pub fn tick_task<M: 'static>(msg: M) -> Task<M>Expand description
Self-rescheduling animation clock: a Task that waits one frame
(~16 ms) and then yields msg, so the host’s ScrollTick arm can call
ScrollState::tick and re-arm while ScrollState::is_animating.
This drives momentum without a perpetual time::every subscription: the
loop stops the moment the host stops returning another tick_task.