textual/docs/examples/guide/screens/modal01.py

from textual.app import App, ComposeResult
from textual.containers import Grid
from textual.screen import Screen
from textual.widgets import Button, Footer, Header, Label

TEXT = """I must not fear.
Fear is the mind-killer.
Fear is the little-death that brings total obliteration.
I will face my fear.
I will permit it to pass over me and through me.
And when it has gone past, I will turn the inner eye to see its path.
Where the fear has gone there will be nothing. Only I will remain."""


class QuitScreen(Screen):
    """Screen with a dialog to quit."""

    def compose(self) -> ComposeResult:
        yield Grid(
            Label("Are you sure you want to quit?", id="question"),
            Button("Quit", variant="error", id="quit"),
            Button("Cancel", variant="primary", id="cancel"),
            id="dialog",
        )

    def on_button_pressed(self, event: Button.Pressed) -> None:
        if event.button.id == "quit":
            self.app.exit()
        else:
            self.app.pop_screen()


class ModalApp(App):
    """A app with a modal dialog."""

    CSS_PATH = "modal01.css"
    BINDINGS = [("q", "request_quit", "Quit")]

    def compose(self) -> ComposeResult:
        yield Header()
        yield Label(TEXT * 8)
        yield Footer()

    def action_request_quit(self) -> None:
        self.push_screen(QuitScreen())


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