Struct bevy::ecs::prelude::State

pub struct State<S>(/* private fields */)
where
    S: States;

A finite-state machine whose transitions have associated schedules ([OnEnter(state)] and [OnExit(state)]).

The current state value can be accessed through this resource. To change the state, queue a transition in the NextState<S> resource, and it will be applied by the next apply_state_transition::<S> system.

The starting state is defined via the Default implementation for S.

use bevy_ecs::prelude::*;

#[derive(Clone, Copy, PartialEq, Eq, Hash, Debug, Default, States)]
enum GameState {
    #[default]
    MainMenu,
    SettingsMenu,
    InGame,
}

fn game_logic(game_state: Res<State<GameState>>) {
    match game_state.get() {
        GameState::InGame => {
            // Run game logic here...
        },
        _ => {},
    }
}

Implementations

impl<S> State<S>

where S: States,

pub fn new(state: S) -> State<S>

Creates a new state with a specific value.

To change the state use NextState<S> rather than using this to modify the State<S>.

pub fn get(&self) -> &S

Get the current state.

Trait Implementations

impl<S> Debug for State<S>

where S: Debug + States,

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl<S> Deref for State<S>

where S: States,

type Target = S

The resulting type after dereferencing.

fn deref(&self) -> &<State<S> as Deref>::Target

Dereferences the value.

impl<S> FromReflect for State<S>

where S: States + TypePath + FromReflect, State<S>: Any + Send + Sync,

fn from_reflect(reflect: &(dyn Reflect + 'static)) -> Option<State<S>>

Constructs a concrete instance of Self from a reflected value.

fn take_from_reflect( reflect: Box<dyn Reflect> ) -> Result<Self, Box<dyn Reflect>>

Attempts to downcast the given value to Self using, constructing the value using from_reflect if that fails.

impl<S> FromWorld for State<S>

where S: States + FromWorld,

fn from_world(world: &mut World) -> State<S>

Creates Self using data from the given World.

impl<S> GetTypeRegistration for State<S>

where S: States + TypePath + FromReflect, State<S>: Any + Send + Sync,

fn get_type_registration() -> TypeRegistration

impl<S> PartialEq<S> for State<S>

where S: States,

fn eq(&self, other: &S) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<S> Reflect for State<S>

where S: States + TypePath + FromReflect, State<S>: Any + Send + Sync,

fn get_represented_type_info(&self) -> Option<&'static TypeInfo>

Returns the TypeInfo of the type represented by this value.

fn into_any(self: Box<State<S>>) -> Box<dyn Any>

Returns the value as a Box<dyn Any>.

fn as_any(&self) -> &(dyn Any + 'static)

Returns the value as a &dyn Any.

fn as_any_mut(&mut self) -> &mut (dyn Any + 'static)

Returns the value as a &mut dyn Any.

fn into_reflect(self: Box<State<S>>) -> Box<dyn Reflect>

Casts this type to a boxed reflected value.

fn as_reflect(&self) -> &(dyn Reflect + 'static)

Casts this type to a reflected value.

fn as_reflect_mut(&mut self) -> &mut (dyn Reflect + 'static)

Casts this type to a mutable reflected value.

fn clone_value(&self) -> Box<dyn Reflect>

Clones the value as a Reflect trait object.

fn set(&mut self, value: Box<dyn Reflect>) -> Result<(), Box<dyn Reflect>>

Performs a type-checked assignment of a reflected value to this value.

fn apply(&mut self, value: &(dyn Reflect + 'static))

Applies a reflected value to this value.

fn reflect_kind(&self) -> ReflectKind

Returns a zero-sized enumeration of “kinds” of type.

fn reflect_ref(&self) -> ReflectRef<'_>

Returns an immutable enumeration of “kinds” of type.

fn reflect_mut(&mut self) -> ReflectMut<'_>

Returns a mutable enumeration of “kinds” of type.

fn reflect_owned(self: Box<State<S>>) -> ReflectOwned

Returns an owned enumeration of “kinds” of type.

fn reflect_partial_eq(&self, value: &(dyn Reflect + 'static)) -> Option<bool>

Returns a “partial equality” comparison result.

fn reflect_hash(&self) -> Option<u64>

Returns a hash of the value (which includes the type).

fn debug(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Debug formatter for the value.

fn serializable(&self) -> Option<Serializable<'_>>

Returns a serializable version of the value.

fn is_dynamic(&self) -> bool

Indicates whether or not this type is a dynamic type.

impl<S> TupleStruct for State<S>

where S: States + TypePath + FromReflect, State<S>: Any + Send + Sync,

fn field(&self, index: usize) -> Option<&(dyn Reflect + 'static)>

Returns a reference to the value of the field with index index as a &dyn Reflect.

fn field_mut(&mut self, index: usize) -> Option<&mut (dyn Reflect + 'static)>

Returns a mutable reference to the value of the field with index index as a &mut dyn Reflect.

fn field_len(&self) -> usize

Returns the number of fields in the tuple struct.

fn iter_fields(&self) -> TupleStructFieldIter<'_>

Returns an iterator over the values of the tuple struct’s fields.

fn clone_dynamic(&self) -> DynamicTupleStruct

Clones the struct into a DynamicTupleStruct.

impl<S> TypePath for State<S>

where S: States + TypePath, State<S>: Any + Send + Sync,

fn type_path() -> &'static str

Returns the fully qualified path of the underlying type.

fn short_type_path() -> &'static str

Returns a short, pretty-print enabled path to the type.

fn type_ident() -> Option<&'static str>

Returns the name of the type, or None if it is anonymous.

fn crate_name() -> Option<&'static str>

Returns the name of the crate the type is in, or None if it is anonymous.

fn module_path() -> Option<&'static str>

Returns the path to the module the type is in, or None if it is anonymous.

impl<S> Typed for State<S>

where S: States + TypePath + FromReflect, State<S>: Any + Send + Sync,

fn type_info() -> &'static TypeInfo

Returns the compile-time info for the underlying type.

impl<S> Resource for State<S>

where S: States, State<S>: Send + Sync + 'static,