bevy/examples/app/plugin.rs
Lena Milizé 73605f43b6 Replace the bool argument of Timer with TimerMode (#6247)
As mentioned in #2926, it's better to have an explicit type that clearly communicates the intent of the timer mode rather than an opaque boolean, which can be only understood when knowing the signature or having to look up the documentation.

This also opens up a way to merge different timers, such as `Stopwatch`, and possibly future ones, such as `DiscreteStopwatch` and `DiscreteTimer` from #2683, into one struct.

Signed-off-by: Lena Milizé <me@lvmn.org>

# Objective

Fixes #2926.

## Solution

Introduce `TimerMode` which replaces the `bool` argument of `Timer` constructors. A `Default` value for `TimerMode` is `Once`.

---

## Changelog

### Added

- `TimerMode` enum, along with variants `TimerMode::Once` and `TimerMode::Repeating`

### Changed

- Replace `bool` argument of `Timer::new` and `Timer::from_seconds` with `TimerMode`
- Change `repeating: bool` field of `Timer` with `mode: TimerMode`

## Migration Guide

- Replace `Timer::new(duration, false)` with `Timer::new(duration, TimerMode::Once)`.
- Replace `Timer::new(duration, true)` with `Timer::new(duration, TimerMode::Repeating)`.
- Replace `Timer::from_seconds(seconds, false)` with `Timer::from_seconds(seconds, TimerMode::Once)`.
- Replace `Timer::from_seconds(seconds, true)` with `Timer::from_seconds(seconds, TimerMode::Repeating)`.
- Change `timer.repeating()` to `timer.mode() == TimerMode::Repeating`.
2022-10-17 13:47:01 +00:00

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1.5 KiB
Rust

//! Demonstrates the creation and registration of a custom plugin.
//!
//! Plugins are the foundation of Bevy. They are scoped sets of components, resources, and systems
//! that provide a specific piece of functionality (generally the smaller the scope, the better).
//! This example illustrates how to create a simple plugin that prints out a message.
use bevy::{prelude::*, utils::Duration};
fn main() {
App::new()
.add_plugins(DefaultPlugins)
// plugins are registered as part of the "app building" process
.add_plugin(PrintMessagePlugin {
wait_duration: Duration::from_secs(1),
message: "This is an example plugin".to_string(),
})
.run();
}
// This "print message plugin" prints a `message` every `wait_duration`
pub struct PrintMessagePlugin {
// Put your plugin configuration here
wait_duration: Duration,
message: String,
}
impl Plugin for PrintMessagePlugin {
// this is where we set up our plugin
fn build(&self, app: &mut App) {
let state = PrintMessageState {
message: self.message.clone(),
timer: Timer::new(self.wait_duration, TimerMode::Repeating),
};
app.insert_resource(state).add_system(print_message_system);
}
}
#[derive(Resource)]
struct PrintMessageState {
message: String,
timer: Timer,
}
fn print_message_system(mut state: ResMut<PrintMessageState>, time: Res<Time>) {
if state.timer.tick(time.delta()).finished() {
info!("{}", state.message);
}
}