Struct EventBus 

pub struct EventBus { /* private fields */ }

Central pub/sub hub for routing events between hats.

Implementations

impl EventBus

pub fn new() -> Self

Creates a new empty event bus.

pub fn add_observer<F>(&mut self, observer: F)

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

Adds an observer that receives all published events.

Multiple observers can be added (e.g., session recorder + TUI). Each observer is called before events are routed to subscribers. This enables recording sessions by subscribing to the event stream without modifying the routing logic.

pub fn set_observer<F>(&mut self, observer: F)

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

👎Deprecated since 2.0.0:

Use add_observer instead

Sets a single observer, clearing any existing observers.

Prefer add_observer when multiple observers are needed. This method is kept for backwards compatibility.

pub fn clear_observers(&mut self)

Clears all observer callbacks.

pub fn register(&mut self, hat: Hat)

Registers a hat with the event bus.

pub fn publish(&mut self, event: Event) -> Vec<HatId>

Publishes an event to all subscribed hats.

Returns the list of hat IDs that received the event. If an observer is set, it receives the event before routing.

pub fn take_pending(&mut self, hat_id: &HatId) -> Vec<Event>

Takes all pending events for a hat.

pub fn take_human_pending(&mut self) -> Vec<Event>

Takes all pending human interaction events.

pub fn peek_pending(&self, hat_id: &HatId) -> Option<&Vec<Event>>

Returns a reference to pending events for a hat without consuming them.

pub fn peek_human_pending(&self) -> &[Event]

Returns a reference to pending human interaction events without consuming them.

pub fn has_pending(&self) -> bool

Checks if there are any pending events for any hat.

pub fn has_human_pending(&self) -> bool

Checks if there are any pending human interaction events.

pub fn next_hat_with_pending(&self) -> Option<&HatId>

Returns the next hat with pending events. BTreeMap iteration is already sorted by key.

pub fn get_hat(&self, id: &HatId) -> Option<&Hat>

Gets a hat by ID.

pub fn hat_ids(&self) -> impl Iterator<Item = &HatId>

Returns all registered hat IDs.

Trait Implementations

impl Default for EventBus

fn default() -> EventBus

Returns the “default value” for a type.