stopwatch05.py

from time import monotonic

from textual.app import App, ComposeResult
from textual.containers import ScrollableContainer
from textual.reactive import reactive
from textual.widgets import Button, Footer, Header, Static


class TimeDisplay(Static):
    """A widget to display elapsed time."""

    start_time = reactive(monotonic)
    time = reactive(0.0)

    def on_mount(self) -> None:
        """Event handler called when widget is added to the app."""
        self.set_interval(1 / 60, self.update_time)

    def update_time(self) -> None:
        """Method to update the time to the current time."""
        self.time = monotonic() - self.start_time

    def watch_time(self, time: float) -> None:
        """Called when the time attribute changes."""
        minutes, seconds = divmod(time, 60)
        hours, minutes = divmod(minutes, 60)
        self.update(f"{hours:02,.0f}:{minutes:02.0f}:{seconds:05.2f}")


class Stopwatch(Static):
    """A stopwatch widget."""

    def on_button_pressed(self, event: Button.Pressed) -> None:
        """Event handler called when a button is pressed."""
        if event.button.id == "start":
            self.add_class("started")
        elif event.button.id == "stop":
            self.remove_class("started")

    def compose(self) -> ComposeResult:
        """Create child widgets of a stopwatch."""
        yield Button("Start", id="start", variant="success")
        yield Button("Stop", id="stop", variant="error")
        yield Button("Reset", id="reset")
        yield TimeDisplay()


class StopwatchApp(App):
    """A Textual app to manage stopwatches."""

    CSS_PATH = "stopwatch04.tcss"
    BINDINGS = [("d", "toggle_dark", "Toggle dark mode")]

    def compose(self) -> ComposeResult:
        """Create child widgets for the app."""
        yield Header()
        yield Footer()
        yield ScrollableContainer(Stopwatch(), Stopwatch(), Stopwatch())

    def action_toggle_dark(self) -> None:
        """An action to toggle dark mode."""
        self.theme = (
            "textual-dark" if self.theme == "textual-light" else "textual-light"
        )


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