Listener<T> class

Listener is one who listen for specific event. Listener register for notification with EventEmitter Once the listener is registered, a Listener interface is returned back to the caller. Caller can use this Listener interface to cancel the registration or check the state.

Constructors

Listener(T event, EventCallback _callback, CancelEvent? _cancelCallback)

Constructor for Listener. This will take four arguments. event, callback are mandatory. _cancelCallback is optional. if _cancelCallback callback is provided, then the listener can use that to cancel the subscription.

Listener.Default(T event, EventCallback _callback)

Constructor for Listener. This will take four arguments. event, callback are mandatory.

Properties

callback → EventCallback

no setter

event → T

The event, the subscriber subscribed to.

final

hashCode → int

The hash code for this object.

no setter, inherited

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

Methods

cancel() → bool

Cancel the event subscription with the subject. Eventhough the cancel method is called, listener doesn't check the cancellation of the subscription. Subscription cancellation shall be implemented in the _cancelCallback function. The Default constructor doesn't provide a mechanism to cancel the subscription. Use the EventEmitter.on to cancel the suscrition effectively. Returns true, if _cancelCallback is successfully executed, false otherwise.

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

inherited

toString() → String

A string representation of this object.

inherited

updateCallback(EventCallback callback) → void

Operators

operator ==(Object other) → bool

The equality operator.

inherited