addAppEventListener function

void Function() addAppEventListener(void listener(AppEvent), { Object? ignoreSource, })

Subscribes listener to every event reported from now on, and returns the call that unsubscribes it.

The seam a live surface uses, where a scenario run uses appEventBuffer. A devbar registers one while it is mounted; a project can register its own.

Pass ignoreSource to skip events a particular reporter tagged, for a surface that reporter already handed a copy to directly. That is how a devbar avoids listing a DevbarHttpClient request twice — it is given the exchange in two halves as it happens, so it ignores the one-piece report the same client makes for everybody else.

A listener that throws is reported to the current Zone and skipped; it never reaches the app code that called recordAppEvent.

Applies no cap of its own — a live surface keeps whatever history it wants, and the devbar's tabs already bound theirs.

Implementation

void Function() addAppEventListener(
  void Function(AppEvent) listener, {
  Object? ignoreSource,
}) {
  var registration = _Registration(listener, ignoreSource);
  _listeners.add(registration);
  return () => _listeners.remove(registration);
}