How can I ensure the event loop exits when the application window is closed?

[SherLock707]

I'm running a widget using:

python palette_ui.py

The issue is that when I close the widget window, the event loop remains active and doesn't exit automatically. Here's the terminal output for reference:

2025-04-17 20:24:36.820 | DEBUG    | fabric.core.application:do_activate:355 - [Fabric] opening a DBus client for Application with name palette
^C 2025-04-17 20:28:20.004 | INFO     | fabric.core.application:on_exit:369 - [Fabric] exiting...

Right now, I have to manually interrupt it with Ctrl+C. Is there a clean way to have the event loop terminate as soon as the main window is closed?

[its-darsh]

I have to manually interrupt it with Ctrl+C. Is there a clean way to have the event loop terminate as soon as the main window is closed?

Yes, you'll need to hook the destroy signal of your window to the Application.quit() method, you can access the application instance through the Window.application property, here's an example...

# ...
app = Application(
    "my-app",
    WaylandWindow(
        # ...
        on_destroy=lambda w, *_: w.application.quit()
    )
)
app.run()

[SherLock707]

Thanks, seems like this should work, but two weird things:

1. window has now borders and I can't grab or select it.
2. Since I can't select it, I can't move or close it.

[SherLock707]

window = Window(child=box_main, type='popup') 
app = Application("palette", window)

---

app = Application(
        "palette-app",
        WaylandWindow(
            child=box_main, 
            type='popup',
            on_destroy=lambda w, *_: w.application.quit()
        )
    )

[SherLock707]

Nevermind, I can you regular window instead of WaylandWindow.

Not sure if this means regular window runs in Xwayland or something.