Enum NextState 

pub enum NextState<S>
where
    S: FreelyMutableState,
{
    Unchanged,
    Pending(S),
    PendingIfNeq(S),
}

The next state of State<S>.

This can be fetched as a resource and used to queue state transitions. To queue a transition, call NextState::set or mutate the value to NextState::Pending directly.

Note that these transitions can be overridden by other systems: only the actual value of this resource during the StateTransition schedule matters.

use bevy_state::prelude::*;
use bevy_ecs::prelude::*;

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

fn start_game(mut next_game_state: ResMut<NextState<GameState>>) {
    next_game_state.set(GameState::InGame);
}

Variants

Unchanged

No state transition is pending

Pending(S)

There is a pending transition for state S

PendingIfNeq(S)

There is a pending transition for state S

This will not trigger state transitions schedules if the target state is the same as the current one.

Implementations

impl<S> NextState<S>

where S: FreelyMutableState,

pub fn set(&mut self, state: S)

Tentatively set a pending state transition to Some(state).

This will run the state transition schedules OnEnter and OnExit. If you want to skip those schedules for the same where we are transitioning to the same state, use set_if_neq instead.

pub fn set_if_neq(&mut self, state: S)

Tentatively set a pending state transition to Some(state).

Like set, but will not run any state transition schedules if the target state is the same as the current one. If set has already been called in the same frame with the same state, the transition schedules will be run anyways.

pub fn reset(&mut self)

Remove any pending changes to State<S>

Trait Implementations

impl<S> Clone for NextState<S>

where S: Clone + FreelyMutableState,

fn clone(&self) -> NextState<S>

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<S> Debug for NextState<S>

where S: Debug + FreelyMutableState,

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

Formats the value using the given formatter.

impl<S> Default for NextState<S>

where S: FreelyMutableState,

fn default() -> NextState<S>

Returns the “default value” for a type.

impl<S> Enum for NextState<S>

where S: FreelyMutableState + TypePath + FromReflect + MaybeTyped + RegisterForReflection, NextState<S>: Any + Send + Sync,

fn field(&self, __name_param: &str) -> Option<&(dyn PartialReflect + 'static)>

Returns a reference to the value of the field (in the current variant) with the given name.

fn field_at( &self, __index_param: usize, ) -> Option<&(dyn PartialReflect + 'static)>

Returns a reference to the value of the field (in the current variant) at the given index.

fn field_mut( &mut self, __name_param: &str, ) -> Option<&mut (dyn PartialReflect + 'static)>

Returns a mutable reference to the value of the field (in the current variant) with the given name.

fn field_at_mut( &mut self, __index_param: usize, ) -> Option<&mut (dyn PartialReflect + 'static)>

Returns a mutable reference to the value of the field (in the current variant) at the given index.

fn index_of(&self, __name_param: &str) -> Option<usize>

Returns the index of the field (in the current variant) with the given name.

fn name_at(&self, __index_param: usize) -> Option<&str>

Returns the name of the field (in the current variant) with the given index.

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

Returns an iterator over the values of the current variant’s fields.

fn field_len(&self) -> usize

Returns the number of fields in the current variant.

fn variant_name(&self) -> &str

The name of the current variant.

fn variant_index(&self) -> usize

The index of the current variant.

fn variant_type(&self) -> VariantType

The type of the current variant.

fn to_dynamic_enum(&self) -> DynamicEnum

Creates a new DynamicEnum from this enum.

fn is_variant(&self, variant_type: VariantType) -> bool

Returns true if the current variant’s type matches the given one.

fn variant_path(&self) -> String

Returns the full path to the current variant.

fn get_represented_enum_info(&self) -> Option<&'static EnumInfo>

Will return None if TypeInfo is not available.

impl<S> FromArg for NextState<S>

where S: FreelyMutableState + TypePath + FromReflect + MaybeTyped + RegisterForReflection, NextState<S>: Any + Send + Sync,

type This<'from_arg> = NextState<S>

The type to convert into.

fn from_arg( arg: Arg<'_>, ) -> Result<<NextState<S> as FromArg>::This<'_>, ArgError>

Creates an item from an argument.

impl<S> FromReflect for NextState<S>

where S: FreelyMutableState + TypePath + FromReflect + MaybeTyped + RegisterForReflection, NextState<S>: Any + Send + Sync,

fn from_reflect( __param0: &(dyn PartialReflect + 'static), ) -> Option<NextState<S>>

Constructs a concrete instance of Self from a reflected value.

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

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

impl<S> GetOwnership for NextState<S>

where S: FreelyMutableState + TypePath + FromReflect + MaybeTyped + RegisterForReflection, NextState<S>: Any + Send + Sync,

fn ownership() -> Ownership

Returns the ownership of Self.

impl<S> GetTypeRegistration for NextState<S>

where S: FreelyMutableState + TypePath + FromReflect + MaybeTyped + RegisterForReflection, NextState<S>: Any + Send + Sync,

fn get_type_registration() -> TypeRegistration

Returns the default TypeRegistration for this type.

fn register_type_dependencies(registry: &mut TypeRegistry)

Registers other types needed by this type.

impl<S> IntoReturn for NextState<S>

where S: FreelyMutableState + TypePath + FromReflect + MaybeTyped + RegisterForReflection, NextState<S>: Any + Send + Sync,

fn into_return<'into_return>(self) -> Return<'into_return>

where NextState<S>: 'into_return,

Converts Self into a Return value.

impl<S> PartialReflect for NextState<S>

where S: FreelyMutableState + TypePath + FromReflect + MaybeTyped + RegisterForReflection, NextState<S>: Any + Send + Sync,

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

Returns the TypeInfo of the type represented by this value.

fn try_apply( &mut self, __value_param: &(dyn PartialReflect + 'static), ) -> Result<(), ApplyError>

Tries to apply 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<NextState<S>>) -> ReflectOwned

Returns an owned enumeration of “kinds” of type.

fn try_into_reflect( self: Box<NextState<S>>, ) -> Result<Box<dyn Reflect>, Box<dyn PartialReflect>>

Attempts to cast this type to a boxed, fully-reflected value.

fn try_as_reflect(&self) -> Option<&(dyn Reflect + 'static)>

Attempts to cast this type to a fully-reflected value.

fn try_as_reflect_mut(&mut self) -> Option<&mut (dyn Reflect + 'static)>

Attempts to cast this type to a mutable, fully-reflected value.

fn into_partial_reflect(self: Box<NextState<S>>) -> Box<dyn PartialReflect>

Casts this type to a boxed, reflected value.

fn as_partial_reflect(&self) -> &(dyn PartialReflect + 'static)

Casts this type to a reflected value.

fn as_partial_reflect_mut(&mut self) -> &mut (dyn PartialReflect + 'static)

Casts this type to a mutable, reflected value.

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

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

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

Returns a “partial equality” comparison result.

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

Debug formatter for the value.

fn reflect_clone(&self) -> Result<Box<dyn Reflect>, ReflectCloneError>

Attempts to clone Self using reflection.

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

Applies a reflected value to this value.

fn to_dynamic(&self) -> Box<dyn PartialReflect>

Converts this reflected value into its dynamic representation based on its kind.

fn reflect_clone_and_take<T>(&self) -> Result<T, ReflectCloneError>

where T: 'static, Self: Sized + TypePath,

For a type implementing PartialReflect, combines reflect_clone and take in a useful fashion, automatically constructing an appropriate ReflectCloneError if the downcast fails.

fn is_dynamic(&self) -> bool

Indicates whether or not this type is a dynamic type.

impl<S> Reflect for NextState<S>

where S: FreelyMutableState + TypePath + FromReflect + MaybeTyped + RegisterForReflection, NextState<S>: Any + Send + Sync,

fn into_any(self: Box<NextState<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<NextState<S>>) -> Box<dyn Reflect>

Casts this type to a boxed, fully-reflected value.

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

Casts this type to a fully-reflected value.

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

Casts this type to a mutable, fully-reflected value.

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

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

impl<S> TypePath for NextState<S>

where S: FreelyMutableState + TypePath, NextState<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 NextState<S>

where S: FreelyMutableState + TypePath + FromReflect + MaybeTyped + RegisterForReflection, NextState<S>: Any + Send + Sync,

fn type_info() -> &'static TypeInfo

Returns the compile-time info for the underlying type.

impl<S> Resource for NextState<S>

where S: FreelyMutableState, NextState<S>: Send + Sync + 'static,