Struct EventEmitter 

pub struct EventEmitter { /* private fields */ }

Callback-based event subscription system.

Embed in MapState and call dispatch each frame with the events drained from InteractionManager.

Implementations

impl EventEmitter

pub fn new() -> Self

Create an empty event emitter.

pub fn on<F>(&mut self, kind: InteractionEventKind, callback: F) -> ListenerId

where F: Fn(&InteractionEvent) + Send + Sync + 'static,

Subscribe to events of a given kind.

Returns a ListenerId that can later be passed to off.

pub fn once<F>(&mut self, kind: InteractionEventKind, callback: F) -> ListenerId

where F: Fn(&InteractionEvent) + Send + Sync + 'static,

Subscribe to a single occurrence of an event kind.

The listener is automatically removed after the first dispatch.

pub fn off(&mut self, id: ListenerId) -> bool

Unsubscribe a previously registered listener.

Returns true if the listener was found and removed.

pub fn dispatch(&mut self, events: &[InteractionEvent])

Dispatch a batch of events to all matching listeners.

once listeners are removed after their first invocation.

pub fn listener_count(&self) -> usize

Number of active listeners.

pub fn listener_count_for(&self, kind: InteractionEventKind) -> usize

Number of listeners for a specific event kind.

Trait Implementations

impl Default for EventEmitter

fn default() -> Self

Returns the “default value” for a type.

impl Send for EventEmitter

impl Sync for EventEmitter