Struct agb::input::ButtonController

pub struct ButtonController { /* private fields */ }

Helper to make it easy to get the current state of the GBA’s buttons.

Example

use agb::input::{ButtonController, Tri};

let mut input = ButtonController::new();

loop {
    input.update(); // call update every loop

    match input.x_tri() {
        Tri::Negative => { /* left is being pressed */ }
        Tri::Positive => { /* right is being pressed */ }
        Tri::Zero => { /* Neither left nor right (or both) are pressed */ }
    }
}

Implementations

impl ButtonController

pub fn new() -> Self

Create a new ButtonController. This is the preferred way to create it.

pub fn update(&mut self)

Updates the state of the button controller. You should call this every frame (either at the start or the end) to ensure that you have the latest state of each button press. Calls to any method won’t change until you call this.

pub fn x_tri(&self) -> Tri

Returns Tri::Positive if right is pressed, Tri::Negative if left is pressed and Tri::Zero if neither or both are pressed. This is the normal behaviour you’ll want if you’re using orthogonal inputs.

pub fn y_tri(&self) -> Tri

Returns Tri::Positive if down is pressed, Tri::Negative if up is pressed and Tri::Zero if neither or both are pressed. This is the normal behaviour you’ll want if you’re using orthogonal inputs.

pub fn vector<T>(&self) -> Vector2D<T>

where T: From<i32> + FixedWidthUnsignedInteger,

Returns true if all the buttons specified in keys are pressed.

pub fn just_pressed_x_tri(&self) -> Tri

Returns Tri::Positive if left was just pressed, Tri::Negative if right was just pressed and Tri::Zero if neither or both are just pressed.

Also returns Tri::Zero after the call to update() if the button is still held.

pub fn just_pressed_y_tri(&self) -> Tri

Returns Tri::Positive if down was just pressed, Tri::Negative if up was just pressed and Tri::Zero if neither or both are just pressed.

Also returns Tri::Zero after the call to update() if the button is still held.

pub fn just_pressed_vector<T>(&self) -> Vector2D<T>

where T: From<i32> + FixedWidthUnsignedInteger,

Returns a vector which represents the direction the button was just pressed in.

pub fn is_pressed(&self, keys: Button) -> bool

Returns true if the provided keys are all pressed, and false if not.

pub fn is_released(&self, keys: Button) -> bool

Returns true if all the buttons specified in keys are not pressed. Equivalent to !is_pressed(keys).

pub fn is_just_pressed(&self, keys: Button) -> bool

Returns true if all the buttons specified in keys went from not pressed to pressed in the last frame. Very useful for menu navigation or selection if you want the players actions to only happen for one frame.

Example

use agb::input::{Button, ButtonController};

let mut button_controller = ButtonController::new();

loop {
    button_controller.update();

    if button_controller.is_just_pressed(Button::A) {
        // A button was just pressed, maybe select the currently selected item
    }
}

pub fn is_just_released(&self, keys: Button) -> bool

Returns true if all the buttons specified in keys went from pressed to not pressed in the last frame. Very useful for menu navigation or selection if you want players actions to only happen for one frame.

Trait Implementations

impl Default for ButtonController

fn default() -> Self

Returns the “default value” for a type.