bevy-collision-plugin/src/main.rs

use bevy::prelude::*;

#[derive(Component)]
struct Person;

#[derive(Component)]
struct Name(String);

#[derive(Resource)]
struct GreetTimer(Timer);

#[derive(Resource)]
struct UpdateTimer(Timer);

pub struct HelloPlugin;

impl Plugin for HelloPlugin {
    fn build(&self, app: &mut App) {
        app.insert_resource(GreetTimer(Timer::from_seconds(2.0, TimerMode::Repeating)));
        app.insert_resource(UpdateTimer(Timer::from_seconds(10.0, TimerMode::Once)));
        app.add_systems(Startup, add_people);
        app.add_systems(Update, (update_people, greet_people).chain());
    }
}


fn add_people(mut commands: Commands) {
    commands.spawn((Person, Name("Alkesey Mirnekov".to_string())));
    commands.spawn((Person, Name("Alkesey Mirnekov 2".to_string())));
    commands.spawn((Person, Name("Alkesey Mirnekov 3".to_string())));
}

fn greet_people(time: Res<Time>, mut timer: ResMut<GreetTimer>, query: Query<&Name, With<Person>>) {
    if timer.0.tick(time.delta()).just_finished() {
        for name in &query {
            println!("hello {}!", name.0);
        }
    }
}

fn update_people(time: Res<Time>, mut timer: ResMut<UpdateTimer>, mut query: Query<&mut Name, With<Person>>) {
    if timer.0.tick(time.delta()).just_finished() {
        for mut name in &mut query {
            name.0 = format!("{} II", name.0);
        }
    }
}

fn main() {
    App::new()
    .add_plugins(DefaultPlugins)
    .add_plugins(HelloPlugin)
    .run();
}