https://github.com/minecraftforge/eventbus
Event Bus
https://github.com/minecraftforge/eventbus
Last synced: 9 months ago
JSON representation
Event Bus
- Host: GitHub
- URL: https://github.com/minecraftforge/eventbus
- Owner: MinecraftForge
- License: lgpl-2.1
- Created: 2018-06-06T23:36:39.000Z (over 7 years ago)
- Default Branch: master
- Last Pushed: 2025-03-26T17:26:00.000Z (9 months ago)
- Last Synced: 2025-03-31T18:19:11.877Z (9 months ago)
- Language: Java
- Size: 622 KB
- Stars: 40
- Watchers: 11
- Forks: 36
- Open Issues: 2
-
Metadata Files:
- Readme: README.md
- License: LICENSE-header.txt
Awesome Lists containing this project
README
# EventBus
A flexible, high-performance, thread-safe subscriber-publisher framework designed with modern Java in mind.
## Overview
The core functionality of EventBus is to provide a simple and efficient way to handle events in a decoupled manner.
Each event may have one or more buses associated with it, which are responsible for managing listeners and dispatching
instances of the event object to them. To maximise performance, the underlying implementation is tailored on the fly
based on the event's type, characteristics, inheritance chain and the number and type of listeners registered to the bus.
## Quickstart guide
First, add the Forge Maven repository and the EventBus dependency to your project:
```gradle
repositories {
maven {
name = "Forge"
url = "https://maven.minecraftforge.net"
}
}
dependencies {
implementation "net.minecraftforge:eventbus:"
}
```
You can find the list of available versions [here][Versions].
Now you can start using EventBus in your project. Simple usage example:
```java
import net.minecraftforge.eventbus.api.event.RecordEvent;
import net.minecraftforge.eventbus.api.bus.EventBus;
// Define an event and a bus for it
record PlayerLoggedInEvent(String username) implements RecordEvent {
public static final EventBus BUS = EventBus.create(PlayerLoggedInEvent.class);
}
// Register an event listener
PlayerLoggedInEvent.BUS.addListener(event -> System.out.println("Player logged in: " + event.username()));
// Post an event to the registered listeners
PlayerLoggedInEvent.BUS.post(new PlayerLoggedInEvent("Paint_Ninja"));
```
Browse the `net.minecraftforge.eventbus.api` package and read the Javadocs for more information. For real-world
examples, check out Forge's extensive use of EventBus [here][Forge usages].
## Nullability
The entirety of EventBus' API is `@NullMarked` and compliant with the [jSpecify specification](https://jspecify.dev/) -
this means that everything is non-null by default unless otherwise specified.
Attempting to pass a `null` value to a method param that isn't explicitly marked as `@Nullable` is an unsupported
operation and won't be considered a breaking change if a future version throws an exception in such cases when it didn't
before.
## Contributing
One of the main goals of EventBus is performance. As such, any changes should be benchmarked with the `jmh` Gradle task
to help ensure that there are no unintended performance regressions. If you are unsure how to do this or would like
to discuss your ideas before submitting a PR, feel free to reach out to us on the [Forge Discord].
[Versions]: https://files.minecraftforge.net/net/minecraftforge/eventbus/
[Forge usages]: https://github.com/MinecraftForge/MinecraftForge/tree/1.21.x/src/main/java/net/minecraftforge/event
[Forge Discord]: https://discord.minecraftforge.net/