Events

The shared emitter supports on, off, once, unsubscribe functions, cancellation, deterministic registration order, and safe listener mutation during emission. It snapshots the listener set before delivery.

beforeOpen, beforeClose, beforeSelect, and component-specific before* events may call preventDefault(). Informational events follow the accepted mutation. Every material mutation contains a typed reason rather than a free-form string.

Listeners are owned by their controller and removed by destroy(). Event payloads contain state and causes, never renderer-specific objects.