Learn Rust Coding · Lesson

Handling Input and Time

React to the player and the clock.

Input as a Resource

Keyboard state lives in the ButtonInput<KeyCode> resource, provided by DefaultPlugins.

Request it read-only with Res. Bevy updates it each frame before your systems run, so you always see the current state.

fn read_keys(keys: Res<ButtonInput<KeyCode>>) {
    if keys.pressed(KeyCode::Space) {
        info!("space held");
    }
}

pressed is true every frame a key is held — ideal for continuous movement. just_pressed is true only on the frame the key goes down.

Use just_pressed for discrete actions like jumping or firing so a single tap fires once.

fn jump(keys: Res<ButtonInput<KeyCode>>) {
    if keys.just_pressed(KeyCode::ArrowUp) {
        info!("jump!");
    }
}