Widget disappears when removed and mounted again

[davidbrochart]

In the following example, a widget mounts a button when s is pressed the first time. When s is pressed again, the widget is removed and mounted again, but the button disappears.
Any idea why?

from textual.app import App, ComposeResult
from textual.widget import Widget
from textual.widgets import Button, Footer


class MyWidget(Widget):

    def __init__(self):
        self.button = Button()
        super().__init__()

    def compose(self) -> ComposeResult:
        yield self.button


class MyApp(App):

    BINDINGS = [("s", "show_button", "Show Button")]

    def __init__(self):
        self.my_widget = None
        super().__init__()

    def compose(self) -> ComposeResult:
        yield Footer()

    async def action_show_button(self) -> None:
        if self.my_widget is None:
            self.my_widget = MyWidget()
        else:
            await self.my_widget.remove()
        await self.mount(self.my_widget)


if __name__ == "__main__":
    app = MyApp()
    app.run()

[davep]

To the best of my knowledge, when you remove a widget you're, in effect, destroying it (for want of a better term). Once you remove a particular instance you can't mont it again. If you want to add a button again you'll want to mount a fresh instance of MyWidget.

[willmcgugan]

Also available as a property, so my_widget.display=False works.

[davep]

Surely you don't expect me to scroll all the way to the bottom of the docs I link to while I'm on holiday? ¯\(ツ)/¯

[davidbrochart]

Thanks, I think using the display property is better indeed. BTW, is there a means to know if a widget is mounted?

[willmcgugan]

App.is_mounted(my_widget)

[davidbrochart]

Thanks @willmcgugan and @davep !