Type Alias TickCallback 

pub type TickCallback = Box<dyn FnMut() -> Vec<Effect> + Send + 'static>;

A per-tick drain closure. Returns the Effects the host should apply this tick (empty when there was nothing pending). FnMut because the canonical body drains a channel receiver, which needs &mut.

Send so the registry (held behind an Arc shared with mode activation paths) is Send; the closure is only ever invoked on the editor thread inside TickCallbackRegistry::run_all.

Aliased Type

pub struct TickCallback(/* private fields */);