bevy/crates/bevy_ecs/examples/events.rs
Tristan Guichaoua 694c06f3d0
Inverse missing_docs logic (#11676)
# Objective

Currently the `missing_docs` lint is allowed-by-default and enabled at
crate level when their documentations is complete (see #3492).
This PR proposes to inverse this logic by making `missing_docs`
warn-by-default and mark crates with imcomplete docs allowed.

## Solution

Makes `missing_docs` warn at workspace level and allowed at crate level
when the docs is imcomplete.
2024-02-03 21:40:55 +00:00

62 lines
2 KiB
Rust

//! In this example a system sends a custom event with a 50/50 chance during any frame.
//! If an event was send, it will be printed by the console in a receiving system.
use bevy_ecs::prelude::*;
fn main() {
// Create a new empty world and add the event as a resource
let mut world = World::new();
world.insert_resource(Events::<MyEvent>::default());
// Create a schedule to store our systems
let mut schedule = Schedule::default();
// Events need to be updated in every frame in order to clear our buffers.
// This update should happen before we use the events.
// Here, we use system sets to control the ordering.
#[derive(SystemSet, Debug, Clone, PartialEq, Eq, Hash)]
pub struct FlushEvents;
schedule.add_systems(bevy_ecs::event::event_update_system::<MyEvent>.in_set(FlushEvents));
// Add systems sending and receiving events after the events are flushed.
schedule.add_systems((
sending_system.after(FlushEvents),
receiving_system.after(sending_system),
));
// Simulate 10 frames of our world
for iteration in 1..=10 {
println!("Simulating frame {iteration}/10");
schedule.run(&mut world);
}
}
// This is our event that we will send and receive in systems
#[derive(Event)]
struct MyEvent {
pub message: String,
pub random_value: f32,
}
// In every frame we will send an event with a 50/50 chance
fn sending_system(mut event_writer: EventWriter<MyEvent>) {
let random_value: f32 = rand::random();
if random_value > 0.5 {
event_writer.send(MyEvent {
message: "A random event with value > 0.5".to_string(),
random_value,
});
}
}
// This system listens for events of the type MyEvent
// If an event is received it will be printed to the console
fn receiving_system(mut event_reader: EventReader<MyEvent>) {
for my_event in event_reader.read() {
println!(
" Received message {:?}, with random value of {}",
my_event.message, my_event.random_value
);
}
}