Module event 

Event functionality.

Structs

EntityComponentsTrigger

An EntityEvent Trigger that, in addition to behaving like a normal EntityTrigger, also runs observers that watch for components that match the slice of ComponentIds referenced in EntityComponentsTrigger. This includes both global observers of those components and “entity scoped” observers that watch the EntityEvent::event_target.

EntityTrigger

An EntityEvent Trigger that does two things:

EventKey

A unique identifier for an Event, used by observers.

GlobalTrigger

A Trigger that runs every “global” Observer (ex: registered via World::add_observer) that matches the given Event.

PropagateEntityTrigger

An EntityEvent Trigger that behaves like EntityTrigger, but “propagates” the event using an Entity Traversal. At each step in the propagation, the EntityTrigger logic will be run, until PropagateEntityTrigger::propagate is false, or there are no entities left to traverse.

Traits

EntityEvent

An EntityEvent is an Event that is triggered for a specific EntityEvent::event_target entity:

Event

An Event is something that “happens” at a given moment.

SetEntityEventTarget

A trait which is used to set the target of an EntityEvent.

Trigger

Trigger determines how an Event is triggered when World::trigger is called. This decides which Observers will run, what data gets passed to them, and the order they will be executed in.

Functions

trigger_entity_internal^⚠

Trigger observers watching for the given entity event. The target_entity should match the EntityEvent::event_target on event for logical correctness.

Derive Macros

EntityEvent

Cheat sheet for derive syntax, see full explanation on EntityEvent trait docs.

Event

Implement the Event trait.