorus]

I'll review this PR and add more content because I think there is a lot to say; currently this PR is poorly written.

[rubyFeedback]

This, by the way, just as additional info, helped us ruby folks too. kou wrote the ruby-gtk4 bindings (or, rather, helped adjust the gobject specific parts but he still had a lot to write nonetheless, all deprecation warnings in a .rb file for instance).

I was able to find out how to load up CSS in ruby-gtk4 thanks to your examples here. In ruby-gtk3 it already worked, so the API did not change much, but it took me some time until I realised I can use Gdk::Display.default. The old code was Gdk::Screen. That may not be super-relevant for the python folks, but it actually is SUPER helpful when other people search for things. In some ways github issue trackers almost replaced StackOverflow ... :D

I also almost did not notice that the API changed, e. g. from the trailing _screen name to the _display change. A bit annoying how much they changed from gtk3 to gtk4 ... CSS is cool, but the migration guide put down by the GNOME/GTK devs is fairly underwhelming really ... trial and error seems to be the way to go.