EventSystemInterface class abstract

Core event system contract for managing listeners, emitting events, and groups.

This interface provides a flexible pub-sub system for decoupling components. Implementations should ensure thread-safety if used in concurrent environments.

Key features:

  • Register listeners with priorities and one-time execution.
  • Group events for batch operations.
  • Emit events synchronously or asynchronously.
  • Manage subscriptions per subscriber for easy cleanup.

Example usage:

class MyEventSystem implements EventSystemInterface {
  // Implementation here
}

final events = MyEventSystem();
events.on('user.created', (user) => print('User: $user'));
await events.emit('user.created', {'id': 1, 'name': 'Alice'});
Implementers
Annotations

Constructors

EventSystemInterface()

Properties

eventGroups → Map<String, Set<String>>
Internal map of group names to sets of event names.
final
hashCode → int
The hash code for this object.
no setterinherited
listeners → Map<String, List<EventRegistration>>
Internal map of event names to their registered listeners.
final
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited
subscriberEvents → Map<Object, Set<String>>
Internal map tracking events registered by each subscriber for cleanup.
final

Methods

addToGroup(String groupName, String event) → void
Adds an event to a named group for batch operations.
clear() → void
Clears all listeners, event groups, and subscriber tracking.
emit(String event, [dynamic payload, bool queue = false]) → Future<void>
Emits an event to all its registered listeners.
emitGroup(String groupName, [dynamic payload, bool queue = false]) → Future<void>
Emits all events within a named group.
hasListeners(String event) → bool
Checks if any listeners are registered for the event.
listenerCount(String event) → int
Returns the number of listeners registered for the event.
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
off(String event, EventListener listener) → void
Removes a specific listener from an event.
offEvent(String event) → void
Removes all listeners for a specific event.
offSubscriber(Object subscriber) → void
Removes all events registered by a specific subscriber.
on(String event, EventListener listener, {EventPriority priority = EventPriority.normal, bool once = false, Object? subscriber}) → void
Registers a listener for a specific event.
once(String event, EventListener listener, {EventPriority priority = EventPriority.normal, Object? subscriber}) → void
Registers a one-time listener for a specific event.
removeFromGroup(String groupName, String event) → void
Removes an event from a named group.
toString() → String
A string representation of this object.
inherited

Operators

operator ==(Object other) → bool
The equality operator.
inherited