Class Timer

src/textual/timer.py:32–203

A class to send timer-based events. Args: event_target: The object which will receive the timer events. interval: The time between timer events, in seconds. name: A name to assign the event (for debugging). callback: An optional callback to invoke when the event

@rich_repr
class Timer:
    """A class to send timer-based events.

    Args:
        event_target: The object which will receive the timer events.
        interval: The time between timer events, in seconds.
        name: A name to assign the event (for debugging).
        callback: An optional callback to invoke when the event is handled.
        repeat: The number of times to repeat the timer, or None to repeat forever.
        skip: Enable skipping of scheduled events that couldn't be sent in time.
        pause: Start the timer paused.
    """

    _timer_count: int = 1

    def __init__(
        self,
        event_target: MessageTarget,
        interval: float,
        *,
        name: str | None = None,
        callback: TimerCallback | None = None,
        repeat: int | None = None,
        skip: bool = True,
        pause: bool = False,
    ) -> None:
        self._target_repr = repr(event_target)
        self._target = weakref.ref(event_target)
        self._interval = interval
        self.name = f"Timer#{self._timer_count}" if name is None else name
        self._timer_count += 1
        self._callback = callback
        self._repeat = repeat
        self._skip = skip
        self._task: Task | None = None
        self._reset: bool = False
        self._original_pause = pause

    @cached_property
    def _active(self) -> Event:
        event = Event()
        if not self._original_pause:
            event.set()
        return event

    def __rich_repr__(self) -> Result:
        yield self._interval
        yield "name", self.name
        yield "repeat", self._repeat, None

    @property
    def target(self) -> MessageTarget:
        target = self._target()
        if target is None:
            raise EventTargetGone()
        return target

    def _start(self) -> None: