Struct UiProjectionQuery

pub struct UiProjectionQuery<'w, 's> { /* private fields */ }

System parameter for the default cursor navigation system.

It uses the bevy GlobalTransform to compute relative positions and change focus to the correct entity. It uses the ScreenBoundaries resource to compute screen boundaries and move the cursor accordingly when it reaches a screen border in a cycling menu.

Trait Implementations

impl<'w, 's> MenuNavigationStrategy for UiProjectionQuery<'w, 's>

fn resolve_2d<'a>( &self, focused: Entity, direction: Direction, cycles: bool, siblings: &'a [Entity], ) -> Option<&'a Entity>

Which Entity in siblings can be reached from focused in direction if any, otherwise None.

impl SystemParam for UiProjectionQuery<'_, '_>

type State = FetchState

Used to store data which persists across invocations of a system.

type Item<'w, 's> = UiProjectionQuery<'w, 's>

The item type returned when constructing this system param. The value of this associated type should be Self, instantiated with new lifetimes.

fn init_state(world: &mut World, system_meta: &mut SystemMeta) -> Self::State

Registers any World access used by this SystemParam and creates a new instance of this param’s State.

fn new_archetype( state: &mut Self::State, archetype: &Archetype, system_meta: &mut SystemMeta, )

For the specified Archetype, registers the components accessed by this SystemParam (if applicable).

fn apply(state: &mut Self::State, system_meta: &SystemMeta, world: &mut World)

Applies any deferred mutations stored in this SystemParam’s state. This is used to apply Commands during apply_deferred.

unsafe fn get_param<'w, 's>( state: &'s mut Self::State, system_meta: &SystemMeta, world: UnsafeWorldCell<'w>, change_tick: Tick, ) -> Self::Item<'w, 's>

Creates a parameter to be passed into a SystemParamFunction.

impl<'w, 's> ReadOnlySystemParam for UiProjectionQuery<'w, 's>

where Option<Res<'w, ScreenBoundaries>>: ReadOnlySystemParam, Query<'w, 's, &'static GlobalTransform>: ReadOnlySystemParam,