bevy-input-sequence

Recognizes and acts on input sequences from the keyboard or a gamepad.

Use Cases

• Hotkeys
• Cheat codes
• Developer UI

Installation

cargo install bevy-input-sequence

Code Examples

Here are some code snippets. These also run as doctests so they do a few things differently than a regular runnable example:

• Instead of DefaultPlugins they use MinimalPlugins.
• Instead of app.run() they call app.update().

The next section describes the runnable examples that come with the crate.

Run a System on a Key Sequence

Run a system whenever the user presses the key sequence H I or "hi" within a time limit.

use bevy::prelude::*;
use bevy_input_sequence::prelude::*;

fn main() {
    App::new()
        .add_plugins(MinimalPlugins)
        .add_plugins(InputSequencePlugin::default())
        .add_systems(Startup, setup)
        .update(); // Normally you'd run it here.
}

fn setup(mut commands: Commands) {
    // Add key sequence.
    commands.queue(
        KeySequence::new(say_hello, 
                         keyseq! { H I })
        .time_limit(Duration::from_secs(2))
    );
}

fn say_hello() {
    info!("hello");
}

Send an Event on Key Sequence

Originally bevy-input-sequence always sent an event. You can still do that with action::send_event().

use bevy::prelude::*;
use bevy_input_sequence::prelude::*;

/// Define an event.
#[derive(Message, Clone, Debug, Default)]
struct MyEvent;

/// Add event as an key sequence.
fn main() {
    App::new()
        .add_plugins(MinimalPlugins)
        .add_plugins(InputSequencePlugin::default())
        .add_message::<MyEvent>()
        .add_systems(Startup, setup)
        .update(); // Normally you'd run it here.
}

fn setup(mut commands: Commands) {
    commands.queue(
        KeySequence::new(action::send_event(MyEvent), 
                         keyseq! { Ctrl-E Alt-L Shift-M })
    );
}

fn check_events(mut events: MessageReader<MyEvent>) {
    for event in events.read() {
        info!("got event {event:?}");
    }
}

Send an Event on Gamepad Button Sequence

Gamepads have something that keyboards don't: identity problems. Which player hit the button sequence may be important to know. So the systems it accepts take an input of Entity.

use bevy::prelude::*;
use bevy_input_sequence::prelude::*;

/// Define an event.
#[derive(Message, Clone, Debug)]
struct MyEvent(Entity);

/// Add event as an key sequence.
fn main() {
    App::new()
        .add_plugins(MinimalPlugins)
        .add_plugins(InputSequencePlugin::default())
        .add_message::<MyEvent>()
        .add_systems(Startup, setup)
        .update(); // Normally you'd run it here.
}

fn setup(mut commands: Commands) {
    commands.queue(
        ButtonSequence::new(action::send_event_with_input(|gamepad| MyEvent(gamepad)), 
            [GamepadButton::North,
             GamepadButton::East,
             GamepadButton::South,
             GamepadButton::West])
    );
}

fn check_events(mut events: MessageReader<MyEvent>) {
    for event in events.read() {
        info!("got event {event:?}");
    }
}

Trigger an Event on Key Sequence

You can also trigger an event with action::trigger() or action::trigger_targets().

use bevy::prelude::*;
use bevy_input_sequence::prelude::*;

/// Define an event.
#[derive(Event, Clone, Debug, Default)]
struct MyEvent;

/// Add event as an key sequence.
fn main() {
    App::new()
        .add_plugins(MinimalPlugins)
        .add_plugins(InputSequencePlugin::default())
        .add_systems(Startup, setup)
        .add_observer(check_trigger)
        .update(); // Normally you'd run it here.
}

fn setup(mut commands: Commands) {
    commands.queue(
        KeySequence::new(action::trigger(MyEvent), 
                         keyseq! { Ctrl-E Alt-L Super-M })
    );
}

fn check_trigger(mut trigger: On<MyEvent>) {
    info!("got event {:?}", trigger.event());
}

KeySequence Creation Patterns

KeySequence::new now returns KeySequenceBuilder, which implements Command. Therefore, you need to call Commands::queue instead of Commands::spawn.

use bevy::prelude::*;
use bevy_input_sequence::prelude::*;

#[derive(Message, Clone, Debug, Default)]
struct MyEvent;

fn create_key_sequence(mut commands: Commands) {
    commands.queue(KeySequence::new(
        action::send_event(bevy::app::AppExit::default()), 
        keyseq! { Ctrl-E L M }
    ));
}

fn create_key_sequence_and_add_it_to_an_entity(mut commands: Commands) {
    let id = commands.spawn_empty().id();
    commands.entity(id).queue(KeySequence::new(
        action::send_event(MyEvent), 
        keyseq! { Ctrl-E L M }
    ));
    // OR
    commands.spawn_empty().queue(KeySequence::new(
        action::send_event(MyEvent), 
        keyseq! { Ctrl-E L M }
    ));
}

Advanced Creation

The KeySequenceBuilder requires a &mut World to build it. You can build it yourself like so:

use bevy::prelude::*;
use bevy_input_sequence::prelude::*;

fn create_key_sequence_within_command(mut commands: Commands) {
    commands.queue(|world: &mut World| {
        let builder = KeySequence::new(
            move || { info!("got it"); },
            keyseq! { Ctrl-E L M }
        );
        let key_sequence: KeySequence = builder.build(world);
        // And then put it somewhere? It ought to go as a component.
    });
}

Runnable Examples

keycode

The keycode example recognizes the key sequences W D S A and W A S D and fires a distinct event.

cargo run --example keycode

keymod

The keymod example recognizes Ctrl-W Ctrl-D Ctrl-S Ctrl-A and fires an event.

cargo run --example keymod

gamepad_button

The gamepad_button example recognizes gamepad buttons North East South West or Y B A X on an Xbox controller and fires an event.

cargo run --example gamepad_button

multiple_input

The multiple_input example recognizes gamepad buttons North East South West, or Y B A X on an Xbox controller, or W D S A on a keyboard and fires an event.

cargo run --example multiple_input

Note: Either W D S A will be recognized from the keyboard, or Y B A X will be recognized from the controller. But a mixed sequence like W D A X will not currently be recognized. If this should be done and how exactly one should do it are under consideration. Please open an issue or PR if you have thoughts on this.

only_if

The only_if example recognizes Space and fires an event if it's in game mode. The Escape key toggles the app between menu and game mode. It does this by only sending the Space event if it's in game mode.

cargo run --example only_if

run_if

The run_if has the same behavior as only_if but achieves it differently. It places the InputSequencePlugin systems in a system set that is configured to only run in game mode. Because of this the Escape key which toggles between game and menu mode cannot be a KeySequence.

cargo run --example run_if

Compatibility

License

This crate is licensed under the MIT License or the Apache License 2.0.