Module bevy_ecs::observer

Types for creating and storing Observers

Structs

• CachedComponentObservers
  Collection of ObserverRunner for Observer registered to a particular trigger targeted at a specific component.
• CachedObservers
  Collection of ObserverRunner for Observer registered to a particular trigger.
• EmitDynamicTrigger
  Emit a trigger for a dynamic component id. This is unsafe and must be verified manually.
• Observer
  An Observer system. Add this Component to an Entity to turn it into an “observer”.
• ObserverDescriptor
  A description of what an Observer observes.
• ObserverState
  Contains Observer information. This defines how a given observer behaves. It is the “source of truth” for a given observer entity’s behavior.
• ObserverTrigger
  Event trigger metadata for a given Observer,
• Observers
  Metadata for observers. Stores a cache mapping trigger ids to the registered observers.
• Trigger
  Type containing triggered Event information for a given run of an Observer. This contains the Event data itself. If it was triggered for a specific Entity, it includes that as well.
• TriggerEvent
  A Command that emits a given trigger for a given set of targets.

Traits

• TriggerTargets
  Represents a collection of targets for a specific Trigger of an Event. Targets can be of type Entity or ComponentId. When a trigger occurs for a given event and TriggerTargets, any Observer that watches for that specific event-target combination will run.

Type Aliases

• BoxedObserverSystem
  Equivalent to BoxedSystem for ObserverSystem.
• ObserverRunner
  Type for function that is run when an observer is triggered. Typically refers to the default runner that runs the system stored in the associated [ObserverSystemComponent], but can be overridden for custom behaviour.