Struct bevy_input::ButtonInput

pub struct ButtonInput<T: Copy + Eq + Hash + Send + Sync + 'static> { /* private fields */ }

A “press-able” input of type T.

Usage

This type can be used as a resource to keep the current state of an input, by reacting to events from the input. For a given input value:

• ButtonInput::pressed will return true between a press and a release event.
• ButtonInput::just_pressed will return true for one frame after a press event.
• ButtonInput::just_released will return true for one frame after a release event.

Multiple systems

In case multiple systems are checking for ButtonInput::just_pressed or ButtonInput::just_released but only one should react, for example when modifying a Resource, you should consider clearing the input state, either by:

• Using ButtonInput::clear_just_pressed or ButtonInput::clear_just_released instead.
• Calling ButtonInput::clear or ButtonInput::reset immediately after the state change.

Performance

For all operations, the following conventions are used:

• n is the number of stored inputs.
• m is the number of input arguments passed to the method.
• *-suffix denotes an amortized cost.
• ~-suffix denotes an expected cost.

See Rust’s std::collections doc on performance for more details on the conventions used here.

| ButtonInput operations | Computational complexity | |———————————–|————————————| | ButtonInput::any_just_pressed | O(m)~ | | ButtonInput::any_just_released | O(m)~ | | ButtonInput::any_pressed | O(m)~ | | ButtonInput::get_just_pressed | O(n) | | ButtonInput::get_just_released | O(n) | | ButtonInput::get_pressed | O(n) | | ButtonInput::just_pressed | O(1)~ | | ButtonInput::just_released | O(1)~ | | ButtonInput::pressed | O(1)~ | | ButtonInput::press | O(1)* | | ButtonInput::release | O(1)* | | ButtonInput::release_all | O(n)* | | ButtonInput::clear_just_pressed | O(1) | | ButtonInput::clear_just_released | *O*(1)~ | | ButtonInput::reset_all | O(n) | | ButtonInput::clear | O(n) |

Window focus

ButtonInput<KeyCode> is tied to window focus. For example, if the user holds a button while the window loses focus, ButtonInput::just_released will be triggered. Similarly if the window regains focus, ButtonInput::just_pressed will be triggered. Currently this happens even if the focus switches from one Bevy window to another (for example because a new window was just spawned).

ButtonInput<GamepadButton> is independent of window focus.

Examples

Reading and checking against the current set of pressed buttons:

fn main() {
    App::new()
        .add_plugins(DefaultPlugins)
        .add_systems(
            Update,
            print_gamepad.run_if(resource_changed::<ButtonInput<GamepadButton>>),
        )
        .add_systems(
            Update,
            print_mouse.run_if(resource_changed::<ButtonInput<MouseButton>>),
        )
        .add_systems(
            Update,
            print_keyboard.run_if(resource_changed::<ButtonInput<KeyCode>>),
        )
        .run();
}

fn print_gamepad(gamepad: Res<ButtonInput<GamepadButton>>) {
    println!("Gamepad: {:?}", gamepad.get_pressed().collect::<Vec<_>>());
}

fn print_mouse(mouse: Res<ButtonInput<MouseButton>>) {
    println!("Mouse: {:?}", mouse.get_pressed().collect::<Vec<_>>());
}

fn print_keyboard(keyboard: Res<ButtonInput<KeyCode>>) {
    if keyboard.any_pressed([KeyCode::ControlLeft, KeyCode::ControlRight])
        && keyboard.any_pressed([KeyCode::AltLeft, KeyCode::AltRight])
        && keyboard.any_pressed([KeyCode::ShiftLeft, KeyCode::ShiftRight])
        && keyboard.any_pressed([KeyCode::SuperLeft, KeyCode::SuperRight])
        && keyboard.pressed(KeyCode::KeyL)
    {
        println!("On Windows this opens LinkedIn.");
    } else {
        println!("keyboard: {:?}", keyboard.get_pressed().collect::<Vec<_>>());
    }
}

Accepting input from multiple devices:

fn main() {
    App::new()
        .add_plugins(DefaultPlugins)
        .add_systems(
            Update,
            something_used.run_if(
                input_just_pressed(KeyCode::KeyE)
                    .or_else(input_just_pressed(GamepadButton::new(
                        Gamepad::new(0),
                        GamepadButtonType::West,
                    ))),
            ),
        )
        .run();
}

fn something_used() {
    println!("Generic use-ish button pressed.");
}

Note

When adding this resource for a new input type, you should:

• Call the ButtonInput::press method for each press event.
• Call the ButtonInput::release method for each release event.
• Call the ButtonInput::clear method at each frame start, before processing events.

Note: Calling clear from a ResMut will trigger change detection. It may be preferable to use DetectChangesMut::bypass_change_detection to avoid causing the resource to always be marked as changed.

Implementations

impl<T> ButtonInput<T>

where T: Copy + Eq + Hash + Send + Sync + 'static,

pub fn press(&mut self, input: T)

Registers a press for the given input.

pub fn pressed(&self, input: T) -> bool

Returns true if the input has been pressed.

pub fn any_pressed(&self, inputs: impl IntoIterator<Item = T>) -> bool

Returns true if any item in inputs has been pressed.

pub fn all_pressed(&self, inputs: impl IntoIterator<Item = T>) -> bool

Returns true if all items in inputs have been pressed.

pub fn release(&mut self, input: T)

Registers a release for the given input.

pub fn release_all(&mut self)

Registers a release for all currently pressed inputs.

pub fn just_pressed(&self, input: T) -> bool

Returns true if the input has been pressed during the current frame.

Note: This function does not imply information regarding the current state of ButtonInput::pressed or ButtonInput::just_released.

pub fn any_just_pressed(&self, inputs: impl IntoIterator<Item = T>) -> bool

Returns true if any item in inputs has been pressed during the current frame.

pub fn clear_just_pressed(&mut self, input: T) -> bool

Clears the just_pressed state of the input and returns true if the input has just been pressed.

Future calls to ButtonInput::just_pressed for the given input will return false until a new press event occurs.

pub fn just_released(&self, input: T) -> bool

Returns true if the input has been released during the current frame.

Note: This function does not imply information regarding the current state of ButtonInput::pressed or ButtonInput::just_pressed.

pub fn any_just_released(&self, inputs: impl IntoIterator<Item = T>) -> bool

Returns true if any item in inputs has just been released.

pub fn clear_just_released(&mut self, input: T) -> bool

Clears the just_released state of the input and returns true if the input has just been released.

Future calls to ButtonInput::just_released for the given input will return false until a new release event occurs.

pub fn reset(&mut self, input: T)

Clears the pressed, just_pressed and just_released data of the input.

pub fn reset_all(&mut self)

Clears the pressed, just_pressed, and just_released data for every input.

See also ButtonInput::clear for simulating elapsed time steps.

pub fn clear(&mut self)

Clears the just pressed and just released data for every input.

See also ButtonInput::reset_all for a full reset.

pub fn get_pressed(&self) -> impl ExactSizeIterator<Item = &T>

An iterator visiting every pressed input in arbitrary order.

pub fn get_just_pressed(&self) -> impl ExactSizeIterator<Item = &T>

An iterator visiting every just pressed input in arbitrary order.

Note: Returned elements do not imply information regarding the current state of ButtonInput::pressed or ButtonInput::just_released.

pub fn get_just_released(&self) -> impl ExactSizeIterator<Item = &T>

An iterator visiting every just released input in arbitrary order.

Note: Returned elements do not imply information regarding the current state of ButtonInput::pressed or ButtonInput::just_pressed.

Trait Implementations

impl<T: Clone + Copy + Eq + Hash + Send + Sync + 'static> Clone for ButtonInput<T>

fn clone(&self) -> ButtonInput<T>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<T: Debug + Copy + Eq + Hash + Send + Sync + 'static> Debug for ButtonInput<T>

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

Formats the value using the given formatter.

impl<T: Copy + Eq + Hash + Send + Sync + 'static> Default for ButtonInput<T>

fn default() -> Self

Returns the “default value” for a type.

impl<T> FromReflect for ButtonInput<T>

where Self: Any + Send + Sync, T: TypePath + Copy + Eq + Hash + Send + Sync + 'static, HashSet<T>: FromReflect + TypePath + RegisterForReflection,

fn from_reflect(reflect: &dyn Reflect) -> Option<Self>

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<T> GetTypeRegistration for ButtonInput<T>

where Self: Any + Send + Sync, T: TypePath + Copy + Eq + Hash + Send + Sync + 'static, HashSet<T>: FromReflect + TypePath + RegisterForReflection,

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<T> Reflect for ButtonInput<T>

where Self: Any + Send + Sync, T: TypePath + Copy + Eq + Hash + Send + Sync + 'static, HashSet<T>: FromReflect + TypePath + RegisterForReflection,

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

Returns the TypeInfo of the type represented by this value.

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

Returns the value as a Box<dyn Any>.

fn as_any(&self) -> &dyn Any

Returns the value as a &dyn Any.

fn as_any_mut(&mut self) -> &mut dyn Any

Returns the value as a &mut dyn Any.

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

Casts this type to a boxed reflected value.

fn as_reflect(&self) -> &dyn Reflect

Casts this type to a reflected value.

fn as_reflect_mut(&mut self) -> &mut dyn Reflect

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 try_apply(&mut self, value: &dyn Reflect) -> 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<Self>) -> ReflectOwned

Returns an owned enumeration of “kinds” of type.

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

Returns a “partial equality” comparison result.

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

Applies a reflected value to this value.

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<T> Struct for ButtonInput<T>

where Self: Any + Send + Sync, T: TypePath + Copy + Eq + Hash + Send + Sync + 'static, HashSet<T>: FromReflect + TypePath + RegisterForReflection,

fn field(&self, name: &str) -> Option<&dyn Reflect>

Returns a reference to the value of the field named name as a &dyn Reflect.

fn field_mut(&mut self, name: &str) -> Option<&mut dyn Reflect>

Returns a mutable reference to the value of the field named name as a &mut dyn Reflect.

fn field_at(&self, index: usize) -> Option<&dyn Reflect>

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

fn field_at_mut(&mut self, index: usize) -> Option<&mut dyn Reflect>

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

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

Returns the name of the field with index index.

fn field_len(&self) -> usize

Returns the number of fields in the struct.

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

Returns an iterator over the values of the reflectable fields for this struct.

fn clone_dynamic(&self) -> DynamicStruct

Clones the struct into a DynamicStruct.

impl<T> TypePath for ButtonInput<T>

where Self: Any + Send + Sync, T: TypePath + Copy + Eq + Hash + Send + Sync + 'static,

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<T> Typed for ButtonInput<T>

where Self: Any + Send + Sync, T: TypePath + Copy + Eq + Hash + Send + Sync + 'static, HashSet<T>: FromReflect + TypePath + RegisterForReflection,

fn type_info() -> &'static TypeInfo

Returns the compile-time info for the underlying type.

impl<T: Copy + Eq + Hash + Send + Sync + 'static> Resource for ButtonInput<T>

where Self: Send + Sync + 'static,