Bevy Sequential Actions

bevy_sequential_actions is a library for the Bevy game engine that aims to execute a list of actions in a sequential manner. This generally means that one action runs at a time, and when it is done, the next action will start, and so on until the list is empty.

Getting Started

An action is anything that implements the Action trait, and can be added to any Entity that contains the ActionsBundle. Each action must signal when they are finished, which is done by calling next_action on either Commands or ActionCommands.

use bevy::prelude::*;

use bevy_sequential_actions::*;

fn main() {
    App::new()
        .add_plugins(MinimalPlugins)
        .add_startup_system(setup)
        .add_system(wait)
        .run();
}

fn setup(mut commands: Commands) {
    // Create entity with ActionsBundle
    let id = commands.spawn_bundle(ActionsBundle::default()).id();

    // Add a single action with default config
    commands.add_action(id, WaitAction(1.0), AddConfig::default());

    // Add multiple actions with custom config
    commands
        .action_builder(
            id,
            AddConfig {
                // Add each action to the back of the queue
                order: AddOrder::Back,
                // Start action if nothing is currently running
                start: false,
                // Repeat the action         
                repeat: false,
            },
        )
        .push(WaitAction(2.0))
        .push(WaitAction(3.0))
        .submit();
}

struct WaitAction(f32);

impl Action for WaitAction {
    fn add(&mut self, actor: Entity, world: &mut World, _commands: &mut ActionCommands) {
        world.entity_mut(actor).insert(Wait(self.0));
    }

    fn remove(&mut self, actor: Entity, world: &mut World) {
        world.entity_mut(actor).remove::<Wait>();
    }

    fn stop(&mut self, actor: Entity, world: &mut World) {
        self.remove(actor, world);
    }
}

#[derive(Component)]
struct Wait(f32);

fn wait(mut wait_q: Query<(Entity, &mut Wait)>, time: Res<Time>, mut commands: Commands) {
    for (actor, mut wait) in wait_q.iter_mut() {
        wait.0 -= time.delta_seconds();
        if wait.0 <= 0.0 {
            // Action is finished, issue next.
            commands.next_action(actor);
        }
    }
}

See the examples for more usage.