Trait Event

pub trait Event: Component {
    type Traversal: Traversal;

    const AUTO_PROPAGATE: bool = false;
}

Something that “happens” and might be read / observed by app logic.

Events can be stored in an Events<E> resource You can conveniently access events using the EventReader and EventWriter system parameter.

Events can also be “triggered” on a World, which will then cause any Observer of that trigger to run.

This trait can be derived.

Events implement the Component type (and they automatically do when they are derived). Events are (generally) not directly inserted as components. More often, the ComponentId is used to identify the event type within the context of the ECS.

Events must be thread-safe.

Provided Associated Constants

const AUTO_PROPAGATE: bool = false

When true, this event will always attempt to propagate when triggered, without requiring a call to Trigger::propagate.

Required Associated Types

type Traversal: Traversal

The component that describes which Entity to propagate this event to next, when propagation is enabled.

Object Safety

This trait is not object safe.

Implementors

impl Event for AppExit

where AppExit: Send + Sync + 'static,

const AUTO_PROPAGATE: bool = false

type Traversal = ()

impl Event for HierarchyEvent

where HierarchyEvent: Send + Sync + 'static,

const AUTO_PROPAGATE: bool = false

type Traversal = ()

impl Event for GamepadEvent

where GamepadEvent: Send + Sync + 'static,

const AUTO_PROPAGATE: bool = false

type Traversal = ()

impl Event for GamepadRumbleRequest

where GamepadRumbleRequest: Send + Sync + 'static,

const AUTO_PROPAGATE: bool = false

type Traversal = ()

impl Event for RawGamepadEvent

where RawGamepadEvent: Send + Sync + 'static,

const AUTO_PROPAGATE: bool = false

type Traversal = ()

impl Event for GamepadAxisChangedEvent

where GamepadAxisChangedEvent: Send + Sync + 'static,

const AUTO_PROPAGATE: bool = false

type Traversal = ()

impl Event for GamepadButtonChangedEvent

where GamepadButtonChangedEvent: Send + Sync + 'static,

const AUTO_PROPAGATE: bool = false

type Traversal = ()

impl Event for GamepadButtonStateChangedEvent

where GamepadButtonStateChangedEvent: Send + Sync + 'static,

const AUTO_PROPAGATE: bool = false

type Traversal = ()

impl Event for GamepadConnectionEvent

where GamepadConnectionEvent: Send + Sync + 'static,

const AUTO_PROPAGATE: bool = false

type Traversal = ()

impl Event for RawGamepadAxisChangedEvent

where RawGamepadAxisChangedEvent: Send + Sync + 'static,

const AUTO_PROPAGATE: bool = false

type Traversal = ()

impl Event for RawGamepadButtonChangedEvent

where RawGamepadButtonChangedEvent: Send + Sync + 'static,

const AUTO_PROPAGATE: bool = false

type Traversal = ()

impl Event for DoubleTapGesture

where DoubleTapGesture: Send + Sync + 'static,

const AUTO_PROPAGATE: bool = false

type Traversal = ()

impl Event for PanGesture

where PanGesture: Send + Sync + 'static,

const AUTO_PROPAGATE: bool = false

type Traversal = ()

impl Event for PinchGesture

where PinchGesture: Send + Sync + 'static,

const AUTO_PROPAGATE: bool = false

type Traversal = ()

impl Event for RotationGesture

where RotationGesture: Send + Sync + 'static,

const AUTO_PROPAGATE: bool = false

type Traversal = ()

impl Event for KeyboardFocusLost

where KeyboardFocusLost: Send + Sync + 'static,

const AUTO_PROPAGATE: bool = false

type Traversal = ()

impl Event for KeyboardInput

where KeyboardInput: Send + Sync + 'static,

const AUTO_PROPAGATE: bool = false

type Traversal = ()

impl Event for MouseButtonInput

where MouseButtonInput: Send + Sync + 'static,

const AUTO_PROPAGATE: bool = false

type Traversal = ()

impl Event for MouseMotion

where MouseMotion: Send + Sync + 'static,

const AUTO_PROPAGATE: bool = false

type Traversal = ()

impl Event for MouseWheel

where MouseWheel: Send + Sync + 'static,

const AUTO_PROPAGATE: bool = false

type Traversal = ()

impl Event for TouchInput

where TouchInput: Send + Sync + 'static,

const AUTO_PROPAGATE: bool = false

type Traversal = ()

impl Event for RemovedComponentEntity

where RemovedComponentEntity: Send + Sync + 'static,

const AUTO_PROPAGATE: bool = false

type Traversal = ()

impl Event for OnAdd

where OnAdd: Send + Sync + 'static,

const AUTO_PROPAGATE: bool = false

type Traversal = ()

impl Event for OnInsert

where OnInsert: Send + Sync + 'static,

const AUTO_PROPAGATE: bool = false

type Traversal = ()

impl Event for OnRemove

where OnRemove: Send + Sync + 'static,

const AUTO_PROPAGATE: bool = false

type Traversal = ()

impl Event for OnReplace

where OnReplace: Send + Sync + 'static,

const AUTO_PROPAGATE: bool = false

type Traversal = ()