Libadwaita themeing is not working in python

Question

This is my first time using pyGOObject and gtk in Python. I want to make an app with libadwaita and came up with this:

import sys
import gi

gi.require_version('Gtk', '4.0')
gi.require_version('Adw', '1')

from gi.repository import Gtk, Adw

class MainWindow(Gtk.ApplicationWindow):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.set_title('Test')
        self.set_default_size(800, 600)

        box = Gtk.Box(orientation=Gtk.Orientation.VERTICAL)
        self.set_child(box)

        button = Gtk.Button.new_with_label("Test")
        button.connect("clicked", self.on_button_clicked)
        box.append(button)

    def on_button_clicked(self, button):
        print("Button was clicked")

class MyApp(Adw.Application):
    def __init__(self, **kwargs):
        super().__init__(**kwargs)
        self.connect('activate', self.on_activate)

    def on_activate(self, app):
        self.win = MainWindow(application=app)
        self.win.present()

app = MyApp(application_id='com.example.GtkApplication')
app.run(sys.argv)

The code runs, but the problem is it doesn't look like libadwaita, it just looks like gtk!

The top bar should look like this:

But it looks like this:

I assume that's not libadwaita, how can I make my app use libadwaita? The widgets and elements look like Libadwaita but not the top bar.

Answer 1

When using libadwaita you should inherit from Adw.ApplicationWindow, like so:

import sys
import gi

gi.require_version('Gtk', '4.0')
gi.require_version('Adw', '1')

from gi.repository import Gtk, Adw

class MainWindow(Adw.ApplicationWindow):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.set_title('Test')
        self.set_default_size(800, 600)

        # ... Your widgets here

class MyApp(Adw.Application):
    def __init__(self, **kwargs):
        super().__init__(**kwargs)
        self.connect('activate', self.on_activate)

    def on_activate(self, app):
        self.win = MainWindow(application=app)
        self.win.present()

app = MyApp(application_id='com.example.GtkApplication')
app.run(sys.argv)